CA2375696C - A method of controlling power - Google Patents
A method of controlling power Download PDFInfo
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- CA2375696C CA2375696C CA002375696A CA2375696A CA2375696C CA 2375696 C CA2375696 C CA 2375696C CA 002375696 A CA002375696 A CA 002375696A CA 2375696 A CA2375696 A CA 2375696A CA 2375696 C CA2375696 C CA 2375696C
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- power
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- 238000000034 method Methods 0.000 title claims abstract description 32
- 230000005540 biological transmission Effects 0.000 description 6
- 230000001413 cellular effect Effects 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 238000001228 spectrum Methods 0.000 description 2
- 241000409886 Acion Species 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- JLYXXMFPNIAWKQ-UHFFFAOYSA-N γ Benzene hexachloride Chemical compound ClC1C(Cl)C(Cl)C(Cl)C(Cl)C1Cl JLYXXMFPNIAWKQ-UHFFFAOYSA-N 0.000 description 1
Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/06—TPC algorithms
- H04W52/16—Deriving transmission power values from another channel
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/28—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
- H04W52/286—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission during data packet transmission, e.g. high speed packet access [HSPA]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/28—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
- H04W52/283—Power depending on the position of the mobile
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/28—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
- H04W52/288—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission taking into account the usage mode, e.g. hands-free, data transmission, telephone
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/30—TPC using constraints in the total amount of available transmission power
- H04W52/32—TPC of broadcast or control channels
Abstract
A method of controlling power with which information is transmitted by a first station (4) to a plurality of second stations (6) on a common channel, different information being intended for different stations, said method comprising the step of transmitting said information in said common channel, wherein information intended for different second stations (6) are transmitted at different power levels.
Description
A METHOD OF CONTROLLING POWER
FIELD OF THE INVENTION
The present invention relates to a method of controlling power with which information is transmitted in a common channel. The method may, but not necessarily be used in a wireless cellular system. The information may, but not necessarily be frames of data.
BACKGROUND OF THE INVENTION
The use of code division multiple access (CDMA) is being proposed for the next generation of cellular telecommunication networks.
Additionally, code division multiple access is also being used in the IS-95 Standard in the USA. CDMA is a direct sequence spread spectrum technique. In a wireless cellular network using CDMA, the mobile terminals in one cell associated with a first base station will use the same frequency as mobile stations in an adjacent cell associated with a second base station. The different mobile stations can be distinguished by the respective base stations as each mobile station will be using a different spreading code.
In the proposals for the wideband CDMA standard, it has been proposed that a mobile station or other user equipment in a RACH
(random access channel)/FACH (forward access channel) state use the uplink RACH channel to transmit data or messages to a base station and listen to the downlink FACH for data or messages from the base station. In the RACH/FACH there is little or not data being transmitted between the mobile station and the base station such that no dedicated channels have been set up therebetween.
The FACH and RACH channels are both common channels which means that all the user equipment including mobile stations in a cell
FIELD OF THE INVENTION
The present invention relates to a method of controlling power with which information is transmitted in a common channel. The method may, but not necessarily be used in a wireless cellular system. The information may, but not necessarily be frames of data.
BACKGROUND OF THE INVENTION
The use of code division multiple access (CDMA) is being proposed for the next generation of cellular telecommunication networks.
Additionally, code division multiple access is also being used in the IS-95 Standard in the USA. CDMA is a direct sequence spread spectrum technique. In a wireless cellular network using CDMA, the mobile terminals in one cell associated with a first base station will use the same frequency as mobile stations in an adjacent cell associated with a second base station. The different mobile stations can be distinguished by the respective base stations as each mobile station will be using a different spreading code.
In the proposals for the wideband CDMA standard, it has been proposed that a mobile station or other user equipment in a RACH
(random access channel)/FACH (forward access channel) state use the uplink RACH channel to transmit data or messages to a base station and listen to the downlink FACH for data or messages from the base station. In the RACH/FACH there is little or not data being transmitted between the mobile station and the base station such that no dedicated channels have been set up therebetween.
The FACH and RACH channels are both common channels which means that all the user equipment including mobile stations in a cell
2 associated with a give:: base station will use these channels.
The data is sent in data frames_ Data i=ames sent from the base station to the mobila 3i.aCi0I1S will incllld;. GE:e identity of t hM
:-ser equipment, for a=r.ample the ider.t_t;i .f a mobile statior..
