US20140301379A1 - Wireless rfid networking systems and methods - Google Patents

Wireless rfid networking systems and methods Download PDF

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Publication number
US20140301379A1
US20140301379A1 US14/245,939 US201414245939A US2014301379A1 US 20140301379 A1 US20140301379 A1 US 20140301379A1 US 201414245939 A US201414245939 A US 201414245939A US 2014301379 A1 US2014301379 A1 US 2014301379A1
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United States
Prior art keywords
rfid
access point
reader
wireless access
readers
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Abandoned
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US14/245,939
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Kambiz Shoarinejad
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Radiofy LLC
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Radiofy LLC
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Priority to US14/245,939 priority Critical patent/US20140301379A1/en
Publication of US20140301379A1 publication Critical patent/US20140301379A1/en
Priority to US15/399,695 priority patent/US10037445B2/en
Priority to US16/035,657 priority patent/US20190012496A1/en
Abandoned legal-status Critical Current

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/03Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
    • G01S19/05Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers providing aiding data
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10019Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
    • G06K7/10079Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/03Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
    • G01S19/09Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers providing processing capability normally carried out by the receiver
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06KGRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
    • G06K19/067Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
    • G06K19/07Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
    • G06K19/0723Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W60/00Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • H04W76/40Connection management for selective distribution or broadcast
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W84/00Network topologies
    • H04W84/18Self-organising networks, e.g. ad-hoc networks or sensor networks
    • H04W84/22Self-organising networks, e.g. ad-hoc networks or sensor networks with access to wired networks
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W88/00Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08Access point devices

