US20040077353A1 - Spread spectrum transceiver module utilizing multiple mode transmission - Google Patents
Spread spectrum transceiver module utilizing multiple mode transmission Download PDFInfo
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- US20040077353A1 US20040077353A1 US10/684,747 US68474703A US2004077353A1 US 20040077353 A1 US20040077353 A1 US 20040077353A1 US 68474703 A US68474703 A US 68474703A US 2004077353 A1 US2004077353 A1 US 2004077353A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/38—TPC being performed in particular situations
- H04W52/46—TPC being performed in particular situations in multi hop networks, e.g. wireless relay networks
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
- H04B1/403—Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
- H04B1/406—Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency with more than one transmission mode, e.g. analog and digital modes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/692—Hybrid techniques using combinations of two or more spread spectrum techniques
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2201/00—Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
- H04B2201/69—Orthogonal indexing scheme relating to spread spectrum techniques in general
- H04B2201/707—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
- H04B2201/70707—Efficiency-related aspects
- H04B2201/7071—Efficiency-related aspects with dynamic control of receiver resources
- H04B2201/70711—Efficiency-related aspects with dynamic control of receiver resources with modular structure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/38—TPC being performed in particular situations
Definitions
- FIG. 1I is a conceptual block diagram of the operation of the transmitter of FIG. 10 when operating in a direct sequence spread spectrum transmission mode
- FIG. 13 is a block diagram of an embodiment of a receiver of the present invention.
- the signal components that determine the composite signal are well correlated, i.e., there is a small probability that a significant change in the signal power envelope will occur over the distance. If a transmission of a data packet can be initiated and completed before the relative movement between the receiver and transmitter exceeds the “small distance” data loss to fading is unlikely to occur.
- the maximum “small distance” wherein a high degree of correlation exists is referred to hereafter as the “correlation distance”.
- RSSI received signal strength indicator
- the wireless access device removes that transceiving device's mode information from active status in the mode table and attempts to choose a better common mode via the blocks 431 , 433 , 435 and 437 .
- the wireless access device might also periodically attempt to choose a better common mode, without requiring channel conditions to change or degrade or participants to detach.
- the data is mapped into I/Q symbols for either BPSK or QPSK modulation.
- the ASIC generates a synchronous chip clock at a multiple of the symbol rate that is applied to the pseudo-random number (PN) generator of FIG. 14A to produce a chipping sequence at the selected spreading ratio.
- the exact chipping sequence is selected by programming the feedback select of FIG. 14A.
- the chipping sequence is multiplied with the I/Q data symbols by use of exclusive OR gates.
- the selected data rate and spreading ratio determine the main lobe bandwidth of the transmitted signal.
- the bandwidth of the main lobe and side lobes are reduced by applying the transversal filters ( 146 and 148 of FIG. 148), which comprise circuitry of the transversal filter 150 of FIG. 10 with the shift registers operating at the chipping rate rather than the symbol rate.
- the main lobe bandwidth is limited to approximately 1.6 times the chip clock frequency.
- Data to be transmitted is sent via a bus 131 to the MAC circuitry 128 from a host unit.
- the data to be transmitted is be modulated by the modulator 130 and frequency controlled by the spreader 124 according to the particular spread spectrum transmission mode to be utilized.
- the spreader 124 receives a chipping clock input that is at a frequency multiple of the source data frequency.
- the output of the spreader 124 is sent to the transmitter up converter and amplifier 314 to transmit the RF data signal through the antenna 112 .
- a restart control device (“RESTART CONTROL”) 190 may be utilized to provide a programmable restart interval and a programmable restart vector.
- the PN generator 122 is preferably controlled by a control input (“CONTROL”) from the MAC circuitry 128 of FIG. 10 and produces a PN code output signal (“PN CODE”).
- FIG. 19 is a block diagram illustrating the host interface circuitry 132 of FIG. 10 for radio module 30 of FIG. 7 and for radio/scanner module 20 of FIG. 8.
- the host interface circuitry 132 is preferably located on the radio interface card 58 of FIGS. 7 and 8.
- a regulator (“REGULATOR”) 254 functions as the power supply 134 of FIG. 10 and provides a regulated voltage signal to the radio interface card 58 which is connected to the MAC circuitry 128 via a host to MAC communications bus (“TO MAC”) which connects to the electronic device in which the radio of the present invention is utilized through connectors (“CONNECTORS”) 60 on the radio interface card 58 of FIGS. 7 and 8.
- TO MAC host to MAC communications bus
- FIG. 22B is a diagram illustrating a specific implementation of the portable terminal of FIG. 22A a single PCMCIA card contains not only a multi-mode wireless transceiver, but also a wired modem transceiver.
- a portable terminal 1520 contains terminal circuitry 1522 comprising processing circuitry 1526 , conventional terminal circuitry 1528 and interface circuitry 1530 .
- the interface circuitry 1530 provides a PCMCIA interface for receiving PCMCIA cards of various functionality.
- the terminal circuitry 1522 is well known and can be found in conventional portable or hand held computing devices.
- FIG. 25 c is a flow diagram illustrating the functionality of one embodiment of the wireless access device of FIG. 25 b in managing a communication channel using a second channel, i.e., the busy/control channel.
- the wireless access device maintains ongoing communication or otherwise waits in an idle state at a block 1781 . If a predetermined time out period (e.g., a B/C service time period) lapses while the access device is in an idle state as indicated at a block 1782 , the access device switches to the predefined mode and associated parameters of the busy/control channel at a block 1783 .
- a predetermined time out period e.g., a B/C service time period
- data may be segmented into Data packets for transmission one packet at a time via the blocks 1781 and 1787 - 92 .
- a listening wireless terminal will can be sure that it will receive a communication channel broadcast via the blocks 1782 - 86 between each Data packet transmission.
- wireless terminals may place their transceivers in a sleep mode until each of the Data packets of the data have been exchanged, and the communication channel is clear.
Abstract
A data transceiver module for digital data communications in a portable handheld data terminal has multiple data spread spectrum modes which include direct sequence and frequency function modulation algorithms. The transceiver module has multiple user or program configurable data rates, modulation, channelization and process gain in order to maximize the performance of radio data transmissions and to maximize interference immunity. Various module housings, which may be PCMCIA type, are able to be mated with a suitably designed data terminal. Media access control protocols and interfaces of multiple nominal operational frequencies are utilized. Wireless access devices in a cell based network each consider a variety of factors when choosing one of a plurality of modes of wireless operation and associated operating parameters. Such selection defines a communication channel to support wireless data, message and communication exchanges. In further embodiments, the wireless access devices also support a second channel, a busy/control channel, for managing communication on the main communication channel and to overcome roaming and hidden terminal problems. Roaming terminal devices are also configured to support the dual channel design. Such configuration in both circumstances may involve the use of a multimode radio that is timeshared between the two channels or two radios, one dedicated to each channel.
Description
- 1. Technical Field
- The present invention relates generally to communication networks utilizing spread spectrum radio transceivers, and, more specifically, to multi-hop RF networks wherein participating devices utilize spread spectrum transceivers that are capable of operating in any of a variety of spread spectrum modes. The spread spectrum modes include, for example, direct sequence transmission across a spreading bandwidth or channelized across the spreading bandwidth, frequency hopping transmission across all or a part of the spreading bandwidth, a hybrid combination of direct sequence transmissions and frequency hopping transmissions, and transmissions on a portion of the spreading bandwidth. The selection of a spread spectrum mode of operation depends upon signal conditions and characteristics of members capable of communication within the RF communication network.
- 2. Description of Related Art
- Communication devices within a wireless local area network employ wireless communication links to transfer data and commands within the local area network. Typical units within a wireless local area network include stationary wireless access devices, mobile radio units, mobile image capture units, printing units, and other units operative with the data and commands. These units often link to a wired local area network through a wireless access device to transfer data and commands to devices located on the wired network. The wireless local area networks typically employ cellular communication techniques to provide the wireless communication links within the local are network.
- One common installation of a wireless local area network serves factory automation functions. Because hard-wiring a local area network within a large, dynamic facility is both expensive and difficult, the wireless local are network provides traditional network functions as well as additional functions germane to the wireless attributes of the network. However, due to difficult transmission and interference conditions within a factory, establishing and maintaining sufficient wireless communication ties oftentimes proves difficult. Attenuation of transmitted signals, multi-path fading, ambient noise, and interference by adjacent cells often disrupts communication within the wireless local area network.
- Spread spectrum transmissions are often used in attempts to overcome communication problems. With spread spectrum transmissions, the bandwidth over which information is broadcast is deliberately made wide relative to the information bandwidth of the source information. Spread spectrum transmission techniques include direct sequence transmission, frequency hopping transmission, a combination of direct sequence transmission and frequency hopping transmission, and may include other techniques that deliberately transmit over a wide spectrum.
- Direct sequence spread spectrum transmitters typically spread by first modulating a data signal with a pseudo random chipping sequence at a multiple of the source data clocking rate. Once constructed, the composite modulation is coupled to a carrier via modulation techniques and then transmitted. Please modulation is typically employed, but frequency modulation or other types of modulation may also be used. Circuitry in a receiving units receives the signal, decodes the signal at the multiple of the source data clocking rate using a particular chipping sequence, and produces received data. In a typical direct sequence system, the pseudo random chipping sequence applied by the receiving unit corresponds to all, or respective portions, of the transmitted signal. In this fashion, the receiving unit receives only intended data and avoids receiving data from adjacent cells operating on the same frequency. Direct sequence spread spectrum modes also provide significant noise rejection characteristics since each component of the source data is essentially transmitted multiple times. The received signal is therefore a composite that may be averaged or weighted to avoid receiving improper data or falsing based upon noise.
- A frequency hopping system commonly uses conventional narrowband modulation but varies the modulation frequency over time in accordance with a known pattern or algorithm, effectively moving the modulated signal over the intended spreading bandwidth. The spread spectrum signal is only discernible to a receiver that has prior knowledge of the spreading function employed and which has obtained synchronization with the spreading operation at the transmitter. By spreading transmissions over the spreading bandwidth, particular portions of the spreading bandwidth within which transmission is difficult may be substantially avoided.
- In the United States and many other countries, spread spectrum communications is used commercially within designated Industrial, Scientific and Medical (ISM) bands. These bands are structured as multi-use bands containing non-communications equipment such as industrial and commercial microwave ovens as well as low power consumer grade transmitters, vehicle location and telemetry systems and other spread spectrum devices of differing characteristics. Operation in ISM bands is unlicensed and uncoordinated, so equipment operating in these bands must be designed to operate successfully without knowledge of the types of devices that may be used in close proximity. The spread spectrum system design must also take into consideration the occupants of the spectrum adjacent to the ISM bands which may be both potential sources of interference to, and susceptible to interference from, various types of spread spectrum products.
- Various forms of modulation across the spreading band may be utilized in commercial spread spectrum packet data communication systems. Full band direct sequence systems occupy the entire width of an ISM band. The spreading ratio, the ratio of the bandwidth of the spread spectrum modulated signal to the information bandwidth of the source modulation, determines the process gain of the system. Regulations within the United States mandate a minimum process gain of 10 dB, which is determined from ten times the logarithm of the spreading ratio. Process gain is a measure of the ability of a spread spectrum system to resist interference. The larger the spreading ratio, the more resistant the system is to interference within the receiver bandwidth. Wide bandwidth modulation is reasonably resistant to low or moderate levels of interference, but even systems with relatively high process gains experience difficulties when subject to strong interference.
- When system throughout requirements dictate high data rates, the minimum process gain requirements in the regulations necessitate using wide bandwidth transmissions. For example, a well-known system NCR Wavelan uses Quadrature PSK modulation at 1 million symbols per second to achieve 2 megabits per second (MBPS) data rates with a source information bandwidth available in the US ISM band at 902 MHz band. In practice, implementation constraints dictate that this system uses the full 26 MHz band. Systems operating at other data rates, including the original Norand system, utilize the full bandwidth at lower source data rates, e.g., 200 kilobits per second (KBPS). Utilization of a wider spreading bandwidth in this case provides greater rejection of multipath fading typical of the indoor RF signal propagation environment.
- When it is anticipated the direct sequence systems may be used in environments with strong in-band interference, a design choice is to employ channelization to reject interference. In the case of channelized direct sequence (DS) modulation, the spreading bandwidth is reduced to a fraction of the total available bandwidth, and a frequency-agile frequency generation systems is employed. By selecting the carrier frequency of operation, communications can be established in a portion of the band where interference is not present. This technique requires the use of selective filters in the receiver intermediate frequency (IF) section to provide the necessary interference rejection. These channelized DS systems utilize interference avoidance rather than relying on process gain to reject interference.
- Utilization of frequency hopping spread spectrum systems is appropriate in environments where interference within the band of operation is not confined to particular portions of the band, but may periodically arise in various parts of the entire band. Frequently hopping is also useful as a multiple access technique. Use of multiple hopping sequences concurrently within a given location allows many simultaneous communication sessions to be supported. Occasionally, devices operating on different hopping sequences will simultaneously occupy the same channel within the band for short periods of time. For moderate numbers of simultaneous hopping sequences, this occurs infrequently.
- Frequency hopping also provides similar multipath rejection capabilities to wideband direct sequence modulation. If a particular channel of operation is in a fade temporarily preventing communication, a jump to a frequency sufficiently removed from the faded frequency will often allow communications to resume.
- Frequency hopping systems require more protocol overhead to aid in establishing and maintaining synchronization between units sharing a given hopping sequence. Additionally, the initial acquisition of the hopping sequence may require that an unsynchronized device scan the band for a period equivalent to may hop times. The overhead for direct sequence systems is lower, with several bit-times usually allocated to receiver acquisition at the beginning of each transmission.
- Spread spectrum communications may not be appropriate for some applications. For example, short hop communications such as communications between a portable hand-held terminal and a peripheral device such as a scanner or printer over a short distance is a very cost sensitive application. Spread spectrum operation requires more circuit complexity and power consumption than is tolerable for this application. Simpler FM or AM techniques such as ON-OFF-Keying (OOK) may be desirable.
- Conventionally, the particular spread spectrum modulation technique is chosen according to the particular applications in which the data transceiver is to be utilized. For example, in a small warehouse having few RF barriers, minimal interference from cellular and wireless phones, and minimal amounts of communication traffic, radio transceivers used therein might only employ direct sequence spread spectrum transmission techniques. Thus, conventionally, such transceivers would be specifically designed, constructed and installed. However, after installation, if communication traffic or local noise increases, the communication might fail to function as required. Likewise, after installation, if RF barriers are installed or if the network is moved to an urban environment with a great deal of noise from neighboring installations, cellular and mobile phones, etc., the network may fail to meet the needs of the customer.
- Similarly, a design might be based on a customer's needs for a small store in a downtown urban area. Because of the greater likelihood of a great amount of radio frequency traffic in the vicinity, the customer requires a radio which is free from interference from nearby radio transmissions with little concern for operating range. Consequently, a different specific type of radio would be designed to meet the needs of the corporation based upon the operating conditions in which the radio is to be used, for example using frequency hopping modulation.
- In the exemplary installations mentioned above, each of the radios would be optimized to meet the needs of the customer. However, a customer's needs continually change, and, if the particular application or environment were to change justifying a different spread spectrum modulation technique, the customer is either forced to change all of their radio transceivers or live with the under-performance they currently receive.
- Moreover, in a typical network installation, a client may have diverse operational requirements. For example, the particular applications of the radio unit may change several times within the same day. The site may also have areas which are relatively noise and barrier free and those which encounter heavy noise and barriers. Some areas may have high traffic volume, while others experience only occasional traffic. In such networks, a single radio transceiver design can never provide optimal performance in all areas. Sacrifices are made in the design characteristics of the transceiver in an attempt to provide best performance overall.
- Similarly, in mobile contexts, a worker may require mobile communications to a vehicle based information system or forwarding to a central communication facility through a vehicle based radio WAN transceiver. The characteristics of the communications medium for this class of operation vary greatly. Interference will vary from location to location. Additionally, it is necessary to allow operation if the worker moves away from the vehicle or inside a building structure. Because each wireless local area network may have been designed for a particular set of criteria with particular spread spectrum operational abilities, mobile units may be non-functional within particular wireless local area networks.
- Thus, there is a need in the art for a communication network that operates dynamically to optimize communication utilizing various spread spectrum transmission techniques, considering the characteristics of RF noise, neighboring interference, RF barriers, participating transceiver unit capabilities and applications to be performed in such dynamic optimization.
- It is another object of the present invention to provide a spread spectrum RF transceiver module, for use in wireless network devices, which utilizes multiple spread spectrum modulation techniques providing multiple configurable modes of data transmission, whereby modes may be selected to attain optimal transmission performance.
- A further object of the present invention is to provide an RF data transceiver module which combines frequency hopping and direct sequence transmission techniques within a single design.
- It is an object of the present invention to provide a spread spectrum RF transceiver module which utilizes common media access protocols and interfaces for multiple nominal carrier frequencies and modulation parameters.
- It is a further object of the present invention to provide a spread spectrum RF transceiver utilizing 900 MHz transmission and having a standard interface with common 2.4 GHz transmission.
- It is a further object of the invention to provide a spread spectrum RF transceiver which may be utilized in several different types of multi-layered data communications networks.
- Another object of the present invention is to produce a wireless local area network and packet wireless data communication system that is flexible to operate reliably in varied and unpredictable RF propagation and interference environments.
- A further object of the present invention is to provide a wireless RF transceiver module capable of utilizing a variety of operational modes thereby allowing large business operation to purchase a single product meeting a multiple usage needs maximizing operational flexibility and minimizing sparing and service concerns.
- It is another object of the present invention to provide a modular wireless LAN modem capable of supporting multiple modes of operation under a single media access protocol with a standardized interface to a hand-held portable data terminal such that the wireless LAN modem may dynamically change modes of operation transparently to the host device, not requiring that the host device be aware of changes in the modes of operation, or that operation of higher protocol layers be impacted.
- Yet another object of the present invention is to produce a modular wireless LAN modem that may be utilized for both in-premise and worker to vehicle application, and for short range communications to peripheral devices.
- These and other objects of the invention will be apparent from examination of the drawings and remainder of the specification which follows.
- The system and radio of the present invention to overcome the limitations of the prior devices as well as other limitations therefore may operate in any of a plurality of spread spectrum modes. A selected spread spectrum mode, or set of spread spectrum modes, is based upon system characteristics as well as transmission characteristics within an operating environment.
- One particular operating environment relates to multi-hop wireless networks that are subject to in-band interference and multi-path fading. However, in these systems, members (hereinafter “transceiver devices”) of the network may have different operating capabilities. Therefore, the system and radio of the present invention provide a mechanism for selecting spread spectrum modes of operation to satisfy network member limitations, data transmission throughput requirements, neighboring system non-interference requirements, as well as noise tolerance requirements.
- By providing a dynamic mechanism for selecting spread spectrum modes of operation, the present invention provides many import objects and advantages that will become apparent with reference to the entire specification and drawings. In particular, in one embodiment, a communication network for collecting and communicating data is disclosed. The network comprises a wireless access device and at least one mobile terminal. The wireless access device comprises a control circuit and a first RF transceiver that selectively operates in one of a plurality of spread spectrum modes. The at least one mobile terminal comprises a second RF transceiver that operates in at least one of a plurality of spread spectrum modes. The control circuit responds to transmissions received from the first RF transceiver to evaluate communication performance and dynamically selects one of the plurality of spread spectrum modes of the first RF transceiver. Such selection also takes into consideration the at least one of the plurality of spread spectrum modes of the second RF transceiver.
- Further, the plurality of spread spectrum modes of the first RF transceiver may comprise direct sequence transmission, frequency hopping, channelized direct sequence and/or hybrid frequency hopping (direct sequence) modes. The control circuitry may evaluate communication performance through reference to received signal strength indications, transmission success rate and neighboring cell operating characteristics.
- Other aspects may be found in a communication system for collecting and communicating data using wireless data signal transmission. Therein a wireless access device capable of communicating with a plurality of radios comprises a radio capable of operating in a plurality of spread spectrum modes. The wireless access device also comprises a spread spectrum mode controller responsive to transmissions and data received for evaluating the data communication system and for controlling the radio to selectively operate in a spread spectrum mode among a plurality of spread spectrum modes.
- The wireless access device may further comprise circuitry for evaluating the plurality of spread spectrum modes to select a spread spectrum mode of operation. Such selection may take involve the identification of a common spread spectrum mode.
- Yet other aspects can be found in a data communication system having spread spectrum capability for collecting and communicating data using wireless data signal transmission. Therein, an RF transceiver comprises an modulator having a spreader, a demodulator having a despreader, a controllable oscillator attached to the modulator and demodulator, and control circuitry that both selectively enables the spreader and despreader and selectively controls the controllable oscillator to cause operation in one of a plurality of modes of spread spectrum operation.
- The data communication system may further comprising a host controller that directs the control circuitry in the selection of the one of the plurality of modes of spread spectrum operation. The host controller may comprise wireless access device control circuitry. In addition, the control circuitry may wirelessly receive instruction regarding selection of the one of the plurality of modes of spread spectrum operation. Many other aspects of the present invention will be appreciated with full reference to the specification, drawings and claims.
- FIG. 1A is a perspective view of a wireless communication network built in accordance with the present invention which incorporates dynamically adapting spread spectrum transceivers and supporting communication protocols;
- FIG. 1B is a flow diagram illustrating the operation of a wireless access device in accordance with present invention whereby multiple wireless devices having potentially different transceiver capabilities are supported;
- FIG. 1C is a block diagram illustrating a radio transceiver built in accordance with the present invention to provide multiple modes of operation;
- FIG. 1D is a block diagram illustrating the operation of the wireless access device having the multi-mode transceiver of FIG. 1C installed therein.
- FIG. 2A is a front elevation view of one embodiment of a hand-held portable data terminal having a transceiver module built in accordance with the present invention;
- FIG. 2B is a side elevation view of the hand-held portable data terminal of FIG. 2A showing a module of the present invention;
- FIG. 3 is a side evaluation view of the hand-held portable data terminal of FIG. 2A showing a module of the present invention;
- FIG. 4 is a side elevation view of the hand-held portable data terminal of FIG. 2A showing a removably insertible module of the present invention;
- FIGS. 4A, 4B and4C illustrate in detail the cooperation between a radio module and the hand-held portable data terminal shown in FIG. 3.
- FIG. 5 is a perspective view of another hand-held portable data terminal which may incorporate the present invention;
- FIG. 6 is a side elevation view of the data terminal of FIG. 5 showing an extendibly retractable rotating carriage housing for receiving a module incorporating the present invention;
- FIG. 7 is an exploded view of a radio module incorporating the present invention;
- FIG. 8 is an exploded view of a radio module of the present invention further containing a scanner;
- FIG. 9 is an exploded view of a radio module of the present invention contained within a PCMCIA type housing;
- FIG. 10 is a functional block diagram of the architecture of the radio modules of the present invention;
- FIG. 1I is a conceptual block diagram of the operation of the transmitter of FIG. 10 when operating in a direct sequence spread spectrum transmission mode;
- FIG. 12 shows a conceptual diagram of the operation of the receiver utilized in conjunction with the transmitter of FIG. 1;
- FIG. 13 is a block diagram of an embodiment of a receiver of the present invention;
- FIG. 14A is a diagram of the pseudo-random number generator shown in FIG. 10;
- FIG. 14B is a schematic block diagram illustrating the interaction of the pseudo-random number generator of FIG. 14A with traverse filtering and formatter circuitry of FIG. 10;
- FIG. 15 is a block diagram illustrating the frequency generator circuitry as shown in FIG. 10;
- FIG. 16 is a block diagram illustrating the transmitter circuitry as shown in FIG. 10;
- FIG. 17 illustrates the circuitry for selecting between the modes of modulation of the present invention.
- FIG. 18 is a block diagram of the MAC circuitry as shown in FIG. 10;
- FIG. 19 is a block diagram illustrating the host interface circuitry as shown in FIG. 10 for the radio module of FIG. 7 and for the radio/scanner module of FIG. 8; and
- FIG. 20 is a block diagram illustrating the host interface circuitry as shown in FIG. 10 for the radio module of FIG. 9.
- FIG. 21 is a diagram illustrating an alternate configuration of portable data terminals according to the present invention.
- FIG. 22A illustrates one embodiment of the data collection terminal of the present invention, having both wired and wireless communication capability.
- FIG. 22B is a diagram illustrating a specific implementation of the portable terminal of FIG. 22A a single PCMCIA card contains not only a multi-mode wireless transceiver, but also a wired modem transceiver.
- FIG. 23 is a diagram illustrating the use of portable terminals according to the present invention utilizing both wired and wireless communication in a network configuration.
- FIG. 24 is a diagram illustrating the use of portable data terminals according to the present invention utilizing both wired and wireless communication to access separate subnetworks in an overall communication network.
- FIG. 25a is a block diagram illustrating an embodiment of the present invention wherein a wireless access device uses a dedicated control/busy channel to manage a plurality of modes of communication with roaming terminals.
- FIG. 25b is a drawing illustrating adcantageous operation of the wireless access device of FIG. 25a when two roaming terminals encounter hidden terminal conditions.
- FIG. 25c is a flow diagram illustrating the functionality of the wireless access device of FIGS. 25a-b in managing communication using a control/busy channel.
- FIG. 26a is a block diagram illustrating an alternate embodiment of that shown in FIG. 25a wherein a wireless access device uses a separate transmitter for the dedicated control/busy channel and a roaming terminal uses either a shared multimode transmitter or a multimode transmitter and a separate busy/control channel receiver.
- FIG. 26b is a drawing illustrating advantageous operation of the wireless access device of FIG. 26a when the two roaming terminals encounter hidden terminal conditions.
- FIG. 26c is a flow diagram illustrating the functionality of the wireless access device of FIGS. 26a-b in managing communication using a control/busy channel.