Eacn mobi.le st,acion wi,l receive all the ^?Ca ==ames sent from a 'base station to the mobile station on -h= FACH. Each mobil..
stat:on is able to :de::tif v the data Lrann e in~ended for that mobile station by the + d ntity i r cluded i:_ t he frame. The frames sent from the mobi le s-ation include info=-'ation identifying th?
source or the frames.
:_s a number oL mobile stations or user equipment share the FACN
c~:annel it is di fficuit to set the power le;:el of thac channel such that'it is at the lowest pass:.ble lev;.l and at a level such that all the mobile stations can receive che signals from the base -station. in CDMLA systems, the number o= users which can be supported by the systa-La with a given qualicy of service depends on the total signal power of all the users and the base station in a cell. Ir the total signal power is relativel_v high, this wiLl prov'ide a relatively ha.gh level of interference. This means that it may be difficult to distinguish the desired signal from tha interference resulting from the other base stations.
_"-_ccordingly minimisation of the power used by each user and the base station will improve the capacitv a.n,^/or quality of service.
EP-A-0-892572 describes a 3CCH carrier supporting a physical HCCH such that at least one BCCH tiz-eslot is entirely received within one of the successive monitoring windows of a mobile station of an adjoining cell.
2a SUMMARX OF THE INVENTION
y ~ ? s Zrl aillt oi eP.1DOdi.:3n ts or rtle present in ven-ioil to provide a nechod W'hich addresses r-:fs problem.
According to one as--ecc of -che presen:. invention, there is p::ovided a method off controlling power with which .i.nformazion is r=ar.smitted by a rirso szation to a pluraiit: o= second stations on a common chanr.ai , d_ffer?n-f informatioz bei ng ir_,_anded for
The data is sent in data frames_ Data i=ames sent from the base station to the mobila 3i.aCi0I1S will incllld;. GE:e identity of t hM
:-ser equipment, for a=r.ample the ider.t_t;i .f a mobile statior..
Eacn mobi.le st,acion wi,l receive all the ^?Ca ==ames sent from a 'base station to the mobile station on -h= FACH. Each mobil..
stat:on is able to :de::tif v the data Lrann e in~ended for that mobile station by the + d ntity i r cluded i:_ t he frame. The frames sent from the mobi le s-ation include info=-'ation identifying th?
source or the frames.
:_s a number oL mobile stations or user equipment share the FACN
c~:annel it is di fficuit to set the power le;:el of thac channel such that'it is at the lowest pass:.ble lev;.l and at a level such that all the mobile stations can receive che signals from the base -station. in CDMLA systems, the number o= users which can be supported by the systa-La with a given qualicy of service depends on the total signal power of all the users and the base station in a cell. Ir the total signal power is relativel_v high, this wiLl prov'ide a relatively ha.gh level of interference. This means that it may be difficult to distinguish the desired signal from tha interference resulting from the other base stations.
_"-_ccordingly minimisation of the power used by each user and the base station will improve the capacitv a.n,^/or quality of service.
EP-A-0-892572 describes a 3CCH carrier supporting a physical HCCH such that at least one BCCH tiz-eslot is entirely received within one of the successive monitoring windows of a mobile station of an adjoining cell.
2a SUMMARX OF THE INVENTION
y ~ ? s Zrl aillt oi eP.1DOdi.:3n ts or rtle present in ven-ioil to provide a nechod W'hich addresses r-:fs problem.
According to one as--ecc of -che presen:. invention, there is p::ovided a method off controlling power with which .i.nformazion is r=ar.smitted by a rirso szation to a pluraiit: o= second stations on a common chanr.ai , d_ffer?n-f informatioz bei ng ir_,_anded for
3 PCT/EP00/04230 different stations, said method comprising the step of transmitting said information in said common channel, wherein information intended for different second stations are transmitted at different power levels.
The power level with which information is transmitted is preferably selected in dependence on a parameter of the intended second station and/or the content of the information. The information may be transmitted in the channel with the higher power if the content of the information is relatively important.
Preferably, the information is in the form of data packets.
The information for a given second station may include information identifying the given station. A second mode of operation may be provided in which the first station sends information to the second stations with substantially the same power level, one of the first and second modes being selected.