Definitions

  • the present invention relates to radio frequency identification (“RFID”), and in particular, to wireless RFID networking systems and methods.
  • RFID radio frequency identification
  • RFID systems are useful in a wide variety of applications.
  • RFID systems are radio communication systems that include small low cost electronic devices that store information including identification (“ID”) information, for example. These devices are referred to as RFID tags.
  • the RFID tags may be designed using backscattering circuit techniques, for example, so that another device can retrieve the ID wirelessly.
  • the retrieving device is typically referred to as a “reader,” and sometimes “an interrogator.”
  • the tags are typically very small, and may be placed on a variety of items including equipment, products, or even people, for example, and identification of such items may be made through a reader. Accordingly, RFID systems may be used to track inventory in a warehouse, the number of products on store shelves, or the location of equipment in a company, to name just a few example applications.
  • RFID systems may include large numbers of tags and readers spread out across potentially wide areas.
  • the large number of tags and readers may result in a correspondingly large volume of information that may need to be processed.
  • Such information may include large volumes of tag IDs.
  • powerful readers are typically used that include complex software capable of interfacing with backend systems that store and ultimately use the data.
  • FIG. 1 is an example of a prior art RFID system.
  • Information from numerous RFID tags 101 A-C is received wirelessly by RFID readers 102 A-C.
  • Each RFID reader includes an RFID client software component 103 A-C (e.g., a Savant Client) that is designed to operate with an RFID central server software component 110 (e.g., a Savant Server) over a network 111 .
  • the central server 110 uses a client-server architecture for moving data between the readers and the server. Since all the RFID specific operations are included in two components, the readers are typically powerful systems that can work with the server to manage the data retrieved from the RFID tags.
  • the RFID central server is coupled to backend data storage and processing system 120 over network 150 .
  • Backend system 120 may be coupled to a database 130 for storing the RFID data, for example.
  • the present invention provides improved wireless RFID networking systems and methods.
  • Embodiments of the present invention include a wireless access point that acquires and processes radio frequency identification (RFID) information.
  • the wireless access point may be coupled to a network of RFID readers over a wireless network.
  • the RFID readers may read a plurality of RFID tags and transmit information to one or more readers.
  • the readers may, in turn, transmit the RFID information to a wireless access point.
  • the wireless access point may include a middleware layer for performing a variety of RFID data processing functions.
  • the wireless RFID reader network may be used to improve positioning of readers and tags, and may include a GPS system or position assisted GPS system at the reader and/or tag level.
  • a wireless access point includes a first physical layer interface, a second physical layer interface, and middleware software.
  • the first physical layer interfaces the wireless access point to a wireless link and communicates first RFID data to the wireless access point from a plurality of RFID readers.
  • the RFID readers read a plurality of RFID tags.
  • the first RFID data results from reading the RFID tags.
  • the second physical layer interfaces the wireless access point to a wired or wireless link and communicates second RFID data from the wireless access point to a server.
  • the middleware controls the wireless access point to receive and store tag information from the RFID tags. In this manner, the wireless access point offloads processing from the server.
  • the middleware controls the wireless access point to process the tag information prior to transmission to the server.
  • the middleware controls the wireless access point to estimate a position of a RFID tag.
  • the middleware controls the wireless access point to pre-process global positioning system (GPS) information for an RFID reader.
  • GPS global positioning system
  • FIG. 1 is an example of a prior art RFID system.
  • FIG. 2 illustrates an RFID network according to one embodiment of the present invention.
  • FIG. 3 illustrates an RFID network according to another embodiment of the present invention.
  • FIGS. 4A-F illustrate examples of RFID middleware on a wireless access point according to other embodiments of the present invention.
  • FIG. 5 illustrates a network configuration according to one embodiment of the present invention.
  • FIG. 6 illustrates a network configuration according to another embodiment of the present invention.
  • FIG. 7 illustrates a network configuration according to another embodiment of the present invention.
  • FIG. 8 illustrates the position of tags within the coverage area of a reader according to another embodiment of the present invention.
  • FIG. 9 illustrates the position of readers within the coverage area of an access point according to another embodiment of the present invention.
  • FIG. 10 illustrates tag positioning according to another embodiment of the present invention.
  • FIG. 11A illustrates determining tag position according to another embodiment of the present invention.
  • FIG. 11B illustrates a method of determining tag position according to another embodiment of the present invention.
  • FIG. 12 illustrates reader positioning according to another embodiment of the present invention.
  • FIG. 13A illustrates determining reader position according to another embodiment of the present invention.
  • FIG. 13B illustrates a method of determining reader position according to another embodiment of the present invention.
  • FIG. 14 illustrates an RFID network with integrated GPS according to another embodiment of the present invention.
  • FIG. 15 illustrates an RFID network with integrated GPS according to another embodiment of the present invention.
  • FIG. 2 illustrates an RFID network according to one embodiment of the present invention.
  • a plurality of RFID tags 201 A-C may receive signals from RFID readers 202 A-C.
  • the tags may be active or passive backscattering circuits (i.e., with or without an internal source of energy such as a battery), for example, or in some embodiments a more complex sensor network capable of wireless automatic identification.
  • the RFID tags will transmit information back to the readers.
  • Readers 202 A may include a variety of devices such as application specific readers, personal digital assistants, cell phones, or other handheld devices.
  • RFID readers 202 A-C are coupled together over a wireless network link 210 (i.e., a communication channel).
  • the wireless network link may be an 802.11 wireless network link, a Bluetooth network link, a Zigbee network link, cellular network link, backscattering link, or other wireless network link using radio frequency signals, for example.
  • RFID reader 202 A may communicate with wireless access point 220 A over a wireless network 210 .
  • RFID reader 202 C may communicate with wireless access point 220 B over a similar wireless network 210 .
  • the readers and wireless access points include physical layer circuits and systems for implementing the wireless transmissions, such as RF transceivers and baseband processors, for example.
  • an RFID reader may be within range of multiple access points.
  • RFID reader 202 B is within range of both access points 220 A and 220 B.
  • information from RFID reader 202 B may communicate wirelessly with both of access points 220 A and/or 220 B.
  • wireless access points 220 A and 220 B are coupled to a server computer 230 over a wired (e.g., Ethernet or RS-485) or wireless network 225 .
  • the wireless access points may be coupled to a central server over a wireless network (in which case the central server may act as a central access point).
  • the server computer 230 may, in turn, be coupled to backend applications and databases 260 over another network 250 , such as the Internet or an intranet, for example.
  • an application layer is added to wireless access points 220 A-B.
  • the application layer includes an access point middleware software component 221 that works with a middleware (“MW”) reader software component 203 to manage the network of RFID readers and related tags.
  • access point middleware 221 A-B may be used for tag or reader registration, tag or reader positioning, or network and data management.
  • Access point middleware 221 A-B may be used to hide the network of RFID readers behind the access point thereby making the network more flexible and reducing the processing burden on the server 230 .
  • server computer 230 includes a middleware host 231 that is part of a distributed middleware system for simplifying management of the reader network.
  • Server computer 230 may further include an RFID central server 232 that communicates with wireless access points 220 and applications 233 for managing and processing data associated with the RFIDs. Additionally, Access point software 221 A-B may be used to offload network management and data processing from the reader, which lowers the cost of the reader, and accordingly, the entire RFID network.
  • FIG. 3 illustrates an RFID network according to another embodiment of the present invention.
  • a plurality of RFID tags 301 A-D may receive signals from RFID readers 302 A-D. In response to the received signals, the RFID tags will transmit information back to the readers.
  • RFID readers 302 A-B are configured in a wireless network and communicate with wireless access point 320 A over a wireless communication channel 310 A
  • RFID readers 302 C-D are configured in a wireless network and communicate with wireless access point 320 B over a wireless communication channel 310 B.
  • Wireless access points 320 A and 320 B are coupled to a server computer 330 over a wired or wireless network 325 .
  • RFID readers 302 A-D include a middleware (“MW”) software component 303 A-D
  • the wireless access points 320 A-B include a middleware application layer component 321 A-B.
  • the access points 320 A-B further include RFID client software components 322 A-B.
  • Embodiments of the present invention may move software functions from the reader to software executed on an application layer on the access point.
  • the RFID clients 322 A-B perform transactions with an RFID central server software component 332 on server computer 330 . Accordingly, the software architecture in this example distributes RFID network processing across the entire network to reduce the processing burden on the reader and thereby reduce the overall cost of the network.
  • FIG. 4A illustrates an example of a network model for an RFID network according to another embodiment of the present invention.
  • This example shows the network model for a reader 410 , access point 420 , and server computer 430 .
  • the reader 410 and the access point 420 communicate over a wireless network link 490 .
  • the access point 420 and the server computer 420 communicate over a wired or wireless network link 491 .
  • the wired or wireless network link 491 may be, for example, a local area network connection such as Ethernet, an intranet, or a wide area network such as the Internet, or any of the wireless networks described above.
  • the network model for reader 410 includes a physical layer, data link layer, network layer, transport layer, and application layer.
  • the application layer may include a reader middleware software component (“Reader MW”) as described above.
  • the physical layer in this case is a wireless network link including a wireless receiver and transmitter coupled to an antenna.
  • Access point 420 includes a physical layer, data link layer, and network layer.
  • an access point 420 is provided that further includes a transport layer and application layer 421 for running access point middleware software 422 (“AP MW”) described above for preprocessing the RFID data.
  • the physical layer may include a wireless receiver and transmitter coupled to an antenna for communicating with one or more readers.
  • the physical layer may also support wired or wireless communication with another computer 430 (e.g., Ethernet).
  • the AP MW 422 coordinates the input of RFID information 422 received from the reader 410 , the storage of the RFID data in a storage unit 424 , and the output of RFID information 425 to be sent to the server computer 430 .
  • Such coordination includes functions such as monitoring and management of the reader 410 (referred to as device management), connectivity management of the connection between the access point 420 and the server 430 , connectivity management of the connection between the readers 410 and access point 420 , fault detection of failures or other problems with the reader 410 , maintenance and upgrades for the reader 410 , and data management (processing) of RFID information.
  • Such data processing may include data aggregation, data smoothing, data filtering, redundancy processing, multiprotocol format negotiation (for example, configuring the reader 410 to communicate with the RFID tags using different protocols, or responding to a request by the server 430 to read all tags having a certain set of protocols).
  • the access point 420 may include a processor, controller, micro-controller, programmable logic device, or other integrated circuit device that executes the AP MW 422 .
  • the storage unit 424 may be a memory, hard disk, or other type of storage system.
  • Server computer 430 includes a physical layer, data link layer, network layer, transport layer, and application layer.
  • the application layer on the server may include a central RFID server and other software for receiving and processing RFID applications.
  • FIG. 4B illustrates a method according to another embodiment of the present invention.
  • tag IDs are received in an application layer of a wireless access point on an input 423 of middleware 422 .
  • information associated with the tag IDs e.g., position information
  • the tag IDs are stored in a repository, such as a database or other data storage facility, for example.
  • the tag IDs and/or the associated information are processed by the middleware. As mentioned above, processing may include data or device monitoring or management, for example.
  • the tag IDs and/or the associated information are transmitted on middleware output 425 over a wired or wireless link 491 to a server 430 for further processing if desired.
  • FIG. 4C illustrates an RFID network according to another embodiment of the present invention.
  • a plurality of RFID tags 411 are located within a location (such as a building or warehouse) that is covered by a plurality of RFID readers 410 (labeled R1, R2, R3 and R4).
  • the RFID tags 411 may receive signals from the RFID readers 410 . In response to the received signals, the RFID tags 411 will transmit information back to the readers 410 .
  • the RFID readers 410 are configured in a wireless network and communicate with a wireless access point 420 over a wireless communication channel.
  • the wireless access point 420 is coupled to a server computer 430 over a wired or wireless network.
  • the access point 420 includes a MW software component (see above regarding FIG. 4A ) that in this case may be configured to offload redundancy processing from the server 430 , as discussed below with reference to FIG. 4D .
  • FIG. 4D illustrates redundancy offload processing according to another embodiment of the present invention.
  • the wireless access point 420 configures the readers 410 to cover a common location. Such configuration may include sequencing the readers 410 for reading operations (of the tags 411 ) or data transmission operations (to the access point 420 ) to manage the likelihood of interference.
  • the access point 420 may configure the reader R1 to read tags during a first time segment, the reader R2 to read tags during a second time segment, etc.
  • the access point 420 may configure the reader R1 to transmit its information to the access point 420 during a first time segment, the reader R2 to transmit its information during a second time segment, etc.
  • the access point 420 may configure the readers 410 to communicate with tags and/or the access point 420 at different frequencies.
  • communication between wireless access point 420 , readers 410 , and tags may be at different time slots and different frequencies.
  • Readers 410 may also use beamforming techniques and directional antennas to communicate with tags, for example, so different beams and/or different polarizations may also be used.
  • a particular RFID tag 411 may be in range of more than one of the readers 410 . Including more than one reader 410 allows for redundancy to improve reliability of the RFID system. For example, a particular RFID tag 411 may be blocked by shelving, etc. from receiving signals from the readers R1, R2 and R3, but may be situated such that it receives signals from the reader R4. As another example, if the reader R1 fails, the other readers R2, R3 and R4 are still operational, allowing the RFID system to continue to function.
  • the readers 410 receive the tag IDs from the tags 411 in the common area.
  • the readers 410 transmit the tag IDs from each reader to the wireless access point 420 .
  • the access point 420 may store the tag IDs in the repository 424 (see FIG. 4A ) along with an identifier that identifies which of the readers 410 read that tag.
  • the storage unit 424 may contain redundant tag data.
  • the access point 420 filters the redundant tag information.
  • the access point 420 sends the unique tag IDs to the server 430 . In this manner, the access point 420 offloads redundancy processing from the server 430 .
  • the server 430 need not be aware of the specifics of the configuration of the readers 410 .
  • FIG. 4E illustrates an RFID network according to another embodiment of the present invention.
  • a plurality of RFID readers 410 A, 410 B and 410 C and a plurality of RFID tags 411 A, 411 B and 411 C are located in an area.
  • the readers 410 A, 410 B and 410 C communicate with a wireless access point 420 over a wireless communication channel.
  • the readers 410 A, 410 B and 410 C have a range represented by “r” in the figure.
  • tag 411 B is within range of reader 410 B
  • tag 411 A is within range of reader 410 A
  • tag 411 C is within range of both reader 410 A and reader 410 C.
  • the readers 410 A, 410 B and 410 C are separated by a distance, represented in the figure by “d1” as the distance between the readers 410 A and 410 C, and by “d2” as the distance between the readers 410 A and 410 B.
  • the access point 420 includes a MW software component (see above regarding FIG. 4A ) that in this case may be configured to offload read request processing from the server 430 , as discussed below with reference to FIG. 4F .
  • FIG. 4F illustrates read request offload processing according to another embodiment of the present invention.
  • the access point 420 determines the position of the readers within range of the access point.
  • the readers 410 A, 410 B and 410 C are within range of the access point 420 .
  • the access point may use a variety of techniques for determining the position of the readers, as discussed below.
  • the access point 420 determines the distance(s) between the readers.
  • the access point 420 may determine the distances based on the position information (see 451 above).
  • the distance between the readers 410 A and 410 C is d1
  • the distance between the readers 410 A and 410 B is d2.
  • the distance between a particular reader and the next-closest reader is relevant for the process of FIG. 4E , so the distance between the readers 410 B and 410 C is not relevant for the process.
  • the access point 420 determines whether the distance between readers (referred to as “d”) is greater than the range of the readers (referred to as “r”). If not, the access point 420 proceeds to 454 ; if so, the access point proceeds to 455 .
  • the distance d1 between the readers 410 A and 410 C is not greater than the range r (so proceed to 454 ); the distance d2 between the readers 410 A and 410 B is greater than the range r (so proceed to 455 ).
  • the access point 420 instructs the readers identified in 453 to sequence their read requests of the tags.
  • a particular tag may be within range of more than one reader.
  • the access point 420 instructing the readers to perform read requests sequentially a particular tag does not receive more than one read request at the same time.
  • the access point 420 instructs the readers 410 A and 410 C to perform their read requests sequentially. When the reader 410 A performs its read request, it reads tags 411 A and 411 C. When the reader 410 C performs its read request, it reads tag 411 C. Sequenced read requests avoid the tag 411 C being read simultaneously.