- FIG. 27 is a block diagram illustrating a further embodiment of the present invention wherein channel selection and operating parameters are delivered by a wireless access device on a dedicated busy/control channel with or without multimode transceiver capabilities.
- FIG. 1A illustrates a
communication network 1 incorporating the teachings of the present invention. The system compriseswireless access devices portable transceiver units wireless code reader 5 and aperipheral device 6. Thewireless access devices wired network 3 to each other and to other wired network devices (not shown). Thewireless access device 2C communicates with thewired network 3 and thewireless access device 2A via wireless transmissions through thewireless access device 2B. - The
wireless access 2A-C may comprise wireless access points or wireless access servers to provide an interface among theportable transceiver units 4A-C, thecode reader 5, theperipheral device 6 and devices on the wired network. Each of thesewireless access devices 2A-C has associated with it a range or cell of communication. For example, theportable transceiver units 4A-C may wander in and out of range of thewireless access device 2A. Similarly, they may wander in and out of range of thewireless access devices 2B-C, i.e., they may wander from cell to cell. Eachaccess device 2A-C, and many more as may prove necessary, are located to provide coverage of a customer's premises. Cell areas typically overlap somewhat to support ubiquitous coverage. - Because cells typically overlap slightly with one another, at any time, a hand-held radio unit may communicate with at least two wireless access devices. To avoid conflicts with transmissions in such overlap areas, it is desirable to configure neighboring cells operate with different spreading codes, different hopping sequences or different modes, for example. However, when the
portable transceiver unit 4B for example passes from one cell to another, it cannot communicate with a neighboring wireless access device without changing its operating characteristics. Thus, the present invention provides several techniques for accommodating devices wishing to communicate in a new cell. - Moreover, the
wireless access devices 2A-C,peripheral device 6 andcode reader 5 may be capable of only some modes of wireless operation. Thus, the present invention provides a mechanism for each of thewireless access devices 2A-C to dynamically attempt to select a common mode of appropriation for each participating device within its cell. Moreover, if a given mode of operation proves dissatisfactory, a wireless access device may dynamically switch modes to attempt to achieve superior performance. - In particular, data throughput concerns and requirements, ambient noise, power consumption of portable units, previously recorded success rates, received signal strength indications, neighboring cell operating modes and success rates, and mode capabilities of participating devices are all considered in determining the mode in which to operate. Each wireless access device engages in such consideration when initially establishing communication in its cell, when attaching or detaching a participating device and as channel conditions are evaluated. In other embodiments, less than all of such considerations need be made. For example, where all transceivers are known to operate in all available modes, consideration of this factor is not necessary. Similarly, if only one cell exists or if problems in overlap regions prove minimal, consideration of neighboring cell operation need not be engaged. Likewise, received signal strength alone may be used as a mode performance indication.
- Using lower power transmissions, a benefit to battery powered portable transceiver units, requires the use of more wireless access devices to cover a premises. Lower power transmissions might also or alternately require a mode having a wider spreading bandwidth or slower data transfer rate to overcome the lower received signal strength. In other cells that have minimal battery power concerns and little or no noise, a spread spectrum mode may be chosen that provides higher data transmission rates. In yet other cells experiencing significant background noise, a direct sequence spreading mode may be employed that provides greater noise tolerance.
- In addition to changing modes, the
wireless access devices 2A-C also support changes to various mode parameters such as data segment sizes, chipping rates, spreading code lengths, etc. By supporting dynamic changes in operating modes and mode parameters, thecommunication network 1 attempts to accommodate any transceiving device that enters any cell. This flexibility allows for expansion without replacing existing equipment. An older radio transceiver may be able to participate with newer transceivers that may support newer modes of operation. Thenetwork 1 would attempt to accommodate such communication in a common, older mode of operation. - RF signals are inherently subject to what is termed “multipath fading”. A signal received by a receiver is a composite of all signals that have reached that receiver by taking all available paths from the transmitter. The received signal is therefore often referred to as a “composite signal” which has a power envelope equal to the vector sum of the individual components of the multipath signals received. If the signals making up the composite signal are of amplitudes that add “out of phase” the desired data signal decreases in amplitude. If the signal amplitudes are approximately equal, an effective null (no detectable signal at the receiver) results. This condition is termed “fading”.
- Normally changes in the propagation environment occur relatively slowly, i.e., over periods of time ranging from several tenths ({fraction (1/10)}'s) of seconds to several seconds. However, in a mobile RF environment, receivers (or the corresponding transmitters) often travel over some distance in the course of receiving a message. Because the signal energy at each receiver is determined by the paths that the signal components take to reach that receiver, the relative motion between the receiver and the transmitter causes the receiver to experience rapid fluctuations in signal energy. Such rapid fluctuations can result in the loss of data if the amplitude of the received signal falls below the sensitivity of the receiver.
- Over small distances, the signal components that determine the composite signal are well correlated, i.e., there is a small probability that a significant change in the signal power envelope will occur over the distance. If a transmission of a data packet can be initiated and completed before the relative movement between the receiver and transmitter exceeds the “small distance” data loss to fading is unlikely to occur. The maximum “small distance” wherein a high degree of correlation exists is referred to hereafter as the “correlation distance”.
- As expressed in wavelengths of the carrier frequency, the correlation distance is on half (½) of the wavelength, while a more conservative value is one quarter (¼) of the wavelength. Taking this correlation distance into consideration, the size of the data packet for segmentation purposes can be calculated. For example, at 915 MHz (a preferred RF transmission frequency), a quarter wavelength is about 8.2 centimeters. A mobile radio moving a ten (10) miles per hour, or 447 centimeters per second, travels the quarter wavelength in about 18.3 milliseconds. In such an environment, as long as the segment packet size remains well under 18.3 milliseconds, significant signal fluctuations during the duration of a packet transmission is unlikely. In such an preferred embodiment, five (5) millisecond data packet segments are chosen which provides a quasi-static multipath communication environment.
- The faster the relative movement between a transmitter and a receiver the greater the effect of fading. Similarly, if the relative movement is slower, fading is less pronounced. In many communication environments, the degree of fading effects varies dramatically both from time to time and from installation to installation.
- One example of a receiver making such a measurement of fading can be found in the abandoned patent application of Ronald L. Mahany, U.S. Ser. No. 07/485,313, filed Feb. 26, 1990, which is incorporated herein by reference. Specifically, in that reference, a received signal strength indicator (RSSI) circuit is found in the receiver. The RSSI circuit sample the signal strength of a transmission. If the signal strength samples are evaluated in sequence and the trend analyzed, the degree of fading can be measured. If the signal strength samples decrease in value, it is likely that fading is present in the network.
- A transceiver using direct-sequence spread spectrum transmission uses a spreading-code of a higher frequency than that of the data rate to encode the data to be sent. This higher frequency is achieved by increasing the chip clock rate (wherein each chip constitutes an element of the spreading-code). Using the same spreading code, the receiver decodes the received signal while ignoring minor faults which occurred in transmission, providing noise immunity and multi-path signal rejection. The frequency and length of the spreading-code can be varied to offer more or less multi-path signal rejection or noise immunity. Although it may result in improved communication, increasing the frequency or length of the spreading-code requires additional overhead which may not be justifiable unless necessary.
- Frequency-hopping is the switching of transmission frequencies according to a sequence that is fixed or pseudo-random and that is available to both the transmitter and receiver. Adaptation to the communication environment via an exchange in frequency-hopping operating parameters is possible, for example, via selective control of the hopping rate or through the use of coding or interleaving. The greater the degree of frequency selectivity of the fading envelope (i.e., when fading is significant only over a portion of the spectrum of hopping frequencies), the greater the benefit of such adaptation.
- Particularly, a parameter indicating the hopping rate can be varied to minimize the probability that the channel characteristics will detrimentally change during the course of a communication exchange. To vary the hopping rate is to vary the length of a hopping frame. Although multiple data (or message) exchanges per hopping frame is contemplated, the preferred hopping frame consists of a single exchange of data, For example, in a polling environment, the hopping frame might consist of: 1) a base station transmitting a polling packet to a roaming terminal; 2) the roaming terminal transmitting data in response; and 3) the base station responding in turn by transmitting an acknowledge packet. Each hopping frame exchange occurs at a different pseudo-randomly chosen frequency.
- For optimization, the hop frame length is adjusted to be as long as possible, while remaining shorter than the coherence time of the channel by some safety margin. Although such adjustment does not eliminate the effects of fading, it increases the probability that the characteristics of the channel will remain consistent during each hopping frame. Thus, in the preferred embodiment, if the polling packet transmission is successfully received, the probability of successful receipt of the data (or message) and acknowledge is high.
- Another parameter for changing frequency-hopping performance is that of coding. Coding on the channel for error correction purposes can be selectively used whenever the probability of data or message loss due to fading is high. In particular, coding methods which provide burst error correction, e.g., Reed-Solomon coding, can be applied if the hop length is likely to exceed the coherence time of the channel. Such coding methods allow some portion of the data to be lost and reconstructed at the expense of a 30-50% reduction in throughput. The operating parameter for coding indicates whether coding should be used and, if so, the type of coding to be used.
- An operating parameter indicating whether interleaving should be used also help to optimize the communication channel. Interleaving involves breaking down the data into segments which are redundantly transmitted in different hopping frames. For example in a three segment exchange, the first and second segments are sequentially combined and sent during a first hopping frame. In a subsequent hopping frame, the second and third segments are sequentially combined and transmitted in a third hopping frame. The receiving transceiver compares each segment received with the redundantly received segment to verify that the transmission was successful. If errors are detected, further transmissions must be made until verification is achieved. Once achieved, the transceiver reconstructs the data from the segments.
- Other methods of interleaving are also contemplated. For example, a simpler form of interleaving would be to sequentially send the data twice without segmentation on two different frequencies (i.e., on two successive hops).
- As can be appreciated, interleaving provides for a redundancy check but at the expense of data or message throughput. The interleaving parameter determines whether interleaving is to be used and, if so, the specific method of interleaving.
- In addition, any combination of the above frequency-hopping parameters might interact to define an overall operating configuration, different from what might be expected from the sum of the individual operating parameters. For example, selecting interleaving and coding, through their respective parameters, might result in a more complex combination scheme which combines segmentation and error correction in some alternate fashion.
- In the United States, data communication equipment operating in the ultra-high frequency (UHF) range under conditions of frequency modulation (FM) is subject to the following limitations.
- 1) The occupied band width is sixteen kilohertz maximum with five kilohertz maximum frequency deviation.
- 2) The channel spacing is 25 kilohertz. This requires the use of highly selected filtering in the receiver to reduce the potential for interference from nearby radio equipment operating on adjacent channels.
- 3) The maximum output power is generally in the range of ten to three hundred watts. For localized operation is a fixed location, however, transmitter power output may be limited to two watts, maximum, and limitations may be placed on antenna height as well. These restrictions are intended to limit system range so as to allow efficient reuse of frequencies.
- For non-return to zero (NRZ) data modulation, the highest modulating frequency is equal to one half the data rate in a baud. Maximum deviation of five kilohertz may be utilized for a highest modulation frequency which is less than three kilohertz, but lower deviations are generally required for higher modulation frequencies. Thus, at a rate of ten thousand baud, and an occupied bandwidth of sixteen kilohertz, the peak FM deviation which can be utilized for NRZ data may be three kilohertz or less.
- Considerations of cost versus performance tradeoffs are the major reason for the selection of the frequency modulation approach used in the system. The approach utilizes shaped non-return-to-zero (NRZ) data for bandwidth efficiency and non-coherent demodulation using a limited-discriminator detector for reasonable performance at weak RF signal levels. However, the channel bandwidth constraints limit the maximum data “high” data rate that can be utilized for transmitting NRZ coded data. Significant improvements in system throughput potential can be realized within the allotted bandwidth by extending the concept of adaptively selecting data rate to include switching between source encoding methods. The preferred approach is to continue to use NRZ coding for the lower system data rate and substitute partial response (PR) encoding for the higher rate. The throughput improvements of NRZ/PR scheme over an HRZ/NRZ implementation are obtained at the expense of additional complexity in the baseband processing circuitry. An example of a transceiver using such an approach can be found in the previously incorporated patent application of Ronald L. Mahany, U.S. Ser. No. 07/485,313, filed Feb. 26, 1990.
- Partial response encoding methods are line coding techniques which allow a potential doubling of the data rate over NRZ encoding using the same baseband bandwidth. Examples of PR encoding methods include duobinary and modified duobinary encoding. Bandwidth efficiency is improved by converting binary data into three level, or pseudo-ternary signals. Because the receiver decision circuitry must distinguish between three instead of two levels, there is a signal to noise (range) penalty for using PR encoding. In an adaptive baud rate switching system, the effects of this degradation are eliminated by appropriate selection of the baud rate switching threshold.
- Since PR encoding offers a doubling of the data rate of NRZ encoded data in the same bandwidth, one possible implementation of a NRZ/PR baud rate switching system would be a 4800/9600 bit/sec system in which the low-pass filter bandwidth is not switched. This might be desirable for example if complex low-pass filters constructed of discrete components had to be used. Use of a single filter could reduce circuit costs and printed circuit board area requirements. This approach might also be desirable if the channel bandwidth were reduced below what is currently available.
- The implementation with bandwidth available is to use PR encoding to increase the high data rate well beyond the 9600 bit/sec implementation previously described. An approach using 4800 bit/sec NRZ encoded data for the low rate thereby providing high reliability and backward compatibility with existing products, and 16K bit/sec PR encoded transmission for the high rate may be utilized. The PR encoding techniques is a hybrid form similar to duobinary and several of its variants which has been devised to aid decoding, minimize the increase in hardware complexity, and provide similar performance characteristics to that of the previously described 4800/9600 bit/sec implementation. While PR encoding could potentially provide a high data rate of up to 20K bit/sec in the available channel bandwidth, 16K bit/sec is preferable because of the practical constraints imposed by oscillator temperature stability and the distortion characteristics of IF bandpass filters.
- All of the above referenced parameters must be maintained in local memory at both the transmitter and the receiver so that successful communication can occur. To change the communication environment by changing an operating parameter requires both synchronization between the transceivers and a method for recovering in case synchronization fails.
- In one embodiment, if a transceiver receiving a transmission (hereinafter referred to as the “destination”) determines that an operating parameter needs to be changed, it must transmit a request for change to the transceiver sending the transmission (hereinafter the “source”). If received, the source may send an first acknowledge to the destination based on the current operating parameter. Thereafter, the source modifies its currently stored operating parameter, stores the modification, and awaits a transmission from the destination based on the newly stored operating parameter. The source may also send a “no acknowledge” message, rejecting the requested modification.
- If the first acknowledge message is received, the destination modifies its currently stored operating parameter, stores the modification, sends a verification message based on the newly stored operating parameter, and awaits a second acknowledge message from the source. If the destination does not receive the first acknowledge is not received, the destination modifies the currently stored parameter, stores the modification as the new operating parameter, and, based on the new parameter, transmits a request for acknowledge. If the source has already made the operating parameter modification (i.e., the destination did not properly receive the first acknowledge message), the destination receives the request based on the new parameters and response with a second acknowledge. After the second acknowledge is received, communication between the source and destination based on the newly stored operating parameter begins.
- If the destination does not receive either the first or the second acknowledge messages from the source after repeated requests, the destination replaces the current operating parameter with a factory preset system-default (which is also loaded upon power-up). Thereafter, using the system-default, the destination transmits repeated requests for acknowledge until receiving a response from the source. The system-default parameters preferably define the most robust configuration for communication.
- If after a time-out period the second request for acknowledge based on the newly stored operating parameters is not received, the source restores the previously modified operating parameters and listens for a request for acknowledge. If after a further time-out period a request for acknowledge is not received, the source replaces the current operating parameter with the factory preset system-default (which is the same as that stored in the destination, and which is also loaded upon power-up). Thereafter, using the common system-default, the source listens for an acknowledge request from the destination. Once received, communication is reestablished.
- Other synchronization and recovery methods are also contemplated. For example, instead of acknowledge requests originating solely from the destination, the source might also participate in such requests. Similarly, although a polling protocol is used to carry out the communication exchanges described above, carrier-sense multiple-access (CSMA) or busy tone protocols might alternately be used.
- In the embodiment illustrated in FIG. 1A, various modes of operation are dynamically controlled by the
wireless access devices 2A-C. Such control involves the consideration by each wireless access device of many factors such as: 1) received signal strength; 2) success/fail rates; 3) mode capabilities of participating devices; 3) neighboring access device operation and performance; 4) application support required; and 5) power concerns. In addition to modifying the parameters of a particular mode (as previously mentioned), the wireless access devices may also select from a plurality of modes (as described in more detail below in reference to FIG. 10). - FIG. 1B is a flow diagram illustrating the operation of a wireless access device in accordance with present invention whereby multiple wireless devices having potentially different transceiver capabilities are supported. In particular, a wireless access device manages ongoing communication within its cell with a previously selected mode and mode parameters at a
block 401. At ablock 403, the wireless access device identifies an attach request from a wireless transceiver (hereinafter the “requesting transceiver”) that may have wandered into the cell. Theaccess device 403 responds at ablock 405 by identifying the available modes of operation of the requesting transceiver. At ablock 407, the modes are added to a mode table, which stores the available modes of all the participating devices. Note that a requesting transceiver only communicates the availability of those modes which are both possible (determined by the transceiver's design) and useful (determined by a current application). - If the requesting device is capable of operating in the currently selected mode, as determined at a
block 409, the wireless access device communicates mode information and parameters to the requesting transceiver at ablock 413. Thereafter, the wireless access device returns to theblock 401 and services all participating devices including the requesting device in the current mode with current parameters. - Alternatively, if the requesting device has a limited number of operating modes, at the
block 409 the current mode may not be a possibility. If the requesting device is not capable of operating in the current mode, the wireless access device attempts to select a new mode at ablock 411. If at least one common mode can be found, e.g., if all the participating devices and the requesting device have at least one common mode, the wireless access device chooses the common mode that it believes will offer optimal performance. Thereafter, at ablock 413, the wireless access device communicates the selected mode and parameter information to the requesting transceiver at theblock 413 and returns to theblock 401. At theblock 401, because a new mode has been selected, the wireless access device vectors to service the event at ablock 419. At ablock 421, the wireless access device broadcasts the mode and parameter information, and, at ablock 423, changes its own mode. Thereafter, the wireless access device returns to service ongoing communication in that mode at theblock 401. - If however a common mode cannot be found for a requesting transceiver at the
block 411, the requesting transceiver is rejected from participating. In such a case, the customer must identify the radios causing the limitations and upgrade them. In another embodiment, the wireless access device operates in a time shared configurations, switching between two or more modes in a sequential fashion. In this embodiment, however, the overall delays in the system may still justify upgrading the radio transceiver(s) causing the limitations. - During the course of ongoing operation at the
block 401, the wireless access device monitors channel performance (a variety of factors described in more detail above), and compares such performance to available other common modes of operation and considers potential parameter modifications. In particular, as represented by theblock 429, if channel conditions degrade below a predefined threshold, the wireless access device vectors to consider changing modes. At ablock 431, the wireless access device consults the mode table. If a new mode is available and warranted, per a determination at ablock 433, the wireless access device responds by selecting an alternate common mode at theblock 435, resets the conditions that caused the vectoring and returns to theblock 401 to complete the mode change via theblocks event block 445, the wireless access device removes that transceiving device's mode information from active status in the mode table and attempts to choose a better common mode via theblocks - FIG. 1C is a block diagram illustrating a radio transceiver used in wireless access devices and any transceiving device, such as a printer, code reader, hand-held terminal, etc., and built in accordance with the present invention to support multiple modes of operation. The
transceiver module 501 comprisescontrol circuitry 503, amodulator 505, ademodulator 507, andoscillator 509 and aswitch circuit 511. The control module may have either an internal or external antenna attached thereto, i.e., anantenna 513. - The
control circuitry 503 manages the operation of the other components of thetransceiver module 501. Thecontrol circuitry 503 receives instructions and data to be transmitted from a host unit (not shown) via a wiredcommunication link 515. Thecontrol circuitry 503 deliver such data to themodulator 505 for modulation (and possibly spreading). Thereafter, the data is delivered to theantenna 513 via theswitch 511. Data and control signals received by theantenna 513 passes through theswitch 511 to thedemodulator 507 for demodulation (and possibly despreading). Thecontrol circuitry 503 receives the demodulated data or control signals for processing and/or delivery to the host unit through thelink 515. - The
control circuitry 503 causes the selection of operating parameters and modes as described previously and in reference to FIG. 1B. Specifically, thecontrol circuitry 503 sets the configuration of themodulator 505,demodulator 507 andoscillator 509. For example, to operate in a direct sequence spread spectrum mode, the control circuitry 503: 1) sets the base frequency of theoscillator 509; 2) sets related mode parameters such as the chipping rate; and 3) delivers enable signals and a spreading code to aspreader circuit 515 anddespreader circuit 517 of themodulator 505 anddemodulator 507, respectively. To operate in a frequency hopping mode, the control circuitry 503: 1) establishes related parameter settings; 2) disables the spreading anddespreading circuits oscillator 509 through the sequence. To operate in a hybrid, direct sequence, frequency hopping mode, the control circuitry 515: 1) establishes related parameter settings; 2) delivers enable signals and a spreading code to aspreader circuit 515 anddespreader circuit 517; 3) selects a hopping sequence of frequencies; and 4) directs theoscillator 509 through the sequence. Similarly, thecontrol circuitry 503 may select any modes, e.g., the modes identified in reference to FIG. 10 below, and set all parameters related thereto. - FIG. 1D is a block diagram illustrating the operation of the wireless access device having the multi-mode transceiver of FIG. 1C installed therein. In particular, a transceiver module501 (as described in relation to FIG. 1C) is installed within a
wireless access device 503. Thewireless access device 503 containscontrol circuitry 505 andinterface circuitry 507 for communicating with awired network 509. In addition to providing typical access device service, thecontrol circuitry 505 of thewireless access device 503 manages all mode and parameter changes for thetransceiver module 501. Thecontrol circuitry 505 monitors, among other factors, the historical performance characteristics of each mode, neighboring access device modes, parameters and performance and current mode performance (via received signal strength indications and success/failure rates). Thecontrol circuitry 505 also maintains and updates the mode table, attachment and detachment of participants, as described above in reference to FIG. 1B for example. Thecontrol circuitry 505 performs such functionality via control signals delivered to the control circuitry of thetransceiver module 503. - When installed in a portable/mobile or stationary transceiver unit (e.g., peripheral device, code reader, hand-held terminal, etc.), a transceiver module responds to communication control through commands received from the wireless access device while attempting to attach. Such commands direct the mode and parameters of operation of the transceiver module in the transceiver unit. In addition, the control circuitry of the
transceiver module 501 directs entry of a default mode and default parameters prior to receiving direction from a wireless access device. Although thetransceiver module 501 may receive additional mode and parameter commands from the host controller within the transceiver unit, in need not do so. Such local control by a transceiver unit, however, may prove advantageous in other wireless network embodiments or in specific applications. For example, other network embodiments might involve only two transceiver units without a wireless access device. As such, the transceiver units may negotiate a mode and related parameters amongst themselves, controlling such changes via host processors within the transceiver units. Negotiation of mode and parameter changes might also involve channel condition monitoring or other factors currently assigned to the wireless access device. - FIG. 2A illustrates a hand-held portable data terminal which incorporates the present invention, designated generally by the numeral10. The
data terminal 10 may be one of several data terminals in a local area network which utilizes radio frequency (RF) communications for data transfer. Thedata terminal 10 illustrated is a mobile data unit that includes a radio transceiver unit incorporating the present invention. Of course, as has been previously described, the present invention may be incorporated into stationary units as well as mobile units. Further, the stationary units may comprise wireless access points, other function performing devices such as printers, stationary scanners, or other devices. Moreover, mobile units incorporating the present invention need not comprise the hand-held radio format illustrated in FIG. 2A. The mobile units could be installed in vehicles, worn by a user, or installed in any other fashion that causes the device to be mobile. - The
data terminal 10 includes anantenna 12 is disposed at thetop end 14 of the data terminal for radio frequency transmission and reception. The data terminal may include adisplay screen 16 for displaying program information and for interfacing the operator with thedata terminal 10. Thedisplay screen 16 may be a reflective super-twist liquid crystal display (LCD), for example. Thedata terminal 10 may include akeypad 18 having a plurality of keys for entering data into thedata terminal 10 and for control of thedata terminal 10 by the operator. - FIG. 2B shows the
data terminal 10 of FIG. 2A which includes a module in which circuitry for accomplishing the present invention is disposed. Thedata terminal 10 has a modularly attachedradio module 20 which also contains scanning circuitry in addition to radio circuitry. Theantenna 12 of FIG. 2A is affixed to the radio/scanner module 20 and may be a type suitable for portable battery powered electronic devices. The radio/scanner module 20 has an extendedouter shell 24 in order to contain both the radio and the scanner circuitry. Abutton 26 may be disposed on either or both sides of the radio/scanner module 20 to activate the scanning circuitry and scan encoded data, such as that contained in a bar code or two dimensional image. Themodule 20 could, in another embodiment, include a digital camera or other functional equipment. As illustrated, the radio/scanner module 20 is constructed to be modularly received by arecession 28 in the data terminal such that a continuous unit is formed by attaching themodule 20 to the data terminal. - FIG. 3 shows a side view of another embodiment of a