The first station may receive information from a controller on the power with which information for a respective second station is to be transmitted. The controller may be arranged to send a channel configuration message to the first station to control which of the first and second modes is to be used. The first station may be arranged to send a message to the controller advising the controller if it can perform the mode contained in the channel configuration message. The controller may be arranged to send a channel configuration message to the first station to advise the first station as to the range of power levels which are to be used to transmit information to the second station.
Values representing the power values may be sent to the first station by the controller, the values being mapped to the power levels which are used by the first station to transmit information to the second station.
The power level with which information is transmitted is preferably selected in dependence on a parameter of the intended second station and/or the content of the information. The information may be transmitted in the channel with the higher power if the content of the information is relatively important.
Preferably, the information is in the form of data packets.
The information for a given second station may include information identifying the given station. A second mode of operation may be provided in which the first station sends information to the second stations with substantially the same power level, one of the first and second modes being selected.
The first station may receive information from a controller on the power with which information for a respective second station is to be transmitted. The controller may be arranged to send a channel configuration message to the first station to control which of the first and second modes is to be used. The first station may be arranged to send a message to the controller advising the controller if it can perform the mode contained in the channel configuration message. The controller may be arranged to send a channel configuration message to the first station to advise the first station as to the range of power levels which are to be used to transmit information to the second station.
Values representing the power values may be sent to the first station by the controller, the values being mapped to the power levels which are used by the first station to transmit information to the second station.
4 Preferably, the controller is a radio network controller. This may be in a CDMA network, such as the UMTS network. The first station may be a base station. The second station may comprise mobile stations or any other suitable form of user equipment.
The common channel may be a forward access channel.
According to a second aspect of the present invention, there is provided a method of controlling power with which information is transmitted by a first station to a plurality of second stations on a common channel, different information being intended for different stations, said method comprising a first mode in which the information is transmitted with a the same power and a second mode in which different powers are used for information intended for different second stations.
According to a third aspect of the present invention, there is provided a network comprising a first station and a plurality of second stations, said first station being arranged to transmit different information intended for different second stations on a common channel, said first station have a mode of operation in which said first station is arranged to transmit information intended for different second stations on the common channel at different power levels, and a controller which is arranged to supply information as to the power to be used for said information to said first station.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and as to how the same may be carried into effect, reference will now be made by way of example to the accompanying drawings in which:
Figure 1 shows a schematic diagram of part of a cellular telecommunications network incorporating base transceiver stations and mobile stations;
Figure 2 shows the hierarchy of elements of the network of Figure 1;
Figure 3 shows a schematic view of a frame to be sent on the FACH
The common channel may be a forward access channel.
According to a second aspect of the present invention, there is provided a method of controlling power with which information is transmitted by a first station to a plurality of second stations on a common channel, different information being intended for different stations, said method comprising a first mode in which the information is transmitted with a the same power and a second mode in which different powers are used for information intended for different second stations.
According to a third aspect of the present invention, there is provided a network comprising a first station and a plurality of second stations, said first station being arranged to transmit different information intended for different second stations on a common channel, said first station have a mode of operation in which said first station is arranged to transmit information intended for different second stations on the common channel at different power levels, and a controller which is arranged to supply information as to the power to be used for said information to said first station.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and as to how the same may be carried into effect, reference will now be made by way of example to the accompanying drawings in which:
Figure 1 shows a schematic diagram of part of a cellular telecommunications network incorporating base transceiver stations and mobile stations;
Figure 2 shows the hierarchy of elements of the network of Figure 1;
Figure 3 shows a schematic view of a frame to be sent on the FACH
5 channel from a base station to a mobile station; and Figure 4 shows a schematic view of the transfer of information between a RNC (radio network controller)and the base station.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will first be made to Figure 1 in which three cells 2 of a cellular telecommunications network are shown. Each cell 2 is served by a respective base transceiver station (BTS) 4. Each base transceiver station 4 is arranged to transmit signals to and receive signals from the mobile stations 6 located in the cell associated with the given base transceiver station 4. Likewise, each mobile station 6 is able to transmit signals to and receive signals from the respective base transceiver station 4.
The cellular telecommunications network shown in Figure 1 uses a code division multiple access technique.
Reference is mode to Figure 2 which shows the hierarchy of a CDMA
system. As can be seen, the mobile station 6 is in wireless communication with the base station. Typically a number of mobile stations will be in communication with each base station although only one mobile station is shown in Figure 2 for clarity. The base station 4 is connected to a radio network controller RNC 10.