  • the access point 420 instructs the readers identified in 453 to read tags in parallel.
  • d is greater than r
  • the access point 420 may instruct the readers to perform their read requests in parallel without a particular tag receiving more than one read request at the same time.
  • the access point 420 instructs the reader 410 B to perform its read requests in parallel with either the reader 410 A or the reader 410 C.
  • Performing read requests in parallel increases the throughput of reading tags. Namely, if one reader can read N tags within a time period, M readers in parallel can read a number of tags equal to M*N in the same time period.
  • the access point 420 offloads read request configuration processing from the server 430 (see FIG. 4A ).
  • the server 430 need not be aware of the specifics of the configuration of the readers 410 A, 410 B and 410 C.
  • FIG. 5 illustrates a network configuration according to one embodiment of the present invention.
  • RFID readers 510 A-E communicate directly with wireless access points 520 A-B over a wireless network.
  • a reader may be within range of a plurality of access points, such as reader 510 C, and may communicate directly with multiple access points.
  • the wireless access points 520 A-B in turn, communicate with a server computer 530 over a wired or wireless connection.
  • FIG. 6 illustrates a network configuration according to another embodiment of the present invention.
  • a plurality of readers 610 A-F may communicate wirelessly with the wireless access point through a local network coordinator reader 610 G.
  • Reader 610 G may connect to access point 620 for providing all reader network traffic over a wireless communication channel.
  • Wireless access point 620 communicates with server computer 630 .
  • the configuration of RFID readers in FIG. 6 is referred to as a “star” network.
  • FIG. 7 illustrates a network configuration according to another embodiment of the present invention.
  • all readers 710 A-G include router components and can communicate directly with all other readers.
  • One reader 710 G may act as the local network coordinator for communicating with wireless access point 720 .
  • the configuration of readers 710 A, 710 B, 710 D, 710 F, and 710 G is referred to as a “complete mesh” network.
  • Various modifications on the above configurations are possible, including hybrid networks.
  • readers 710 C and 710 E communicate through readers 710 B and 710 D, respectively, which results in a hybrid network.
  • FIG. 8 illustrates the position of tags within the coverage area of a reader according to another embodiment of the present invention.
  • the range of an RFID reader 810 is illustrated in FIG. 8 .
  • Different RFID readers may have different ranges depending on the particular technologies selected to implement the system.
  • the maximum range at which a reader can send out a signal and receive a response from an RFID tag is depicted by R1.
  • Tags 801 A-D within this range will receive a signal from the reader and provide a response signal to the reader.
  • the distance between reader 810 and tag 801 E is greater than R1. Therefore, tag 801 E may not receive a sufficiently large signal to provide a response, or the response signal may be too small to be detected by reader 801 E. In either case, tag 801 E is outside the coverage area of reader 810 and will not be detected.
  • FIG. 9 illustrates the position of readers within the coverage area of an access point according to another embodiment of the present invention.
  • the range of an access point 920 is illustrated in FIG. 9 .
  • Different access point-reader combinations may have different ranges depending on the particular wireless communication technologies selected to implement the system.
  • the maximum range at which an access point can establish a wireless communication with an RFID reader is depicted by R2.
  • Readers 910 A-D are within range, and accordingly may establish a communication link to the access point 920 .
  • the distance between access point 920 and reader 910 E is greater than R2. Therefore, reader 910 E may not communicate with access point 902 . Accordingly, reader 910 E is outside the coverage area of access point 920 .
  • FIG. 10 illustrates tag positioning according to another embodiment of the present invention.
  • information stored on the tag and transmitted to the reader in response to a read request may be processed by software on the reader, the access point, or both.
  • a reader sends out a read request signal and the tag responds by transmitting tag information.
  • the reader receives the tag information (e.g., tag IDs).
  • the tag information is stored locally on the reader.
  • the reader may include a local database for storing tag information, for example.
  • an initial position of the tag is determined.
  • the tag position may be determined to within the range of the reader based on the position of the reader (e.g., if the position of the reader is known).
  • some readers may reside in known fixed locations. The location may be programmed into the reader, for example, and used to identify the position of the tag (e.g., if a reader with a range of 25 ft is located in the North corner of a warehouse at a certain address, then any tag detected by the reader is within 25 ft of that location).
  • tag positions may be determined more accurately from the power of the tag signal received in the reader, the angle of reception, the time of arrival, the time difference of arrival (e.g., between multiple readers as discussed below), a carrier phase measurement, triangulation with other readers, or through a global positioning system (“GPS”).
  • GPS global positioning system
  • differential measurement techniques may be used to more accurately determine tag positions. For example, If one tag is within range of two readers, the power, angle, time of arrival and carrier phase may be measured by both readers, and middleware in the access point may be used to more accurately calculate the tag position relative to each reader. Similarly, if two tags are read by one reader, differential calculations may be applied. In one embodiment, multiple tags read by at least two readers may be read, and the middleware may calculate measured differences between tags in each reader and again between different readers to obtain a double difference calculation of the parameter of interest, thereby improving the position calculation even more.
  • received tag IDs are entered into a local tag location register in the reader.
  • the tag IDs are transmitted to the access point at 1005 .
  • the tag IDs may be entered into a global tag location register on the access point, for example, at 1006 .
  • an RFID system may include readers with overlapping coverage areas. Accordingly, a tag may respond to multiple readers. If a tag responds to multiple readers, the tag ID may be entered into a local tag location register on a plurality of readers. Additionally, if each reader is communicating wirelessly with the same access point, the tag ID and an identification of each reader (i.e., a reader ID) will be sent to the access point.
  • the access point may store the tag ID multiple times—once for each reader—together with each reader's ID.
  • the tag is attached to an object that may move from one location to another.
  • the tags may be in fixed locations and the readers move from one location to another. Accordingly, at 1007 , tags may move from one reader's coverage area to another reader's coverage area.
  • tags that leave a coverage area are de-registered from the local tag location register.
  • the global tag location register is updated. Accordingly, tags that have left the coverage area are de-registered and tags that enter the coverage area are registered. In one embodiment, tag registration may be updated with each read cycle initiated by a reader, for example.
  • FIG. 11A illustrates determining tag position according to another embodiment of the present invention.
  • a tag may be detected by more than one reader.
  • a tag 1140 is within the coverage area of three (3) readers 1110 , 1120 , and 1130 .
  • a method of determining tag position according to another embodiment of the present invention is shown in FIG. 11B .
  • the tag ID is received on multiple readers. If each reader's position is known, then the position of the tag may be estimated based on the reader positions. For example, if the positions of reader 1110 and 1120 are known, then the distances between these positions may be calculated. Additionally, if the range of each reader is known, then the region of overlapping coverage may also be determined.
  • the position of the tag can be estimated to within the region of overlapping coverage.
  • the range of the tag from each reader may be estimated by the power of the tag signal received in the reader, the angle of reception, the time of arrival, the time difference of arrival, and carrier phase as mentioned above.
  • the ranges from the tag to each reader are determined.
  • the ranges are transmitted to an access point.
  • location software may be used to estimate the position of the tag from data received from each reader. This may include calculating overlapping regions, determining ranges, or performing triangulation based on three tag-to-reader ranges to improve the accuracy of the tag position. In one embodiment, optimization techniques, such as least squares estimates may be used to further improve the tag position accuracy.
  • the tag position is stored in a global tag location register (“GTLR”) on the access point.
  • GTLR global tag location register
  • the tag position may be transmitted back to each reader over the wireless channel.
  • the tag position may be stored in local tag location registers (“LTLR”) for each reader.
  • Tag position updates may be performed under the control of each reader or under the control of the access point. Tag position updates may occur periodically at predetermined intervals, after each read cycle, or in response to user commands or other events (e.g., automatically when a reader comes within the coverage area of a new access point).
  • the access point when an access point detects that a new reader has entered its coverage area, the access point may send commands to the new reader or all readers in the area to scan for tags in each reader's coverage area specifically for a position update. After new tag information is received by each reader, tag positions may be determined and the information may be updated on the access point or readers or both (e.g., in the GTLR or LTLR).
  • FIG. 12 illustrates reader positioning according to another embodiment of the present invention.
  • readers may be moved from one location to another, or the readers may be integrated on mobile devices such as personal digital assistants (“PDA”), cell phones, or any other handheld electronic device. If the readers are movable, then a reader may move between coverage areas of different access points.
  • Embodiments of the present invention may track reader positions dynamically to improve RFID system performance.
  • a reader may enter the coverage area of an access point.
  • the reader registers with the access point.
  • the initial reader position is determined based on the known position of the access point.
  • the reader ID is entered into a local reader location register (“LRLR”) in the access point.
  • LRLR local reader location register
  • the reader ID is transmitted to a server computer system, which may be coupled to multiple access points, for example.
  • Embodiments of the present invention include coupling a remote server to the access point over a computer network, such as the Internet or an intranet.
  • the reader ID is entered into a global reader location register (“GRLR”) on the server.
  • GRLR global reader location register
  • the reader may move from one access point coverage area to another.
  • the reader is de-registered from the LRLR on the access point.
  • the GRLR on the server is updated to reflect that the reader is no longer in the access point's area.
  • FIG. 13A illustrates determining reader position according to another embodiment of the present invention.
  • a reader may be detected by more than one access point.
  • a reader 1340 is within the coverage area of three (3) access points 1310 , 1320 , and 1330 .
  • a method of determining reader position according to one embodiment of the present invention is shown in FIG. 13B .
  • the reader ID is received on multiple access points. If each access point's position is known, then the position of the reader may be estimated based on the access point positions. For example, if the positions of access points 1310 and 1320 are known, then the distances between these positions may be calculated.
  • the region of overlapping coverage may also be determined. If a reader is detected by multiple access points, the position of the reader can be estimated to within the region of overlapping coverage. In other embodiments, the range of the reader from each access point may be estimated.
  • the ranges from the reader to each access point are determined.
  • the ranges are transmitted to a server.
  • location software may be used to estimate the position of the reader from data received from each access point. This may include calculating overlapping regions, determining ranges, or performing triangulation based on three different reader-to-access point ranges to improve the accuracy of the reader position. In one embodiment, optimization techniques, such as least squares error minimization of the distance estimates, may be used to further improve the triangulation results and the reader position accuracy.
  • the reader position is stored in a global reader location register (“GRLR”) on the server.
  • the reader position may be transmitted back to each access point over the wired or wireless network.
  • the reader position may be stored in local reader location registers (“LRLR”) for each access point.
  • Reader position updates may be performed under the control of each access point or under the control of the server. Reader position updates may occur periodically at predetermined intervals, after each read cycle, or in response to user commands or other events (e.g., automatically when a reader enters or leaves the coverage area of an access point).
  • an access point when it detects that a new reader has entered its coverage area, it may send a signal to the server to trigger all access points to perform a scan for readers in each area specifically for a position update. After new reader information is received by each access point, reader positions may be determined and the information may be updated on the server or access points or both (e.g., in the GRLR or LRLR).
  • FIG. 14 illustrates an RFID network with integrated GPS according to another embodiment of the present invention.
  • the tags 1401 , readers 1402 , or access points 1420 may include limited or full GPS functionality, and the wireless RFID reader network may be used to improve positioning of readers and tags using the GPS system or assisted GPS system at the reader level (i.e., between the access point and reader) or at the tag level (i.e., between the reader and the tag).
  • access points 1420 may have full GPS systems 1422 integrated into the access point, readers may have no GPS, partial GPS or full GPS integrated into the reader, and tags may have no GPS, partial GPS or full GPS integrated into the tag.
  • a full GPS receiver is included in one or more access points 1420 A-B and the GPS receiver included in each reader 1402 A-C may support any combination of three modes, namely, autonomous mode, reader-based mode, and reader-assisted mode.
  • Access point GPS 1422 tracks signals from satellites to determine the position of the access point.
  • the reader also includes a full GPS receiver, which is used to track all or a number of the visible satellite signals and calculate the reader position and possibly velocity internally in the reader.
  • reader-based mode or reader-assisted modes the position and satellite information from the access point are used to improve the speed and accuracy in determining the reader locations.
  • the reader may receive information as to which satellites to track.
  • the readers may be provided with a smaller range of code and frequency offsets to search, thereby reducing the GPS acquisition time for the reader and enabling the GPS acquisition for the reader in regions with lower received GPS signal SNR.
  • the readers may also receive GPS navigation data to enable the GPS receiver 1403 A-C embedded in readers 1402 A-C to increase the coherent correlation interval as described below, and thereby track weaker GPS signals (i.e., improving sensitivity).
  • the reader obtains the assisting data from the access point and tracks all or a number of visible satellite signals to obtain the GPS raw measurements (any combination of pseudoranges, pseudodopplers, and accumulated carrier phase) and to calculate the reader position and possibly velocity internally in the reader.
  • the final reader position and/or velocity are calculated inside the access point and not in the reader.
  • the reader uses the assisting data from the access point to improve its signal acquisition and tracking performance and to obtain the GPS raw measurements or just the GPS signal correlations.
  • the GPS raw measurements or GPS correlation outputs are then transmitted back to the access point where the reader position and/or velocity are calculated which may then be communicated back to the reader.
  • the GPS in the access point may use a tracking loop and a correlation scheme to track the signals from different satellites.
  • the process of tracking and correlating data in a GPS can be computationally intensive.
  • the access point transmits the tracking information to the reader over the wireless communication channel so that the reader can track satellites faster and with reduced processing.
  • the access point may correlate data signals from satellites with a locally generated pseudo-random (“PN”) code (e.g., a high speed pulse train) in order to track each satellite.
  • PN pseudo-random
  • the GPS signal comprises 50 Hz data modulated into a 1 MHz spread spectrum code, then the correlation length cannot be more than 20 ms ( 1/50 Hz) or the data will change and the correlation may become destructive.
  • the access point may pass on this information to the reader over the wireless network so that the reader will not be required to decode the data from the satellite. This allows the reader to correlate over longer time periods (i.e., greater than 20 ms), thereby improving the processing gain, allowing averaging to occur over a longer period of time, and thereby allowing the reader to track weaker signals.
  • the reader receives the GPS information from the access point, it performs the correlation as described above to obtain the GPS raw measurements.
  • the reader then may use the GPS raw measurements to obtain the reader position and/or velocity internally (reader-based) or may communicate the GPS raw measurements to the access point where the reader position and/or velocity are calculated (reader-assisted).
  • each tag 1501 includes limited GPS functionality (e.g., a correlation engine).
  • Access point GPS 1505 tracks signals from satellites to determine the position of the access point. The position and satellite information from the access point may be used to improve the speed and accuracy in determining both the reader locations and the tag location.
  • the embedded GPS functionality in the tags may support autonomous, tag-based, and tag-assisted modes. In autonomous mode, a full GPS receiver functionality should be embedded in the tags.
  • the tags still have a full GPS receiver embedded in them, except that they can also get the assisting data from the reader to improve their GPS signal acquisition and tracking.
  • the tags only have a limited functionality GPS receiver such as a correlation engine embedded in them to only obtain the GPS raw measurements or possibly just the correlation results and communicate them back with the reader where the tag position and/or velocity are calculated.
  • the tag may receive information from the reader as to which satellites to track.
  • the tags may be provided with a smaller range of code and frequency offsets to search, thereby reducing the GPS acquisition time for the tag and enabling the GPS acquisition for the tag in regions with lower received GPS signal SNR.
  • the tags may also receive GPS navigation data to enable the GPS receiver 1502 embedded in tag 1501 to increase the coherent correlation interval as described above, and thereby track weaker GPS signals (i.e., improving sensitivity).
  • each reader 1503 may have a full GPS system to interact directly with the tag's limited GPS system 1502 .