data terminal 10 with an alternate modular radio module attached thereto. Themodule 30 includes a radio incorporating the teachings of the present invention but does not include the image capture electronics of the radio/scanner module 20 of FIG. 2B. Because themodule 30 is more compact thanradio scanner module 20 of FIG. 2B, the body ofradio module 30 is generally flush with the body of thedata terminal 10 when attached thereto. - FIG. 4 shows a
data terminal 10 that is removably attachable to the radio/scanner module 20 of FIG. 2B. The motion required for attachment of themodule 20 to thedata terminal 10 generally follows the direction ofline 32. Themodule 20 is positioned toward the terminal 10 and then locked into place by a downward movement. L-shapedlatches 34 may be used to removably secure themodule 20 to the terminal 10. - FIGS. 4A, 4B and4C illustrate in detail the cooperation between a radio module and the hand-held portable data terminal shown in FIG. 3. The
radio module 30 houses aradio unit 340. Anantenna connector 342 connects to antenna connector pins 344 at an end of theradio unit 340 to provide electrical connection to an antenna which may be internally or externally mounted on themodule 30. An array of connectingpins 346 preferably connect theradio unit 340 to the data terminal which may have a receptacle for receiving the connecting pins 346. Theradio module 30 may include ahand strap 348, one end of which being connected to themodule 30 and the other end being connected to the terminal 10, to facilitate manipulation of the terminal 10 in one hand and to prevent accidental dropping, for example. - FIG. 5 depicts another type of hand-held
portable data terminal 36 that incorporates the present invention and that is designed to receive standard PCMCIA computer feature card modules. The terminal 36 may have amodule carriage housing 38 which may receive various types of PCMCIA cards 40: Type I (3.3 mm in thickness), Type II (5.0 mm in thickness) or Type III (10.5 mm in thickness) PCMCIA sized modules for example. - FIG. 6 shows the data terminal of36 of FIG. 5 having a rotatably extendible and
retractable carriage housing 38. Thecarriage housing 38 is shown in the extended position holding a TypeIII PCMCIA module 42 which may, for example, contain the radio circuitry of the present invention. - FIG. 7 is an exploded view of the internal components of a
radio module 30 of the present invention such as themodule 30 of FIG. 3. The circuitry ofradio module 30 of the present invention such as themodule 30 is preferably mounted on a circuit card assembly (CCA)board 44 containing, for example, the transmitter and receiver electronic components (not shown). Theradio CCA 44 may have metallic coverings, or cans (not shown), soldered to the board over critical radio components to provide two-way electromagnetic shielding to reduce or eliminate radio frequency interference. - In embodiment of FIG. 7, the
radio module CCA 44 is contained within ametallic radio cover 46 to provide electromagnetic shielding of theradio CCA 44. Theradio CCA 44 andradio cover 46 may be attached to a mountingframe 48 which provides supporting structure for the internal components of theradio module 30.Radio cover 46 and mountingframe 48 may be fabricated of ABS type plastic or of a conductive metal to provide electromagnetic shielding. Theradio CCA 44 and theradio cover 36 may be attached to the mountingframe 48 by a plurality offasteners 50 which may be four #2 screws in a preferred embodiment. - An
internal antenna 52 may be connected to the radio circuitry of theradio CCA 44 in lieu of the externallinear antenna 12 shown in FIG. 2A and completely contained within theradio module 30. Theradio module 30 may utilize the antenna means of U.S. Pat. No. 5, 322, 991 issued Jun. 21, 1994 and assigned to NORAND Corporation of Cedar Rapids, Iowa, the assignee of the present application, Said U.S. Pat. No. 5,322,991 is hereby incorporated by reference in its entirety. The antenna 53 may comprise a quarter-wavelength single loop of wire of approximately 83 mm for transmissions near 900 MHz. When theloop antenna 52 is driven by the output of theradio module 44, a uniform circulatory current flowing through theantenna 52 results in a radiation pattern similar to that of a magnetic dipole. Theantenna 52 preferably has a nominal impedance of 50 S. - An
internal shield 56 may be utilized and inserted between the radio circuit card assembly (CCA) 44 and the radio interface card (RIC) 58 which contains the electronic circuitry necessary6 to interface the electronics of theradio CCA 44 with the electronics of thedata terminal 10 of FIG. 2A. Theradio interface card 58 may be a type used for a 2.4 GHz radio since the interface to theradio CCA 44 is baseband. The 900MHz radio 44 of the present invention may be designed to appear as a 2.4 GHz radio accepting the same frequency control inputs and employing the same media access control protocols as a 2.4 GHz radio. -
Electrical connectors 60 may be mounted at an end of theradio interface card 58 for providing electrical connection to the CPU board (not shown) of the portable data terminal with which theradio module 30 is utilized, such asterminal 10 of FIG. 2A. A mountingfastener 62, which may be a screw, fastens the radio interface card to theradio module assembly 30. An acoustic-electric transducer such asbuzzer 64 may be included with theradio module 30 and electronically connected to theradio CCA 44 5to provide the operator with audio information and cues, for example a beep or buzz when theradio module 30 is powered on. Frame mounting screws 66 may be utilized to fasten the assembly to theouter shell 68 via mountingframe 48. The entire module assembly may be wrapped in a metallic foil to provide electromagnetic shielding to theradio module 30. Theouter shell 68 is preferably a type of ABS plastic and is formed to modularly and contiguously fit therecession 28 of thedata terminal 10 as shown in FIG. 2B. - FIG. 8 is an exploded view of the radio/
scanner module 20 illustrated in FIGS. 2B and 4. The components and assembly thereof of the radio/scanner module 20 are substantially similar, with some slight modifications thereof where necessary, to that of theradio module 30 of FIG. 7, the principle difference being the addition of scanner circuitry in the radio/scanner module 20 for reading optically readable data files such as standard bar codes. The radio/scanner module 20 includesradio interface card 58 withelectrical connectors 60, mountingframe 48,internal shield 56,radio CCA 44,antenna 52,radio cover 46, andbuzzer 64 as shown in FIG. 7 (and as described in the discussion of FIG. 7). - In addition to the above components, the radio/
scanner module 20 includes a scanner printedcircuit board 70 on which the scanner electronic circuitry are mounted. A flexcircuit connection assembly 72 may be utilized to interconnect the electronic circuitry, such as the circuitry ofscanner card 70 andinterface card 58. Theouter shell 74 of the radio scanner module is substantially similar to theouter shell 68 ofradio module 30 as shown in FIG. 7, modified to accommodate the additional components of the radio/scanner module 20. - A rubber
nose end cap 76 may be attached to the forward end of theouter shell 74 for providing impact shock absorption and protection. Aseal label 78 may be used to provide an adhesive seal between rubbernose end cap 76 andouter shell 74. Alens 80 mounted with alens seal support 82 may be disposed in therubber end cap 76 to provide a sealed light aperture for the scanner circuitry. Scanning of an optically readable data file may be controlled with ascam button 86 which covers am input keyboard andelastomer 84 and is supported by ascan button bezel 88 mounted in abutton aperture 90 on a side of theouter shell 74. The radio/scanner may have a plurality of scan orinput buttons 86. For example, an additional button may be provided on the side of theouter shell 74 opposite thebutton 86 shown in FIG. 8. - Frame mounting screws92 are provided to mount the mounting
frame 48 containing the module assembly to theouter shell 74. Theouter shell 74 and radio/scanner module are formed to modularly and contiguously attach to thedata terminal 10 as illustrated in FIGS. 2B and 4 in a manner substantially similar the attachment ofradio module 30 todata terminal 10. Theentire module assembly 20 may be wrapped in a metallic foil to provide electromagnetic shielding to theradio module 20. - FIG. 9 is an exploded view of the PCMCIA Type
III radio module 42 of FIG. 6. ThePCMCIA radio module 42 may also be constructed within a smaller sized PCMCIA module such as Type II or Type I enclosure by combining the circuitry of theradio interface card 58 and the radiocircuit card assembly 44 on a single printed circuit board, for example. ThePCMCIA radio module 44 may contain the radiocircuit card assembly 44 and theradio interface card 58 of FIGS. 7 and 8. Theradio interface card 58 is preferably adapted to conform to PCMCIA device interface standards for utilization inPCMCIA radio module 42. The circuitry of theradio CCA 44 and theradio interface card 68 may be interconnected by a board toboard connector 94. Alternatively, all of the circuitry of theRIC 58 and theCCA 44 may be combined on a single printed circuit board for smaller sized radio modules (20, 30 or 42). -
Standoffs 96 may be soldered directly to theradio interface card 58 and are provided to separate theradio CCA 44 from theradio interface card 58 and to provide attachment thereto with fasteners 98 (preferably #2-56 screws). Thescrews 98 preferably attach theradio CCA 44 to a custom PCMCIAType III frame 100 which provides structural support and protection of thecircuit boards electrical receptacle 102 may be provided to electrically connect the radio module to standard PCMCIA connectors in the electronic equipment in which themodule 42 is to be utilized, such as thedata terminal 36 of FIGS. 5 and 6. - An
antenna connector 104 may be mounted on theradio CCA 44 for connection of the module to an antenna which may be, for example, theantenna 12 of FIG. 2A, theantenna 52 of FIGS. 6 and 7 of the antenna means of U.S. Pat. No. 5,322,991 issued Jun. 21, 1994 incorporated herein. Alternate antenna clips 106 may be utilized for adapting theradio module 42 to various antenna connection configurations. - The
PCMCIA radio module 42 may be contained within top and bottom covers 108 and 110 respectively which are preferably comprised of tin plated cold rolled steel. The module covers 108 and 110 may provide two way electromagnetic shielding of the radio frequency circuitry. When theradio module 42 is assembled and contained withintop cover 108 andbottom cover 110 the module preferably conforms to PCMCIA Type III dimensions. Themodule 42 may also be adapted to conform to PCMCIA Type II or Type I dimensions as well. - The transceiver module as shown in FIG. 9 may be utilized in a standard desktop or portable computer such as a laptop computer which is designed to utilize standard PCMCIA computer modules. The portable computer may be implemented as part of a multilayered communication network such as a communications node to communicate, for example, with several data terminal in a connected wired network, as well as with nodes in the wireless network. In this fashion, the computer could serve as a wireless access point, a wireless access server, or another type of wireless device providing access to the wireless network. A preferred embodiment of the present invention implements Layer1 (the physical layer) and the medium access control (MAC) sub-layer of Layer 2 (the data link layer) of the International Standards Organization Reference Model (ISORM) operating under an ODI or NDIS driver. A driver interface to the MAC sub-layer allows the utilization of industry standard multi-layer communications protocol above the MAC sub-layer.
- FIG. 10 is a functional block diagram of an embodiment of the
radio modules - The antenna section includes an
antenna 112 for transmitting and receiving radio frequency energy. Theantenna 112 may be one of the antennas described in the discussion of FIGS. 7, 8 and 9. The radio circuitry corresponds to the radio circuitry of theradio CCA 44 of FIGS. 7, 8 and 9 and contains thereceiver circuitry 114, thetransmitter circuitry 118 and the frequency generator (“FREQ. GENERATOR”) 116. - The radio frequency (RF)
transceiver 298 of the present invention comprises areceiver 114 and atransmitter 118. Thetransmitter 118 preferably comprises a data formatter and spreader (“BASE BAND FORMATTER/SPREADER”) 124, a selectabletransversal filter 150 comprising programmable transversal filters (“PROGRAMMABLE TRANSVERSAL FILTER”) 146 and 148 (See FIG. 11), a binary phase shift keying (BPSK) modulator (“BPSK MODULATOR”) 130, and a transmitter up converter and linear transmit power amplifier (“TX UP CONVERTER & AMP”) 314. Thereceiver 114 preferably comprises a receiver downconvertor 304, a selectable bandwidth intermediate frequency (IF) stage (“SELECTIBLE BW IF”) at a fixed IF center frequency, a non coherent I/Q base band converter (“BASEBAND CONVERTOR”), and a demodulator/despreader (“DEMOD. DESPREAD.”). - A common radio frequency bandpass filter (“BPF”)399 is shared by both the
transmitter 114 and thereceiver 118. Thetransceiver 298 is coupled to anantenna 112 through anantenna switch circuit 302. Afrequency generator 116 is common to both thereceiver 114 and thetransmitter 118, producing a frequency agile main VCO output (“MAIN VCO”) 332, and an auxiliary output (“AUX VCO”) 334 at twice the IF frequency. A divide by 2 circuit (316 and 318) in the transmit path of theauxiliary VCO signal 334 is activated when thetransceiver 298 is switch to the transmit mode. - The transmit operation the media access control (MAC) microprocessor (“MAC μP”)128 enables the various transmit circuits through the control bus (see CONTROL of FIG. 18). In particular, however, the
MAC μP 128 controls the various components illustrated in FIG. 10 as illustrated. However, in other embodiments of the present invention, theMAC μP 128 may control only a portion of the components or even more of the components. To implement the teachings of the present invention, theMAC μP 128 controls the various elements illustrated in FIG. 10 so as to perform transmission and reception in any of the various spread spectrum modes. In order to accomplish such various modes, theMAC μP 128 must control thefrequency generator 116 to cause modulation over all of a spreading bandwidth via variations in the MAIN VCO frequency. In addition, theMAC μP 128 provides control to themodulator 130,RECEIVER DOWN CONVERTER 304, TX UP CONVERTER & 314, the SELECTABLE BW IF 322, theMODULATOR 130, theSELECTABLE TRANSVERSAL FILTER 150, theDEMODULATOR DESPREADER 184, and the FORMATTER/SPREADER 124 in order to cause the circuitry to perform in the various spread spectrum modes. - As is known, each of the various spread spectrum modes requires packaging, modulating, transmitting, and receiving data in particular formats and frequencies. Thus, the
MAC μP 128 provides control over the elements illustrated in FIG. 10 in a fashion so as to enable each of the various spread spectrum modes. Techniques known in the art may be employed to cause the components illustrated in FIG. 10 to perform in particular spread spectrum modes. - The functions of the baseband formatter/
spreader 124 may be contained in a digital application-specific integrated circuit, or ASIC, (not shown) with circuitry configurable to the desired transmission mode by thecontrol microprocessor 128. The ASIC preferably produces a clock at the correct data rate for the selected mode which is used to time serial transfer of a data frame from the transmit data output of the MAC μP 128 (see TXD of FIG. 18). - In the direct sequence (DS) modes, the data is mapped into I/Q symbols for either BPSK or QPSK modulation. The ASIC generates a synchronous chip clock at a multiple of the symbol rate that is applied to the pseudo-random number (PN) generator of FIG. 14A to produce a chipping sequence at the selected spreading ratio. The exact chipping sequence is selected by programming the feedback select of FIG. 14A. The chipping sequence is multiplied with the I/Q data symbols by use of exclusive OR gates. The selected data rate and spreading ratio determine the main lobe bandwidth of the transmitted signal. The bandwidth of the main lobe and side lobes are reduced by applying the transversal filters (146 and 148 of FIG. 148), which comprise circuitry of the
transversal filter 150 of FIG. 10 with the shift registers operating at the chipping rate rather than the symbol rate. The main lobe bandwidth is limited to approximately 1.6 times the chip clock frequency. - The remainder of the
Transmitter 118 is a standard I/Q modem. The I/Q waveforms are applied to a quadrature PSK modulator operating at ½ the Auxiliary VCO frequency. The modulated signal is filtered to reduce harmonic content, then undergoes a second conversion with theMain VCO output 332 to produce a final output frequency. This signal is filtered to reduce the image of the mix product from this second conversion, and then amplified by theantenna 112 through theantenna switch 302 andRF bandpass filter 300. - In the receive mode, the
receiver circuitry 118 is switched on and the transmitter circuitry switched off through the control interface. Incoming signals present at the antenna are amplified and converted to the IF frequency by mixing with themain VCO output 332. The output of the receiver downconverter 304 is applied to the selectable bandwidth IFfilter 322, which is programmed to the correct bandwidth for the selected mode of operation by theMAC μP 128. Thefilters - The filtered output is applied to a limiting amplifier, then to the I/
Q baseband converter 312. Thelimiter 182 produces a received signal strength indication that is proportional to log of the signal energy in the IF. This is applied to an A/D converter 126 then to thecontrol μP 128. This function is useful for detecting proximity to the transmitting unit, or to an interferor, and is also useful as an OOK detector. - The
baseband converter 312 contains an internal divide-by-two circuit which produces a carrier at ½ the Auxiliary VCO frequency which is also at the nominal IF frequency. This is mixed with the limited IF signal to produce baseband I/Q waveforms. These in turn are applied to comparators that serve as hard decision circuits, then to the correlator 330 (see FIG. 17) within the ASIC. - The
frequency generation system 116 must be programmed to produce the Main VCO output. A serial interface within the control bus provides this capability. In the DS modes the Main VCO is programmed to the correct channel frequency and remains there until a mode change or the need to avoid interference is detected. For wideband DS operation, The Main VCO is programmed to the center of the frequency range. - For FH or hybrid operation, i.e., frequency hopping combined with direct sequence operation, the Main VCO is periodically reprogrammed to provide the hopping function. The
MAC μP 128 maintains a timer, and table of channels representing the hop sequence. When the timer expires, the MAC μP initiates the hop to the next frequency in the sequence. Frames passed between the various devices within the WLAN establish shared timing references so that all units hop in synchronism. - The
MAC μP 128 provides mode control, host interface, transmit frame generation, channel access control, receive frame processing, retries of erred packets, power management of radio circuitry, and frequency hopping control. The frequency hopping control is a superset of the remaining functions, allowing common programming of the remaining functions for both DS and FH. - The host interface for the PCMCIA version is compliant with the PCMCIA physical interface. The software interface is structured to comply with the factory industry standards NDIS and ODI formats.
- Data to be transmitted is sent via a
bus 131 to theMAC circuitry 128 from a host unit. The data to be transmitted is be modulated by themodulator 130 and frequency controlled by thespreader 124 according to the particular spread spectrum transmission mode to be utilized. Thespreader 124 receives a chipping clock input that is at a frequency multiple of the source data frequency. The output of thespreader 124 is sent to the transmitter up converter andamplifier 314 to transmit the RF data signal through theantenna 112. - The radio modules of the present invention may utilize several modes of spread spectrum RF data transmission. In one embodiment of the present invention, the various modes can be user selectable depending upon the particular application in which the radio modules are to be utilized. In another embodiment, the modes of operation are be automatically and dynamically selected, e.g., by the
MAC μP 128 based upon criteria previously described. Such selection might also be performed by or with the assistance of the terminal unit or a digital signal processor provided for such task. - In a particular example, a microprocessor in the host terminal may retrieve stored modes of operation utilized on the previous day to which a higher logical multiplier is used to determine which transmission mode or modes are to be selected for that day's data transmissions. Additionally, data such as the average signal strength, most frequently utilizes transmission mode, the average level of interference and noise for a particular mode or transmission success rate (e.g. percentages of transmissions) may be saved in nonvolatile memory and factored into the mode selection routine. A description of particular spread spectrum modes follows in Table 1. The modulation techniques as described in Table 1 may be direct sequencing (DS), frequency hopping (FH) or on-off-keying (OOK) or a combination thereof. The rate at which data may be transmitted is given is kilobits per second (kb/s) and the channel bandwidth is given for each mode for the operational frequency range of 902 to 928 MHz. The full bandwidth of an embodiment of the radio is 26 MHz Table 1.
TABLE 1 Spread Spectrum Transmission Modes MODULATION DATA MODE TECHNIQUE RATE BANDWIDTH 1 DS 250 kb/s full band 2 CHANNELIZED DS 250 kb/ s 5 channel 5 MHz 3 DS 500 kb/s full band 4 FH 250 kb/s 50 channels 500 kHz 5 FH/ DS 10 kb/s 50 channels 500 kHz 6 OOK 19.2 kb/s 50 channels 500 kHz 7 DS 10 kb/s 50 channels 500 kHz - The various spread spectrum modes are utilized to obtain optimum performance for particular modes of operation of the data terminal. The radio of the present invention preferably has a transmission range of up to 300 feet for closely spaced interior surfaces and up to 1300 feet in open spaces resulting in an operational coverage area from 280,000 to 5,300,000 square feet.
- Utilization of the various transmissions modes results in variable immunity of the data signals from RF interference. The data terminal in which the radio is utilized thereby has the ability to extract the best system performance in every application regardless of multipath signal levels, interference levels and the sources thereof. The data terminal also thereby has the ability to dynamically trade data rate in return for coverage range (coverage range being a function of process gain) without the need to change radio hardware. Although not shown, capable of operating in the 2.4 GHz circuitry of FIG. 10 or other frequency ranges. Multiple intermediate frequency filter topology may be implemented to achieve interference rejection via varying filter selectivity.
-
MODES MODE 1 provides good coverage area and rejection of multipath signal.MODE 3 provides shorter coverage are in return for a high speed data rate. -
MODE 2 is a channelized direct sequence mode having a process gain of 17 dB. A single direct sequence cordless telephone operating in the vicinity will not degrade performance on at least four of the channels.MODE 2 provides a reasonable coverage area and jammer avoidance with channelization. -
MODE 4 utilizes full band frequency hopping having a process gain of 17.1 dB. A single direct sequence cordless telephone will not degrade average throughput by more than 10 percent.MODE 4 provides moderate coverage area and high system capacity with dynamic jammer immunity with frequency hoping. -
MODE 5 is a direct sequence mode which is frequency hopped having a process gain of 37 dB. A single direct sequence cordless telephone operating in the vicinity will not degrade average throughput by more than 10 percent.MODE 5 provides a long and high coverage area and dynamic jammer immunity with frequency hopping in return for a low data rate. -
MODE 6 is an on-off-keying (OOK) modulation mode having a process gain of 0 dB.MODE 6 may be utilized as a low speed, low power link to a nearby scanner or printer for example. -
MODE 6 the transceiver module is intended to communicator with peripheral devices containing simple AM transceivers. The Main VCO is set to the center frequency of the peripheral AM receiver. For OOK transmission, the data formatter is configured to produce a CW output signal. OOK signaling is providing by strobing the enable line on the transmitter, shown in FIG. 16. - For OOK reception, the Main VCO is set to receive at the AM transmitter center frequency. The RSSI output from the limiting amplifier is used for AM detection. The signaling rate is limited by the speed at which the A/D can quantize the RSSI (preferably sampling several times per symbol), and at which the MAC μP128 can process the sampled data to extract the modulation.
-
MODE 7 is a channelized direct sequence mode having a process gain of 20 dB. A single cordless telephone operating in the vicinity will not degrade performance on more than nine of the channels. - Other modes may also be included other than those listed above. Other possibly included modes may be variations or new combinations of the above modes or modes utilizing different modulation techniques and frequencies such as other standard RF transmission techniques which may be contemplated by the present invention. For example, an additional mode in an alternative embodiment may include voice communications transmissions utilizing standard audio modulation techniques achieved by switching channels or transmissions modes. Using voice communications the transceiver module may allow data terminal operators of a multi-level radio-frequency communications network to verbally communicate with one another or their supervisors throughout the entire network. Voice and data communications may be utilized with a single portable battery powered electronic device rather than having a data terminal for data communications and a separate mobile radio for voice communications, for example. Similarly, the process gains, sampling rates, etc., are exemplary value which may be modified as proves desirable.
- FIG. 11 is a conceptual block diagram of the operation of the transmitter of FIG. 10 when operating in a direct sequence spread spectrum transmission mode. As illustrated, in the operation, data is received by the BASE BAND FORMATTER/SPREADER which, based upon the CONTROL SPREADER signal received from the
MAC μP 128, spreads the code based upon a particular code spreading sequence or pattern. The BASE BAND FORMATTER/SPREADER provides data on two output paths so that the data may be modulated according to the BPSK modulation scheme. The spread code is then processed by a programmabletransversal filter 150 having two separate filters, 146 and 148, one for each data path. Once filtered, the data is modulated by thecomponents - FIG. 12 shows a conceptual diagram of the operation of the receiver utilized in conjunction with the transmitter of FIG. 11. In the embodiment, data received by the
antenna 112 passes through a zero-degreephase shift block 152. From the block, one path goes directly to one input of amultiplier 158 while the second path passes through an RF DELAY block 154 and then passes to a second input of themultiplier 158. DELAY CONTROL is supplied to the RF DELAY block 154 by theMAC μP 128 dependent upon the frequency of the received signal to cause a desired phase shift. From themultiplier 158 the signal passes through a baseband data filter 160 then through X2 block 162 prior to its furthered processing. - FIG. 13 is a block diagram of the
receiver 114 of the present invention. Thereceiver 114 may be located on theradio card CCA 44 of FIGS. 7, 8 and 9.Wideband filter 170 provides additional interference protection in the narrow band modes. Apreselector filter 164 receives an RF data transmission signal from the antenna 112 (not shown). Thepreselector filter 164 may be a two pole bandpass filter (BPF) designed to have a wide bandwidth to keep the insertion loss low. In anexemplary embodiment filter 164 has a center frequency of 915 MHz, a bandwidth of 26 MHz and an insertion loss of 3.5 dB. However, thefilter 164 could be controllable as well based upon desired filtering characteristics. - The output of the
preselector filter 164 is fed into two low noise RF amplifiers (LNA) 166 and 168 each of which preferably has a gain of 10 and a noise figure of 2.2 dB. The gain of the RF amplifies 166 and 168 is sufficient to overcome any noise which may be present on the input RF data signal. The amplified signal may be sent to a bandpass filter (BPF) 170 for additional preselection filtering.Bandpass filter 170 is preferably designed to have four poles to provide high stop band rejection of possible signal images present in the data signal, having design values of 915 MHz center frequency, bandwidth of 26 MHz and an insertion loss of 3.5 dB.Bandpass filter 170 could also be controlled to provide desired filtering characteristics. - The output of
filter 170 is sent to the input of a mixer (“MIXER”) 170 which mixes the data signal with theoutput 332 from the main voltage controlled oscillator of thefrequency generator circuitry 116 of FIG. 10 which preferably has an output frequency of 844 MHz. The output of themixer 172 is passed through anadditional bandpass filter 174 having a center frequency of 71 MHz, a 26 MHz bandwidth and insertion loss of 2.0. - The data signal is passed through an intermediate frequency
selectable bandwidth filter 322 comprisingfilters signal path 180, which varies the filtering of the data signal according to the various modes of operation.Bandpass filter 176 is utilized forMODE 2 operation and has a bandwidth of 5 MHz and an insertion loss of 8 dB.MODES direct signal path 180 with an overall bandwidth of 26 MHz from the output offilter 174.MODES bandpass filter 178 which has a bandwidth of 500 kHz and an insertion loss of 8 dB. Multiple intermediate frequency filter topologies may be implemented to achieve interference rejection via varying filter selectivity. - The data signal is fed into an intermediate frequency amplifier (IF)182 to overcome the losses from the filters. The
IF amplifier 182 is a high gain amplifier having a gain and a noise factor of 7 dB. The output of theIF amplifier 182 drives the demodulator 181 which also receives the output from the auxiliary voltage controlled oscillator of thefrequency generator circuitry 116 of FIG. 10 which may operate at a frequency of 142 MHz. Thedemodulator 184 may have data signal products I and Q which are fed into the inputs of the despreader circuitry 120 of FIG. 10. Thereceiver 114 may have a noise figure of less than 7 dB, an image rejection figure of 60 dB and adjacent channel rejection of 40 dB. - FIGS. 14A and 14B are diagrams illustrating the operation of the pseudo-random number generator circuitry (“PN GENERATOR”)122 of the
traverse filter 150 of FIG. 10. The pseudo-randomnumber generator circuitry 122 is preferably located on theradio interface card 58 of FIGS. 7, 8 and 9. Thepseudo-random number generator 122 produces a pseudorandom binary output which is mixed with the data signal code in order to minimize the rate distortion for a given number of bits used to represent the data signal. ThePN generator 122 may be comprising an 8-bit shift register (“8-BIT SHIFT REGISTER”) 186 utilizing a feed back selector control (“FEEDBACK SELECT”) 188 which provides programmable feedback. A restart control device (“RESTART CONTROL”) 190 may be utilized to provide a programmable restart interval and a programmable restart vector. ThePN generator 122 is preferably controlled by a control input (“CONTROL”) from theMAC circuitry 128 of FIG. 10 and produces a PN code output signal (“PN CODE”). - In the frequency hop (FH) mode, data is converted to an I/Q format for minimum shift keying (MSK) modulation. Narrowband modulation is preferably employed so the spreader function may disabled. The power spectral density of MSK modulation exhibits a main lobe bandwidth of approximately 1.5 times the symbol rate, but also contains substantial energy in the side lobes. This energy might create interference to other in-band or out of band systems and may also degrade operation if several frequency hopping sequences are used for increased throughput or multiple access. To reduce side lobe energy, transversal filtering is employed in the I/Q modulation paths. These consist of shift registers clocked at the symbol rate or a multiple thereof. The digital outputs from the shift registers are summed using a weighted resistor ladder (350 and 352) is external to the ASIC and constitutes the interface between digital and analog processing.