Again more than one base station is usually connected to each RNC
10 although only one is shown for clarity. Typically more than one RNC is provided in a network. The RNC 10 is connected to other elements of the network 12.
The RNC 10 is arranged to control the base station and also passes on the data packets to be transmitted to the mobile
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will first be made to Figure 1 in which three cells 2 of a cellular telecommunications network are shown. Each cell 2 is served by a respective base transceiver station (BTS) 4. Each base transceiver station 4 is arranged to transmit signals to and receive signals from the mobile stations 6 located in the cell associated with the given base transceiver station 4. Likewise, each mobile station 6 is able to transmit signals to and receive signals from the respective base transceiver station 4.
The cellular telecommunications network shown in Figure 1 uses a code division multiple access technique.
Reference is mode to Figure 2 which shows the hierarchy of a CDMA
system. As can be seen, the mobile station 6 is in wireless communication with the base station. Typically a number of mobile stations will be in communication with each base station although only one mobile station is shown in Figure 2 for clarity. The base station 4 is connected to a radio network controller RNC 10.
Again more than one base station is usually connected to each RNC
10 although only one is shown for clarity. Typically more than one RNC is provided in a network. The RNC 10 is connected to other elements of the network 12.
The RNC 10 is arranged to control the base station and also passes on the data packets to be transmitted to the mobile
6 station by the base station. The RNC 10 will also receive from the base station packets of data which it has received from the mobile station.
Common channels are defined between the mobile stations in the cell associated with a given base station and the given base station. These common channels are the forward access channel (FACH) in the downlink direction and the random access channel (RACH) in the uplink direction. The common channel may alternatively be a downlink shared channel to which a number of mobile stations are allocated. With common channels the same spreading code is used for all communications on a given channel.
As mentioned hereinbefore, the data sent to the mobile station and the data sent from the mobile station is in packet form. The data packets which are sent to the mobile stations on the FACH
will include information identifying the mobile station for which a given packet is intended. A mobile station will receive all the packets sent on the common FACH channel and is able to identify the packets which are intended for it from the information identifying the mobile station. Similarly packets of data which are transmitted to the base station by the mobile stations on the common RACH channel will include information in the data packet which allows the base station to identify from which mobile station the data packet had been received.
The mobile stations and the base stations use the common channels when the amount of data is small and/or sporadic. This means that dedicated channels do not then need to be established. This increases the radio resources available so that more users can be supported and/or the quality of the users is improved.
The base station receives the frames in the RACH channel from 7-he mobile stations and forwards these frames to the RNC 10 via the Iub interface between the base station 4 and the RNC 10. The packets of data to be transmitted to the mobile station on the
Common channels are defined between the mobile stations in the cell associated with a given base station and the given base station. These common channels are the forward access channel (FACH) in the downlink direction and the random access channel (RACH) in the uplink direction. The common channel may alternatively be a downlink shared channel to which a number of mobile stations are allocated. With common channels the same spreading code is used for all communications on a given channel.
As mentioned hereinbefore, the data sent to the mobile station and the data sent from the mobile station is in packet form. The data packets which are sent to the mobile stations on the FACH
will include information identifying the mobile station for which a given packet is intended. A mobile station will receive all the packets sent on the common FACH channel and is able to identify the packets which are intended for it from the information identifying the mobile station. Similarly packets of data which are transmitted to the base station by the mobile stations on the common RACH channel will include information in the data packet which allows the base station to identify from which mobile station the data packet had been received.
The mobile stations and the base stations use the common channels when the amount of data is small and/or sporadic. This means that dedicated channels do not then need to be established. This increases the radio resources available so that more users can be supported and/or the quality of the users is improved.
The base station receives the frames in the RACH channel from 7-he mobile stations and forwards these frames to the RNC 10 via the Iub interface between the base station 4 and the RNC 10. The packets of data to be transmitted to the mobile station on the
7 FACH channel are received by the base station from the RNC 10.
The packets are transferred from the RNC 10 to the base station 4 via the Iub interface. For the transmission of packets between the base station 4 and the RNC 10, the CCH (common channel) frame protocol is used. The frame structure used for the communication of the data between the RNC 10 and the base station 4 will be described hereinafter.