Abstract

Embodiments of the present invention include a wireless access point that acquires and processes radio frequency identification (RFID) information. The wireless access point may be coupled to a network of RFID readers over a wireless network. The RFID readers may read a plurality of RFID tags and transmit information to one or more readers. The readers may, in turn, transmit the RFID information to a wireless access point. The wireless access point may include a middleware layer for performing a variety of RFID data processing functions. In one embodiment, the wireless RFID reader network may be used to improve positioning of readers and tags, and may include a GPS system or position assisted GPS system at the reader and/or tag level.

Description

    BACKGROUND
  • The present invention relates to radio frequency identification (“RFID”), and in particular, to wireless RFID networking systems and methods.
  • RFID systems are useful in a wide variety of applications. RFID systems are radio communication systems that include small low cost electronic devices that store information including identification (“ID”) information, for example. These devices are referred to as RFID tags. The RFID tags may be designed using backscattering circuit techniques, for example, so that another device can retrieve the ID wirelessly. The retrieving device is typically referred to as a “reader,” and sometimes “an interrogator.” The tags are typically very small, and may be placed on a variety of items including equipment, products, or even people, for example, and identification of such items may be made through a reader. Accordingly, RFID systems may be used to track inventory in a warehouse, the number of products on store shelves, or the location of equipment in a company, to name just a few example applications.
  • RFID systems may include large numbers of tags and readers spread out across potentially wide areas. The large number of tags and readers may result in a correspondingly large volume of information that may need to be processed. Such information may include large volumes of tag IDs. In order to process such information, powerful readers are typically used that include complex software capable of interfacing with backend systems that store and ultimately use the data.
  • FIG. 1 is an example of a prior art RFID system. Information from numerous RFID tags 101A-C is received wirelessly by RFID readers 102A-C. Each RFID reader includes an RFID client software component 103A-C (e.g., a Savant Client) that is designed to operate with an RFID central server software component 110 (e.g., a Savant Server) over a network 111. The central server 110 uses a client-server architecture for moving data between the readers and the server. Since all the RFID specific operations are included in two components, the readers are typically powerful systems that can work with the server to manage the data retrieved from the RFID tags. The RFID central server, in turn, is coupled to backend data storage and processing system 120 over network 150. Backend system 120 may be coupled to a database 130 for storing the RFID data, for example.
  • It is generally desirable to reduce the cost of the tags and the readers that access them. Additionally, it is desirable to improve the management of the RFID tags and the features and flexibility of the RFID system. Existing RFID systems are expensive because, as mentioned above, readers require powerful processors to execute the client software required to interface with the server to make the system operational. It would be beneficial if a new architecture were developed to lower the overall RFID system cost and improve the features and flexibility of the RFID system.
  • Thus, there is a need to improve RFID systems. Accordingly, the present invention provides improved wireless RFID networking systems and methods.
  • SUMMARY
  • Embodiments of the present invention include a wireless access point that acquires and processes radio frequency identification (RFID) information. The wireless access point may be coupled to a network of RFID readers over a wireless network. The RFID readers may read a plurality of RFID tags and transmit information to one or more readers. The readers may, in turn, transmit the RFID information to a wireless access point. The wireless access point may include a middleware layer for performing a variety of RFID data processing functions. In one embodiment, the wireless RFID reader network may be used to improve positioning of readers and tags, and may include a GPS system or position assisted GPS system at the reader and/or tag level.
  • According to one embodiment of the present invention, a wireless access point includes a first physical layer interface, a second physical layer interface, and middleware software. The first physical layer interfaces the wireless access point to a wireless link and communicates first RFID data to the wireless access point from a plurality of RFID readers. The RFID readers read a plurality of RFID tags. The first RFID data results from reading the RFID tags. The second physical layer interfaces the wireless access point to a wired or wireless link and communicates second RFID data from the wireless access point to a server. The middleware controls the wireless access point to receive and store tag information from the RFID tags. In this manner, the wireless access point offloads processing from the server.
  • According to another embodiment of the present invention, the middleware controls the wireless access point to process the tag information prior to transmission to the server.
  • According to yet another embodiment of the present invention, the middleware controls the wireless access point to estimate a position of a RFID tag.
  • According to still another embodiment of the present invention, the middleware controls the wireless access point to pre-process global positioning system (GPS) information for an RFID reader.
  • These and other features of the present invention are detailed in the following drawings and related description.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is an example of a prior art RFID system.
  • FIG. 2 illustrates an RFID network according to one embodiment of the present invention.
  • FIG. 3 illustrates an RFID network according to another embodiment of the present invention.
  • FIGS. 4A-F illustrate examples of RFID middleware on a wireless access point according to other embodiments of the present invention.
  • FIG. 5 illustrates a network configuration according to one embodiment of the present invention.
  • FIG. 6 illustrates a network configuration according to another embodiment of the present invention.
  • FIG. 7 illustrates a network configuration according to another embodiment of the present invention.
  • FIG. 8 illustrates the position of tags within the coverage area of a reader according to another embodiment of the present invention.
  • FIG. 9 illustrates the position of readers within the coverage area of an access point according to another embodiment of the present invention.
  • FIG. 10 illustrates tag positioning according to another embodiment of the present invention.
  • FIG. 11A illustrates determining tag position according to another embodiment of the present invention.
  • FIG. 11B illustrates a method of determining tag position according to another embodiment of the present invention.
  • FIG. 12 illustrates reader positioning according to another embodiment of the present invention.
  • FIG. 13A illustrates determining reader position according to another embodiment of the present invention.
  • FIG. 13B illustrates a method of determining reader position according to another embodiment of the present invention.
  • FIG. 14 illustrates an RFID network with integrated GPS according to another embodiment of the present invention.
  • FIG. 15 illustrates an RFID network with integrated GPS according to another embodiment of the present invention.
  • DETAILED DESCRIPTION
  • Described herein are techniques for networking RFID system components. In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention as defined by the claims may include some or all of the features in these examples alone or in combination with other features described below, and may further include obvious modifications and equivalents of the features and concepts described herein.
  • FIG. 2 illustrates an RFID network according to one embodiment of the present invention. A plurality of RFID tags 201A-C may receive signals from RFID readers 202A-C. The tags may be active or passive backscattering circuits (i.e., with or without an internal source of energy such as a battery), for example, or in some embodiments a more complex sensor network capable of wireless automatic identification. In response to the received signals, the RFID tags will transmit information back to the readers. Readers 202A may include a variety of devices such as application specific readers, personal digital assistants, cell phones, or other handheld devices. RFID readers 202A-C are coupled together over a wireless network link 210 (i.e., a communication channel). The wireless network link may be an 802.11 wireless network link, a Bluetooth network link, a Zigbee network link, cellular network link, backscattering link, or other wireless network link using radio frequency signals, for example. Thus, RFID reader 202A may communicate with wireless access point 220A over a wireless network 210. Similarly, RFID reader 202C may communicate with wireless access point 220B over a similar wireless network 210. Accordingly, the readers and wireless access points include physical layer circuits and systems for implementing the wireless transmissions, such as RF transceivers and baseband processors, for example. In some cases, an RFID reader may be within range of multiple access points. In this example, RFID reader 202B is within range of both access points 220A and 220B. Accordingly, information from RFID reader 202B may communicate wirelessly with both of access points 220A and/or 220B. In this example, wireless access points 220A and 220B are coupled to a server computer 230 over a wired (e.g., Ethernet or RS-485) or wireless network 225. However, in some applications the wireless access points may be coupled to a central server over a wireless network (in which case the central server may act as a central access point). The server computer 230 may, in turn, be coupled to backend applications and databases 260 over another network 250, such as the Internet or an intranet, for example.
  • In one embodiment, an application layer is added to wireless access points 220A-B. The application layer includes an access point middleware software component 221 that works with a middleware (“MW”) reader software component 203 to manage the network of RFID readers and related tags. In one embodiment, access point middleware 221A-B may be used for tag or reader registration, tag or reader positioning, or network and data management. Access point middleware 221A-B may be used to hide the network of RFID readers behind the access point thereby making the network more flexible and reducing the processing burden on the server 230. For example, in one embodiment, server computer 230 includes a middleware host 231 that is part of a distributed middleware system for simplifying management of the reader network. Server computer 230 may further include an RFID central server 232 that communicates with wireless access points 220 and applications 233 for managing and processing data associated with the RFIDs. Additionally, Access point software 221A-B may be used to offload network management and data processing from the reader, which lowers the cost of the reader, and accordingly, the entire RFID network.
  • FIG. 3 illustrates an RFID network according to another embodiment of the present invention. A plurality of RFID tags 301A-D may receive signals from RFID readers 302A-D. In response to the received signals, the RFID tags will transmit information back to the readers. RFID readers 302A-B are configured in a wireless network and communicate with wireless access point 320A over a wireless communication channel 310A, and RFID readers 302C-D are configured in a wireless network and communicate with wireless access point 320B over a wireless communication channel 310B. Wireless access points 320A and 320B are coupled to a server computer 330 over a wired or wireless network 325. RFID readers 302A-D include a middleware (“MW”) software component 303A-D, and the wireless access points 320A-B include a middleware application layer component 321A-B. In this example, the access points 320A-B further include RFID client software components 322A-B. Embodiments of the present invention may move software functions from the reader to software executed on an application layer on the access point. The RFID clients 322A-B perform transactions with an RFID central server software component 332 on server computer 330. Accordingly, the software architecture in this example distributes RFID network processing across the entire network to reduce the processing burden on the reader and thereby reduce the overall cost of the network.
  • FIG. 4A illustrates an example of a network model for an RFID network according to another embodiment of the present invention. This example shows the network model for a reader 410, access point 420, and server computer 430. The reader 410 and the access point 420 communicate over a wireless network link 490. The access point 420 and the server computer 420 communicate over a wired or wireless network link 491. The wired or wireless network link 491 may be, for example, a local area network connection such as Ethernet, an intranet, or a wide area network such as the Internet, or any of the wireless networks described above.
  • The network model for reader 410 includes a physical layer, data link layer, network layer, transport layer, and application layer. The application layer may include a reader middleware software component (“Reader MW”) as described above. The physical layer in this case is a wireless network link including a wireless receiver and transmitter coupled to an antenna.
  • Access point 420 includes a physical layer, data link layer, and network layer. In one embodiment of the present invention, an access point 420 is provided that further includes a transport layer and application layer 421 for running access point middleware software 422 (“AP MW”) described above for preprocessing the RFID data. The physical layer may include a wireless receiver and transmitter coupled to an antenna for communicating with one or more readers. The physical layer may also support wired or wireless communication with another computer 430 (e.g., Ethernet).
  • The AP MW 422 coordinates the input of RFID information 422 received from the reader 410, the storage of the RFID data in a storage unit 424, and the output of RFID information 425 to be sent to the server computer 430. Such coordination includes functions such as monitoring and management of the reader 410 (referred to as device management), connectivity management of the connection between the access point 420 and the server 430, connectivity management of the connection between the readers 410 and access point 420, fault detection of failures or other problems with the reader 410, maintenance and upgrades for the reader 410, and data management (processing) of RFID information. Such data processing may include data aggregation, data smoothing, data filtering, redundancy processing, multiprotocol format negotiation (for example, configuring the reader 410 to communicate with the RFID tags using different protocols, or responding to a request by the server 430 to read all tags having a certain set of protocols). The access point 420 may include a processor, controller, micro-controller, programmable logic device, or other integrated circuit device that executes the AP MW 422. The storage unit 424 may be a memory, hard disk, or other type of storage system.
  • Server computer 430 includes a physical layer, data link layer, network layer, transport layer, and application layer. The application layer on the server may include a central RFID server and other software for receiving and processing RFID applications.
  • FIG. 4B illustrates a method according to another embodiment of the present invention. At 401, tag IDs are received in an application layer of a wireless access point on an input 423 of middleware 422. At 402, information associated with the tag IDs (e.g., position information) may also be received in middleware 422. At 403, the tag IDs are stored in a repository, such as a database or other data storage facility, for example. At 404, the tag IDs and/or the associated information are processed by the middleware. As mentioned above, processing may include data or device monitoring or management, for example. At 405, the tag IDs and/or the associated information are transmitted on middleware output 425 over a wired or wireless link 491 to a server 430 for further processing if desired.
  • FIG. 4C illustrates an RFID network according to another embodiment of the present invention. A plurality of RFID tags 411 are located within a location (such as a building or warehouse) that is covered by a plurality of RFID readers 410 (labeled R1, R2, R3 and R4). The RFID tags 411 may receive signals from the RFID readers 410. In response to the received signals, the RFID tags 411 will transmit information back to the readers 410. The RFID readers 410 are configured in a wireless network and communicate with a wireless access point 420 over a wireless communication channel. The wireless access point 420 is coupled to a server computer 430 over a wired or wireless network. The access point 420 includes a MW software component (see above regarding FIG. 4A) that in this case may be configured to offload redundancy processing from the server 430, as discussed below with reference to FIG. 4D.
  • FIG. 4D illustrates redundancy offload processing according to another embodiment of the present invention. At 441, the wireless access point 420 configures the readers 410 to cover a common location. Such configuration may include sequencing the readers 410 for reading operations (of the tags 411) or data transmission operations (to the access point 420) to manage the likelihood of interference. For example, the access point 420 may configure the reader R1 to read tags during a first time segment, the reader R2 to read tags during a second time segment, etc. As another example, the access point 420 may configure the reader R1 to transmit its information to the access point 420 during a first time segment, the reader R2 to transmit its information during a second time segment, etc. Alternatively, the access point 420 may configure the readers 410 to communicate with tags and/or the access point 420 at different frequencies. In yet other embodiments, communication between wireless access point 420, readers 410, and tags may be at different time slots and different frequencies. Readers 410 may also use beamforming techniques and directional antennas to communicate with tags, for example, so different beams and/or different polarizations may also be used.
  • With reference to FIG. 4C, a particular RFID tag 411 may be in range of more than one of the readers 410. Including more than one reader 410 allows for redundancy to improve reliability of the RFID system. For example, a particular RFID tag 411 may be blocked by shelving, etc. from receiving signals from the readers R1, R2 and R3, but may be situated such that it receives signals from the reader R4. As another example, if the reader R1 fails, the other readers R2, R3 and R4 are still operational, allowing the RFID system to continue to function.
  • At 442, according to the particulars of the configuration (see 441 above), the readers 410 receive the tag IDs from the tags 411 in the common area. At 443, according to the particulars of the configuration (see 441 above), the readers 410 transmit the tag IDs from each reader to the wireless access point 420. The access point 420 may store the tag IDs in the repository 424 (see FIG. 4A) along with an identifier that identifies which of the readers 410 read that tag. As multiple ones of the readers 410 may read the same tag 411, the storage unit 424 may contain redundant tag data.
  • At 444, the access point 420 filters the redundant tag information. At 445, the access point 420 sends the unique tag IDs to the server 430. In this manner, the access point 420 offloads redundancy processing from the server 430. The server 430 need not be aware of the specifics of the configuration of the readers 410.
  • FIG. 4E illustrates an RFID network according to another embodiment of the present invention. A plurality of RFID readers 410A, 410B and 410C and a plurality of RFID tags 411A, 411B and 411C are located in an area. The readers 410A, 410B and 410C communicate with a wireless access point 420 over a wireless communication channel. The readers 410A, 410B and 410C have a range represented by “r” in the figure. Thus, tag 411B is within range of reader 410B, tag 411A is within range of reader 410A, and tag 411C is within range of both reader 410A and reader 410C. The readers 410A, 410B and 410C are separated by a distance, represented in the figure by “d1” as the distance between the readers 410A and 410C, and by “d2” as the distance between the readers 410A and 410B. The access point 420 includes a MW software component (see above regarding FIG. 4A) that in this case may be configured to offload read request processing from the server 430, as discussed below with reference to FIG. 4F.
  • FIG. 4F illustrates read request offload processing according to another embodiment of the present invention. At 451, the access point 420 determines the position of the readers within range of the access point. With reference to FIG. 4E as an example, the readers 410A, 410B and 410C are within range of the access point 420. The access point may use a variety of techniques for determining the position of the readers, as discussed below.
  • At 452, the access point 420 determines the distance(s) between the readers. The access point 420 may determine the distances based on the position information (see 451 above). With reference to FIG. 4E as an example, the distance between the readers 410A and 410C is d1, and the distance between the readers 410A and 410B is d2. According to one embodiment, the distance between a particular reader and the next-closest reader is relevant for the process of FIG. 4E, so the distance between the readers 410B and 410C is not relevant for the process.
  • At 453, the access point 420 determines whether the distance between readers (referred to as “d”) is greater than the range of the readers (referred to as “r”). If not, the access point 420 proceeds to 454; if so, the access point proceeds to 455. With reference to FIG. 4E as an example, the distance d1 between the readers 410A and 410C is not greater than the range r (so proceed to 454); the distance d2 between the readers 410A and 410B is greater than the range r (so proceed to 455).