- In the direct sequence (DS) modes, the data is mapped into I/Q symbols for either BPSK or QPSK modulation. The ASIC generates a synchronous chip clock at a multiple of the symbol rate that is applied to the
pseudo-random number generator 122 to produce a chipping sequence at the selected spreading ratio. The exact chipping sequence is selected by programming the feedback select 188. The chipping sequence is multiplied with the I/Q data symbols by use of exclusive OR gates (324 and 326). The selected data rate and spreading ration determine the main lobe bandwidth of the transmitted signal. The bandwidths of the main lobe and side lobes are reduced by applying the transversal filters (146 and 148) with the shift registers operating at the chipping rate rather than the symbol rate. The main lobe bandwidth is preferably limited to approximately 1.6 times the chip clock frequency. - FIG. 15 is a block diagram illustrating the
frequency generator circuitry 116 of FIG. 10. Thefrequency generators 116 are preferably located on theradio card CCA 44 of FIGS. 7, 8 and 9. Theradio interface card 58 of FIGS. 7, 8 and 9 may provide data signals (“DATA”, “CLOCK”, “STROBE” and “LOCK DET”) 190 and a clock signal (“CLOCK”) 192 which is preferably a 30 MHz clock to the fractional number frequency agile synthesizer (“FRACTIONAL N SYNTHESIZER”) 194. The 30 MHz clock signal may be divided to produce frequencies of which 30 MHz is a multiple. Thesynthesizer 194 may also receive frequency input signals from a main voltage-control oscillator (MAIN VCO) 196 and from an auxiliary-voltage controlled oscillator (AUXILLARY VCO) 198. Thesynthesizer 194 preferably switches between transmission and receiving modes in 200:s or less. - The
main VCO 196 preferably operates at a nominal frequency of 844 MHz while theauxiliary VCO 198 preferably operates at a nominal frequency of 142 MHz. Thesynthesizer 194 has loopfilter feedback paths oscillators oscillators main VCO 196 supplies a signal to thedown converter mixer 172 of thereceiver 114 of FIG. 13 and provide a signal to themodulator 206 of thetransmitter 118 of FIG. 11 after being fed through a divide by 2 circuit (“DIVIDE BY 2”) 204. - FIG. 16 is block diagram illustrating the functionality of the
transmitter circuitry 118 of FIG. 10. Thetransmitter 118 is located on theradio card CCA 44 of FIGS. 7, 8 and 9. Thetransmitter 118 receives data signal input products I and Q from the modulator andspreader circuitry auxiliary VCO 198 of FIG. 15 which are then combined and mixed with output of themain VCO 196 of FIG. 15 using an up converter mixer in thetransmitter modulator 206. - The output of the
transmitter modulator 206 is preferably fed into a high pass filter (HPF) 208 having the data signal below the nominal carrier frequency of 900 MHz for single side band (SSB) transmission. The output of the high pass filter (BPF) 210 which preferably has a counter frequency of 915 MHz and a band width of 26 MHz. The output of bandpass filter 219 is fed into two amplifier (AMP) 214 preferably having a gain of 20 and a second amplifier (AMP) 214 preferably having again 30 to provide the necessary transmission output power. The power of the data signal at the output ofamplifier 214 is nominally at least 1 watt which is fed through a lowpass filter (LPF) 216 and a bandpass filter (BPF) 218. Because of the insertion losses of thefilters transmitter 118 has a nominal output power of at least 250 mW which is transmitted viaantenna 112 of FIG. 10. - FIG. 17 illustrates the circuitry for selecting between the modes of modulation of the present invention. In frequency hopping mode the correlator (“CORRELATOR”)330 us bypassed and the decision and timing recovery block (“DECISION TIMING RECOVERY”) 332 performs MSK detection. An alternative approach would be to use an FM discriminator, a function that is commonly available in limiting amplifier IC's. This is possible because MSK signal are known to be capable of demodulation as either FM or PSK signals.
- In DS modes the
correlator 330 preferably extracts the data symbols from the chipping sequence. The decision andtiming recovery block 332 outputs send the recovered data (“DATA”) and a clock signal (“CLOCK”) to theMAC μP 128 for frame processing. - FIG. 18 is a block diagram of the
MAC circuitry 128 of FIG. 10. TheMAC circuitry 128 is preferably located on theradio interface card 58 of FIGS. 7, 8 and 9. The mediumaccess control circuitry 128 may be utilized in the protocol of communications media used in a particular communications network. Themedia access circuitry 128 may also utilize the 2.4 GHz MAC protocols to provide operation on both 9000 MHz and 2.4 GHz networks. - The media access protocol may be controlled by a MAC microprocessor (“MAC μP”)224 which receives a timing control signal from a crystal oscillator (“XTAL”) 246. The MAC microprocessor 224 may communicate with the electronic device in which the radio of the present invention is to be utilized via a host communications bus (“HOST”). The MAC microprocessor 224 may further have input and
output signals 248 from an analog-to-digital converter (“A/D”), digital-to-analog converter (“D/A”), an electrically erasable read only memory (E2ROM”) or a reset control circuit (“RESET”) for example. The MAC microprocessor 224 may utilize random access memory (“RAM”) 250 which may be either volatile or nonvolatile memory. TheMAC microprocessor 244 may also receive an input fromOTP 252. A control bus (“CONTROL”) is utilized to control the circuitry of theradio card 44 of FIGS. 7, 8 and 9. - The
MAC microprocessor 244 may have registers to read the status of and control the functions of theradio interface card 58. Registers may also be provided to control the transmission power state of the radio of the present invention. TheMAC microprocessor 244 may provide a parallel-to serial converter for control and programming of thesynthesizer 194 of FIG. 15. Additionally, the MAC microprocessor 224 may provide a programmable periodic timer, clock control of the CPU of thedata terminal 10 and PCMCIA programmable clock generation. - FIG. 19 is a block diagram illustrating the
host interface circuitry 132 of FIG. 10 forradio module 30 of FIG. 7 and for radio/scanner module 20 of FIG. 8. Thehost interface circuitry 132 is preferably located on theradio interface card 58 of FIGS. 7 and 8. A regulator (“REGULATOR”) 254 functions as the power supply 134 of FIG. 10 and provides a regulated voltage signal to theradio interface card 58 which is connected to theMAC circuitry 128 via a host to MAC communications bus (“TO MAC”) which connects to the electronic device in which the radio of the present invention is utilized through connectors (“CONNECTORS”) 60 on theradio interface card 58 of FIGS. 7 and 8. Further connection is made to a buzzer (“BUZZER”)circuit 256 which may be thebuzzer 64 of FIGS. 7 and 8. A bus connection to the radio/scanner module 20 of FIG. 8 is provided for control of thescanner 258 which may be a laser scan engine (“LASER SCAN ENGINE”). - FIG. 20 is a block diagram illustrating the
host interface circuitry 132 of FIG. 10 forPCMCIA radio module 42 of FIG. 9. The PCMCIA radio modulehost interface circuitry 132 is preferably located on theradio interface card 58 of FIG. 9. A FET switched power supply (“POWER SUPPLY FET SWITCH”) 260 functions as the power supply 134 of FIG. 10 and provides a supply voltage output (“TO RIC”) to theradio interface card 58 of FIG. 9. A microcontroller (“μC”) 262 provides interfacing signals (“TO MAC and PCMCIA CONNECTOR”) between theMAC circuitry 128 of FIG. 2B and the electronic device in which the radio of the present invention is to be utilized throughPCMCIA connectors 102 of FIG. 9. - FIG. 21 is a diagram illustrating an alternate configuration of portable data terminals according to the present invention. Specifically, a
communication network 1450 provides an overall network environment for portabledata collection terminals 1454. Ahost computer 1451 is connected to accesspoints 1452 via awired connection 1453. Theaccess points 1452 are in turn communicatively coupled to portabledata collection terminals 1454 viawireless links 1455. The wireless links 1455 may be one or more of a plurality of wireless communications technologies, including narrowband radio frequency, spread spectrum radio frequency, infrared, and others. - A
dock 1456 and aportable data terminal 1458 according to the present invention may be connected to thewired backbone 1453, and may serve a function similar to anaccess point 1452. Thedock 1456 may provide power to the terminal 1458, or alternatively the dock may be absent and the terminal 1458 may run for a limited time under the power of its battery. The terminal 1458 connects directly to thewired backbone 1453, and also communicates with another terminal 1454 through awireless link 1455. The terminal 1458 may, for example, be equipped with protocol converter circuitry to convert communication on thewire backbone 1453 into wireless communication on thelink 1455, and also to convert wireless communication on thelink 1455 to a format for communication on thewire backbone 1453. The communication module associated with terminal 1458 thus improves the versatility of theterminal 1458. - FIG. 22A illustrates one embodiment of the data collection terminal of the present invention, having both wired and wireless communication capability. A
data terminal 1500 is shown having acommunication module 1502 and abase module 1504. Thecommunication module 1502 contains awired transceiver 1506, awireless transceiver 1508, and processing andinterface circuitry 1510. Thebase module 1504 contains a control processor andinterface 1512, anapplication processor 1514, andterminal circuitry 1516 containing data input and display portions and other circuitry well known in the art. The blocks shown incommunication module 1502 andbase module 1504 are simplified for exemplary purposes, and it will be understood by one skilled in the art that adata terminal 1500 according to the present invention is not limited to the block circuitry shown in FIG. 22A. In another embodiment, thecommunication module 1502 may contain additional transceivers for communicating on other mediums and in other networks. The processing andinterface circuitry 1510 of thecommunication module 1502 isolates the circuitry of thebase module 1504 from the differing operating characteristics of the transceivers, so that communication by any of the transceivers can be accommodated by the circuitry and software routines of thebase module 1504. - In operation, the processing and
interface circuitry 1510 of thecommunication module 1502 is programmed with the network configuration to route communication through either thewired transceiver 1506 or thewireless transceiver 1508. An incoming message on thewired transceiver 1506 may be routed and processed to a terminal display portion, or may be routed to a host computer, a dock, or anotherportable data terminal 1500 through thewired transceiver 1506 or through thewireless transceiver 1508, whichever is appropriate. Similarly, an incoming message on thewireless transceiver 1508 may be routed to display or through thewireless transceiver 1508 or through thewired transceiver 1506, whichever is appropriate for the destination. By provided for the routing functions to be done in thecommunication module 1502, the power used in thebase module 1504 can be minimized. Specifically, the interface with thecontrol processor 1512 and theapplication processor 1514 need not be used, which allows the main terminal in thebase module 1504 to remain dormant while communications are routed in thecommunication module 1502. - The choice of which transceiver to use in routing communication is based on a “least cost” analysis, considering factors such as the power required to send the message through a particular transceiver, the speed at which the message will be received from a particular transceiver, the possibility of error associated with each transceiver, etc. A wired connection is usually selected when available, but routing decisions may vary with the different characteristics of each message and the mobility of the terminal. The processing and
interface circuitry 1510 in thecommunication module 1502 is preferably capable of performing the least cost routing analysis for all communication messages, without activating any processing power from thebase module 1504. - FIG. 22B is a diagram illustrating a specific implementation of the portable terminal of FIG. 22A a single PCMCIA card contains not only a multi-mode wireless transceiver, but also a wired modem transceiver. In particular, a portable terminal1520 contains
terminal circuitry 1522 comprisingprocessing circuitry 1526,conventional terminal circuitry 1528 andinterface circuitry 1530. Theinterface circuitry 1530 provides a PCMCIA interface for receiving PCMCIA cards of various functionality. Theterminal circuitry 1522 is well known and can be found in conventional portable or hand held computing devices. - Via the
interface circuitry 1530, theportable terminal 1520 accepts PCMCIA cards. As illustrated, the PCMCIA card inserted constitutes acommunication module 1524 which provides both wired and wireless access. Specifically, thecommunication module 1524 comprisesprocessing circuitry 1532, a multi-mode wireless transceiver 1534 (such as set forth previously), awired modem transceiver 1536 andinterface circuitry 1544. When in use, thewired modem transceiver 1536 interfaces via ajack 1540 to a telephone line (not shown). Similarly, the wirelessmulti-mode transceiver 1534 communicates via anantenna 1538. - Whether the
modem transceiver 1536 ormulti-mode transceiver 1534 is being used, theprocessing circuitry 1526 always delivers and receives data and messages via theinterface circuitry 1530 in the same manner and format, i.e., theinterface circuitry 1530 supports a common communication interface and protocol. Theprocessing circuitry 1532 of thecommunication module 1524 receives data and messages via theinterface circuitry 1544. If themodem transceiver 1536 is being used, theprocessing circuitry 1532 appropriately (de)segments and (de)compresses the data/messages utilizing a digital signal processor (DSP) 1542. Otherwise, theprocessing circuitry 1532, including theDSP 1542, participate to assist in wireless communication via themulti-mode transceiver 1534. Thus, themodule 1524 not only saves on PCMCIA slots (as required when a conventional radio card and a conventional modem card are both being used), but also saves costs and increases reliability by sharing common circuitry resources. In particular, the modem andmulti-mode transceivers interface circuitry 1544 andprocessing circuitry 1532 which includes theDSP 1542. - FIG. 23 is a diagram illustrating the use of portable terminals according to the present invention utilizing both wired and wireless communication in a network configuration. Specifically, a server1515 is shown connected to mobile computing devices (MCDs) 1554 via a wired
communication link 1552. Thecommunication link 1552 may alternatively be an infrared link, or another communication technology.MCDs 1554 are connected to each other and to the server via thelink 1552.MCDs 1554 are also communicatively coupled to each other viawireless links 1556. - The network involving the
server 1550, thecommunication link 1552, and theMCDs 1554 represents a primary communication network, that is preferable to use when there are no interference or disconnection problems in the network. The network between MCDs 1554 involvingwireless links 1556 represents an auxiliary or backup network, which is used where there are problems with the primary network, or to run diagnostics on the primary network. TheMCDs 1554 are equipped to automatically switch from the primary network to the auxiliary network when a problem arises on the primary network. This network redundancy allows theMCDs 1554 to remain in constant communication with each other and withserver 1550. - For example, a wired network on a
communication link 1552 does not recognize connection well, and may not immediately detect a loss of connectivity.MCDs 1554 utilizewireless links 1556 to diagnose a lack of connection on thewired network 1552. For example, anMCD 1554 may activate its radio to send a test message to another component of the network, either anotherMCD 1554 or theserver 1550, to test communication on thewired link 1552 by sending a reply test message back to the inquiringMCD 1554. The test routine is preferably implemented and controlled by the processing/interface circuitry 1510 in the communication module 1502 (see FIG. 49) of theMCD 1554. If the reply communication test is not received, theMCD 1554 will know that there is a problem on the primary network, and will informother MCDs 1554 to switch to the auxiliary network. TheMCDs 1554 can continue to check the primary network viawireless links 1556 until the primary network is back in service. - Some
MCDs 1554 may be out of range to effect wireless communication withserver 1550 by awireless link 1556. An out-of-range condition is determined according to the particular communication and connection protocol implemented byMCDs 1554 and other network components such asserver 1550. In this situation, the out-of-range MCD 1554 sends its message, along with an out-of-range condition indicator, to anotherMCD 1554 that is in communication with theserver 1550, and the in-range MCD 1554 forwards the message on to the server. Similarly, theserver 1550 sends its messages intended for the out-of-range MCD 1554 to an in-range MCD 1554 to be forwarded over awireless link 1556. TheMCDs 1554 are capable of automatically switching from the wired network to the wireless network and vice versa for each communication attempt. - FIG. 24 is a diagram illustrating the use of portable data terminals according to the present invention utilizing both wired and wireless communication to access separate subnetworks in an overall communication network. Specifically, a wired network includes wired
server 1600 and mobile computing devices (MCDs) 1606 connected by a wiredcommunication link 1604.MCDs 1606 are also part of a wireless network withwireless server 1602, and are communicatively coupled to each other and thewireless server 1602 viawireless communication links 1608.Wireless links 1608 may be radio frequency communication links, such as narrowband, direct sequence spread spectrum, frequency hopping spread spectrum or other radio technologies. Alternatively,wireless links 1608 may be infrared communication links, or other wireless technologies. In another embodiment, thewired server 1600 and thewired communication links 1604 may utilize infrared communication technology, with thewireless communication links 1608 being radio frequency links. The present invention contemplates various combinations of communication technologies, all accommodated by communication modules ofMCDs 1606. The communication modules of MCDs 1606 include any number of transceivers operable on any number of communication mediums, since the differences in their operating characteristics are isolated from the base module of theMCDs 1606 by a communication processor. TheMCDs 1606 are preferably able to automatically switch between the wired and wireless networks, controlled primarily by a communication processor in their communication modules. - Some
MCDs 1606 may be out of range to effect wireless communication withwireless server 1602 by awireless link 1608. An out-of-range condition is determined according to the particular communication and connection protocol implemented byMCDs 1606 and other network components such aswireless server 1602. In this situation, the out-of-range MCD 1606 sends its message, along with an out-of-range condition indicator, to anotherMCD 1606 that is in communication with thewireless server 1602, either over awireless link 1608 or alternatively over awired link 1604 if bothMCDs 1606 are constituents of a wired network. The in-range MCD 1606 then forwards the message on to thewireless server 1602 overwireless link 1608. Similarly, thewireless server 1602 sends its messages intended for the out-of-range MCD 1606 to an in-range MCD 1606 to be forwarded over awireless link 1608 or awired link 1604, if both MCDs are constituents of a wired network. - FIG. 25a is a block diagram illustrating an embodiment of the present invention wherein a wireless access device uses a dedicated control/busy channel to manage a plurality of modes of communication with roaming terminals. Specifically, a
wireless access device 1701 manages communication in a cell of network with a plurality of wireless terminals, such as awireless terminal 1703. The network may contain a plurality of other cells each managed by an associated wireless access device to provide site or premises wide ubiquitous wireless coverage for the plurality of stationary and roaming wireless terminals. As illustrated, for example, the network may also contain wired communication links therein as provided, for example, by a wiredEthernet backbone LAN 1705. - The
wireless access device 1701 comprisescontrol circuitry 1711, amultimode transceiver 1713, anEthernet transceiver 1715 and anantenna 1717. TheEthernet transceiver 1715 supports communication between thebackbone LAN 1705 and thecontrol circuitry 1711. Similarly, themultimode transceiver 1713 supports communication into a wireless network cell to wireless devices within range such as thewireless terminal 1703 via theantenna 1717. Themultimode transceiver 1713 is more fully described below in reference, for example, to FIG. 1C. - A
wireless terminal 1703 also comprises a multimode transceiver, amultimode transceiver 1721, as well as an associatedantenna 1723 andconventional terminal circuitry 1725. Using themultimode transceiver 1721 and associatedantenna 1723, thewireless terminal 1703 communicates with thewireless access device 1701 when it is within transmission/reception range. - The
wireless access device 1701 selects (and may periodically reselect) one of a plurality of communication modes and associated parameters of operation based on a variety of factors mentioned previously such as recent success rate, RSSI, neighboring cell operation, etc. However, when thewireless terminal 1723 roams within range of thewireless access device 1701, the roaming terminal must identify the currently selected mode and associated parameters being used by thewireless access device 1701 to maintain the cell's communication. Although thewireless terminal 1703 could be configured to scan each available mode to identify the currently selected mode and parameters, such efforts often prove time consuming. - Instead, the
wireless terminal 1703 andwireless access device 1701 are preconfigured with mode and parameter information that defines a default, busy/control channel. Thus, upon roaming into range of thewireless access device 1701, thewireless terminal 1703 first switches to the busy/control channel by operating themultimode transceiver 1721 according to the preconfigured mode and parameters, and then begins listening. Within a predefined maximum time period thereafter, thewireless terminal 1703 will receive transmissions from thewireless access device 1701 identifying the currently selected communication channel mode and associated parameters. Thewireless access device 1701 periodically broadcasts such information on the busy/control channel to capture terminal that happens to need communication channel definitions (e.g., selected mode and parameters) to participate. Thewireless terminal 1703 utilizes identified mode and associated parameter information to switch themultimode transceiver 1721 over to the selected communication channel and begins participation thereon. - FIG. 25b is a drawing illustrating advantageous operation of the wireless access device of FIG. 25a when configured to handle hidden terminal conditions. In particular, each of
wireless terminals terminals - To fully appreciate this process, first assume that the
wireless terminals wireless terminal 1751 utilizing the predefined mode and parameters begins listening for transmissions on a busy/control channel. Within some time period thereafter, the wireless access device 1755 participates on the busy/control channel to transmit: 1) the currently selected communication channel definition (i.e., mode and parameters); 2) pending message and communication request indicators; and 3) current channel conditions. After identifying a need to participate, thewireless terminal 1751 awaits a transmission from wireless access device 1755 (on the busy/control channel) that the selected communication channel is clear (not in use). When the channel is clear, thewireless terminal 1751 adopts the selected communication channel definition and begins participating thereon. - Second, assume that, while the
wireless terminal 1751 is engaged in ongoing communication with acomputing device 1761 on abackbone LAN 1763 via the wireless access device 1755, thewireless terminal 1753 comes within range of the wireless access device 1755 and desires to participate on the currently selected communication channel. Thewireless terminal 1753 adapts itself to participates on the busy/control channel and identifies, in periodic transmissions from the wireless access device 1755, that the communication channel is busy. Thus, thewireless terminal 1753 must monitor the busy/control channel to identify when the communication channel is clear before adapting to the communication channel to participate. - This operation works whether or not the