In the embodiments of the invention the power at which the FACH
is transmitted is set at the minimum value which allows the frames to be correctly received at the mobile stations. The power level at which the frames are sent should be such that the mobile stations can receive the frames within the cell and that the degree of interference caused in other cells is as low as possible. Additionaliy the interference to other users in the cell should be minimised. This allows transmission resources to be saved.
In a first embodiment of the present invention, fixed power control is used. The FACH channel is configured in the base station. This differs from the second embodiment where the FACH
channel is set up by the RNC 10. The configuring of the FACH
channel in the base station can be done with a layer 3 message over the Iub interface which is between the base station and the RNC. Alternatively, the configuring of the FACH channel in the base station can be done in response to O&M (operation and maintenance) procedures.
In the fixed power control mode, a constant value for the FACH
channel transmission power is set. This set power level is used for every frame transmitted on the FACH channel. In other words all of the frames transmitted by the base station in the FACH
channel will have the same transmitted power regardless of the mobile station for which the data frame is intended. The power is thus constant for each FACH channel frame and for each mobile
The packets are transferred from the RNC 10 to the base station 4 via the Iub interface. For the transmission of packets between the base station 4 and the RNC 10, the CCH (common channel) frame protocol is used. The frame structure used for the communication of the data between the RNC 10 and the base station 4 will be described hereinafter.
In the embodiments of the invention the power at which the FACH
is transmitted is set at the minimum value which allows the frames to be correctly received at the mobile stations. The power level at which the frames are sent should be such that the mobile stations can receive the frames within the cell and that the degree of interference caused in other cells is as low as possible. Additionaliy the interference to other users in the cell should be minimised. This allows transmission resources to be saved.
In a first embodiment of the present invention, fixed power control is used. The FACH channel is configured in the base station. This differs from the second embodiment where the FACH
channel is set up by the RNC 10. The configuring of the FACH
channel in the base station can be done with a layer 3 message over the Iub interface which is between the base station and the RNC. Alternatively, the configuring of the FACH channel in the base station can be done in response to O&M (operation and maintenance) procedures.
In the fixed power control mode, a constant value for the FACH
channel transmission power is set. This set power level is used for every frame transmitted on the FACH channel. In other words all of the frames transmitted by the base station in the FACH
channel will have the same transmitted power regardless of the mobile station for which the data frame is intended. The power is thus constant for each FACH channel frame and for each mobile
8 station.
The power value set by the RNC can be modified by the base station if required. For example if conditions change or if the base station receives requests to increase its power from the mobile stations, the power level may be altered.
Any suitable method can be used to determine the power at which the FACH channel is to be transmitted. For example, the base station can measure the received signal strength from the mobile stations and select a signal strength based on the received signals. Alternatively, if the base station knows the location of the mobile stations, the signal strength can be selected such that the mobile station which is furthest from the base station receives the frames with the minimum level required. Any other suitable method can be used to determine the power which takes into account at least one parameter relating to the mobile stations. In preferred embodiments of the present invention the value used to transmit the frames to the mobile stations is always the same but will vary in order to take into account changes in the cell.
In a second embodiment of the present invention, dynamic power control is used. In dynamic power control the power with which each frame is transmitted is varied in dependence on a parameter of the destination mobile station. Thus the power at which data frames are transmitted may vary from frame to frame. In this embodiment, when the forward access channel is to be set up, it is indicated to the base station that the power with which each frame is to be transmitted is set by the RNC 10. This information may be provided from the RNC 10 to the base station via the Iub interface or in any other suitable manner.
The RNC 10 receives information from the mobile stations via the base station. This information may include measurement reports
The power value set by the RNC can be modified by the base station if required. For example if conditions change or if the base station receives requests to increase its power from the mobile stations, the power level may be altered.
Any suitable method can be used to determine the power at which the FACH channel is to be transmitted. For example, the base station can measure the received signal strength from the mobile stations and select a signal strength based on the received signals. Alternatively, if the base station knows the location of the mobile stations, the signal strength can be selected such that the mobile station which is furthest from the base station receives the frames with the minimum level required. Any other suitable method can be used to determine the power which takes into account at least one parameter relating to the mobile stations. In preferred embodiments of the present invention the value used to transmit the frames to the mobile stations is always the same but will vary in order to take into account changes in the cell.