  • At 454, the access point 420 instructs the readers identified in 453 to sequence their read requests of the tags. In the case where d is not greater than r, a particular tag may be within range of more than one reader. In such a case, by the access point 420 instructing the readers to perform read requests sequentially, a particular tag does not receive more than one read request at the same time. With reference to FIG. 4E as an example, the access point 420 instructs the readers 410A and 410C to perform their read requests sequentially. When the reader 410A performs its read request, it reads tags 411A and 411C. When the reader 410C performs its read request, it reads tag 411C. Sequenced read requests avoid the tag 411C being read simultaneously.
  • At 455, the access point 420 instructs the readers identified in 453 to read tags in parallel. In the case where d is greater than r, there is no risk that a particular tag may be within range of more than one reader. Thus, the access point 420 may instruct the readers to perform their read requests in parallel without a particular tag receiving more than one read request at the same time. With reference to FIG. 4E as an example, the access point 420 instructs the reader 410B to perform its read requests in parallel with either the reader 410A or the reader 410C.
  • Performing read requests in parallel increases the throughput of reading tags. Namely, if one reader can read N tags within a time period, M readers in parallel can read a number of tags equal to M*N in the same time period. In the manner described above, the access point 420 offloads read request configuration processing from the server 430 (see FIG. 4A). The server 430 need not be aware of the specifics of the configuration of the readers 410A, 410B and 410C.
  • FIG. 5 illustrates a network configuration according to one embodiment of the present invention. Embodiments of the present invention may be implemented using a variety of network configurations. In FIG. 5, RFID readers 510A-E communicate directly with wireless access points 520A-B over a wireless network. In come cases, a reader may be within range of a plurality of access points, such as reader 510C, and may communicate directly with multiple access points. The wireless access points 520A-B, in turn, communicate with a server computer 530 over a wired or wireless connection. FIG. 6 illustrates a network configuration according to another embodiment of the present invention. In this example, a plurality of readers 610A-F may communicate wirelessly with the wireless access point through a local network coordinator reader 610G. Reader 610G may connect to access point 620 for providing all reader network traffic over a wireless communication channel. Wireless access point 620, in turn, communicates with server computer 630. The configuration of RFID readers in FIG. 6 is referred to as a “star” network. FIG. 7 illustrates a network configuration according to another embodiment of the present invention. In this example, all readers 710A-G include router components and can communicate directly with all other readers. One reader 710G may act as the local network coordinator for communicating with wireless access point 720. The configuration of readers 710A, 710B, 710D, 710F, and 710G is referred to as a “complete mesh” network. Various modifications on the above configurations are possible, including hybrid networks. In this example, readers 710C and 710E communicate through readers 710B and 710D, respectively, which results in a hybrid network.
  • FIG. 8 illustrates the position of tags within the coverage area of a reader according to another embodiment of the present invention. The range of an RFID reader 810 is illustrated in FIG. 8. Different RFID readers may have different ranges depending on the particular technologies selected to implement the system. The maximum range at which a reader can send out a signal and receive a response from an RFID tag is depicted by R1. Tags 801A-D within this range will receive a signal from the reader and provide a response signal to the reader. The distance between reader 810 and tag 801E is greater than R1. Therefore, tag 801E may not receive a sufficiently large signal to provide a response, or the response signal may be too small to be detected by reader 801E. In either case, tag 801E is outside the coverage area of reader 810 and will not be detected.
  • FIG. 9 illustrates the position of readers within the coverage area of an access point according to another embodiment of the present invention. The range of an access point 920 is illustrated in FIG. 9. Different access point-reader combinations may have different ranges depending on the particular wireless communication technologies selected to implement the system. The maximum range at which an access point can establish a wireless communication with an RFID reader is depicted by R2. Readers 910A-D are within range, and accordingly may establish a communication link to the access point 920. The distance between access point 920 and reader 910E is greater than R2. Therefore, reader 910E may not communicate with access point 902. Accordingly, reader 910E is outside the coverage area of access point 920.
  • FIG. 10 illustrates tag positioning according to another embodiment of the present invention. When a tag is within a reader's coverage area, information stored on the tag and transmitted to the reader in response to a read request may be processed by software on the reader, the access point, or both. To initiate the process, a reader sends out a read request signal and the tag responds by transmitting tag information. At 1001, the reader receives the tag information (e.g., tag IDs). At 1002, the tag information is stored locally on the reader. In one embodiment, the reader may include a local database for storing tag information, for example.
  • Features of the present invention include determining the position of tags. Accordingly, at 1003 an initial position of the tag is determined. For example, in one embodiment the tag position may be determined to within the range of the reader based on the position of the reader (e.g., if the position of the reader is known). In particular, some readers may reside in known fixed locations. The location may be programmed into the reader, for example, and used to identify the position of the tag (e.g., if a reader with a range of 25 ft is located in the North corner of a warehouse at a certain address, then any tag detected by the reader is within 25 ft of that location). In other embodiments described in more detail below, tag positions may be determined more accurately from the power of the tag signal received in the reader, the angle of reception, the time of arrival, the time difference of arrival (e.g., between multiple readers as discussed below), a carrier phase measurement, triangulation with other readers, or through a global positioning system (“GPS”). In one embodiment, differential measurement techniques may be used to more accurately determine tag positions. For example, If one tag is within range of two readers, the power, angle, time of arrival and carrier phase may be measured by both readers, and middleware in the access point may be used to more accurately calculate the tag position relative to each reader. Similarly, if two tags are read by one reader, differential calculations may be applied. In one embodiment, multiple tags read by at least two readers may be read, and the middleware may calculate measured differences between tags in each reader and again between different readers to obtain a double difference calculation of the parameter of interest, thereby improving the position calculation even more.
  • At 1004, received tag IDs are entered into a local tag location register in the reader. In one embodiment, the tag IDs are transmitted to the access point at 1005. The tag IDs may be entered into a global tag location register on the access point, for example, at 1006. In some embodiments, an RFID system may include readers with overlapping coverage areas. Accordingly, a tag may respond to multiple readers. If a tag responds to multiple readers, the tag ID may be entered into a local tag location register on a plurality of readers. Additionally, if each reader is communicating wirelessly with the same access point, the tag ID and an identification of each reader (i.e., a reader ID) will be sent to the access point. The access point may store the tag ID multiple times—once for each reader—together with each reader's ID.
  • In some applications, the tag is attached to an object that may move from one location to another. Alternatively, the tags may be in fixed locations and the readers move from one location to another. Accordingly, at 1007, tags may move from one reader's coverage area to another reader's coverage area. At 1008, tags that leave a coverage area are de-registered from the local tag location register. At 1009, the global tag location register is updated. Accordingly, tags that have left the coverage area are de-registered and tags that enter the coverage area are registered. In one embodiment, tag registration may be updated with each read cycle initiated by a reader, for example.
  • FIG. 11A illustrates determining tag position according to another embodiment of the present invention. As mentioned above, a tag may be detected by more than one reader. For example, as shown in FIG. 11A, a tag 1140 is within the coverage area of three (3) readers 1110, 1120, and 1130. A method of determining tag position according to another embodiment of the present invention is shown in FIG. 11B. At 1101, the tag ID is received on multiple readers. If each reader's position is known, then the position of the tag may be estimated based on the reader positions. For example, if the positions of reader 1110 and 1120 are known, then the distances between these positions may be calculated. Additionally, if the range of each reader is known, then the region of overlapping coverage may also be determined. If a tag is detected by multiple readers, the position of the tag can be estimated to within the region of overlapping coverage. In other embodiments, the range of the tag from each reader may be estimated by the power of the tag signal received in the reader, the angle of reception, the time of arrival, the time difference of arrival, and carrier phase as mentioned above. At 1102, the ranges from the tag to each reader are determined. At 1103, the ranges are transmitted to an access point. At 1104, location software may be used to estimate the position of the tag from data received from each reader. This may include calculating overlapping regions, determining ranges, or performing triangulation based on three tag-to-reader ranges to improve the accuracy of the tag position. In one embodiment, optimization techniques, such as least squares estimates may be used to further improve the tag position accuracy.
  • At 1105, the tag position is stored in a global tag location register (“GTLR”) on the access point. At 1106, the tag position may be transmitted back to each reader over the wireless channel. At 1107, the tag position may be stored in local tag location registers (“LTLR”) for each reader. Tag position updates may be performed under the control of each reader or under the control of the access point. Tag position updates may occur periodically at predetermined intervals, after each read cycle, or in response to user commands or other events (e.g., automatically when a reader comes within the coverage area of a new access point). For example, in one embodiment, when an access point detects that a new reader has entered its coverage area, the access point may send commands to the new reader or all readers in the area to scan for tags in each reader's coverage area specifically for a position update. After new tag information is received by each reader, tag positions may be determined and the information may be updated on the access point or readers or both (e.g., in the GTLR or LTLR).
  • FIG. 12 illustrates reader positioning according to another embodiment of the present invention. In some embodiments, readers may be moved from one location to another, or the readers may be integrated on mobile devices such as personal digital assistants (“PDA”), cell phones, or any other handheld electronic device. If the readers are movable, then a reader may move between coverage areas of different access points. Embodiments of the present invention may track reader positions dynamically to improve RFID system performance. At 1201, a reader may enter the coverage area of an access point. At 1202, the reader registers with the access point. At 1203, the initial reader position is determined based on the known position of the access point. At 1204, the reader ID is entered into a local reader location register (“LRLR”) in the access point. At 1205, the reader ID is transmitted to a server computer system, which may be coupled to multiple access points, for example. Embodiments of the present invention include coupling a remote server to the access point over a computer network, such as the Internet or an intranet. At 1206, the reader ID is entered into a global reader location register (“GRLR”) on the server. At 1207, the reader may move from one access point coverage area to another. At 1208, the reader is de-registered from the LRLR on the access point. At 1209, the GRLR on the server is updated to reflect that the reader is no longer in the access point's area.
  • FIG. 13A illustrates determining reader position according to another embodiment of the present invention. As mentioned above, a reader may be detected by more than one access point. For example, as shown in FIG. 13A, a reader 1340 is within the coverage area of three (3) access points 1310, 1320, and 1330. A method of determining reader position according to one embodiment of the present invention is shown in FIG. 13B. At 1301, the reader ID is received on multiple access points. If each access point's position is known, then the position of the reader may be estimated based on the access point positions. For example, if the positions of access points 1310 and 1320 are known, then the distances between these positions may be calculated. Additionally, if the range of each access point is known, then the region of overlapping coverage may also be determined. If a reader is detected by multiple access points, the position of the reader can be estimated to within the region of overlapping coverage. In other embodiments, the range of the reader from each access point may be estimated. At 1302, the ranges from the reader to each access point are determined At 1303, the ranges are transmitted to a server. At 1304, location software may be used to estimate the position of the reader from data received from each access point. This may include calculating overlapping regions, determining ranges, or performing triangulation based on three different reader-to-access point ranges to improve the accuracy of the reader position. In one embodiment, optimization techniques, such as least squares error minimization of the distance estimates, may be used to further improve the triangulation results and the reader position accuracy.
  • At 1305, the reader position is stored in a global reader location register (“GRLR”) on the server. At 1306, the reader position may be transmitted back to each access point over the wired or wireless network. At 1307, the reader position may be stored in local reader location registers (“LRLR”) for each access point. Reader position updates may be performed under the control of each access point or under the control of the server. Reader position updates may occur periodically at predetermined intervals, after each read cycle, or in response to user commands or other events (e.g., automatically when a reader enters or leaves the coverage area of an access point). For example, in one embodiment, when an access point detects that a new reader has entered its coverage area, it may send a signal to the server to trigger all access points to perform a scan for readers in each area specifically for a position update. After new reader information is received by each access point, reader positions may be determined and the information may be updated on the server or access points or both (e.g., in the GRLR or LRLR).
  • FIG. 14 illustrates an RFID network with integrated GPS according to another embodiment of the present invention. In some embodiments, the tags 1401, readers 1402, or access points 1420 may include limited or full GPS functionality, and the wireless RFID reader network may be used to improve positioning of readers and tags using the GPS system or assisted GPS system at the reader level (i.e., between the access point and reader) or at the tag level (i.e., between the reader and the tag). For example, access points 1420 may have full GPS systems 1422 integrated into the access point, readers may have no GPS, partial GPS or full GPS integrated into the reader, and tags may have no GPS, partial GPS or full GPS integrated into the tag. In one embodiment, a full GPS receiver is included in one or more access points 1420A-B and the GPS receiver included in each reader 1402A-C may support any combination of three modes, namely, autonomous mode, reader-based mode, and reader-assisted mode. Access point GPS 1422 tracks signals from satellites to determine the position of the access point. In the autonomous mode, the reader also includes a full GPS receiver, which is used to track all or a number of the visible satellite signals and calculate the reader position and possibly velocity internally in the reader. In reader-based mode or reader-assisted modes, the position and satellite information from the access point are used to improve the speed and accuracy in determining the reader locations. The reader may receive information as to which satellites to track. The readers may be provided with a smaller range of code and frequency offsets to search, thereby reducing the GPS acquisition time for the reader and enabling the GPS acquisition for the reader in regions with lower received GPS signal SNR. The readers may also receive GPS navigation data to enable the GPS receiver 1403A-C embedded in readers 1402A-C to increase the coherent correlation interval as described below, and thereby track weaker GPS signals (i.e., improving sensitivity). In the reader-based mode, the reader obtains the assisting data from the access point and tracks all or a number of visible satellite signals to obtain the GPS raw measurements (any combination of pseudoranges, pseudodopplers, and accumulated carrier phase) and to calculate the reader position and possibly velocity internally in the reader. In reader-assisted mode, on the other hand, the final reader position and/or velocity are calculated inside the access point and not in the reader. Specifically, the reader uses the assisting data from the access point to improve its signal acquisition and tracking performance and to obtain the GPS raw measurements or just the GPS signal correlations. The GPS raw measurements or GPS correlation outputs are then transmitted back to the access point where the reader position and/or velocity are calculated which may then be communicated back to the reader.
  • For example, in one embodiment, the GPS in the access point may use a tracking loop and a correlation scheme to track the signals from different satellites. However, the process of tracking and correlating data in a GPS can be computationally intensive. In one embodiment, the access point transmits the tracking information to the reader over the wireless communication channel so that the reader can track satellites faster and with reduced processing. For example, the access point may correlate data signals from satellites with a locally generated pseudo-random (“PN”) code (e.g., a high speed pulse train) in order to track each satellite. If the GPS signal comprises 50 Hz data modulated into a 1 MHz spread spectrum code, then the correlation length cannot be more than 20 ms ( 1/50 Hz) or the data will change and the correlation may become destructive. However, since the access point is decoding and correlating the GPS data, the access point may pass on this information to the reader over the wireless network so that the reader will not be required to decode the data from the satellite. This allows the reader to correlate over longer time periods (i.e., greater than 20 ms), thereby improving the processing gain, allowing averaging to occur over a longer period of time, and thereby allowing the reader to track weaker signals. After the reader receives the GPS information from the access point, it performs the correlation as described above to obtain the GPS raw measurements. The reader then may use the GPS raw measurements to obtain the reader position and/or velocity internally (reader-based) or may communicate the GPS raw measurements to the access point where the reader position and/or velocity are calculated (reader-assisted).
  • In another embodiment, GPS information transmitted to readers 1402A-C may be further transmitted to tags 1401. FIG. 15 illustrates another embodiment of the present invention. In this example, each tag 1501 includes limited GPS functionality (e.g., a correlation engine). Access point GPS 1505 tracks signals from satellites to determine the position of the access point. The position and satellite information from the access point may be used to improve the speed and accuracy in determining both the reader locations and the tag location. Similar to reader-access point GPS related interactions, the embedded GPS functionality in the tags may support autonomous, tag-based, and tag-assisted modes. In autonomous mode, a full GPS receiver functionality should be embedded in the tags. For tag-based mode, the tags still have a full GPS receiver embedded in them, except that they can also get the assisting data from the reader to improve their GPS signal acquisition and tracking. In tag-assisted mode, the tags only have a limited functionality GPS receiver such as a correlation engine embedded in them to only obtain the GPS raw measurements or possibly just the correlation results and communicate them back with the reader where the tag position and/or velocity are calculated. The tag may receive information from the reader as to which satellites to track. The tags may be provided with a smaller range of code and frequency offsets to search, thereby reducing the GPS acquisition time for the tag and enabling the GPS acquisition for the tag in regions with lower received GPS signal SNR. The tags may also receive GPS navigation data to enable the GPS receiver 1502 embedded in tag 1501 to increase the coherent correlation interval as described above, and thereby track weaker GPS signals (i.e., improving sensitivity). In some embodiments, each reader 1503 may have a full GPS system to interact directly with the tag's limited GPS system 1502.
  • The above description illustrates various embodiments of the present invention along with examples of how aspects of the present invention may be implemented. The above examples and embodiments should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of the present invention as defined by the following claims. Based on the above disclosure and the following claims, other arrangements, embodiments, implementations and equivalents will be evident to those skilled in the art and may be employed without departing from the spirit and scope of the invention as defined by the claims. The terms and expressions that have been employed here are used to describe the various embodiments and examples. These terms and expressions are not to be construed as excluding equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible within the scope of the appended claims.