terminals circles terminals terminals wireless terminal 1753 attempted to transmit on the communication channel while the terminal 1751 was transmitting, a collision would occur at the wireless access device 1755. However, this is not the case because both of theterminals terminals - Participation by the wireless access device1755 on the busy/control channel need only be by transmitting, although receiving might also be employed in case the busy/control channel is to be shared. Similarly, participation by the
wireless terminals - In addition, should the two
terminals wireless terminals transceivers terminal 1751 and only proceed with relaying functionality (or spanning tree wireless routing, for example) per confirmation by theterminal 1751. However, if the terminal 1753 does participate, the wireless access device 1755 concludes that there is a good chance that theterminals terminals terminals terminals terminals - FIG. 25c is a flow diagram illustrating the functionality of one embodiment of the wireless access device of FIG. 25b in managing a communication channel using a second channel, i.e., the busy/control channel. The wireless access device maintains ongoing communication or otherwise waits in an idle state at a
block 1781. If a predetermined time out period (e.g., a B/C service time period) lapses while the access device is in an idle state as indicated at ablock 1782, the access device switches to the predefined mode and associated parameters of the busy/control channel at ablock 1783. At ablock 1784, on the busy/control channel, the access device transmits: 1) the currently selected communication channel definition (mode and parameters); 2) channel status indications; and 3) pending message/communication request indications. Thereafter, at ablock 1785, the access device switches back to the selected communication channel mode and parameters, resets the B/C service time period (at a block 1786) and returns to theblock 1781 to participate on the communication channel. - If, while participating on the selected communication channel at the
block 1781, a request for poll (RFP) transmission is received from a wireless terminal as indicated at anevent block 1787, the wireless access device responds by switching to the busy/control channel at ablock 1788 to deliver communication channel definition, channel “busy” indications and any pending message/communication request indications at ablock 1789. Although the busy indication may only indicate that the selected communication channel is not available, it also indicates an estimated amount of time during which the channel will be busy. The wireless access device derives this estimate from the overall data size to be transferred as determined from the data itself or from a field in the RFP transmission, if known. This way, a waiting wireless transceiver may go to sleep while an ongoing exchange is taking place and wake up when the exchange is scheduled to have finished. - Thereafter, at a
block 1790, the wireless access device switches back to the selected communication channel mode and parameters, resets the B/C service time period (at a block 1791), transmits a Poll or Data message (whichever is appropriate under the circumstances) on the communication channel at ablock 1792, and returns to theblock 1781 to await a Data or Ack (acknowledge) message from a participating wireless transceiver. In particular, in response to an RFP from a participating wireless device that has Data to deliver via the wireless access device, the wireless access device delivers a Poll message at theblock 1792 to the participant, prompting for the Data. Otherwise, if the RFP indicates a desire by the participating wireless terminal to receive Data, the wireless access device sends the Data at theblock 1792. The Data sent at theblock 1792 may be of any length including dedicated bandwidth for an unknown duration. Thus, if a wireless terminal listens for a period of time greater than the B/C service time period and detects no transmission from the access device on the busy/control channel, the wireless terminal concludes that the selected communication channel is busy. - Alternately, data may be segmented into Data packets for transmission one packet at a time via the
blocks 1781 and 1787-92. In this way, a listening wireless terminal will can be sure that it will receive a communication channel broadcast via the blocks 1782-86 between each Data packet transmission. Upon receipt, wireless terminals may place their transceivers in a sleep mode until each of the Data packets of the data have been exchanged, and the communication channel is clear. - Upon receiving the data (or Data packet) or an acknowledge (ACK) message indicating successful receipt of data (or a Data packet) as indicated at an
event block 1793, the wireless access device broadcasts a Poll, Ack or Clear message or sends data (or packets thereof) as proves appropriate at ablock 1798. The access device then switches to the busy/channel at ablock 1794 to transmit the currently selected communication channel definition, busy or clear indications and pending messages/requests at ablock 1794. Afterwards, the wireless access device switches back to the communication channel at ablock 1796, resets the B/C service time period at ablock 1797 and returns to theblock 1781 to continue communication exchanges or enter an idle state if the exchange is complete. - FIG. 26a is a block diagram illustrating an alternate embodiment of that shown in FIG. 25a wherein a wireless access device uses a separate transmitter for the dedicated control/busy channel and a roaming terminal uses either a shared multimode transmitter or a multimode transmitter and a separate busy/control channel receiver. In the previous embodiments of FIGS. 25a-c, the wireless access device and wireless transceivers each used a multimode transceiver to support participation on two wireless channels: the selected communication channel and the busy/control channel. As illustrated, this need not be the case. Instead, a
wireless access device 1801 participates using two radios when communicating with a wireless transceiver 1803 (having only a single multimode radio) and a wireless transceiver 1805 (having two radios). With a dual radio configuration, participation on both channels may occur at the same time, increasing overall performance in many circumstances. - In particular, a
wireless access device 1801 comprisescontrol circuitry 1811, anEthernet transceiver 1813, a busy/control transmitter 1815 andcorresponding antenna 1817, and amultimode transceiver 1819 andcorresponding antenna 1821. Having separate radio units and antennas, thewireless access device 1801 participates on: 1) a selected communication channel defined by mode and parameter information, servicing data exchanges in the communication network cell; and 2) the busy/control channel defined by predetermined mode and parameter information known to all wireless transmitters, controlling access to the selected communication channel. Such participation is often simultaneous, preventing a wireless terminal from having to wait long on the busy/control channel for a transmission. - In one configuration, where hidden terminals prove to be of little concern, the
wireless terminals wireless access device 1801 is participating on the selected communication channel with thewireless terminal 1805, for example, thewireless access device 1801 concurrently delivers communication channel definition, busy/clear status and message/request indications on the busy/control channel. Such information can be repeatedly transmitted at any time interval desired or may be transmitted continuously. - Similarly, although a wireless transceiver may operate with a single multimode radio as described previously, it may also take advantage of multiple radios. Specifically, the
wireless transceiver 1803 comprisesterminal circuitry 1831 and only one radio, amultimode transceiver 1833. Thus, thewireless transceiver 1803 is forced to time share participation on the busy/control channel and the selected communication channel—often all that is needed. However, thewireless terminal 1805 comprisesterminal circuitry 1845 and two radios, a busy/control channel receiver 1847 and amultimode transceiver 1849. As such, thewireless terminal 1805 may place themultimode transceiver 1849 in a low power state, and only powering up its busy/control channel receiver 1847 to check in. Characteristics of the busy/control channel may be chosen to permit significant overall power savings and simplicity in the design of thereceiver 1847. - FIG. 26b is a drawing illustrating advantageous operation of the wireless access device of FIG. 26a when configured to overcome the hidden terminal conditions. As with FIG. 25b, the range of a
wireless access device 1911 is defined by a dashedcircle 1913. Similarly, thewireless terminals circles wireless terminals wireless access device 1911 is within range of each of thewireless terminals - Unlike the wireless access device1755 (of FIG. 25b), the
wireless access device 1911 participates on both a busy/control channel and a selected communication channel simultaneously. Thewireless access device 1911 delivers all communication channel information either continuously or periodically on the busy/control channel, while idle or servicing any wireless terminal on the communication channel. By doing so, thewireless access device 1911 is free to set any length data segments or none at all on a selected communication channel, while delivering communication channel information as often as desired on the busy/control channel. Thus, the busy/control channel and communication channel can be designed for optimized performance without having to consider time sharing of a single channel or time sharing a transceiver. - Thus, the busy/control channel can be designed to minimize the listening time of the
wireless terminals terminals wireless access device 1911 will participate on the busy/control channel. - FIG. 26c is a flow diagram illustrating the functionality of one embodiment of the wireless access device of FIG. 26b in managing a communication channel using a control/busy channel with dual radios. Specifically, a wireless access device waits in an idle state or is engaged in ongoing communication on the selected communication channel at a
block 1951. As soon as a B/C time period lapses as indicated by anevent block 1953, the wireless access device branches to ablock 1955 to transmit mode, parameter and status information regarding the currently selected communication channel along with indicators of pending messages and communication requests. Afterwards, the wireless access device resets the B/C time period at ablock 1957 and branches back to theblock 1951 to continue servicing the selected communication channel or reenter an idle state. Thus, a preset (B/C time period) intervals, the wireless access device delivers the selected communication channel information on the busy/control channel. The B/C time period may be configured to either minimize transmission overhead or minimize wireless terminal listening times. The B/C time period might also be set to zero, causing the wireless access device to continuously transmit the selected control channel information (i.e., the selected mode and parameters, busy or clear status, predicted duration of a current exchange, and pending messages and communication requests). The B/C period is thus a synchronous period. Thus, a maximum value of the B/C period (or an other commonly known value) provides a wireless terminal with a guaranteed maximum listening time. - Although the B/C time interval may prove sufficient to communicate updates to the selected communication channel information, the wireless access device is also configured to immediately identify any mode or parameter changes of the selected communication channel. In particular, at a
block 1961, if for any of a variety of reasons the wireless access device decides to switch the mode and/or parameters of the communication channel, the wireless access device vectors to immediately deliver such information on the busy/control channel via theblocks block 1963 and theblocks - Unlike the single radio (shared) embodiments previously mentioned, the wireless access device services the
block - FIG. 27 is a block diagram illustrating further embodiments of the present invention wherein channel selection and operating parameters are delivered by a wireless access device on a dedicated busy/control channel with or without multimode transceiver capabilities. In particular, supporting a plurality of wireless terminals such as a terminal2013, a
wireless access device 2011 maintains two channels: a communication channel and a busy/control channel as previously described. To carry out such functionality, thewireless access device 2011 may comprisecontrol circuitry 2021, anEthernet transceiver 2023 and either a single, configurable transceiver 2025 (for operating on both the communication and busy/control channels) or a single transceiver 2025 (for the communication channel which may have only limited if any configuration capability) and a single transmitter 2027 (for operating on the control channel). - With the single,
configurable transceiver 2025, the wireless access device may operate identically to that described in reference to FIGS. 25A-C. However, theconfigurable transceiver 2025 may not provide multimode operation, but only support multiple channels operating in a single mode. For example, thetransceiver 2025 may only support the mode of channelized direct sequence. Although only a single mode is available, the parameters such as (and defining) spreading codes, spreading code lengths, channel center frequency and channel bandwidth, for example, alone, and without mode change, provide thewireless access device 2011 with the ability to support a dedicated busy/control channel and provide a plurality of other channels for maintaining the communication channel. - Alternatively, the
wireless access device 2011 may also comprise a dedicated busy/control transmitter 2027. If it does, thewireless access device 2011 with amultimode transceiver 2025 would operate as detailed in reference to FIGS. 26A-C. If configured with asingle mode transceiver 2025 supporting only one channel, thewireless access device 2011 would still maintain the communication and busy/control channels buy need only identify parameter and pending messages and communication requests on the busy/control channel. Of course the busy/control channel would still solve the hidden terminal problems and provide the associated benefits described above. Finally, with thetransmitter 2027 supporting the busy/control channel, thetransceiver 2025 might support multiple communication channels without supporting multiple modes of operation. In such configurations, thewireless access device 2011 need not report mode change information on the busy/control channel. Reporting all other information and aforementioned control would still take place. - The
wireless transmitter 2013 could accommodate the same wireless configuration as described in reference to thewireless access device 2011. Along withconventional terminal circuitry 2029, it may have a multimode or non-multimode, configurable ornon-configurable transceiver 2031. Thetransceiver 2031 might operate independently or utilize a supporting busy/control receiver 2033. Lastly, although not necessary, thetransmitter 2027 andreceiver 2033 might each constitute transceivers. - As is evident from the description that is provided above, the implementation of the present invention can vary greatly depending upon the desired goal of the user. However, the scope of the present invention is intended to cover all variations and substitutions which are and which may become apparent from the illustrative embodiment of the present invention that is provided above, and the scope of the invention should be extended to the claimed invention and its equivalents. It is to be understood that many variations and modifications may be effected without departing from the scope of the present disclosure.
Claims (10)
1. A communication network for collecting and communicating data, comprising:
a wireless access device comprising a control circuit and a first RF transceiver that selectively operates in one of a plurality of spread spectrum modes;
at least one mobile terminal comprising a second RF transceiver that operates in at least one of a plurality of spread spectrum modes; and
the control circuit responsive to transmissions received from the first RF transceiver for evaluating communication performance and dynamically selecting one of the plurality of spread spectrum modes of the first RF transceiver while taking into consideration the at least one of the plurality of spread spectrum modes of the second RF transceiver.
2. The communication network of claim 1 wherein the plurality of spread spectrum modes of the first RF transceiver comprising a direct sequence transmission mode and a frequency hopping mode.
3. The communication network of claim 1 wherein the plurality of spread spectrum modes of the first RF transceiver comprising a direct sequence transmission mode and a channelized direct sequence mode.
4. The communication network of claim 1 wherein the plurality of spread spectrum modes of the first RF transceiver comprising a frequency hopping mode and a hybrid frequency hopping mode.
5. The communication network of claim 1 wherein said first RF transceiver operates to support a communication channel and a busy/control channel on a time shared basis.
6. In a communication network, a plurality of wireless access device capable of communicating with a plurality of wireless terminals, each of the plurality of wireless access device comprising:
a first radio controllable to support a communication channel operating pursuant to one of a plurality of modes;
a second radio supporting a busy/control channel independent of the communication channel;
a controller that selects one of the plurality of modes and controls the first radio to support the selection; and
the controller utilizes the second radio to communicate on the busy/control channel to manage the communication channel.
7. In the communication network of claim 6 , wherein the plurality of modes includes a plurality of spread spectrum modes.
8. In the communication network of claim 7 , wherein the first radio comprises a multimode radio and the second radio comprises a transmitter.
9. In a communication network, a plurality of wireless access device capable of communicating with a plurality of wireless terminals, each of the plurality of wireless access device comprising:
a transceiver controllable to operate pursuant to any of a plurality of communication modes;
a controller that selects from the plurality of modes a communication channel and an independent, busy/control channel; and
the controller controls the transceiver to support data routing on the communication channel while managing access to the communication channel via the busy/control channel.
10. In the communication network of claim 9 , wherein the plurality of communication modes includes a plurality of spread spectrum modes.
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US12/720,231 Abandoned US20100158077A1 (en) | 1996-06-03 | 2010-03-09 | Spread spectrum transceiver module utilizing multiple mode transmission |
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Cited By (47)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020003792A1 (en) * | 2000-06-09 | 2002-01-10 | Schmidl Timothy M. | Wireless communications with frequency band selection |
US20020037016A1 (en) * | 2000-08-08 | 2002-03-28 | Hitachi, Ltd. | Base station transmitting data spread with a plurality of slots respective to a plurality of radio terminals and codes, and a cellular system thereof |
US20020197984A1 (en) * | 2001-06-22 | 2002-12-26 | Tadlys Ltd. | Flexible wireless local networks |
US20030207699A1 (en) * | 2002-05-06 | 2003-11-06 | Extricom Ltd. | Enhancing wireless lan capacity using transmission power control |
US20040002366A1 (en) * | 2002-06-26 | 2004-01-01 | International Business Machines Corporation | Apparatus, method and program to optimize battery life in a wireless device |
US20040042424A1 (en) * | 2002-08-30 | 2004-03-04 | Hsu Hsien-Tsung | Switch method and device thru MAC protocol for wireless network |
US20050129093A1 (en) * | 2003-12-15 | 2005-06-16 | Jayasuriyar Rajanik M. | Digital communication system and method |
US20060135145A1 (en) * | 2004-12-17 | 2006-06-22 | Bbnt Solutions Llc | Methods and apparatus for reduced energy communication in an ad hoc network |
US20060229083A1 (en) * | 2004-12-17 | 2006-10-12 | Bbn Technologies Corp. | Methods and apparatus for reduced energy communication in an ad hoc network |
US20070070983A1 (en) * | 2005-09-28 | 2007-03-29 | Bbn Technologies Corp. | Methods and apparatus for improved efficiency communication |
US20070075843A1 (en) * | 2005-10-03 | 2007-04-05 | Riveiro Juan C | Multi-Wideband Communications over Power Lines |
US20070076666A1 (en) * | 2005-10-03 | 2007-04-05 | Riveiro Juan C | Multi-Wideband Communications over Power Lines |
US20070135159A1 (en) * | 2003-11-21 | 2007-06-14 | Nokia Corporation | Service discovery in a wireless communication system |
US20070229231A1 (en) * | 2005-10-03 | 2007-10-04 | Hurwitz Jonathan E D | Multi-Wideband Communications over Multiple Mediums within a Network |
US7286844B1 (en) | 2003-01-31 | 2007-10-23 | Bbn Technologies Corp. | Systems and methods for three dimensional antenna selection and power control in an Ad-Hoc wireless network |
US20080008081A1 (en) * | 2006-07-06 | 2008-01-10 | Gigle Semiconductor Inc. | Adaptative multi-carrier code division multiple access |
US20080043992A1 (en) * | 2006-07-25 | 2008-02-21 | Gigle Semiconductor Inc. | Feedback impedance control for driving a signal |
US20080069036A1 (en) * | 2006-09-15 | 2008-03-20 | Samsung Electronics Co., Ltd. | Method for implementing clear channel assessment function in wireless mesh network and mobile terminal thereof |
US20080075119A1 (en) * | 2004-07-13 | 2008-03-27 | Yincheng Zhang | Method for Reporting the Frequency Resource Arrangement and Frequency Information of the Multi-Frequency Cell |
US20080117896A1 (en) * | 2006-11-21 | 2008-05-22 | Veronica Romero | Network repeater |
US20080120376A1 (en) * | 2006-11-17 | 2008-05-22 | Brent, Inc. | Method for using collaborative point-of-view management within an electronic forum |
US20080130640A1 (en) * | 2005-10-03 | 2008-06-05 | Jonathan Ephraim David Hurwitz | Multi-Wideband Communications over Multiple Mediums |
US20080159358A1 (en) * | 2007-01-02 | 2008-07-03 | David Ruiz | Unknown Destination Traffic Repetition |
WO2008082638A1 (en) * | 2006-12-29 | 2008-07-10 | Knox Michael E | High isolation signal routing assembly for full duplex communication |
US20080268859A1 (en) * | 2007-04-28 | 2008-10-30 | Nec Corporation | Method and device for resource allocation control in radio communications system |
US20080287069A1 (en) * | 2007-05-15 | 2008-11-20 | Osamu Yoshimura | Wireless Communication Apparatus, Program, Wireless Communication Method and Wireless Communication System |
US20090028074A1 (en) * | 2005-06-22 | 2009-01-29 | Knox Michael E | Antenna feed network for full duplex communication |
US20090129316A1 (en) * | 2007-08-20 | 2009-05-21 | Bbn Technologies Corp. | Systems and methods for adaptive routing in mobile ad-hoc networks and disruption tolerant networks |
US7542437B1 (en) | 2003-10-02 | 2009-06-02 | Bbn Technologies Corp. | Systems and methods for conserving energy in a communications network |
US7551892B1 (en) | 2004-02-26 | 2009-06-23 | Bbn Technologies Corp | Low-power ad hoc network entry |
US20090274221A1 (en) * | 2008-05-01 | 2009-11-05 | International Business Machines Corporation | Method, hardware product, and computer program product for performing high data rate wireless transmission |
US20100035562A1 (en) * | 2008-08-05 | 2010-02-11 | Motorola, Inc. | Method and System for Signal Processing and Transmission |
US20100117734A1 (en) * | 2008-10-13 | 2010-05-13 | Jonathan Ephraim David Hurwitz | Programmable Gain Amplifier and Transconductance Compensation System |
US7795973B2 (en) | 2008-10-13 | 2010-09-14 | Gigle Networks Ltd. | Programmable gain amplifier |
US7797016B2 (en) | 2002-08-07 | 2010-09-14 | Extricom Ltd. | Wireless LAN with central management of access points |
US7924728B2 (en) | 2006-08-25 | 2011-04-12 | Raytheon Bbn Technologies Corp | Systems and methods for energy-conscious communication in wireless ad-hoc networks |
US8111640B2 (en) | 2005-06-22 | 2012-02-07 | Knox Michael E | Antenna feed network for full duplex communication |
US8111718B1 (en) | 2007-12-05 | 2012-02-07 | Clearwire IP Holdings, LLC | Communication system and method that reduces interference |
US20120315899A1 (en) * | 2011-06-09 | 2012-12-13 | Celeno Communications (Israel) Ltd. | Device roaming in hybrid wi-fi/wireline and multi-ap networks |
US20130010719A1 (en) * | 2011-07-07 | 2013-01-10 | Nir Shapira | Method for managing the spectrum of a multi-band wireless communication system |
US8588844B2 (en) | 2010-11-04 | 2013-11-19 | Extricom Ltd. | MIMO search over multiple access points |
US8724492B2 (en) | 2011-04-08 | 2014-05-13 | Motorola Mobility Llc | Method and apparatus for multi-radio coexistence on adjacent frequency bands |