In a second embodiment of the present invention, dynamic power control is used. In dynamic power control the power with which each frame is transmitted is varied in dependence on a parameter of the destination mobile station. Thus the power at which data frames are transmitted may vary from frame to frame. In this embodiment, when the forward access channel is to be set up, it is indicated to the base station that the power with which each frame is to be transmitted is set by the RNC 10. This information may be provided from the RNC 10 to the base station via the Iub interface or in any other suitable manner.
The RNC 10 receives information from the mobile stations via the base station. This information may include measurement reports
9 where the mobile station provides information on the strength with which it receives signals from the base station.
Alternatively or additionally, the RNC 10 may receive information from the base station as to the strength with which it has received signals from the mobile station. Either or both of these types of information allow the RNC 10 to determine an appropriate power level with which a given frame should be transmitted to a given mobile station on the FACH. This type of power control is referred to as open loop power control.
Any other suitable information may be supplied to the RNC 10 in order to allow it to determine a suitable power level. This may be in addition to or as an alternative to the received signal strength report(s). For example, the received signal strength reports may include an indication as to the quality of the signal. The RNC 10 may use information on the position of the mobile station to determine the strength with which frames are transmitted to the mobile station. The position may be obtained from information provided by the base station and/or the mobile station.
The base station may in certain circumstances alter the power set by the RNC 10. The base station may take into account other factors in modifying the power with which it transmits to the mobile stations. These factors can for example take into account the conditions in the cell, the location of the mobile station in the cell, the total amount of traffic or users in the cell or the like. Alternative the power level can be altered in response to the strength of signals received at the base station.
The power used for the transmission of a frame may be selected in accordance with the importance of the data contained within the frame. If the data contained in the frame is relatively important the power with which that frame is transmitted can be increased.
Based on the determination made by the RNC 10, a power is determined which is the power with which a given frame is to be transmitted to the mobile station. This power level is inserted in the CCH frame protocol frame and is sent to the base station 5 4. The base station 4 uses this power level to transmit the associated frame to the mobile station on the common channel FACH. The power level sent by the RNC 10 to the base station can be the actual power level to be used. However in preferred embodiments of the invention, the power level can be sent as a
Alternatively or additionally, the RNC 10 may receive information from the base station as to the strength with which it has received signals from the mobile station. Either or both of these types of information allow the RNC 10 to determine an appropriate power level with which a given frame should be transmitted to a given mobile station on the FACH. This type of power control is referred to as open loop power control.
Any other suitable information may be supplied to the RNC 10 in order to allow it to determine a suitable power level. This may be in addition to or as an alternative to the received signal strength report(s). For example, the received signal strength reports may include an indication as to the quality of the signal. The RNC 10 may use information on the position of the mobile station to determine the strength with which frames are transmitted to the mobile station. The position may be obtained from information provided by the base station and/or the mobile station.
The base station may in certain circumstances alter the power set by the RNC 10. The base station may take into account other factors in modifying the power with which it transmits to the mobile stations. These factors can for example take into account the conditions in the cell, the location of the mobile station in the cell, the total amount of traffic or users in the cell or the like. Alternative the power level can be altered in response to the strength of signals received at the base station.
The power used for the transmission of a frame may be selected in accordance with the importance of the data contained within the frame. If the data contained in the frame is relatively important the power with which that frame is transmitted can be increased.
Based on the determination made by the RNC 10, a power is determined which is the power with which a given frame is to be transmitted to the mobile station. This power level is inserted in the CCH frame protocol frame and is sent to the base station 5 4. The base station 4 uses this power level to transmit the associated frame to the mobile station on the common channel FACH. The power level sent by the RNC 10 to the base station can be the actual power level to be used. However in preferred embodiments of the invention, the power level can be sent as a
10 coded value. This coded value is received by the base station and is mapped onto the actual power level using the maximum and minimum power limits.
In the FACH channel set up message sent from the RNC 10 to the base station 4, there is an indication as the maximum and minimum transmission power levels which are forwarded to the base station for the packets transmitted passed from the RNC 10 to the base station 4. The CCH frame protocol frames from the RNC to the base station contain the power level to be used by the base station for the transmission of the frame in the FACH channel. The structure of the frame sent from the RNC 10 to the base station 4 is shown in Figure 3. The frame contains information on the power level PC, the data DATA, the frame number FN and an error correction part CRC.