Claims (21)

1. A wireless access point apparatus for acquiring and processing radio frequency identification (RFID) information, comprising:
a first physical layer interface to a wireless link, wherein said first physical layer interface communicates first RFID data to said wireless access point from a plurality of RFID readers, wherein said plurality of RFID readers read a plurality of RFID tags, and wherein said first RFID data results from reading said plurality of RFID tags;
a second physical layer interface to a wired or wireless link, wherein said second physical layer interface communicates second RFID data from said wireless access point to a server;
wherein said wireless access point executes processing including:
receiving, from a first RFID reader of said plurality of RFID readers, first tag information related to a first RFID tag of said plurality of RFID tags; and
storing said first tag information as said first RFID data.
2. The apparatus of claim 1, wherein said wireless access point executes processing further including:
processing said first RFID data; and
transmitting said second RFID data to said server, wherein said second RFID data corresponds to said first RFID data having been processed.
3. The apparatus of claim 2, wherein said step of processing said first RFID data includes:
filtering said first RFID data to remove redundant data.
4. The apparatus of claim 1, wherein said wireless access point executes processing further including:
determining a distance between each of said plurality of RFID readers; and
configuring a read request of said plurality of RFID readers, selectively, according to said step of determining said distance.
5. The apparatus of claim 1, wherein said wireless access point executes processing further including:
updating said first RFID data when said first RFID tag moves from a first coverage area to a second coverage area, wherein said first coverage area is associated with said first RFID reader and said second coverage area is associated with a second RFID reader of said plurality of RFID readers.
6. The apparatus of claim 1, wherein said wireless access point and said plurality of RFID readers are configured in a star network configuration.
7. The apparatus of claim 1, wherein said wireless access point and said plurality of RFID readers are configured in a mesh network configuration.
8. The apparatus of claim 1, wherein said wireless access point and said plurality of RFID readers are configured in a hybrid network configuration.
9. The apparatus of claim 1, wherein said first tag information includes a position of said first RFID tag.
10. The apparatus of claim 1, wherein said wireless access point executes further processing comprising:
receiving, from said first RFID reader, registration information indicating that said first RFID reader is in a first coverage area, wherein said first coverage area corresponds to said wireless access point;
storing said registration information;
transmitting said registration information to said server;
receiving, from said server when said first RFID reader has moved into a second coverage area corresponding to another wireless access point, revised registration information; and
updating said registration information with said revised registration information.
11. A method of acquiring and processing radio frequency identification (RFID) information, comprising:
reading, by a first RFID reader of a plurality of RFID readers, a first RFID tag of a plurality of RFID tags;
transmitting, on a wireless network link, first tag information related to said first RFID tag from said first RFID reader to a wireless access point;
storing, on said wireless access point, said first tag information as first RFID data;
processing, by said wireless access point, said first RFID data; and
transmitting, on a wired or wireless network link, second RFID data from said wireless access point to a server, wherein said second RFID data corresponds to said first RFID data having been processed.
12. The method of claim 11, wherein said step of processing said first RFID data includes:
filtering said first RFID data to remove redundant data.
13. The method of claim 11, further comprising:
determining a distance between each of said plurality of RFID readers; and
configuring, by said wireless access point, a read request of said plurality of RFID readers, selectively, according to said step of determining said distance.
14. The method of claim 11, further comprising:
updating, by said wireless access point, said first RFID data when said first RFID tag moves from a first coverage area to a second coverage area, wherein said first coverage area is associated with said first RFID reader and said second coverage area is associated with a second RFID reader of said plurality of RFID readers.
15. The method of claim 11, wherein said first tag information includes a position of said first RFID tag.
16. The method of claim 11, further comprising:
transmitting, on said wireless network link from said first RFID reader to said wireless access point, registration information indicating that said first RFID reader is in a first coverage area, wherein said first coverage area corresponds to said wireless access point;
storing, on said wireless access point, said registration information;
transmitting, on said wired or wireless network link, said registration information from said wireless access point to said server;
transmitting, on said wired or wireless network link, revised registration information from said server to said wireless access point, when said first RFID reader has moved into a second coverage area corresponding to another wireless access point; and
updating, on said wireless access point, said registration information with said revised registration information.
17. A wireless access point apparatus for acquiring and processing radio frequency identification (RFID) information, comprising:
a first physical layer interface to a wireless link, wherein said first physical layer interface communicates first RFID data to said wireless access point from a plurality of RFID readers, wherein said plurality of readers read a plurality of RFID tags, and wherein said first RFID data results from reading said plurality of RFID tags;
a second physical layer interface to a wired or wireless link, wherein said second physical layer interface communicates second RFID data from said wireless access point to a server;
wherein said wireless access point executes processing including:
receiving, from more than one RFID reader of said plurality of RFID readers, a plurality of first tag information related to a first RFID tag of said plurality of RFID tags;
estimating a position of said first RFID tag based on said plurality of first tag information and on a position of each of said more than one RFID reader; and
transmitting said second RFID data to said server, wherein said second RFID data includes said position of said first RFID tag.
18. The wireless access point of claim 17, wherein said step of estimating said position is based on a region of overlapping coverage of said more than one RFID reader.
19. The wireless access point of claim 17, wherein said step of estimating said position is based on a received power, angle of reception, time of arrival, a carrier phase.
20. The wireless access point of claim 19, wherein said step of estimating said position is based on a differential measurement between two tags or two readers.
21-32. (canceled)
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017046085A (en) * 2015-08-25 2017-03-02 清水建設株式会社 Position management system
US9959435B1 (en) * 2015-11-25 2018-05-01 Impinj, Inc. Location-based access to RFID tag information
WO2018081319A1 (en) * 2016-10-25 2018-05-03 The Board Of Trustees Of The Leland Stanford Junior University Backscattering ambient ism band signals
US10037445B2 (en) 2005-11-07 2018-07-31 Radiofy Llc Systems and methods for managing coverage area of wireless communication devices
US10338205B2 (en) 2016-08-12 2019-07-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter communication among commodity WiFi radios
US11009600B2 (en) 2006-12-18 2021-05-18 Innovo Surgical, Inc. RFID location systems and methods
US11163050B2 (en) 2013-08-09 2021-11-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter estimation using progressive self interference cancellation
US11209536B2 (en) 2014-05-02 2021-12-28 The Board Of Trustees Of The Leland Stanford Junior University Method and apparatus for tracking motion using radio frequency signals