US20160218766A1 (en) * | 2015-01-28 | 2016-07-28 | Lam Research Corporation | Dual Push Between A Host Computer System And An RF Generator |
US9413414B2 (en) | 2006-12-29 | 2016-08-09 | Mode-1 Corp. | High isolation signal routing assembly for full duplex communication |
US9780437B2 (en) | 2005-06-22 | 2017-10-03 | Michael E. Knox | Antenna feed network for full duplex communication |
US10075507B2 (en) | 2013-09-05 | 2018-09-11 | NCS Technologies, Inc. | Systems and methods providing a mobile zero client |
US20220223997A1 (en) * | 2021-01-13 | 2022-07-14 | Zebra Technologies Corporation | User-Installable Wireless Communications Module |
Families Citing this family (179)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6697415B1 (en) * | 1996-06-03 | 2004-02-24 | Broadcom Corporation | Spread spectrum transceiver module utilizing multiple mode transmission |
US7068992B1 (en) * | 1999-12-30 | 2006-06-27 | Motient Communications Inc. | System and method of polling wireless devices having a substantially fixed and/or predesignated geographic location |
US20020059388A1 (en) * | 2000-01-21 | 2002-05-16 | David Thompson | E-mail and messaging systems and methods |
US7215777B2 (en) * | 2001-01-16 | 2007-05-08 | Microsoft Corporation | Sending notification through a firewall over a computer network |
US20020093956A1 (en) * | 2001-01-16 | 2002-07-18 | Gurin Michael H. | Dynamic communication and method of use |
US7024223B1 (en) * | 2001-03-05 | 2006-04-04 | Novatel Wireless, Inc. | Systems and methods for a multi-platform wireless modem |
US6985461B2 (en) * | 2001-03-22 | 2006-01-10 | Symbol Technologies, Inc. | Software for installation and configuration management of network nodes |
US6941152B2 (en) * | 2001-04-24 | 2005-09-06 | Ipr Licensing, Inc. | Wireless subscriber network registration system for configurable services |
WO2002093881A2 (en) * | 2001-05-14 | 2002-11-21 | Innovision Research & Technology Plc | Portable communication devices |
EP1271871A1 (en) * | 2001-06-20 | 2003-01-02 | Motorola, Inc. | Compensation of mismatch between quadrature paths |
US7603081B2 (en) * | 2001-09-14 | 2009-10-13 | Atc Technologies, Llc | Radiotelephones and operating methods that use a single radio frequency chain and a single baseband processor for space-based and terrestrial communications |
WO2003025723A2 (en) * | 2001-09-19 | 2003-03-27 | Enfora, Inc. | All-in-one modular wireless device |
US7127096B2 (en) * | 2001-11-20 | 2006-10-24 | Accuimage Diagnostics Corp. | Method and software for improving coronary calcium scoring consistency |
US7265663B2 (en) | 2001-11-28 | 2007-09-04 | Trivinci Systems, Llc | Multimedia racing experience system |
US20030105558A1 (en) * | 2001-11-28 | 2003-06-05 | Steele Robert C. | Multimedia racing experience system and corresponding experience based displays |
KR100588753B1 (en) * | 2001-12-13 | 2006-06-13 | 매그나칩 반도체 유한회사 | PSK type modulator |
US20070171878A1 (en) * | 2001-12-21 | 2007-07-26 | Novatel Wireless, Inc. | Systems and methods for a multi-mode wireless modem |
US7319715B1 (en) * | 2001-12-21 | 2008-01-15 | Novatel Wireless, Inc. | Systems and methods for a multi-mode wireless modem |
US7010621B2 (en) * | 2002-02-14 | 2006-03-07 | The Boeing Company | System having a spread-spectrum clock for further suppression of electromagnetic emissions in network devices communicating via a network bus |
DE10207858A1 (en) * | 2002-02-19 | 2003-08-28 | Deutsche Telekom Ag | Method and system for the provision of information and communication in vehicles |
JP3719993B2 (en) * | 2002-02-22 | 2005-11-24 | 株式会社東芝 | Wireless terminal station and wireless communication system |
US20030198307A1 (en) * | 2002-04-19 | 2003-10-23 | Compaq Information | Dynamic clock control to reduce radio interference in digital equipment |
JP3465707B1 (en) * | 2002-05-27 | 2003-11-10 | 日本電気株式会社 | Carrier sense multiple access receiver and its interference suppression method |
DE10224165A1 (en) * | 2002-05-31 | 2003-12-24 | Advanced Micro Devices Inc | Phase error correction using despread signals |
US6954446B2 (en) * | 2002-06-25 | 2005-10-11 | Motorola, Inc. | Multiple mode RF communication device |
US6985720B2 (en) * | 2002-07-12 | 2006-01-10 | Qualcomm, Incorporated | Apparatus and method for transparent and integrated wireless messaging in a multi-mode environment |
US7194283B2 (en) * | 2002-08-14 | 2007-03-20 | Intel Corporation | Method and apparatus for communication using multiple communication protocols |
US7149331B1 (en) | 2002-09-03 | 2006-12-12 | Cedara Software Corp. | Methods and software for improving thresholding of coronary calcium scoring |
US7044387B2 (en) * | 2002-09-05 | 2006-05-16 | Honeywell International Inc. | RFID tag and communication protocol for long range tag communications and power efficiency |
CA2510526C (en) * | 2002-12-16 | 2010-11-23 | Research In Motion Limited | Methods and apparatus for reducing power consumption in cdma communication device |
CA2415668A1 (en) * | 2003-01-06 | 2004-07-06 | Sirific Wireless Corporation | Integrated, configurable multi-mode transmitter |
US6980839B2 (en) * | 2003-04-30 | 2005-12-27 | Sony Corporation | Apparatus, system and method for use in powering on a remote wireless device |
US7664036B2 (en) * | 2003-05-22 | 2010-02-16 | Broadcom Corporation | Dynamic real-time quality management of packetized communications in a network environment |
US7260358B2 (en) * | 2003-06-11 | 2007-08-21 | Hewlett-Packard Development Company, L.P. | Data-storage system having a wireless connection architecture for wireless data exchange between modules |
WO2004114239A2 (en) | 2003-06-13 | 2004-12-29 | Wildseed Ltd. | Emulated radio frequency identification |
US7221312B2 (en) | 2003-06-18 | 2007-05-22 | General Dynamics C4 Systems, Inc. | Method and system for detecting interference for global positioning systems |
EP1692784B1 (en) * | 2003-12-09 | 2016-06-29 | Awarepoint Corporation | Plug-in network appliance |
KR100579525B1 (en) * | 2003-12-30 | 2006-05-15 | 삼성전자주식회사 | Channel time allocation method in WPAN |
US20050165919A1 (en) * | 2004-01-09 | 2005-07-28 | Lu Qian | System and method to simulate and manage a wireless local area network (WLAN) |
US7221927B2 (en) * | 2004-02-13 | 2007-05-22 | Trapeze Networks, Inc. | Station mobility between access points |
JP2005252501A (en) * | 2004-03-03 | 2005-09-15 | Nec Corp | Communications system, communication control unit, and communication control method |
US7519390B2 (en) * | 2004-03-10 | 2009-04-14 | Spreadtrum Communications Inc. | Transmitter and receiver architecture for multi-mode wireless device |
DE102004014739B4 (en) * | 2004-03-25 | 2009-10-15 | Advanced Micro Devices, Inc., Sunnyvale | Rate-dependent transmission gain control for WLAN systems |
FR2871312B1 (en) * | 2004-06-03 | 2006-08-11 | St Microelectronics Sa | CHARGE MODULATION IN AN ELECTROMAGNETIC TRANSPONDER |
JP2005354126A (en) * | 2004-06-08 | 2005-12-22 | Hitachi Communication Technologies Ltd | Radio communication terminal, radio base station, and radio communication system |
US7432803B2 (en) * | 2004-06-25 | 2008-10-07 | City Theatrical Inc. | Wireless control system and method thereof |
US20060068792A1 (en) * | 2004-09-30 | 2006-03-30 | Motorola, Inc. | System and method for using determination of the operating parameters of a mobile device |
ATE379900T1 (en) * | 2004-12-09 | 2007-12-15 | Research In Motion Ltd | APPARATUS AND METHOD FOR TWO OR MORE ßDELIVERY TRAFFIC INDICATION MESSAGE (DTIM)ß PERIODS IN WIRELESS NETWORKS |
EP1829230A1 (en) * | 2004-12-15 | 2007-09-05 | Freescale Semiconductor, Inc. | Fractional-n frequency generation and automatic frequency control in a wireless communication unit |
US7593417B2 (en) * | 2005-01-21 | 2009-09-22 | Research In Motion Limited | Handling broadcast and multicast traffic as unicast traffic in a wireless network |
US8005032B2 (en) * | 2005-01-21 | 2011-08-23 | Research In Motion Limited | Maintaining delivery traffic indication message (DTIM) periods on a per-wireless client device basis |
US7529925B2 (en) | 2005-03-15 | 2009-05-05 | Trapeze Networks, Inc. | System and method for distributing keys in a wireless network |
US7391320B1 (en) | 2005-04-01 | 2008-06-24 | Horizon Hobby, Inc. | Method and system for controlling radio controlled devices |
WO2006130988A1 (en) * | 2005-06-10 | 2006-12-14 | Telecommunications Research Laboratories | Wireless communication system |
US8213484B2 (en) * | 2005-06-16 | 2012-07-03 | Qualcomm Incorporated | Wireless communication network with extended coverage range |
US7801555B2 (en) * | 2005-07-22 | 2010-09-21 | Qualcomm Incorporated | User operation of a wireless device capable of communicating with multiple networks |
WO2007028008A2 (en) * | 2005-08-31 | 2007-03-08 | Two Technologies, Inc. | Systems for integrating peripheral devices with hand-held computing devices |
US8638762B2 (en) * | 2005-10-13 | 2014-01-28 | Trapeze Networks, Inc. | System and method for network integrity |
US7551619B2 (en) * | 2005-10-13 | 2009-06-23 | Trapeze Networks, Inc. | Identity-based networking |
US7573859B2 (en) * | 2005-10-13 | 2009-08-11 | Trapeze Networks, Inc. | System and method for remote monitoring in a wireless network |
US7724703B2 (en) | 2005-10-13 | 2010-05-25 | Belden, Inc. | System and method for wireless network monitoring |
WO2007044986A2 (en) | 2005-10-13 | 2007-04-19 | Trapeze Networks, Inc. | System and method for remote monitoring in a wireless network |
US8285326B2 (en) * | 2005-12-30 | 2012-10-09 | Honeywell International Inc. | Multiprotocol wireless communication backbone |
FR2896362B1 (en) * | 2006-01-16 | 2008-04-18 | Wavecom Sa | RADIO COMMUNICATION MODULE WITH TRANSMISSION MEANS CONTROLLED BY INTERFERENCE DETECTION MEANS, DEVICE AND USE THEREOF |
WO2007104152A2 (en) * | 2006-03-14 | 2007-09-20 | Jamie Hackett | Long-range radio frequency receiver-controller module and wireless control system comprising same |
US7558266B2 (en) | 2006-05-03 | 2009-07-07 | Trapeze Networks, Inc. | System and method for restricting network access using forwarding databases |
KR100781521B1 (en) * | 2006-05-03 | 2007-12-03 | 삼성전자주식회사 | Method and apparatus for discovering modification of device in wireless network environment |
US7657286B2 (en) * | 2006-05-11 | 2010-02-02 | Nokia Corporation | Multiradio control interface element in modem |
US8966018B2 (en) * | 2006-05-19 | 2015-02-24 | Trapeze Networks, Inc. | Automated network device configuration and network deployment |
US7577453B2 (en) | 2006-06-01 | 2009-08-18 | Trapeze Networks, Inc. | Wireless load balancing across bands |
US7664532B2 (en) * | 2006-06-02 | 2010-02-16 | Nokia Corporation | Radio transmission scheduling according to multiradio control in a radio modem |
US8818322B2 (en) * | 2006-06-09 | 2014-08-26 | Trapeze Networks, Inc. | Untethered access point mesh system and method |
US7912982B2 (en) * | 2006-06-09 | 2011-03-22 | Trapeze Networks, Inc. | Wireless routing selection system and method |
US9191799B2 (en) | 2006-06-09 | 2015-11-17 | Juniper Networks, Inc. | Sharing data between wireless switches system and method |
US9258702B2 (en) | 2006-06-09 | 2016-02-09 | Trapeze Networks, Inc. | AP-local dynamic switching |
US8046019B2 (en) * | 2006-08-04 | 2011-10-25 | Futurewei Technologies, Inc. | Method and system for optimal allocation of uplink transmission power in communication networks |
US7649951B2 (en) | 2006-08-16 | 2010-01-19 | Harris Corporation | System and method for communicating data using symbol-based randomized orthogonal frequency division multiplexing (OFDM) with applied frequency domain spreading |
US7751488B2 (en) * | 2006-08-16 | 2010-07-06 | Harris Corporation | System and method for communicating data using symbol-based randomized orthogonal frequency division multiplexing (OFDM) |
US7860147B2 (en) * | 2006-08-16 | 2010-12-28 | Harris Corporation | Method of communicating and associated transmitter using coded orthogonal frequency division multiplexing (COFDM) |
US7903749B2 (en) * | 2006-08-16 | 2011-03-08 | Harris Corporation | System and method for applying frequency domain spreading to multi-carrier communications signals |
US7813433B2 (en) * | 2006-08-16 | 2010-10-12 | Harris Corporation | System and method for communicating data using symbol-based randomized orthogonal frequency division multiplexing (OFDM) with selected subcarriers turned on or off |
US8340110B2 (en) * | 2006-09-15 | 2012-12-25 | Trapeze Networks, Inc. | Quality of service provisioning for wireless networks |
US7949364B2 (en) * | 2006-10-03 | 2011-05-24 | Nokia Corporation | System for managing radio modems |
US8072952B2 (en) * | 2006-10-16 | 2011-12-06 | Juniper Networks, Inc. | Load balancing |
US20080151844A1 (en) * | 2006-12-20 | 2008-06-26 | Manish Tiwari | Wireless access point authentication system and method |
WO2008083339A2 (en) * | 2006-12-28 | 2008-07-10 | Trapeze Networks, Inc. | Application-aware wireless network system and method |
US7873061B2 (en) | 2006-12-28 | 2011-01-18 | Trapeze Networks, Inc. | System and method for aggregation and queuing in a wireless network |
US8325654B2 (en) | 2006-12-28 | 2012-12-04 | Futurewei Technologies, Inc. | Integrated scheduling and power control for the uplink of an OFDMA network |
KR100833896B1 (en) * | 2007-01-12 | 2008-06-02 | 삼성전자주식회사 | Apparatus and method for saving power in dual mode portable terminal |
US20080226075A1 (en) * | 2007-03-14 | 2008-09-18 | Trapeze Networks, Inc. | Restricted services for wireless stations |
US20080276303A1 (en) * | 2007-05-03 | 2008-11-06 | Trapeze Networks, Inc. | Network Type Advertising |
US20080285628A1 (en) * | 2007-05-17 | 2008-11-20 | Gizis Alexander C | Communications systems and methods for remotely controlled vehicles |
US20080291830A1 (en) * | 2007-05-25 | 2008-11-27 | Nokia Corporation | Multiradio control incorporating quality of service |
KR101518222B1 (en) * | 2007-05-25 | 2015-05-11 | 코닌클리케 필립스 엔.브이. | Channel change decision mechanism and method for a wireless network |
US8902904B2 (en) * | 2007-09-07 | 2014-12-02 | Trapeze Networks, Inc. | Network assignment based on priority |
US7856047B2 (en) * | 2007-09-21 | 2010-12-21 | Honeywell International Inc. | System and method for concurrent frequency hopping of radio communications |
US8428100B2 (en) * | 2007-10-08 | 2013-04-23 | Honeywell International Inc. | System and methods for securing data transmissions over wireless networks |
US9408250B2 (en) * | 2007-10-08 | 2016-08-02 | Honeywell International Inc. | Wireless networks for highly dependable applications |
US8238942B2 (en) * | 2007-11-21 | 2012-08-07 | Trapeze Networks, Inc. | Wireless station location detection |
US8249603B2 (en) | 2008-02-29 | 2012-08-21 | Research In Motion Limited | Methods and apparatus for line selection in a communication device |
US8270983B2 (en) | 2008-02-29 | 2012-09-18 | Research In Motion Limited | Methods and apparatus for line selection in a communication device |
US8185150B2 (en) * | 2008-02-29 | 2012-05-22 | Research In Motion Limited | Methods and apparatus for line selection in a communication device |
US9467557B2 (en) * | 2008-02-29 | 2016-10-11 | Blackberry Limited | Methods and apparatus for line selection in a communication device |
US20100195553A1 (en) * | 2008-03-18 | 2010-08-05 | Myers Theodore J | Controlling power in a spread spectrum system |
US8520721B2 (en) | 2008-03-18 | 2013-08-27 | On-Ramp Wireless, Inc. | RSSI measurement mechanism in the presence of pulsed jammers |
US8477830B2 (en) | 2008-03-18 | 2013-07-02 | On-Ramp Wireless, Inc. | Light monitoring system using a random phase multiple access system |
US8958460B2 (en) * | 2008-03-18 | 2015-02-17 | On-Ramp Wireless, Inc. | Forward error correction media access control system |
US8150357B2 (en) | 2008-03-28 | 2012-04-03 | Trapeze Networks, Inc. | Smoothing filter for irregular update intervals |
US8474023B2 (en) * | 2008-05-30 | 2013-06-25 | Juniper Networks, Inc. | Proactive credential caching |
US8978105B2 (en) | 2008-07-25 | 2015-03-10 | Trapeze Networks, Inc. | Affirming network relationships and resource access via related networks |
US8238298B2 (en) * | 2008-08-29 | 2012-08-07 | Trapeze Networks, Inc. | Picking an optimal channel for an access point in a wireless network |
US8244296B2 (en) * | 2008-10-15 | 2012-08-14 | Apple Inc. | Dynamic thermal control for wireless transceivers |
US8170606B2 (en) * | 2008-10-15 | 2012-05-01 | Apple Inc. | Dynamic thermal control for wireless transceivers |
US8672726B2 (en) * | 2008-10-31 | 2014-03-18 | Horizon Hobby, Inc. | Methods of completing a remotely controlled model vehicle system with a separate controller |
KR101587092B1 (en) * | 2008-11-04 | 2016-01-20 | 엘지전자 주식회사 | Mobile terminal |
US8363699B2 (en) | 2009-03-20 | 2013-01-29 | On-Ramp Wireless, Inc. | Random timing offset determination |
US8594160B2 (en) * | 2009-04-02 | 2013-11-26 | Panasonic Corporation | Radio transmitting/receiving circuit, wireless communication apparatus, and radio transmitting/receiving method |
PL2239973T3 (en) * | 2009-04-09 | 2016-08-31 | Airbus Defence & Space Oy | Recording communications |
US9634373B2 (en) | 2009-06-04 | 2017-04-25 | Ubiquiti Networks, Inc. | Antenna isolation shrouds and reflectors |
US9496620B2 (en) | 2013-02-04 | 2016-11-15 | Ubiquiti Networks, Inc. | Radio system for long-range high-speed wireless communication |
US8836601B2 (en) | 2013-02-04 | 2014-09-16 | Ubiquiti Networks, Inc. | Dual receiver/transmitter radio devices with choke |
KR101290025B1 (en) * | 2009-11-30 | 2013-07-30 | 한국전자통신연구원 | WIRELESS COMMUNICATION SYSTEM AND METHOD FOR SHARING sensing antenna, sensing receiver and data antenna, data transmitter-receiver |
WO2011067862A1 (en) * | 2009-12-04 | 2011-06-09 | 富士通株式会社 | Base station device, mobile terminal, communication system, and radio communication method |
US8761689B2 (en) * | 2010-07-09 | 2014-06-24 | Blackberry Limited | Methods and apparatus for use in communicating data which includes the selection of an RF channel for communications |
CN102375527A (en) * | 2010-08-12 | 2012-03-14 | 财团法人工业技术研究院 | Method and system for triggering electronic device to execute corresponding function |
US8472887B2 (en) * | 2010-09-09 | 2013-06-25 | The United States Of America As Represented By The Secretary Of The Army | Radio frequency integrated circuit for enhanced transmit/receive performance in low power applications and method of making the same |
US9167599B2 (en) * | 2010-09-22 | 2015-10-20 | Motorola Solutions, Inc. | Channel structure for non-contention based windows and contention based random access requests |
US8761065B2 (en) * | 2010-11-16 | 2014-06-24 | Intel Corporation | Techniques for wakeup signaling for a very low power WLAN device |
JP5756908B2 (en) * | 2012-03-09 | 2015-07-29 | パナソニックIpマネジメント株式会社 | Multi-hop communication system, handset |
US9288784B2 (en) | 2012-05-18 | 2016-03-15 | Bose Corporation | Controlling communication mode changes in a communication system |
CN102820896A (en) * | 2012-09-10 | 2012-12-12 | 苏州云达通信科技有限公司 | Device for preventing same frequency interference between communication modules |
US8761142B2 (en) | 2012-10-19 | 2014-06-24 | Ubiquiti Networks, Inc. | Distributed seamless roaming in wireless networks |
US9179409B2 (en) * | 2012-12-03 | 2015-11-03 | Qualcomm Incorporated | Multiple access scheme for narrowband channels |
TW201427421A (en) * | 2012-12-19 | 2014-07-01 | Sunplus Technology Co Ltd | A fast blind scan method insensitive to adjacent channel interference |
US9397820B2 (en) | 2013-02-04 | 2016-07-19 | Ubiquiti Networks, Inc. | Agile duplexing wireless radio devices |
US9543635B2 (en) | 2013-02-04 | 2017-01-10 | Ubiquiti Networks, Inc. | Operation of radio devices for long-range high-speed wireless communication |
US20160218406A1 (en) | 2013-02-04 | 2016-07-28 | John R. Sanford | Coaxial rf dual-polarized waveguide filter and method |
US8855730B2 (en) | 2013-02-08 | 2014-10-07 | Ubiquiti Networks, Inc. | Transmission and reception of high-speed wireless communication using a stacked array antenna |
US10051072B2 (en) | 2013-06-21 | 2018-08-14 | Google Llc | Detecting co-presence in the physical world |
BR112016007701B1 (en) | 2013-10-11 | 2023-01-31 | Ubiquiti Inc | METHOD FOR CONTROLLING THE RECEPTION OF A WIRELESS BROADBAND RADIO |
US9369991B2 (en) | 2013-11-08 | 2016-06-14 | Gogo Llc | Hybrid communications for devices on vehicles |
US9467828B2 (en) | 2013-11-08 | 2016-10-11 | Gogo Llc | Systems and methods for configuring an electronic device for cellular-based communications |
US9232546B2 (en) | 2013-11-08 | 2016-01-05 | Gogo Llc | Systems and methods for two-part electronic device registration |
US9967020B2 (en) | 2013-11-08 | 2018-05-08 | Gogo Llc | Facilitating communications between on-board electronic devices and terrestrial devices |
US9577857B2 (en) | 2013-11-08 | 2017-02-21 | Gogo Llc | Adaptive modulation in a hybrid vehicle communication system |
US9197314B1 (en) | 2013-11-08 | 2015-11-24 | Gogo Llc | Data delivery to devices on vehicles using multiple forward links |
US9326217B2 (en) | 2013-11-08 | 2016-04-26 | Gogo Llc | Optimizing usage of modems for data delivery to devices on vehicles |
LT3114884T (en) | 2014-03-07 | 2020-02-10 | Ubiquiti Inc. | Cloud device identification and authentication |
US10574474B2 (en) | 2014-03-07 | 2020-02-25 | Ubiquiti Inc. | Integrated power receptacle wireless access point (AP) adapter devices |
US9325516B2 (en) | 2014-03-07 | 2016-04-26 | Ubiquiti Networks, Inc. | Power receptacle wireless access point devices for networked living and work spaces |
EP3120642B1 (en) | 2014-03-17 | 2023-06-07 | Ubiquiti Inc. | Array antennas having a plurality of directional beams |
DK3127187T3 (en) | 2014-04-01 | 2021-02-08 | Ubiquiti Inc | Antenna device |
US9648468B2 (en) | 2014-05-01 | 2017-05-09 | Gogo Llc | Systems and methods for facilitating voice-based communications |
US9712668B2 (en) | 2014-05-01 | 2017-07-18 | Gogo Llc | Systems and methods for notifying electronic devices of voice-based communication requests |
US10425536B2 (en) | 2014-05-08 | 2019-09-24 | Ubiquiti Networks, Inc. | Phone systems and methods of communication |
US9503956B2 (en) | 2014-05-30 | 2016-11-22 | Gogo Llc | Systems and methods for facilitating communications originating from a non-terrestrial network |
US9716542B2 (en) | 2014-05-30 | 2017-07-25 | Gogo Llc | Systems and methods for facilitating communications destined for a non-terrestrial network |
US9655073B2 (en) | 2014-05-30 | 2017-05-16 | Gogo Llc | Systems and methods for communicating with non-terrestrial electronic devices |
US10069580B2 (en) | 2014-06-30 | 2018-09-04 | Ubiquiti Networks, Inc. | Wireless radio device alignment tools and methods |
WO2016003862A1 (en) | 2014-06-30 | 2016-01-07 | Ubiquiti Networks, Inc. | Methods and tools for assisting in the configuration of a wireless radio network using functional maps |
CN112714501B (en) | 2014-08-29 | 2023-09-29 | 韦勒斯标准与技术协会公司 | Wireless communication method and wireless communication terminal |
ES2873999T3 (en) | 2014-08-31 | 2021-11-04 | Ubiquiti Inc | Methods and devices for monitoring and improving the status of a wireless network |
US10164332B2 (en) | 2014-10-14 | 2018-12-25 | Ubiquiti Networks, Inc. | Multi-sector antennas |
WO2016137938A1 (en) | 2015-02-23 | 2016-09-01 | Ubiquiti Networks, Inc. | Radio apparatuses for long-range communication of radio-frequency information |
WO2017044924A1 (en) | 2015-09-11 | 2017-03-16 | Ubiquiti Networks, Inc. | Compact public address access point apparatuses |
PL3353989T3 (en) | 2015-09-25 | 2021-08-30 | Ubiquiti Inc. | Compact and integrated key controller apparatus for monitoring networks |
CN206743244U (en) | 2015-10-09 | 2017-12-12 | 优倍快网络公司 | Multiplexer device |
US9628126B1 (en) | 2016-05-03 | 2017-04-18 | David R. Hall | Method and system for a dual modulation low data rate network |
US10291428B2 (en) | 2016-05-03 | 2019-05-14 | Hall Labs Llc | System and method for cloud-networked stand-alone dual modulation LAN |
CN109154932A (en) * | 2016-05-12 | 2019-01-04 | M2Md科技股份有限公司 | The management method and system of different classes of radio communication service are provided from different mobile networks |
WO2018199991A1 (en) * | 2017-04-28 | 2018-11-01 | Intel Corporation | Cell selection techniques for directional communications |
CN107483715B (en) * | 2017-07-04 | 2021-03-02 | 上海小蚁科技有限公司 | Method and system for communication between terminal and equipment, terminal and storage medium |
WO2019014229A1 (en) | 2017-07-10 | 2019-01-17 | Ubiquiti Networks, Inc. | Wearable video camera medallion with circular display |
CN111466108B (en) | 2017-09-27 | 2022-12-06 | 优倍快公司 | System for automatic secure remote access to a local network |
WO2019139993A1 (en) | 2018-01-09 | 2019-07-18 | Ubiquiti Networks, Inc. | Quick connecting twisted pair cables |
CN114556440A (en) | 2019-09-13 | 2022-05-27 | 优倍快公司 | Augmented reality for internet connectivity installation |
WO2022046075A1 (en) * | 2020-08-28 | 2022-03-03 | Siemens Industry Software, Inc. | Method and system for protocol processing |
AU2022252814B2 (en) * | 2021-07-09 | 2023-11-09 | RANlytics Limited | A system for monitoring and measuring multiple heterogeneous radio communications networks |
WO2023122776A1 (en) * | 2021-12-22 | 2023-06-29 | The Regents Of The University Of California | Timo: time interleaved multiple outputs for enabling multiplexing gains with a single rf chain |
Citations (99)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3665164A (en) * | 1970-07-09 | 1972-05-23 | Ricca Data Systems Inc | Apparatus for reading optically cardlike elements and a merchandising system utilizing the same |