In a third embodiment of the present invention, the FACH may sometimes use fixed power control and at other times may use dynamic power control. This third embodiment will be described in relation to Figure 4.
In this third embodiment, the FACH channel set up message 14 sent from the RNC 10 to the base station 4 will include an indication if fixed or dynamic power control is used. The set up message may have a power mode bit which has one value if fixed power control is used and another value if dynamic power control is used. The
In the FACH channel set up message sent from the RNC 10 to the base station 4, there is an indication as the maximum and minimum transmission power levels which are forwarded to the base station for the packets transmitted passed from the RNC 10 to the base station 4. The CCH frame protocol frames from the RNC to the base station contain the power level to be used by the base station for the transmission of the frame in the FACH channel. The structure of the frame sent from the RNC 10 to the base station 4 is shown in Figure 3. The frame contains information on the power level PC, the data DATA, the frame number FN and an error correction part CRC.
In a third embodiment of the present invention, the FACH may sometimes use fixed power control and at other times may use dynamic power control. This third embodiment will be described in relation to Figure 4.
In this third embodiment, the FACH channel set up message 14 sent from the RNC 10 to the base station 4 will include an indication if fixed or dynamic power control is used. The set up message may have a power mode bit which has one value if fixed power control is used and another value if dynamic power control is used. The
11 base station will send an acknowledgement message advising the RNC that it has understood which mode is to be used and that the FACH channel is to be set up.
If the set up message from the RNC 10 to the base station 4 does not include any indication as to the power control mode, it may be assumed that the dynamic power control mode is being used. It should be noted that if the RNC 10 is arranged to always provide power control information to the base station, the RNC can provide constant power control values in the fixed power control mode and varying power control values in the normal mode. In this latter case, the base station would not need to be advised of the mode.
If the base station is not able to support one of the modes, the base station will advise the RNC of this in the acknowledgement message which it sends to the RNC 10.
A given base station may not be able to support one of the modes, probably the dynamic mode. In that case, the other mode will be used. In a network some base stations will be able to use both modes whilst other base stations will only be able to support one or other of the modes.
In a default mode of operation, the power used to transmit the FACH channel may be set to a default value. This default value may be relatively high to ensure that all the mobile stations are able to receive their data frames. This default mode may be provided in any of the three embodiments described hereinbefore.
One or other of the dynamic and fixed power control modes may be a default mode.
The frame protocol used may have any suitable format. For example the frame protocol may be in accordance with the 25.435 and 25.437 standards of the UMTS (universal mobile telecommunications
If the set up message from the RNC 10 to the base station 4 does not include any indication as to the power control mode, it may be assumed that the dynamic power control mode is being used. It should be noted that if the RNC 10 is arranged to always provide power control information to the base station, the RNC can provide constant power control values in the fixed power control mode and varying power control values in the normal mode. In this latter case, the base station would not need to be advised of the mode.
If the base station is not able to support one of the modes, the base station will advise the RNC of this in the acknowledgement message which it sends to the RNC 10.
A given base station may not be able to support one of the modes, probably the dynamic mode. In that case, the other mode will be used. In a network some base stations will be able to use both modes whilst other base stations will only be able to support one or other of the modes.
In a default mode of operation, the power used to transmit the FACH channel may be set to a default value. This default value may be relatively high to ensure that all the mobile stations are able to receive their data frames. This default mode may be provided in any of the three embodiments described hereinbefore.
One or other of the dynamic and fixed power control modes may be a default mode.
The frame protocol used may have any suitable format. For example the frame protocol may be in accordance with the 25.435 and 25.437 standards of the UMTS (universal mobile telecommunications
12 system).
In this description, reference has been made to mobile stations.
However, it should be appreciated that ernbodiments of the present invention are applicable to any other type of user equipment which communicates with the base station or similar station using radio waves or the like. The user equipment may in some embodiments of the invention be computer terminals or the like. The user equipment need not be mobile.
It should be appreciated that in the new CDMA standard, base stations are sometimes referred to as node B.
It should be appreciated that whilst embodiments of the present invention have been described in the context of a CDMA system, embodiments of the present invention can be used with any other spread spectrum technique, with time division multiple access systems, frequency division multiple access and hybrids thereof.
In this description, reference has been made to mobile stations.
However, it should be appreciated that ernbodiments of the present invention are applicable to any other type of user equipment which communicates with the base station or similar station using radio waves or the like. The user equipment may in some embodiments of the invention be computer terminals or the like. The user equipment need not be mobile.