Families Citing this family (134)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8260896B2 (en) * 2007-02-02 2012-09-04 Mwa Intelligence, Inc. Monitoring business machines using a mesh network on field nodes
US20060289650A1 (en) * 2005-06-27 2006-12-28 Mobile Aspects, Inc. Networked monitoring system
EP1929679A4 (en) * 2005-09-30 2010-09-15 Sandlinks Systems Ltd A wide area dynamic rfid system using uwb
JP4983017B2 (en) * 2005-12-21 2012-07-25 富士通株式会社 Information access system and method for accessing information in a contactless information storage device
US8138891B2 (en) * 2006-03-07 2012-03-20 Sensormatic Electronics, LLC RFID network control and redundancy
US7812719B2 (en) * 2006-05-01 2010-10-12 Djuric Petar M RFID system and method for localizing and tracking a moving object with an RFID tag
US7961098B2 (en) * 2006-09-08 2011-06-14 Symbol Technologies, Inc. Methods and apparatus for a pervasive locationing and presence-detection system
US20080120414A1 (en) * 2006-11-17 2008-05-22 Nandakishore Kushalnagar Representing resource constrained devices in a network
US8344949B2 (en) 2008-03-31 2013-01-01 Golba Llc Wireless positioning approach using time-delay of signals with a known transmission pattern
US8193978B2 (en) 2007-11-14 2012-06-05 Golba Llc Positioning system and method using GPS with wireless access points
US8314736B2 (en) * 2008-03-31 2012-11-20 Golba Llc Determining the position of a mobile device using the characteristics of received signals and a reference database
US8838481B2 (en) 2011-07-26 2014-09-16 Golba Llc Method and system for location based hands-free payment
US8838477B2 (en) 2011-06-09 2014-09-16 Golba Llc Method and system for communicating location of a mobile device for hands-free payment
US20080186145A1 (en) * 2007-02-05 2008-08-07 Honeywell International Inc. Method of cooperation between mobile and fixed rfid readers
DE102007027141A1 (en) * 2007-06-13 2008-12-18 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Device for determining a device position
US20080315999A1 (en) * 2007-06-25 2008-12-25 Parelec Israel Ltd. Wireless communication system for tracking assets with affixed electronic smart tags and methods thereof
US7768394B2 (en) * 2007-07-02 2010-08-03 Honeywell International Inc. System and apparatus for integrated location detection and wireless communications
US7911338B2 (en) * 2007-07-30 2011-03-22 Eaton Corporation Wireless system and wireless module therefor
US7881253B2 (en) * 2007-07-31 2011-02-01 Honeywell International Inc. Apparatus and method supporting a redundancy-managing interface between wireless and wired networks
US7823778B1 (en) * 2007-08-08 2010-11-02 Cellco Partnership Wireless inventory scanner system and method
EP2188868B1 (en) 2007-09-11 2018-07-11 RF Controls, LLC Radio frequency signal acquisition and source location system
KR100984514B1 (en) * 2007-10-11 2010-09-30 인하대학교 산학협력단 Method of Analizing the Construction Productivity Using ???? Based on the Wireless Communication
KR100920517B1 (en) * 2007-11-27 2009-10-09 한국전자통신연구원 Apparatus and method for managing radio frequency identification reader
FI126720B (en) * 2007-12-04 2017-04-28 Sensire Oy Method, system and equipment for data collection
FI122943B (en) * 2007-12-04 2012-09-14 Sensire Oy A device, method, and system for transmitting information from RFID devices
KR100902247B1 (en) 2007-12-14 2009-06-11 한국전자통신연구원 Medthod of controlling many password codes of radio frequency identification tag on mobile radio frequency identification device platform
US8077014B2 (en) * 2008-01-17 2011-12-13 Intermec Ip Corp. Method, apparatus, and system for radio frequency identification (RFID) tag association and relative positioning
US8402455B2 (en) * 2008-03-17 2013-03-19 Landis+Gyr Innovations, Inc. Methods and systems for distributing firmware through an over-the-air network
US7800541B2 (en) 2008-03-31 2010-09-21 Golba Llc Methods and systems for determining the location of an electronic device
US9829560B2 (en) 2008-03-31 2017-11-28 Golba Llc Determining the position of a mobile device using the characteristics of received signals and a reference database
US8717144B2 (en) * 2008-04-29 2014-05-06 Intelleflex Corporation RFID system with distributed readers
US8190725B2 (en) 2008-07-01 2012-05-29 Microsoft Corporation Standardized mechanism of remote management of embedded radio modules
US8754748B2 (en) * 2008-07-10 2014-06-17 Symbol Technologies, Inc. RFID wireless scanning system for non-RFID mobile devices, and related operating methods
US8414471B2 (en) 2008-10-28 2013-04-09 Mobile Aspects, Inc. Endoscope storage cabinet, tracking system, and signal emitting member
US20100148931A1 (en) * 2008-12-12 2010-06-17 Ravikanth Srinivasa Pappu Radio devices and communications
US20100156601A1 (en) * 2008-12-22 2010-06-24 Lang Lin LLRP-Based Flexible Reader System And Method
TW201032138A (en) * 2009-02-23 2010-09-01 Champtek Inc RFID location method and system for the same
US8120488B2 (en) * 2009-02-27 2012-02-21 Rf Controls, Llc Radio frequency environment object monitoring system and methods of use
US8860551B2 (en) * 2009-03-23 2014-10-14 International Business Machines Corporation Automated RFID reader detection
JP5500619B2 (en) * 2009-03-30 2014-05-21 日本電気株式会社 GPS terminal, positioning method, communication system, and program
EP2432270B1 (en) * 2009-05-15 2019-07-10 Huawei Device Co., Ltd. Method, device and system for controlling access point
US8344823B2 (en) 2009-08-10 2013-01-01 Rf Controls, Llc Antenna switching arrangement
KR20110016098A (en) * 2009-08-11 2011-02-17 삼성전자주식회사 Apparatus and method for offering information of goods on mobile communication terminal
EP2472994A4 (en) * 2009-08-25 2012-09-26 Huawei Tech Co Ltd Data communication method, data communication system and devices thereof
EP2476082A4 (en) * 2009-09-10 2013-08-14 Rf Controls Llc Calibration and operational assurance method and apparatus for rfid object monitoring systems
JP4865031B2 (en) * 2009-12-10 2012-02-01 株式会社東芝 Communication device
KR101003017B1 (en) * 2009-12-30 2010-12-21 동아대학교 산학협력단 Rfid system having multi-subscription function and operation method thereof
US8675539B1 (en) 2010-05-07 2014-03-18 Qualcomm Incorporated Management-packet communication of GPS satellite positions
US8743699B1 (en) * 2010-05-07 2014-06-03 Qualcomm Incorporated RFID tag assisted GPS receiver system
US9760853B2 (en) * 2010-06-21 2017-09-12 Mark D. Rose Low-power wirelessly-linked RFID tracking system
US8648699B2 (en) 2010-07-19 2014-02-11 Mobile Aspects, Inc. Item tracking system and arrangement
KR20120012943A (en) * 2010-08-03 2012-02-13 한국전자통신연구원 Real time location system and method using rfid tags which relay gps signal
US8849926B2 (en) * 2010-08-06 2014-09-30 Simon Fraser University System and method for self-calibrating, self-organizing and localizing sensors in wireless sensor networks
US8498201B2 (en) 2010-08-26 2013-07-30 Honeywell International Inc. Apparatus and method for improving the reliability of industrial wireless networks that experience outages in backbone connectivity
US8068011B1 (en) 2010-08-27 2011-11-29 Q Street, LLC System and method for interactive user-directed interfacing between handheld devices and RFID media
CN101916355B (en) * 2010-08-31 2012-07-04 中国地质大学(武汉) Wireless sensor network technology-based multi-standard RFID identification equipment
EP2624741B1 (en) * 2010-10-07 2017-09-20 Trophy Association of wireless detector with an imaging apparatus
US8750793B2 (en) 2010-10-14 2014-06-10 Blackberry Limited Near-field communication (NFC) system with mobile wireless communications devices determining geographic positions of NFC tags and related methods
EP2442128B1 (en) * 2010-10-14 2016-05-11 BlackBerry Limited Near-field communication (nfc) system with mobile wireless communications devices determining geographic positions of nfc tags and related methods
US8924498B2 (en) 2010-11-09 2014-12-30 Honeywell International Inc. Method and system for process control network migration
US8115623B1 (en) 2011-03-28 2012-02-14 Robert M Green Method and system for hand basket theft detection
US8094026B1 (en) 2011-05-02 2012-01-10 Robert M Green Organized retail crime detection security system and method
US20120313759A1 (en) * 2011-06-13 2012-12-13 Timekeeping Systems, Inc. Tracking system for persons and/or objects
US20130002879A1 (en) * 2011-07-01 2013-01-03 Sensormatics Electronics, Llc Systems and methods for tracking a commodity
US9165231B2 (en) * 2011-08-24 2015-10-20 Ricoh Company, Ltd. Image recognition in passive RFID devices
US20130099896A1 (en) * 2011-10-24 2013-04-25 Telefonaktiebolaget L M Ericsson (Publ) Sensor Location and Tagging System
CN102426655B (en) * 2011-11-12 2013-09-11 成都雷电微力科技有限公司 RFID reader-writer chip integrated with global positioning system (GPS) module
US9086470B2 (en) 2011-11-29 2015-07-21 Shalom Daskal Method and apparatus for mapping buildings
KR101325376B1 (en) * 2012-02-28 2013-11-08 부산대학교 산학협력단 System and method for providing test rfid
US9245158B2 (en) 2012-04-05 2016-01-26 Ricoh Co., Ltd. Low power radio frequency communication
US9747538B2 (en) 2012-04-05 2017-08-29 Ricoh Co., Ltd. Low power radio frequency communication
US8976022B2 (en) * 2012-04-13 2015-03-10 Khalid Hamad Motleb ALNAFISAH Mobile tracking identification system, method, and computer program product
KR102034526B1 (en) 2012-10-18 2019-10-22 한국전자통신연구원 Apparatus and method for managing indoor moving objects information considering indoor map and positioning infrastructure
WO2014151935A2 (en) * 2013-03-15 2014-09-25 Wal-Mart Stores, Inc. Systems and methods for radio frequency identification device management
US9746352B2 (en) * 2013-03-29 2017-08-29 Symboticware Incorporated Method and apparatus for underground equipment monitoring
EP3011755A4 (en) * 2013-06-17 2017-01-18 Hewlett-Packard Enterprise Development LP Guide segment identification
CN103390181B (en) * 2013-07-03 2016-12-28 南京邮电大学 A kind of RFID dynamic labels data processing architecture and method
US9110838B2 (en) 2013-07-31 2015-08-18 Honeywell International Inc. Apparatus and method for synchronizing dynamic process data across redundant input/output modules
US9892618B2 (en) 2013-08-09 2018-02-13 Mobile Aspects, Inc. Signal emitting member attachment system and arrangement
US9709672B2 (en) * 2013-08-16 2017-07-18 Drnc Holdings, Inc. Method and system for identifying and finding a range of an object
US9251455B2 (en) * 2013-08-22 2016-02-02 Verily Life Sciences Llc Using unique identifiers to retrieve configuration data for tag devices
US9958533B2 (en) 2013-09-06 2018-05-01 Drnc Holdings, Inc. Method and system for locating wireless devices within a local region
US9348013B2 (en) 2013-09-18 2016-05-24 Mobile Aspects, Inc. Item hanger arrangement, system, and method
US9224124B2 (en) 2013-10-29 2015-12-29 Mobile Aspects, Inc. Item storage and tracking cabinet and arrangement
US10078811B2 (en) 2013-11-29 2018-09-18 Fedex Corporate Services, Inc. Determining node location based on context data in a wireless node network
EP3078219B1 (en) * 2013-12-04 2021-04-21 Nokia Technologies Oy Access point information for wireless access
US10034400B2 (en) 2013-12-04 2018-07-24 Mobile Aspects, Inc. Item storage arrangement system and method
US20150271643A1 (en) * 2014-02-25 2015-09-24 Ahmad Jalali Position determination using time of arrival measurements in a wireless local area network
US9784816B2 (en) 2014-02-25 2017-10-10 Ubiqomm Llc Systems and methods of location and tracking
US9998859B2 (en) 2014-02-25 2018-06-12 Bridgewest Finance Llc Systems and methods of location and tracking
US10132917B2 (en) 2014-02-25 2018-11-20 Bridgewest Finance Llc Systems and methods of location and tracking
US9720404B2 (en) 2014-05-05 2017-08-01 Honeywell International Inc. Gateway offering logical model mapped to independent underlying networks
US10042330B2 (en) 2014-05-07 2018-08-07 Honeywell International Inc. Redundant process controllers for segregated supervisory and industrial control networks
US10453023B2 (en) 2014-05-28 2019-10-22 Fedex Corporate Services, Inc. Methods and node apparatus for adaptive node communication within a wireless node network
US10536526B2 (en) 2014-06-25 2020-01-14 Honeywell International Inc. Apparatus and method for virtualizing a connection to a node in an industrial control and automation system
US20160034729A1 (en) * 2014-07-29 2016-02-04 Promega Corporation Rfid integrated antenna system
US9699022B2 (en) 2014-08-01 2017-07-04 Honeywell International Inc. System and method for controller redundancy and controller network redundancy with ethernet/IP I/O
US10211662B2 (en) 2014-08-15 2019-02-19 Analog Devices Global Wireless charging platform using environment based beamforming for wireless sensor network
US11322969B2 (en) 2014-08-15 2022-05-03 Analog Devices International Unlimited Company Wireless charging platform using beamforming for wireless sensor network
US10148485B2 (en) 2014-09-03 2018-12-04 Honeywell International Inc. Apparatus and method for on-process migration of industrial control and automation system across disparate network types
MX2017003717A (en) 2014-09-22 2017-11-30 Drnc Holdings Inc Transmission apparatus for a wireless device using delta-sigma modulation.
US11238397B2 (en) 2015-02-09 2022-02-01 Fedex Corporate Services, Inc. Methods, apparatus, and systems for generating a corrective pickup notification for a shipped item using a mobile master node
US10162827B2 (en) 2015-04-08 2018-12-25 Honeywell International Inc. Method and system for distributed control system (DCS) process data cloning and migration through secured file system
US10409270B2 (en) 2015-04-09 2019-09-10 Honeywell International Inc. Methods for on-process migration from one type of process control device to different type of process control device
EP3292506B1 (en) 2015-05-06 2022-11-23 Crown Equipment Corporation Diagnostic tag for an industrial vehicle tag reader
MX363894B (en) 2015-05-06 2019-04-05 Crown Equip Corp Industrial vehicle comprising tag reader and reader module.
US11281873B2 (en) 2015-05-28 2022-03-22 Hds Mercury, Inc. Product and equipment location and automation system and method
US10410176B2 (en) 2015-05-28 2019-09-10 Hds Mercury, Inc. Product and equipment location and automation system and method
US10491479B2 (en) 2015-07-08 2019-11-26 Fedex Corporate Services, Inc. Systems, apparatus, and methods of time gap related monitoring for an event candidate related to an ID node within a wireless node network
CN107852568A (en) * 2015-07-13 2018-03-27 乌贝库米有限公司 System and method for positioning and tracking
JP6957496B2 (en) 2016-03-23 2021-11-02 フェデックス コーポレイト サービシズ,インコーポレイティド Radio node-based methods for auto-tuning the broadcast settings of nodes in a radio node network, non-temporary computer-readable media containing instructions to perform that method, and auto-tuning broadcast node equipment in a radio node network.
US11125852B2 (en) * 2016-08-03 2021-09-21 Black & Decker Inc. Construction jobsite computer data network and location system
WO2018109564A1 (en) * 2016-12-16 2018-06-21 Assa Abloy Ab Methods and devices for physical access control systems
JP7018457B2 (en) * 2017-02-14 2022-02-10 サフラン パッセンジャー イノベーションズ, エルエルシー Systems and methods for maneuvering wireless network traffic in vehicles
US11213773B2 (en) 2017-03-06 2022-01-04 Cummins Filtration Ip, Inc. Genuine filter recognition with filter monitoring system
US10296482B2 (en) 2017-03-07 2019-05-21 Honeywell International Inc. System and method for flexible connection of redundant input-output modules or other devices
US10401816B2 (en) 2017-07-20 2019-09-03 Honeywell International Inc. Legacy control functions in newgen controllers alongside newgen control functions
WO2019018618A1 (en) 2017-07-21 2019-01-24 Walmart Apollo, Llc System and method for managing inventory via rfid tags
JP2019056676A (en) * 2017-09-22 2019-04-11 パナソニックIpマネジメント株式会社 Position management device, position management system and position management method
US10515494B2 (en) 2017-10-13 2019-12-24 Global Tel*Link Corporation System and method for remote monitoring of released individual
US20190128994A1 (en) * 2017-10-31 2019-05-02 Richard Kozdras Sensor system
WO2019107954A1 (en) 2017-11-30 2019-06-06 Samsung Electronics Co., Ltd. Apparatus and method for searching and registering tags in local positioning system
EP3506086A1 (en) * 2017-12-28 2019-07-03 ELATEC GmbH Method for updating or upgrading firmware of a radio frequency identification reader
US10546168B1 (en) * 2018-07-17 2020-01-28 Accenture Global Solutions Limited Managing a plurality of tag reader devices
US11551537B2 (en) * 2019-04-11 2023-01-10 Nexite Ltd. Wireless dual-mode identification tag
CN114844531A (en) 2019-04-11 2022-08-02 奈克赛特公司 System for simultaneous tag triggering and sequential tag reading
US11162750B1 (en) * 2019-09-16 2021-11-02 Donald L. Weeks Detection of firearms in a security zone using radio frequency identification tag embedded within weapon bolt carrier
CN112532342B (en) * 2019-09-17 2023-05-16 华为技术有限公司 Data transmission method and device in back reflection communication
US11063651B1 (en) * 2020-01-31 2021-07-13 Trakpoint Solutions, Inc. Method for waking from energy-efficient hibernation
US11304137B2 (en) * 2020-01-31 2022-04-12 Trakpoint Solutions, Inc. Method for waking from energy-efficient hibernation
EP4275160A1 (en) 2021-01-11 2023-11-15 Nexite Ltd. Contactless and automatic operations of a retail store
US11546732B2 (en) * 2021-03-31 2023-01-03 Neoma Limited System and a method for generating person-specific service suggestions for a person at a facility
DE102021124194A1 (en) 2021-09-20 2023-03-23 Aesculap Ag System and method for monitoring at least one medical device
US20230186329A1 (en) 2021-12-13 2023-06-15 Nexite Ltd. Systems and methods for estimating foot traffic

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040243588A1 (en) * 2003-05-29 2004-12-02 Thomas Tanner Systems and methods for administering a global information database
US20050057370A1 (en) * 2003-09-17 2005-03-17 Jogesh Warrior System and method for using mobile collectors for accessing a wireless sensor network
US20050242188A1 (en) * 2004-04-28 2005-11-03 Sarosh Vesuna System and method for providing location information in transaction processing
US20060022800A1 (en) * 2004-07-30 2006-02-02 Reva Systems Corporation Scheduling in an RFID system having a coordinated RFID tag reader array
US20060039316A1 (en) * 2004-08-20 2006-02-23 Minoru Ogushi Wireless communication system
US20060047789A1 (en) * 2004-09-01 2006-03-02 Microsoft Corporation Rule-based filtering and alerting
US20060097873A1 (en) * 2004-11-10 2006-05-11 Rockwell Automation Technologies, Inc. Systems and methods that integrate radio frequency identification (RFID) technology with agent-based control systems
US20060108411A1 (en) * 2004-11-10 2006-05-25 Rockwell Automation Technologies, Inc. Systems and methods that integrate radio frequency identification (RFID) technology with industrial controllers
US20060143439A1 (en) * 2004-12-06 2006-06-29 Xpaseo Method and system for sensor data management
US20060176169A1 (en) * 2004-12-17 2006-08-10 The Regents Of The University Of California System for sensing environmental conditions
US20060261938A1 (en) * 2005-05-19 2006-11-23 Lai Kin Y A Radio Frequency Identification (RFID) system
US20070043827A1 (en) * 2005-08-22 2007-02-22 Bea Systems, Inc. RFID edge server with security WSRM
US20070045424A1 (en) * 2005-08-26 2007-03-01 Ynjiun Wang Data collection device having dynamic access to multiple wireless networks
US20070099623A1 (en) * 2005-10-17 2007-05-03 Reva Systems Corporation Configuration management system and method for use in an RFID system including a multiplicity of RFID readers
US20070208680A1 (en) * 2005-10-05 2007-09-06 Siemens Corporate Research Inc Method and Apparatus For Complex RFID Event Processing
US8345653B2 (en) * 2005-11-07 2013-01-01 Radiofy Llc Wireless RFID networking systems and methods