US3947817A (en) * | 1974-01-07 | 1976-03-30 | Recognition Equipment Incorporated | Hand operated optical character recognition wand |
US4002892A (en) * | 1973-09-15 | 1977-01-11 | Zielinski Adolf H | Portable calculator |
US4005400A (en) * | 1974-04-30 | 1977-01-25 | Societe Suisse Pour L'industrie Horologere Management Services S.A. | Data entry and decoding system for scripted data |
US4017725A (en) * | 1975-01-03 | 1977-04-12 | Litton Business Systems, Inc. | Solar powered portable calculator |
US4020527A (en) * | 1976-01-02 | 1977-05-03 | Neill Wilbur J O | Grip for a hand held portable device |
US4091270A (en) * | 1976-07-19 | 1978-05-23 | Hewlett-Packard Company | Electronic calculator with optical input means |
US4133034A (en) * | 1977-07-27 | 1979-01-02 | Etter Berwyn E | Method and means of assimilating utility meter data |
US4136821A (en) * | 1976-09-01 | 1979-01-30 | Nippondenso Co., Ltd. | Method and apparatus for recognizing code information |
US4141492A (en) * | 1977-10-03 | 1979-02-27 | R. R. Donnelley & Sons, Inc. | Signature verifier with indicia sensor |
US4158130A (en) * | 1977-05-09 | 1979-06-12 | Ncr Corporation | Interchangeable auxiliary keyboard |
US4158194A (en) * | 1976-12-27 | 1979-06-12 | Recognition Equipment Incorporated | Optical recognition system |
US4188103A (en) * | 1978-04-21 | 1980-02-12 | Polaroid Corporation | Range synchronized flash photographic apparatus and method for achieving optimum flash exposure |
US4247908A (en) * | 1978-12-08 | 1981-01-27 | Motorola, Inc. | Re-linked portable data terminal controller system |
US4322612A (en) * | 1979-10-22 | 1982-03-30 | General Instrument Corporation | Self-service wagering system |
US4385285A (en) * | 1981-04-02 | 1983-05-24 | Ncr Corporation | Check dispensing terminal |
US4500776A (en) * | 1982-11-08 | 1985-02-19 | Vadim Laser | Method and apparatus for remotely reading and decoding bar codes |
US4506344A (en) * | 1982-06-04 | 1985-03-19 | Pitney Bowes Inc. | Hand held electronic postage meter having secure postage meter doors |
US4511970A (en) * | 1981-04-08 | 1985-04-16 | Hitachi, Ltd. | Portable terminal device |
US4519068A (en) * | 1983-07-11 | 1985-05-21 | Motorola, Inc. | Method and apparatus for communicating variable length messages between a primary station and remote stations of a data communications system |
US4523297A (en) * | 1980-05-30 | 1985-06-11 | Compagnie Internationale Pour L'informatique Cii-Honeywell Bull | Hand-held processor with two-way dialog between microprocessor in case and microprocessor on carrier insertable into casing slot |
US4523087A (en) * | 1981-04-07 | 1985-06-11 | Benton William M | Transaction verification system using optical coupling data communication link |
US4570057A (en) * | 1981-12-28 | 1986-02-11 | Norand Corporation | Instant portable bar code reader |
US4569421A (en) * | 1980-11-17 | 1986-02-11 | Sandstedt Gary O | Restaurant or retail vending facility |
US4578571A (en) * | 1983-11-14 | 1986-03-25 | Numa Corporation | Portable bar code scanning device and method |
US4634845A (en) * | 1984-12-24 | 1987-01-06 | Ncr Corporation | Portable personal terminal for use in a system for handling transactions |
US4641292A (en) * | 1983-06-20 | 1987-02-03 | George Tunnell | Voice controlled welding system |
US4654818A (en) * | 1983-12-16 | 1987-03-31 | Texas Instruments Incorporated | Data processing device having memory selectively interfacing with computer |
US4661993A (en) * | 1984-10-12 | 1987-04-28 | At&T Company | Technique for improving radio system performance during fading |
US4718110A (en) * | 1985-10-24 | 1988-01-05 | General Electric Company | Portable two way radio with split universal device connector apparatus |
US4718103A (en) * | 1985-10-08 | 1988-01-05 | Hitachi, Ltd. | Method and apparatus for on-line recognizing handwritten patterns |
US4727245A (en) * | 1986-10-14 | 1988-02-23 | Mars, Inc. | Portable data scanner with removable modular printer |
US4734566A (en) * | 1985-02-19 | 1988-03-29 | Nippondenso Co., Ltd. | Apparatus and method for recognizing optical information |
USD295411S (en) * | 1985-03-15 | 1988-04-26 | American Telephone And Telegraph Company, At&T Bell Laboratories | Combined voice and data terminal or similar article |
US4743773A (en) * | 1984-08-23 | 1988-05-10 | Nippon Electric Industry Co., Ltd. | Bar code scanner with diffusion filter and plural linear light source arrays |
US4749353A (en) * | 1982-05-13 | 1988-06-07 | Texas Instruments Incorporated | Talking electronic learning aid for improvement of spelling with operator-controlled word list |
US4752965A (en) * | 1984-02-24 | 1988-06-21 | The De La Rue Company Plc | Sign verification |
US4825057A (en) * | 1985-02-28 | 1989-04-25 | Symbol Technologies, Inc. | Portable laser diode scanning head |
US4831275A (en) * | 1986-11-12 | 1989-05-16 | Quential, Inc. | Method and means for self-referencing and self-focusing a bar-code reader |
US4835372A (en) * | 1985-07-19 | 1989-05-30 | Clincom Incorporated | Patient care system |
US4837858A (en) * | 1987-04-30 | 1989-06-06 | Motorola, Inc. | Subscriber unit for a trunked voice/data communication system |
US4836256A (en) * | 1987-01-30 | 1989-06-06 | Meliconi S.R.L. | Shockproof protective sheath for remote controls, in particular those of television receivers |
US4842966A (en) * | 1987-03-31 | 1989-06-27 | Mitsubishi Denki Kabushiki Kaisha | Battery holder mechanism |
US4890832A (en) * | 1982-10-13 | 1990-01-02 | Sharp Kabushiki Kaisha | Compact electronic apparatus with removable processing units |
US4897532A (en) * | 1985-02-28 | 1990-01-30 | Symbol Technologies, Inc. | Portable laser diode scanning head |
US4910775A (en) * | 1988-04-21 | 1990-03-20 | Telecash | Portable electronic device for use in conjunction with a screen |
US4916441A (en) * | 1988-09-19 | 1990-04-10 | Clinicom Incorporated | Portable handheld terminal |
US4984247A (en) * | 1988-09-29 | 1991-01-08 | Ascom Zelcom Ag | Digital radio transmission system for a cellular network, using the spread spectrum method |
US4983818A (en) * | 1989-01-30 | 1991-01-08 | Metrologic Instruments, Inc. | Data acquisition system with laser scanner module |
US5002184A (en) * | 1989-06-12 | 1991-03-26 | Grid Systems Corporation | Soft case protection for a hand held computer |
US5008879A (en) * | 1988-11-14 | 1991-04-16 | Datapoint Corporation | LAN with interoperative multiple operational capabilities |
US5012407A (en) * | 1984-12-11 | 1991-04-30 | Finn Charles A | Computer system which accesses operating system information and command handlers from optical storage via an auxiliary processor and cache memory |
US5022046A (en) * | 1989-04-14 | 1991-06-04 | The United States Of America As Represented By The Secretary Of The Air Force | Narrowband/wideband packet data communication system |
US5023824A (en) * | 1987-10-02 | 1991-06-11 | Norand Corporation | Hand-held computerized data collection terminal with indented hand grip and conforming battery drawer |
US5097484A (en) * | 1988-10-12 | 1992-03-17 | Sumitomo Electric Industries, Ltd. | Diversity transmission and reception method and equipment |
US5101406A (en) * | 1989-08-24 | 1992-03-31 | Telesystems Slw Inc. | Wireless communications system |
US5117501A (en) * | 1988-08-08 | 1992-05-26 | General Electric Company | Dynamic regrouping in a trunked radio communications system |
US5181200A (en) * | 1990-10-29 | 1993-01-19 | International Business Machines Corporation | Handoff method and apparatus for mobile wireless workstation |
US5202817A (en) * | 1989-06-07 | 1993-04-13 | Norand Corporation | Hand-held data capture system with interchangeable modules |
US5216233A (en) * | 1989-03-09 | 1993-06-01 | Norand Corporation | Versatile RF terminal-scanner system |
US5218187A (en) * | 1990-01-18 | 1993-06-08 | Norand Corporation | Hand-held data capture system with interchangeable modules |
US5282222A (en) * | 1992-03-31 | 1994-01-25 | Michel Fattouche | Method and apparatus for multiple access between transceivers in wireless communications using OFDM spread spectrum |
US5291516A (en) * | 1991-05-13 | 1994-03-01 | Omnipoint Data Company, Inc. | Dual mode transmitter and receiver |
US5297144A (en) * | 1991-01-22 | 1994-03-22 | Spectrix Corporation | Reservation-based polling protocol for a wireless data communications network |
US5321542A (en) * | 1990-10-29 | 1994-06-14 | International Business Machines Corporation | Control method and apparatus for wireless data link |
US5390166A (en) * | 1993-07-14 | 1995-02-14 | Motorola, Inc. | Method for recovering a data signal using diversity in a radio frequency, time division multiple access communication system |
US5404375A (en) * | 1993-08-23 | 1995-04-04 | Westinghouse Electric Corp. | Process and apparatus for satellite data communication |
US5410752A (en) * | 1992-09-30 | 1995-04-25 | Scholefield; Christopher | Hybrid data communications system and method employing multiple sub-networks |
US5410141A (en) * | 1989-06-07 | 1995-04-25 | Norand | Hand-held data capture system with interchangable modules |
US5410740A (en) * | 1993-03-24 | 1995-04-25 | Telefonaktiebolaget L M Ericsson | Control of a radio communications system base station |
US5513184A (en) * | 1991-02-28 | 1996-04-30 | At&T Corp. | Wireless communication system |
US5525621A (en) * | 1994-05-20 | 1996-06-11 | Cytos Pharmaceuticals Llc | Imidazole derivatives as protective agents in reperfusion injury and severe inflammatory responses |
US5528621A (en) * | 1989-06-29 | 1996-06-18 | Symbol Technologies, Inc. | Packet data communication system |
US5572516A (en) * | 1994-01-31 | 1996-11-05 | Matsushita Electric Industrial Co., Ltd. | Mobile unit communication system |
US5619530A (en) * | 1994-04-04 | 1997-04-08 | Motorola, Inc. | Method and apparatus for detecting and handling collisions in a radio communication system |
US5734645A (en) * | 1993-11-01 | 1998-03-31 | Telefonaktiebolaget Lm Ericsson | Layer 2 protocol in a cellular communication system |
US5748621A (en) * | 1995-03-10 | 1998-05-05 | Kabushiki Kaisha Toshiba | Digital mobile communication system |
US5768267A (en) * | 1995-10-18 | 1998-06-16 | Telefonaktiebolaget Lm Ericsson | Method for system registration and cell reselection |
US5887020A (en) * | 1991-05-13 | 1999-03-23 | Omnipoint Corporation | Multi-band, multi-mode spread-spectrum communication system |
US5896574A (en) * | 1996-10-09 | 1999-04-20 | International Business Machines Corporation | Wireless modem with a supplemental power source |
US6012634A (en) * | 1995-03-06 | 2000-01-11 | Motorola, Inc. | Dual card and method therefor |
US6026119A (en) * | 1994-06-15 | 2000-02-15 | Motorola, Inc. | Wireless packet data communications modem and method of use therein |
US6035216A (en) * | 1997-06-12 | 2000-03-07 | Acer Peripherals, Inc. | Device for receiving a SIM card for portable telephone set |
US6049536A (en) * | 1996-06-05 | 2000-04-11 | Hitachi, Ltd. | CDMA communication method and spread spectrum communication system |
US6188720B1 (en) * | 1995-05-12 | 2001-02-13 | Itt Manufacturing Enterprises, Inc. | Modulation and signaling converter |
US6223053B1 (en) * | 1996-06-26 | 2001-04-24 | Cisco Systems, Inc. | Universal radio for use in various cellular communication systems |
US6404393B1 (en) * | 2000-10-04 | 2002-06-11 | 3Com Corporation | Embedded antenna in a type II PCMCIA card |
US6531985B1 (en) * | 2000-08-14 | 2003-03-11 | 3Com Corporation | Integrated laptop antenna using two or more antennas |
US6539207B1 (en) * | 2000-06-27 | 2003-03-25 | Symbol Technologies, Inc. | Component for a wireless communications equipment card |
US6697415B1 (en) * | 1996-06-03 | 2004-02-24 | Broadcom Corporation | Spread spectrum transceiver module utilizing multiple mode transmission |
US6714983B1 (en) * | 1989-04-14 | 2004-03-30 | Broadcom Corporation | Modular, portable data processing terminal for use in a communication network |
US6717801B1 (en) * | 2000-09-29 | 2004-04-06 | Hewlett-Packard Development Company, L.P. | Standardized RF module insert for a portable electronic processing device |
US6757523B2 (en) * | 2000-03-31 | 2004-06-29 | Zeus Wireless, Inc. | Configuration of transmit/receive switching in a transceiver |
US6865216B1 (en) * | 1998-08-20 | 2005-03-08 | Skyworks Solutions Inc. | Frequency hopping spread spectrum modulation and direct sequence spread spectrum modulation cordless telephone |
US7024223B1 (en) * | 2001-03-05 | 2006-04-04 | Novatel Wireless, Inc. | Systems and methods for a multi-platform wireless modem |
US7024224B2 (en) * | 2002-03-05 | 2006-04-04 | Microsoft Corporation | Detachable radio module |
US7044387B2 (en) * | 2002-09-05 | 2006-05-16 | Honeywell International Inc. | RFID tag and communication protocol for long range tag communications and power efficiency |
US7171237B2 (en) * | 2001-05-31 | 2007-01-30 | Cts Corporation | Modular transceiver-modem with reduced profile antenna duplexer |
US7194283B2 (en) * | 2002-08-14 | 2007-03-20 | Intel Corporation | Method and apparatus for communication using multiple communication protocols |
Family Cites Families (95)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3826900A (en) | 1972-10-13 | 1974-07-30 | Ncr | Cordless scanning probe |
US4058838A (en) | 1976-11-10 | 1977-11-15 | International Telephone And Telegraph Corporation | Packet-switched facsimile communications system |
US4115870A (en) | 1976-11-18 | 1978-09-19 | Wordsmith, Inc. | Hand-held data processing terminal |
JPS53138254A (en) | 1977-05-06 | 1978-12-02 | Triumph Werke Nuernberg Ag | Pocket type computer |
JPS5424543A (en) | 1977-07-26 | 1979-02-23 | Nippon Denso Co Ltd | Bar code reader |
US4277837A (en) | 1977-12-30 | 1981-07-07 | International Business Machines Corporation | Personal portable terminal for financial transactions |
US4165554A (en) | 1978-06-12 | 1979-08-28 | Faget Charles J | Hand-held portable calculator assembly |
US4282425A (en) | 1979-07-25 | 1981-08-04 | Norand Corporation | Instant portable bar code reader |
SE419908B (en) | 1980-01-17 | 1981-08-31 | Micronic Ab | KOMMUNIKATIONSLENK |
US4628193A (en) | 1980-01-30 | 1986-12-09 | Blum Alvin S | Code reading operations supervisor |
US4415065A (en) | 1980-11-17 | 1983-11-15 | Sandstedt Gary O | Restaurant or retail vending facility |
DE3043557C2 (en) | 1980-11-19 | 1987-12-23 | Hartmut 6900 Heidelberg Bernot | Device for acquiring, transmitting and processing data in optically readable codes |
US4414661A (en) | 1981-07-02 | 1983-11-08 | Trancom Ab | Apparatus for communicating with a fleet of vehicles |
US4422745A (en) | 1981-07-31 | 1983-12-27 | National School Studios, Inc. | Camera system |
US4766300A (en) | 1984-08-06 | 1988-08-23 | Norand Corporation | Instant portable bar code reader |
US4758717A (en) | 1982-01-25 | 1988-07-19 | Symbol Technologies, Inc. | Narrow-bodied, single-and twin-windowed portable laser scanning head for reading bar code symbols |
US4845350B1 (en) | 1982-01-25 | 1991-04-30 | Narrow-bodied,single-and twin-windowed portable laser scanning head for reading bar code symbols | |
US4460120A (en) | 1982-01-25 | 1984-07-17 | Symbol Technologies, Inc. | Narrow bodied, single- and twin-windowed portable laser scanning head for reading bar code symbols |
JPS58219661A (en) | 1982-06-15 | 1983-12-21 | Sharp Corp | Card-shaped electronic calculator |
US4488679A (en) | 1982-11-01 | 1984-12-18 | Western Publishing Company, Inc. | Code and reading system |
US4603262A (en) | 1983-08-22 | 1986-07-29 | Optel Systems Inc. | Optical device for detecting coded symbols |
US4689761A (en) | 1984-08-14 | 1987-08-25 | Metaphor Computer Systems | Multiple independent input peripherals |
US4773032A (en) | 1984-11-20 | 1988-09-20 | Fujitsu Limited | Terminal input apparatus |
DE3513817A1 (en) | 1985-04-17 | 1986-10-23 | Preh, Elektrofeinmechanische Werke Jakob Preh Nachf. Gmbh & Co, 8740 Bad Neustadt | REMOTE CONTROL TRANSMITTER HOUSING |
USD299234S (en) | 1985-05-17 | 1989-01-03 | Kabushiki Kaisha Toshiba | Data entry terminal for electronic computers |
JPS624046A (en) | 1985-06-26 | 1987-01-10 | 株式会社 サト− | Unit type thermal lebel printer |
GB8521159D0 (en) | 1985-08-23 | 1985-10-02 | Pa Consulting Services | Two-way radio communications system |
US4621189A (en) | 1985-10-08 | 1986-11-04 | Telxon Corporation | Hand held data entry apparatus |
US4857716A (en) | 1986-05-12 | 1989-08-15 | Clinicom Incorporated | Patient identification and verification system and method |
US4850009A (en) | 1986-05-12 | 1989-07-18 | Clinicom Incorporated | Portable handheld terminal including optical bar code reader and electromagnetic transceiver means for interactive wireless communication with a base communications station |
JP2538878B2 (en) | 1986-05-26 | 1996-10-02 | 株式会社東芝 | Information input device and method for controlling character entry area in information input device |
US4972496A (en) | 1986-07-25 | 1990-11-20 | Grid Systems Corporation | Handwritten keyboardless entry computer system |
US5227614A (en) | 1986-08-15 | 1993-07-13 | Norand Corporation | Core computer processor module, and peripheral shell module assembled to form a pocket size data capture unit |
US4877949A (en) | 1986-08-08 | 1989-10-31 | Norand Corporation | Hand-held instant bar code reader system with automated focus based on distance measurements |
USD303112S (en) | 1986-08-20 | 1989-08-29 | Universal Data Incorporated | Portable hand held data entry terminal |
US5059778A (en) | 1986-09-29 | 1991-10-22 | Mars Incorporated | Portable data scanner apparatus |
US4703161A (en) | 1986-09-30 | 1987-10-27 | Mclean Roger D | Ruggedized calculator |
CA1290020C (en) | 1987-02-09 | 1991-10-01 | Steven Messenger | Wireless local area network |
GB2201125A (en) | 1987-02-16 | 1988-08-24 | De La Rue Syst | Verification device |
US4953113A (en) | 1987-10-02 | 1990-08-28 | Chadima Jr George E | Hand-held computerized data collection terminal with indented gripconforming configuration |
US4793812A (en) | 1987-10-05 | 1988-12-27 | Xerox Corporation | Hand held optical scanner for omni-font character recognition |
EP0345337A4 (en) | 1987-12-07 | 1991-12-18 | Bt Telecom, Inc. | System for interfacing an alarm reporting device with a cellular radio transceiver |
US4942356A (en) | 1988-05-12 | 1990-07-17 | Snap-On Tools Corporation | Modular electronic device |
US4881839A (en) | 1988-06-14 | 1989-11-21 | Texas Instruments Incorporated | Portable electronic data handling/data entry system |
US5070536A (en) | 1988-08-04 | 1991-12-03 | Norand Corporation | Mobile radio data communication system and method |
US4940974A (en) | 1988-11-01 | 1990-07-10 | Norand Corporation | Multiterminal communication system and method |
JPH02210522A (en) | 1989-02-10 | 1990-08-21 | Toshiba Corp | Personal computer |
US4979183A (en) * | 1989-03-23 | 1990-12-18 | Echelon Systems Corporation | Transceiver employing direct sequence spread spectrum techniques |
US5708833A (en) * | 1993-04-27 | 1998-01-13 | Norand Corporation | Antenna cap, antenna connectors and telephone line connectors for computer devices utilizing radio and modem cards |
US6014705A (en) * | 1991-10-01 | 2000-01-11 | Intermec Ip Corp. | Modular portable data processing terminal having a higher layer and lower layer partitioned communication protocol stack for use in a radio frequency communications network |
JP2781227B2 (en) * | 1989-06-30 | 1998-07-30 | 株式会社リコー | Group 4 facsimile communication adapter device |
JP2720076B2 (en) | 1989-07-17 | 1998-02-25 | 京セラ株式会社 | Automatic calibration device for direct spread spectrum receiver |
US4967188A (en) | 1989-07-26 | 1990-10-30 | Ncr Corporation | Method for detecting low battery voltage in portable scanning systems |
US5046130A (en) | 1989-08-08 | 1991-09-03 | Motorola, Inc. | Multiple communication path compatible automatic vehicle location unit |
JPH0334186U (en) | 1989-08-08 | 1991-04-03 | ||
US5049862A (en) | 1989-10-06 | 1991-09-17 | Communication Intelligence Corporation ("Cic") | Keyless flat panel portable computer--computer aided notebook |
GB9019489D0 (en) | 1990-09-06 | 1990-10-24 | Ncr Co | Antenna control for a wireless local area network station |
US5142534A (en) | 1990-10-17 | 1992-08-25 | O'neill Communications, Inc. | Wireless integrated voice-data communication system |
US5179572A (en) * | 1991-06-17 | 1993-01-12 | Scs Mobilecom, Inc. | Spread spectrum conference calling system and method |
US5351269A (en) * | 1990-12-05 | 1994-09-27 | Scs Mobilecom, Inc. | Overlaying spread spectrum CDMA personal communications system |
US5228056A (en) * | 1990-12-14 | 1993-07-13 | Interdigital Technology Corporation | Synchronous spread-spectrum communications system and method |
US5365544A (en) * | 1990-12-05 | 1994-11-15 | Interdigital Technology Corporation | CDMA communications and geolocation system and method |
US5790587A (en) | 1991-05-13 | 1998-08-04 | Omnipoint Corporation | Multi-band, multi-mode spread-spectrum communication system |
US5708680A (en) | 1991-05-14 | 1998-01-13 | Norand Corporation | Network utilizing a controller and base transceivers to route voice packets |
US5285469A (en) * | 1991-06-03 | 1994-02-08 | Omnipoint Data Corporation | Spread spectrum wireless telephone system |
JP2949533B2 (en) | 1991-09-03 | 1999-09-13 | 日本電信電話株式会社 | Mobile communication wireless zone configuration method |
US5268933A (en) | 1991-09-27 | 1993-12-07 | Motorola, Inc. | Data packet alignment in a communication system |
WO1993012597A1 (en) * | 1991-12-16 | 1993-06-24 | Omnipoint Corporation | Spread-spectrum data publishing system |
US5561845A (en) | 1992-10-02 | 1996-10-01 | Orion Industries, Inc. | Apparatus and method for preserving coverage in an overlapping coverage area |
EP0599244B1 (en) * | 1992-11-27 | 1999-04-14 | Denso Corporation | Portable electronic device |
US5373149A (en) * | 1993-02-01 | 1994-12-13 | At&T Bell Laboratories | Folding electronic card assembly |
US5440244A (en) * | 1993-02-10 | 1995-08-08 | Cirrus Logic, Inc. | Method and apparatus for controlling a mixed voltage interface in a multivoltage system |
US5363401A (en) | 1993-02-25 | 1994-11-08 | Harris Corporation | Mechanism for extracting hybrid (fh/ds) spread spectrum signals within multi-signal type environment |
JPH06261043A (en) | 1993-03-05 | 1994-09-16 | Hitachi Ltd | Radio channel lan system and its control method |
US6928302B1 (en) * | 1993-04-27 | 2005-08-09 | Broadcom Corporation | Radio card having independent antenna interface supporting antenna diversity |
US5363402A (en) | 1993-09-08 | 1994-11-08 | Rockwell International Corp. | HF radio apparatus operable in multiple communication modes |
GB9321657D0 (en) | 1993-10-20 | 1993-12-08 | Ncr Int Inc | Power management system for a wireless network |
US5960344A (en) | 1993-12-20 | 1999-09-28 | Norand Corporation | Local area network having multiple channel wireless access |
US5546397A (en) | 1993-12-20 | 1996-08-13 | Norand Corporation | High reliability access point for wireless local area network |
US6295031B1 (en) * | 1993-12-23 | 2001-09-25 | Symbol Technologies, Inc. | Memory card assembly having an integral antenna |
DE69433872T2 (en) | 1994-10-26 | 2005-07-14 | International Business Machines Corp. | Medium access control scheme for wireless local area networks with interleaved variable length time division frames |
JP2842267B2 (en) * | 1994-12-30 | 1998-12-24 | 日本電気株式会社 | Portable radio |
US5574747A (en) * | 1995-01-04 | 1996-11-12 | Interdigital Technology Corporation | Spread spectrum adaptive power control system and method |
US5781612A (en) * | 1995-03-10 | 1998-07-14 | Northern Telecom Limited | Radio terminal interfaces for voice and data telecommunications, and methods for their operation |
US5937348A (en) * | 1995-10-05 | 1999-08-10 | International Business Machines Corporation | Cordless communication system for a portable computer modem |
US6005884A (en) * | 1995-11-06 | 1999-12-21 | Ems Technologies, Inc. | Distributed architecture for a wireless data communications system |
US6047165A (en) * | 1995-11-14 | 2000-04-04 | Harris Corporation | Wireless, frequency-agile spread spectrum ground link-based aircraft data communication system |
US5822362A (en) * | 1996-03-15 | 1998-10-13 | Aironet Wireless Communications, Inc. | Sinusoidal phase modulation method and system |
JP3063648B2 (en) * | 1996-10-28 | 2000-07-12 | ケイディディ株式会社 | Spread spectrum communication system |
US5832026A (en) * | 1996-12-04 | 1998-11-03 | Motorola, Inc. | Method for correcting errors from a fading signal in a frequency hopped spread spectrum communcation system |
US5926501A (en) * | 1996-12-12 | 1999-07-20 | Motorola, Inc. | Method and apparatus for dynamic channel configuration |
US6138010A (en) * | 1997-05-08 | 2000-10-24 | Motorola, Inc. | Multimode communication device and method for operating a multimode communication device |
US6618580B2 (en) * | 2000-02-14 | 2003-09-09 | Intel Corporation | Apparatus and method for remotely powering-down a wireless transceiver |
US7079847B2 (en) * | 2001-03-21 | 2006-07-18 | Agere Systems Inc. | Controller and transceiver employable in a wireless communications network |
KR20060039392A (en) * | 2003-04-16 | 2006-05-08 | 메모리 파마슈티칼스 코포레이션 | Phosphodiesterase 4 inhibitors |
-
1996
- 1996-06-03 US US08/973,195 patent/US6697415B1/en not_active Expired - Lifetime
-
2003
- 2003-10-14 US US10/684,650 patent/US7676198B2/en not_active Expired - Fee Related
- 2003-10-14 US US10/684,747 patent/US20040077353A1/en not_active Abandoned
-
2010
- 2010-03-09 US US12/720,231 patent/US20100158077A1/en not_active Abandoned
Patent Citations (101)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3665164A (en) * | 1970-07-09 | 1972-05-23 | Ricca Data Systems Inc | Apparatus for reading optically cardlike elements and a merchandising system utilizing the same |
US4002892A (en) * | 1973-09-15 | 1977-01-11 | Zielinski Adolf H | Portable calculator |
US3947817A (en) * | 1974-01-07 | 1976-03-30 | Recognition Equipment Incorporated | Hand operated optical character recognition wand |
US4005400A (en) * | 1974-04-30 | 1977-01-25 | Societe Suisse Pour L'industrie Horologere Management Services S.A. | Data entry and decoding system for scripted data |
US4017725A (en) * | 1975-01-03 | 1977-04-12 | Litton Business Systems, Inc. | Solar powered portable calculator |
US4020527A (en) * | 1976-01-02 | 1977-05-03 | Neill Wilbur J O | Grip for a hand held portable device |
US4091270A (en) * | 1976-07-19 | 1978-05-23 | Hewlett-Packard Company | Electronic calculator with optical input means |
US4136821A (en) * | 1976-09-01 | 1979-01-30 | Nippondenso Co., Ltd. | Method and apparatus for recognizing code information |
US4158194A (en) * | 1976-12-27 | 1979-06-12 | Recognition Equipment Incorporated | Optical recognition system |
US4158130A (en) * | 1977-05-09 | 1979-06-12 | Ncr Corporation | Interchangeable auxiliary keyboard |
US4133034A (en) * | 1977-07-27 | 1979-01-02 | Etter Berwyn E | Method and means of assimilating utility meter data |
US4133034B1 (en) * | 1977-07-27 | 1986-08-19 | ||
US4141492A (en) * | 1977-10-03 | 1979-02-27 | R. R. Donnelley & Sons, Inc. | Signature verifier with indicia sensor |
US4188103A (en) * | 1978-04-21 | 1980-02-12 | Polaroid Corporation | Range synchronized flash photographic apparatus and method for achieving optimum flash exposure |
US4247908A (en) * | 1978-12-08 | 1981-01-27 | Motorola, Inc. | Re-linked portable data terminal controller system |
US4322612A (en) * | 1979-10-22 | 1982-03-30 | General Instrument Corporation | Self-service wagering system |
US4523297A (en) * | 1980-05-30 | 1985-06-11 | Compagnie Internationale Pour L'informatique Cii-Honeywell Bull | Hand-held processor with two-way dialog between microprocessor in case and microprocessor on carrier insertable into casing slot |
US4569421A (en) * | 1980-11-17 | 1986-02-11 | Sandstedt Gary O | Restaurant or retail vending facility |
US4385285A (en) * | 1981-04-02 | 1983-05-24 | Ncr Corporation | Check dispensing terminal |
US4523087A (en) * | 1981-04-07 | 1985-06-11 | Benton William M | Transaction verification system using optical coupling data communication link |
US4511970A (en) * | 1981-04-08 | 1985-04-16 | Hitachi, Ltd. | Portable terminal device |
US4570057A (en) * | 1981-12-28 | 1986-02-11 | Norand Corporation | Instant portable bar code reader |
US4749353A (en) * | 1982-05-13 | 1988-06-07 | Texas Instruments Incorporated | Talking electronic learning aid for improvement of spelling with operator-controlled word list |
US4506344A (en) * | 1982-06-04 | 1985-03-19 | Pitney Bowes Inc. | Hand held electronic postage meter having secure postage meter doors |
US4890832A (en) * | 1982-10-13 | 1990-01-02 | Sharp Kabushiki Kaisha | Compact electronic apparatus with removable processing units |
US4500776A (en) * | 1982-11-08 | 1985-02-19 | Vadim Laser | Method and apparatus for remotely reading and decoding bar codes |
US4641292A (en) * | 1983-06-20 | 1987-02-03 | George Tunnell | Voice controlled welding system |
US4519068A (en) * | 1983-07-11 | 1985-05-21 | Motorola, Inc. | Method and apparatus for communicating variable length messages between a primary station and remote stations of a data communications system |
US4578571A (en) * | 1983-11-14 | 1986-03-25 | Numa Corporation | Portable bar code scanning device and method |
US4654818A (en) * | 1983-12-16 | 1987-03-31 | Texas Instruments Incorporated | Data processing device having memory selectively interfacing with computer |
US4752965A (en) * | 1984-02-24 | 1988-06-21 | The De La Rue Company Plc | Sign verification |
US4743773A (en) * | 1984-08-23 | 1988-05-10 | Nippon Electric Industry Co., Ltd. | Bar code scanner with diffusion filter and plural linear light source arrays |
US4661993A (en) * | 1984-10-12 | 1987-04-28 | At&T Company | Technique for improving radio system performance during fading |
US5012407A (en) * | 1984-12-11 | 1991-04-30 | Finn Charles A | Computer system which accesses operating system information and command handlers from optical storage via an auxiliary processor and cache memory |
US4634845A (en) * | 1984-12-24 | 1987-01-06 | Ncr Corporation | Portable personal terminal for use in a system for handling transactions |
US4734566A (en) * | 1985-02-19 | 1988-03-29 | Nippondenso Co., Ltd. | Apparatus and method for recognizing optical information |
US4825057A (en) * | 1985-02-28 | 1989-04-25 | Symbol Technologies, Inc. | Portable laser diode scanning head |
US4897532A (en) * | 1985-02-28 | 1990-01-30 | Symbol Technologies, Inc. | Portable laser diode scanning head |
USD295411S (en) * | 1985-03-15 | 1988-04-26 | American Telephone And Telegraph Company, At&T Bell Laboratories | Combined voice and data terminal or similar article |
US4835372A (en) * | 1985-07-19 | 1989-05-30 | Clincom Incorporated | Patient care system |
US4718103A (en) * | 1985-10-08 | 1988-01-05 | Hitachi, Ltd. | Method and apparatus for on-line recognizing handwritten patterns |
US4718110A (en) * | 1985-10-24 | 1988-01-05 | General Electric Company | Portable two way radio with split universal device connector apparatus |
US4727245A (en) * | 1986-10-14 | 1988-02-23 | Mars, Inc. | Portable data scanner with removable modular printer |
US4831275A (en) * | 1986-11-12 | 1989-05-16 | Quential, Inc. | Method and means for self-referencing and self-focusing a bar-code reader |
US4836256A (en) * | 1987-01-30 | 1989-06-06 | Meliconi S.R.L. | Shockproof protective sheath for remote controls, in particular those of television receivers |
US4842966A (en) * | 1987-03-31 | 1989-06-27 | Mitsubishi Denki Kabushiki Kaisha | Battery holder mechanism |
US4837858A (en) * | 1987-04-30 | 1989-06-06 | Motorola, Inc. | Subscriber unit for a trunked voice/data communication system |
US5023824A (en) * | 1987-10-02 | 1991-06-11 | Norand Corporation | Hand-held computerized data collection terminal with indented hand grip and conforming battery drawer |
US4910775A (en) * | 1988-04-21 | 1990-03-20 | Telecash | Portable electronic device for use in conjunction with a screen |
US5117501A (en) * | 1988-08-08 | 1992-05-26 | General Electric Company | Dynamic regrouping in a trunked radio communications system |
US4916441A (en) * | 1988-09-19 | 1990-04-10 | Clinicom Incorporated | Portable handheld terminal |
US4984247A (en) * | 1988-09-29 | 1991-01-08 | Ascom Zelcom Ag | Digital radio transmission system for a cellular network, using the spread spectrum method |
US5097484A (en) * | 1988-10-12 | 1992-03-17 | Sumitomo Electric Industries, Ltd. | Diversity transmission and reception method and equipment |
US5008879B1 (en) * | 1988-11-14 | 2000-05-30 | Datapoint Corp | Lan with interoperative multiple operational capabilities |
US5008879A (en) * | 1988-11-14 | 1991-04-16 | Datapoint Corporation | LAN with interoperative multiple operational capabilities |
US4983818A (en) * | 1989-01-30 | 1991-01-08 | Metrologic Instruments, Inc. | Data acquisition system with laser scanner module |
US5216233A (en) * | 1989-03-09 | 1993-06-01 | Norand Corporation | Versatile RF terminal-scanner system |
US5022046A (en) * | 1989-04-14 | 1991-06-04 | The United States Of America As Represented By The Secretary Of The Air Force | Narrowband/wideband packet data communication system |
US6714983B1 (en) * | 1989-04-14 | 2004-03-30 | Broadcom Corporation | Modular, portable data processing terminal for use in a communication network |
US5410141A (en) * | 1989-06-07 | 1995-04-25 | Norand | Hand-held data capture system with interchangable modules |
US5202817A (en) * | 1989-06-07 | 1993-04-13 | Norand Corporation | Hand-held data capture system with interchangeable modules |
US5002184A (en) * | 1989-06-12 | 1991-03-26 | Grid Systems Corporation | Soft case protection for a hand held computer |
US5528621A (en) * | 1989-06-29 | 1996-06-18 | Symbol Technologies, Inc. | Packet data communication system |
US5101406A (en) * | 1989-08-24 | 1992-03-31 | Telesystems Slw Inc. | Wireless communications system |
US5218187A (en) * | 1990-01-18 | 1993-06-08 | Norand Corporation | Hand-held data capture system with interchangeable modules |
US5181200A (en) * | 1990-10-29 | 1993-01-19 | International Business Machines Corporation | Handoff method and apparatus for mobile wireless workstation |
US5321542A (en) * | 1990-10-29 | 1994-06-14 | International Business Machines Corporation | Control method and apparatus for wireless data link |
US5297144A (en) * | 1991-01-22 | 1994-03-22 | Spectrix Corporation | Reservation-based polling protocol for a wireless data communications network |
US5513184A (en) * | 1991-02-28 | 1996-04-30 | At&T Corp. | Wireless communication system |
US5887020A (en) * | 1991-05-13 | 1999-03-23 | Omnipoint Corporation | Multi-band, multi-mode spread-spectrum communication system |
US5291516A (en) * | 1991-05-13 | 1994-03-01 | Omnipoint Data Company, Inc. | Dual mode transmitter and receiver |
US5282222A (en) * | 1992-03-31 | 1994-01-25 | Michel Fattouche | Method and apparatus for multiple access between transceivers in wireless communications using OFDM spread spectrum |
US5410752A (en) * | 1992-09-30 | 1995-04-25 | Scholefield; Christopher | Hybrid data communications system and method employing multiple sub-networks |
US5410740A (en) * | 1993-03-24 | 1995-04-25 | Telefonaktiebolaget L M Ericsson | Control of a radio communications system base station |
US5390166A (en) * | 1993-07-14 | 1995-02-14 | Motorola, Inc. | Method for recovering a data signal using diversity in a radio frequency, time division multiple access communication system |
US5404375A (en) * | 1993-08-23 | 1995-04-04 | Westinghouse Electric Corp. | Process and apparatus for satellite data communication |
US5734645A (en) * | 1993-11-01 | 1998-03-31 | Telefonaktiebolaget Lm Ericsson | Layer 2 protocol in a cellular communication system |
US5572516A (en) * | 1994-01-31 | 1996-11-05 | Matsushita Electric Industrial Co., Ltd. | Mobile unit communication system |
US5619530A (en) * | 1994-04-04 | 1997-04-08 | Motorola, Inc. | Method and apparatus for detecting and handling collisions in a radio communication system |
US5525621A (en) * | 1994-05-20 | 1996-06-11 | Cytos Pharmaceuticals Llc | Imidazole derivatives as protective agents in reperfusion injury and severe inflammatory responses |
US6026119A (en) * | 1994-06-15 | 2000-02-15 | Motorola, Inc. | Wireless packet data communications modem and method of use therein |
US6012634A (en) * | 1995-03-06 | 2000-01-11 | Motorola, Inc. | Dual card and method therefor |
US5748621A (en) * | 1995-03-10 | 1998-05-05 | Kabushiki Kaisha Toshiba | Digital mobile communication system |
US6188720B1 (en) * | 1995-05-12 | 2001-02-13 | Itt Manufacturing Enterprises, Inc. | Modulation and signaling converter |
US5768267A (en) * | 1995-10-18 | 1998-06-16 | Telefonaktiebolaget Lm Ericsson | Method for system registration and cell reselection |
US6697415B1 (en) * | 1996-06-03 | 2004-02-24 | Broadcom Corporation | Spread spectrum transceiver module utilizing multiple mode transmission |
US6049536A (en) * | 1996-06-05 | 2000-04-11 | Hitachi, Ltd. | CDMA communication method and spread spectrum communication system |
US6223053B1 (en) * | 1996-06-26 | 2001-04-24 | Cisco Systems, Inc. | Universal radio for use in various cellular communication systems |
US5896574A (en) * | 1996-10-09 | 1999-04-20 | International Business Machines Corporation | Wireless modem with a supplemental power source |
US6035216A (en) * | 1997-06-12 | 2000-03-07 | Acer Peripherals, Inc. | Device for receiving a SIM card for portable telephone set |
US6865216B1 (en) * | 1998-08-20 | 2005-03-08 | Skyworks Solutions Inc. | Frequency hopping spread spectrum modulation and direct sequence spread spectrum modulation cordless telephone |
US6757523B2 (en) * | 2000-03-31 | 2004-06-29 | Zeus Wireless, Inc. | Configuration of transmit/receive switching in a transceiver |
US6539207B1 (en) * | 2000-06-27 | 2003-03-25 | Symbol Technologies, Inc. | Component for a wireless communications equipment card |
US6531985B1 (en) * | 2000-08-14 | 2003-03-11 | 3Com Corporation | Integrated laptop antenna using two or more antennas |
US6717801B1 (en) * | 2000-09-29 | 2004-04-06 | Hewlett-Packard Development Company, L.P. | Standardized RF module insert for a portable electronic processing device |
US6404393B1 (en) * | 2000-10-04 | 2002-06-11 | 3Com Corporation | Embedded antenna in a type II PCMCIA card |
US7024223B1 (en) * | 2001-03-05 | 2006-04-04 | Novatel Wireless, Inc. | Systems and methods for a multi-platform wireless modem |
US7171237B2 (en) * | 2001-05-31 | 2007-01-30 | Cts Corporation | Modular transceiver-modem with reduced profile antenna duplexer |
US7024224B2 (en) * | 2002-03-05 | 2006-04-04 | Microsoft Corporation | Detachable radio module |
US7194283B2 (en) * | 2002-08-14 | 2007-03-20 | Intel Corporation | Method and apparatus for communication using multiple communication protocols |
US7044387B2 (en) * | 2002-09-05 | 2006-05-16 | Honeywell International Inc. | RFID tag and communication protocol for long range tag communications and power efficiency |
Cited By (84)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9014205B2 (en) | 2000-06-09 | 2015-04-21 | Texas Instruments Incorporated | Wireless communications with frequency band selection |
US20020003792A1 (en) * | 2000-06-09 | 2002-01-10 | Schmidl Timothy M. | Wireless communications with frequency band selection |
US7050402B2 (en) * | 2000-06-09 | 2006-05-23 | Texas Instruments Incorporated | Wireless communications with frequency band selection |
US20080170556A1 (en) * | 2000-06-09 | 2008-07-17 | Schmidl Timothy M | Wireless communications with frequency band selection |
US20050078628A1 (en) * | 2000-08-08 | 2005-04-14 | Hitachi, Ltd | Base station transmitting data spread with a plurality of slots respective to a plurality of radio terminals and codes, and a cellular system thereof |
US20050078621A1 (en) * | 2000-08-08 | 2005-04-14 | Hitachi, Ltd | Base station transmitting data spread with a plurality of slots respective to a plurality of radio terminals and codes, and a cellular system thereof |
US20020037016A1 (en) * | 2000-08-08 | 2002-03-28 | Hitachi, Ltd. | Base station transmitting data spread with a plurality of slots respective to a plurality of radio terminals and codes, and a cellular system thereof |
US20020197984A1 (en) * | 2001-06-22 | 2002-12-26 | Tadlys Ltd. | Flexible wireless local networks |
US6907229B2 (en) * | 2002-05-06 | 2005-06-14 | Extricom Ltd. | Enhancing wireless LAN capacity using transmission power control |
US20030207699A1 (en) * | 2002-05-06 | 2003-11-06 | Extricom Ltd. | Enhancing wireless lan capacity using transmission power control |
US20040002366A1 (en) * | 2002-06-26 | 2004-01-01 | International Business Machines Corporation | Apparatus, method and program to optimize battery life in a wireless device |
US7003331B2 (en) * | 2002-06-26 | 2006-02-21 | Lenovo (Singapore) Pte. Ltd. | Apparatus, method and program to optimize battery life in a wireless device |
US7797016B2 (en) | 2002-08-07 | 2010-09-14 | Extricom Ltd. | Wireless LAN with central management of access points |
US20040042424A1 (en) * | 2002-08-30 | 2004-03-04 | Hsu Hsien-Tsung | Switch method and device thru MAC protocol for wireless network |
US7286844B1 (en) | 2003-01-31 | 2007-10-23 | Bbn Technologies Corp. | Systems and methods for three dimensional antenna selection and power control in an Ad-Hoc wireless network |
US8026849B2 (en) | 2003-01-31 | 2011-09-27 | Raytheon Bbn Technologies Corp. | Systems and methods for three dimensional antenna selection and power control in an ad-hoc wireless network |
US7542437B1 (en) | 2003-10-02 | 2009-06-02 | Bbn Technologies Corp. | Systems and methods for conserving energy in a communications network |
US8787965B2 (en) * | 2003-11-21 | 2014-07-22 | Nokia Corporation | Service discovery in a wireless communication system |
US20070135159A1 (en) * | 2003-11-21 | 2007-06-14 | Nokia Corporation | Service discovery in a wireless communication system |
US20050129093A1 (en) * | 2003-12-15 | 2005-06-16 | Jayasuriyar Rajanik M. | Digital communication system and method |
US7551892B1 (en) | 2004-02-26 | 2009-06-23 | Bbn Technologies Corp | Low-power ad hoc network entry |
US20080075119A1 (en) * | 2004-07-13 | 2008-03-27 | Yincheng Zhang | Method for Reporting the Frequency Resource Arrangement and Frequency Information of the Multi-Frequency Cell |
US8027292B2 (en) * | 2004-07-13 | 2011-09-27 | Zte Corporation | Method for reporting the frequency resource arrangement and frequency information of the multi-frequency cell |
US7330736B2 (en) * | 2004-12-17 | 2008-02-12 | Bbn Technologies Corp. | Methods and apparatus for reduced energy communication in an ad hoc network |
US8145201B2 (en) | 2004-12-17 | 2012-03-27 | Raytheon Bbn Technologies Corp. | Methods and apparatus for reduced energy communication in an ad hoc network |
US20060229083A1 (en) * | 2004-12-17 | 2006-10-12 | Bbn Technologies Corp. | Methods and apparatus for reduced energy communication in an ad hoc network |
US20060135145A1 (en) * | 2004-12-17 | 2006-06-22 | Bbnt Solutions Llc | Methods and apparatus for reduced energy communication in an ad hoc network |
US8111640B2 (en) | 2005-06-22 | 2012-02-07 | Knox Michael E | Antenna feed network for full duplex communication |
US20090028074A1 (en) * | 2005-06-22 | 2009-01-29 | Knox Michael E | Antenna feed network for full duplex communication |
US9780437B2 (en) | 2005-06-22 | 2017-10-03 | Michael E. Knox | Antenna feed network for full duplex communication |
US20070070983A1 (en) * | 2005-09-28 | 2007-03-29 | Bbn Technologies Corp. | Methods and apparatus for improved efficiency communication |
US7725096B2 (en) | 2005-10-03 | 2010-05-25 | Gigle Semiconductor Sl | Multi-wideband communications over power lines |
US8406239B2 (en) * | 2005-10-03 | 2013-03-26 | Broadcom Corporation | Multi-wideband communications over multiple mediums |
US20070075843A1 (en) * | 2005-10-03 | 2007-04-05 | Riveiro Juan C | Multi-Wideband Communications over Power Lines |
US20070076666A1 (en) * | 2005-10-03 | 2007-04-05 | Riveiro Juan C | Multi-Wideband Communications over Power Lines |
US20070229231A1 (en) * | 2005-10-03 | 2007-10-04 | Hurwitz Jonathan E D | Multi-Wideband Communications over Multiple Mediums within a Network |
US8213895B2 (en) | 2005-10-03 | 2012-07-03 | Broadcom Europe Limited | Multi-wideband communications over multiple mediums within a network |
US20080130640A1 (en) * | 2005-10-03 | 2008-06-05 | Jonathan Ephraim David Hurwitz | Multi-Wideband Communications over Multiple Mediums |
US7899436B2 (en) | 2005-10-03 | 2011-03-01 | Juan Carlos Riveiro | Multi-wideband communications over power lines |
US20090252209A1 (en) * | 2005-10-03 | 2009-10-08 | Juan Carlos Riveiro | Power Line Communication Networks and Methods employing Multiple Widebands |
US7877078B2 (en) | 2005-10-03 | 2011-01-25 | Juan Carlos Riveiro | Power line communication networks and methods employing multiple widebands |
US20090323829A1 (en) * | 2005-10-03 | 2009-12-31 | Juan Carlos Riveiro | Multi-Wideband Communications over Power Lines |
US7860146B2 (en) | 2006-07-06 | 2010-12-28 | Gigle Networks, Inc. | Adaptative multi-carrier code division multiple access |
US20080008081A1 (en) * | 2006-07-06 | 2008-01-10 | Gigle Semiconductor Inc. | Adaptative multi-carrier code division multiple access |
US8885814B2 (en) | 2006-07-25 | 2014-11-11 | Broadcom Europe Limited | Feedback impedance control for driving a signal |
US20080043992A1 (en) * | 2006-07-25 | 2008-02-21 | Gigle Semiconductor Inc. | Feedback impedance control for driving a signal |
US8149733B2 (en) | 2006-08-25 | 2012-04-03 | Raytheon Bbn Technologies Corp. | Systems and methods for synchronizing communication networks |
US7924728B2 (en) | 2006-08-25 | 2011-04-12 | Raytheon Bbn Technologies Corp | Systems and methods for energy-conscious communication in wireless ad-hoc networks |
US20080069036A1 (en) * | 2006-09-15 | 2008-03-20 | Samsung Electronics Co., Ltd. | Method for implementing clear channel assessment function in wireless mesh network and mobile terminal thereof |
WO2008064078A2 (en) * | 2006-11-17 | 2008-05-29 | Brent, Inc. | Method for using collaborative point-of-view management within an electronic forum |
US20080120376A1 (en) * | 2006-11-17 | 2008-05-22 | Brent, Inc. | Method for using collaborative point-of-view management within an electronic forum |
WO2008064078A3 (en) * | 2006-11-17 | 2008-08-21 | Brent Inc | Method for using collaborative point-of-view management within an electronic forum |
US8160970B2 (en) | 2006-11-17 | 2012-04-17 | Brent, Inc. | Method for using collaborative point-of-view management within an electronic forum |
US20080117896A1 (en) * | 2006-11-21 | 2008-05-22 | Veronica Romero | Network repeater |
US7808985B2 (en) | 2006-11-21 | 2010-10-05 | Gigle Networks Sl | Network repeater |
WO2008082638A1 (en) * | 2006-12-29 | 2008-07-10 | Knox Michael E | High isolation signal routing assembly for full duplex communication |
US20090268642A1 (en) * | 2006-12-29 | 2009-10-29 | Knox Michael E | High isolation signal routing assembly for full duplex communication |
US9413414B2 (en) | 2006-12-29 | 2016-08-09 | Mode-1 Corp. | High isolation signal routing assembly for full duplex communication |
US8077639B2 (en) | 2006-12-29 | 2011-12-13 | Knox Michael E | High isolation signal routing assembly for full duplex communication |
US20080159358A1 (en) * | 2007-01-02 | 2008-07-03 | David Ruiz | Unknown Destination Traffic Repetition |
US20080268859A1 (en) * | 2007-04-28 | 2008-10-30 | Nec Corporation | Method and device for resource allocation control in radio communications system |
US8688134B2 (en) * | 2007-04-28 | 2014-04-01 | Nec Corporation | Method and device for resource allocation control in radio communications system |
US8160505B2 (en) * | 2007-05-15 | 2012-04-17 | Sony Corporation | Wireless communication apparatus, program, wireless communication method and wireless communication system |
US20080287069A1 (en) * | 2007-05-15 | 2008-11-20 | Osamu Yoshimura | Wireless Communication Apparatus, Program, Wireless Communication Method and Wireless Communication System |
US20090129316A1 (en) * | 2007-08-20 | 2009-05-21 | Bbn Technologies Corp. | Systems and methods for adaptive routing in mobile ad-hoc networks and disruption tolerant networks |
US8149716B2 (en) | 2007-08-20 | 2012-04-03 | Raytheon Bbn Technologies Corp. | Systems and methods for adaptive routing in mobile ad-hoc networks and disruption tolerant networks |
US8111718B1 (en) | 2007-12-05 | 2012-02-07 | Clearwire IP Holdings, LLC | Communication system and method that reduces interference |
US8005161B2 (en) * | 2008-05-01 | 2011-08-23 | International Business Machines Corporation | Method, hardware product, and computer program product for performing high data rate wireless transmission |
US20090274221A1 (en) * | 2008-05-01 | 2009-11-05 | International Business Machines Corporation | Method, hardware product, and computer program product for performing high data rate wireless transmission |
US20100035562A1 (en) * | 2008-08-05 | 2010-02-11 | Motorola, Inc. | Method and System for Signal Processing and Transmission |
US7956689B2 (en) | 2008-10-13 | 2011-06-07 | Broadcom Corporation | Programmable gain amplifier and transconductance compensation system |
US20100117734A1 (en) * | 2008-10-13 | 2010-05-13 | Jonathan Ephraim David Hurwitz | Programmable Gain Amplifier and Transconductance Compensation System |
US7795973B2 (en) | 2008-10-13 | 2010-09-14 | Gigle Networks Ltd. | Programmable gain amplifier |
US8588844B2 (en) | 2010-11-04 | 2013-11-19 | Extricom Ltd. | MIMO search over multiple access points |
US9247506B2 (en) | 2011-04-08 | 2016-01-26 | Google Technology Holdings LLC | Method and apparatus for multi-radio coexistence on adjacent frequency bands |
US8724492B2 (en) | 2011-04-08 | 2014-05-13 | Motorola Mobility Llc | Method and apparatus for multi-radio coexistence on adjacent frequency bands |
US20120315899A1 (en) * | 2011-06-09 | 2012-12-13 | Celeno Communications (Israel) Ltd. | Device roaming in hybrid wi-fi/wireline and multi-ap networks |
US8548461B2 (en) * | 2011-06-09 | 2013-10-01 | Celeno Communications (Israel) Ltd | Device roaming in hybrid Wi-Fi/wireline and multi-AP networks |
US20130010719A1 (en) * | 2011-07-07 | 2013-01-10 | Nir Shapira | Method for managing the spectrum of a multi-band wireless communication system |
US10154502B2 (en) * | 2011-07-07 | 2018-12-11 | Celeno Communications Ltd. | Method for managing the spectrum of a multi-band wireless communication system |
US10075507B2 (en) | 2013-09-05 | 2018-09-11 | NCS Technologies, Inc. | Systems and methods providing a mobile zero client |
US20160218766A1 (en) * | 2015-01-28 | 2016-07-28 | Lam Research Corporation | Dual Push Between A Host Computer System And An RF Generator |
US9667303B2 (en) * | 2015-01-28 | 2017-05-30 | Lam Research Corporation | Dual push between a host computer system and an RF generator |
US20220223997A1 (en) * | 2021-01-13 | 2022-07-14 | Zebra Technologies Corporation | User-Installable Wireless Communications Module |
Also Published As
Publication number | Publication date |
---|---|
US6697415B1 (en) | 2004-02-24 |
US7676198B2 (en) | 2010-03-09 |
US20040077352A1 (en) | 2004-04-22 |
US20100158077A1 (en) | 2010-06-24 |
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