Family Cites Families (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3303501A (en) 1964-04-22 1967-02-07 Seismograph Service Corp Radio location system with lane identification facilities
US3778159A (en) 1970-03-10 1973-12-11 Laser Systems & Electronics Distance measuring apparatus and method utilizing phase comparison of modulated light beams
US4283726A (en) 1978-09-05 1981-08-11 Lewis C. Spence Dual frequency distance measuring system
SE456867B (en) 1985-12-12 1988-11-07 Stiftelsen Inst Mikrovags SET MEASURING DISTANCE AND / OR SPEED BETWEEN TWO OBJECTIVES
US6131067A (en) 1995-10-09 2000-10-10 Snaptrack, Inc. Client-server based remote locator device
US5663734A (en) * 1995-10-09 1997-09-02 Precision Tracking, Inc. GPS receiver and method for processing GPS signals
US7057492B2 (en) 1995-10-11 2006-06-06 Motorola, Inc. Enabling/enhancing a feature of an electronic device using radio frequency identification technology
US6185427B1 (en) 1996-09-06 2001-02-06 Snaptrack, Inc. Distributed satellite position system processing and application network
US6215441B1 (en) 1997-04-15 2001-04-10 Snaptrack, Inc. Satellite positioning reference system and method
US6204765B1 (en) 1997-12-23 2001-03-20 Inkrmec Ip Corp. Method of detecting relative direction of motion of a radio frequency (RF) tag
US5999124A (en) 1998-04-22 1999-12-07 Snaptrack, Inc, Satellite positioning system augmentation with wireless communication signals
US6111536A (en) 1998-05-26 2000-08-29 Time Domain Corporation System and method for distance measurement by inphase and quadrature signals in a radio system
GB9821046D0 (en) 1998-09-28 1998-11-18 Whitesmith Howard W Detection system
US6831902B1 (en) * 1999-09-08 2004-12-14 Qwest Communications International, Inc. Routing information packets in a distributed network
US6496806B1 (en) 1999-12-16 2002-12-17 Samsys Technologies Inc. Method and system for tracking clustered items
US7161470B2 (en) 2000-01-14 2007-01-09 3M Innovative Properties Company User interface for portable RFID reader
US6868073B1 (en) 2000-06-06 2005-03-15 Battelle Memorial Institute K1-53 Distance/ranging by determination of RF phase delta
US7580378B2 (en) 2000-06-06 2009-08-25 Alien Technology Corporation Distance/ranging determination using relative phase data
US7024331B2 (en) 2000-11-15 2006-04-04 Scientific Generics Limited Tag tracking
AU2002214159B2 (en) 2000-11-15 2006-09-07 Turftrax Group Limited Tag tracking
US6809054B1 (en) * 2000-11-21 2004-10-26 Uop Llc FCC spent catalyst distributor
US6659344B2 (en) 2000-12-06 2003-12-09 Ncr Corporation Automated monitoring of activity of shoppers in a market
US6859761B2 (en) 2001-01-16 2005-02-22 Bluesoft Ltd. Accurate distance measurement using RF techniques
US6731908B2 (en) 2001-01-16 2004-05-04 Bluesoft, Inc. Distance measurement using half-duplex RF techniques
US6717516B2 (en) 2001-03-08 2004-04-06 Symbol Technologies, Inc. Hybrid bluetooth/RFID based real time location tracking
US6700535B2 (en) 2001-06-01 2004-03-02 Texas Instruments Incorporated Location estimation in narrow bandwidth wireless communication systems
DE10155251A1 (en) 2001-11-09 2003-06-18 Siemens Ag Transponder system and method for distance measurement
US6891500B2 (en) 2002-03-18 2005-05-10 Christopher J. Hall Method and apparatus for geolocating a wireless communications device
US6920330B2 (en) 2002-03-26 2005-07-19 Sun Microsystems, Inc. Apparatus and method for the use of position information in wireless applications
US7565108B2 (en) 2002-03-26 2009-07-21 Nokia Corporation Radio frequency identification (RF-ID) based discovery for short range radio communication with reader device having transponder functionality
US7920827B2 (en) 2002-06-26 2011-04-05 Nokia Corporation Apparatus and method for facilitating physical browsing on wireless devices using radio frequency identification
US6963289B2 (en) 2002-10-18 2005-11-08 Aeroscout, Ltd. Wireless local area network (WLAN) channel radio-frequency identification (RFID) tag system and method therefor
US6750769B1 (en) 2002-12-12 2004-06-15 Sun Microsystems, Inc. Method and apparatus for using RFID tags to determine the position of an object
DE10261098A1 (en) 2002-12-20 2004-07-15 Siemens Ag Method for determining the distance between a base station and a mobile object and base station and identification system for such a method
US7045996B2 (en) 2003-01-30 2006-05-16 Hewlett-Packard Development Company, L.P. Position determination based on phase difference
WO2004092999A2 (en) 2003-04-17 2004-10-28 Symbol Technologies, Inc. Multimode wireless local area network/radio frequency identification asset tag
CA2533145C (en) 2003-07-23 2013-04-09 Qualcomm Incorporated Selecting a navigation solution used in determining the position of a device in a wireless communication system
US7038573B2 (en) 2003-09-08 2006-05-02 Single Chip Systems Corporation Systems and methods for tracking the location of items within a controlled area
US20050088284A1 (en) 2003-10-09 2005-04-28 Zai Li-Cheng R. Method and system of using a RFID reader network to provide a large operating area
US20060012465A1 (en) * 2003-10-23 2006-01-19 Nesslab Co., Ltd. Collision prevention method for RFID system and RFID system
US7026935B2 (en) 2003-11-10 2006-04-11 Impinj, Inc. Method and apparatus to configure an RFID system to be adaptable to a plurality of environmental conditions
US20050129139A1 (en) 2003-12-03 2005-06-16 Jones Aled W. Tag tracking
US7423527B2 (en) 2004-02-13 2008-09-09 Blue Vector Systems Radio frequency identification (RFID) network system and method
JP4328705B2 (en) 2004-02-27 2009-09-09 均 北吉 RFID tag device
US7119738B2 (en) 2004-03-01 2006-10-10 Symbol Technologies, Inc. Object location system and method using RFID
US7630323B2 (en) * 2004-03-11 2009-12-08 Symbol Technologies, Inc. Self-configuring wireless personal area network
US20050245235A1 (en) * 2004-04-29 2005-11-03 Sarosh Vesuna System and method for wireless network security
US7548153B2 (en) 2004-07-09 2009-06-16 Tc License Ltd. Multi-protocol or multi-command RFID system
US20080008109A1 (en) * 2004-09-21 2008-01-10 Jeffrey Ollis Method and apparatus for bridging wireless control networks
US8180291B2 (en) 2004-09-30 2012-05-15 Intel Corporation Power-scavenging receiver to generate a signal to be used to control operational state
ES2391566T3 (en) 2004-10-29 2012-11-27 Skyhook Wireless, Inc. Database and location beacon server, method to build a location beacon database, and location-based service that uses it
US7333014B2 (en) * 2004-11-04 2008-02-19 International Business Machines Corporation Notifying users of device events in a networked environment
US8253539B2 (en) * 2004-11-30 2012-08-28 Symbol Technologies, Inc. Rfid reader management system and method
US7397424B2 (en) 2005-02-03 2008-07-08 Mexens Intellectual Property Holding, Llc System and method for enabling continuous geographic location estimation for wireless computing devices
US20060197652A1 (en) * 2005-03-04 2006-09-07 International Business Machines Corporation Method and system for proximity tracking-based adaptive power control of radio frequency identification (RFID) interrogators
US20070046467A1 (en) * 2005-08-31 2007-03-01 Sayan Chakraborty System and method for RFID reader to reader communication
US20060267731A1 (en) * 2005-05-31 2006-11-30 Chen Thomas C H System and apparatus of Internet-linked RFID sensor network for object identifying, sensing, monitoring, tracking and networking
US7388491B2 (en) * 2005-07-20 2008-06-17 Rockwell Automation Technologies, Inc. Mobile RFID reader with integrated location awareness for material tracking and management
US7283091B1 (en) 2005-08-08 2007-10-16 Trimble Navigation Limited Radio positioning system for providing position and time for assisting GPS signal acquisition in mobile unit
US20070075838A1 (en) * 2005-10-04 2007-04-05 Symbol Technologies, Inc. Method and apparatus for avoiding radio frequency identification (RFID) tag response collisions
US20070096876A1 (en) * 2005-10-20 2007-05-03 Raj Bridgelall Adaptive RFID devices
US7538727B2 (en) 2005-10-31 2009-05-26 Avago Technologies General Ip (Singapore) Pte. Ltd. System and method for determining the bearing of a source location from a receiver location
US20080045236A1 (en) 2006-08-18 2008-02-21 Georges Nahon Methods and apparatus for gathering and delivering contextual messages in a mobile communication system
US20080143584A1 (en) 2006-12-18 2008-06-19 Radiofy Llc, A California Limited Liability Company Method and system for determining the distance between an RFID reader and an RFID tag using phase
US8294554B2 (en) 2006-12-18 2012-10-23 Radiofy Llc RFID location systems and methods
US20080284646A1 (en) 2007-05-18 2008-11-20 Broadcom Corporation Use of broadcast position data for subsequent gps location fix
US8204008B2 (en) 2007-06-22 2012-06-19 Apple Inc. Techniques for resource block mapping in a wireless communication system
US7800541B2 (en) 2008-03-31 2010-09-21 Golba Llc Methods and systems for determining the location of an electronic device
US8107466B2 (en) 2008-04-01 2012-01-31 Mitac International Corp. Flexible network switch fabric for clustering system

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040243588A1 (en) * 2003-05-29 2004-12-02 Thomas Tanner Systems and methods for administering a global information database
US20050057370A1 (en) * 2003-09-17 2005-03-17 Jogesh Warrior System and method for using mobile collectors for accessing a wireless sensor network
US20050242188A1 (en) * 2004-04-28 2005-11-03 Sarosh Vesuna System and method for providing location information in transaction processing
US20060022800A1 (en) * 2004-07-30 2006-02-02 Reva Systems Corporation Scheduling in an RFID system having a coordinated RFID tag reader array
US20060039316A1 (en) * 2004-08-20 2006-02-23 Minoru Ogushi Wireless communication system
US20060047789A1 (en) * 2004-09-01 2006-03-02 Microsoft Corporation Rule-based filtering and alerting
US20060097873A1 (en) * 2004-11-10 2006-05-11 Rockwell Automation Technologies, Inc. Systems and methods that integrate radio frequency identification (RFID) technology with agent-based control systems
US20060108411A1 (en) * 2004-11-10 2006-05-25 Rockwell Automation Technologies, Inc. Systems and methods that integrate radio frequency identification (RFID) technology with industrial controllers
US20060143439A1 (en) * 2004-12-06 2006-06-29 Xpaseo Method and system for sensor data management
US20060176169A1 (en) * 2004-12-17 2006-08-10 The Regents Of The University Of California System for sensing environmental conditions
US20060261938A1 (en) * 2005-05-19 2006-11-23 Lai Kin Y A Radio Frequency Identification (RFID) system
US20070043827A1 (en) * 2005-08-22 2007-02-22 Bea Systems, Inc. RFID edge server with security WSRM
US20070045424A1 (en) * 2005-08-26 2007-03-01 Ynjiun Wang Data collection device having dynamic access to multiple wireless networks
US20070208680A1 (en) * 2005-10-05 2007-09-06 Siemens Corporate Research Inc Method and Apparatus For Complex RFID Event Processing
US20070099623A1 (en) * 2005-10-17 2007-05-03 Reva Systems Corporation Configuration management system and method for use in an RFID system including a multiplicity of RFID readers
US8345653B2 (en) * 2005-11-07 2013-01-01 Radiofy Llc Wireless RFID networking systems and methods

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10037445B2 (en) 2005-11-07 2018-07-31 Radiofy Llc Systems and methods for managing coverage area of wireless communication devices
US11009600B2 (en) 2006-12-18 2021-05-18 Innovo Surgical, Inc. RFID location systems and methods
US11921192B2 (en) 2006-12-18 2024-03-05 Innovo Surgical, Inc. RFID location systems and methods
US11163050B2 (en) 2013-08-09 2021-11-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter estimation using progressive self interference cancellation
US11209536B2 (en) 2014-05-02 2021-12-28 The Board Of Trustees Of The Leland Stanford Junior University Method and apparatus for tracking motion using radio frequency signals
JP2017046085A (en) * 2015-08-25 2017-03-02 清水建設株式会社 Position management system
US9959435B1 (en) * 2015-11-25 2018-05-01 Impinj, Inc. Location-based access to RFID tag information
US10204245B1 (en) 2015-11-25 2019-02-12 Impinj, Inc. Location-based access to RFID tag information
US10733395B1 (en) 2015-11-25 2020-08-04 Impinj, Inc. Location-based access to RFID tag information
US10338205B2 (en) 2016-08-12 2019-07-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter communication among commodity WiFi radios
WO2018081319A1 (en) * 2016-10-25 2018-05-03 The Board Of Trustees Of The Leland Stanford Junior University Backscattering ambient ism band signals
US11483836B2 (en) 2016-10-25 2022-10-25 The Board Of Trustees Of The Leland Stanford Junior University Backscattering ambient ism band signals

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US8107446B2 (en) 2012-01-31
US10037445B2 (en) 2018-07-31
WO2007056333A3 (en) 2007-09-13
US8693455B2 (en) 2014-04-08
US20170193255A1 (en) 2017-07-06
US20130187761A1 (en) 2013-07-25
US20120113902A1 (en) 2012-05-10
US20190012496A1 (en) 2019-01-10

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