It should be appreciated that in the new CDMA standard, base stations are sometimes referred to as node B.
It should be appreciated that whilst embodiments of the present invention have been described in the context of a CDMA system, embodiments of the present invention can be used with any other spread spectrum technique, with time division multiple access systems, frequency division multiple access and hybrids thereof.
Claims (25)
1. A method of controlling power with which information is transmitted by a first station to a plurality of second stations on a common channel, different parts of said information being intended for different stations, said method comprising the step of transmitting said different parts of said information in said common channel, wherein said different parts of said information intended for different second stations are transmitted at different power levels, wherein said first station receives information from a radio network controller on the power with which information for a respective second station is to be transmitted.
2. A method as claimed in claim 1, wherein the power level with which information is transmitted is selected in dependence on a parameter of the intended second station and/or the content of the information.
3. A method as claimed in claim 2, wherein the information is transmitted in said channel with a higher power if the content of the information is important.
4. A method as claimed in any one of claims 1 to 3, wherein said information is in the form of data packets.
5. A method as claimed in any one of claims 1 to 4, wherein said information for a given second station includes information identifying the given station.
6. A method as claimed in any one of claims 1 to 5, wherein a second mode of operation is provided in which the first station sends information to said second stations with substantially the same power level, one of said first and second modes being selected.
7. A method as claimed in claim 6, wherein the radio network controller is arranged to send a channel configuration message to the first station to control which of said first and second modes is be used.
8. A method as claimed in claim 7, wherein said first station is arranged to send a message to said radio network controller advising the radio network controller if it can perform the mode contained in the channel configuration message.
9. A method as claimed in claimed in any of claims 1 to 8, wherein said radio network controller is arranged to send a channel configuration message to the first station to advise the first station as to the range of power levels are to be used to transmit information to the second stations.
10. A method as claimed in any of claims 1 to 9, wherein values representing the power levels are sent to the first station by said radio network controller, said values being mapped to the power levels which are used by said first station to transmit information to said second station.
11. A method as claimed in any one of claims 1 to 10, wherein said first station is a base station.
12. A method as claimed in any one of claims 1 to 11, wherein said second stations comprise mobile stations.
13. A method as claimed in any one of claims 1 to 12, wherein said common channel is a forward access channel.
14. A method of controlling power with which user data is transmitted by a first station to a plurality of second stations on a common channel, different parts of said user data being intended for different stations, said method comprising a first mode in which the different parts of said user data is transmitted with a the same power and a second mode in which different powers are used for said different parts of said user data intended for different second stations.
15. A network comprising a first station and a plurality of second stations, said first station being arranged to transmit different parts of information intended for different second stations on a common channel, said first station having a mode of operation in which said first station is arranged to transmit said different parts of said information intended for different second stations on the common channel at different power levels said network further comprising a radio network controller which is arranged to supply information as to the power to be used for said information to said first station.
16. A network as claimed in claim 15, wherein said power level is selected in dependence on a parameter of the intended second station and/or the content of the information.
17. A network as claimed in any one of claims 15 and 16, wherein said first station is a base station and said second stations are user terminals.
18. A network as claimed in any one of claims 15 to 17, wherein information sent from said radio network controller to the base station comprises said power information and said information for a second station.
19. A network as claimed in any of claims 15 to 18, wherein a second mode of operation is provided in which the first station sends information to said second stations with substantially the same power level, one of said first and second modes being selected.
20. A network as claimed in claim 19, wherein the radio network controller is arranged to send a channel configuration message to the first station to control which of said first and second modes is be used.
21. A network as claimed in any one of claims 19 and 20, wherein said first station is arranged to send a message to said radio network controller advising the controller if it can perform the mode contained in the channel configuration message.
22. A network as claimed in claimed in any of claims 15 to 21, wherein said radio network controller is arranged to send a channel configuration message to the first station to advise the first station as to the range of power levels are to be used to transmit information to the second stations.
23. A radio network controller for controlling power with which information is transmitted by a base station to a plurality of user terminals on a common channel, different parts of said information being intended for different user terminals, said controller being arranged to control the power levels of said different parts of said information intended for different user terminals.
24. A base station for transmitting information to a plurality of user terminals on a common channel, different parts of said information being intended for different user terminals, said base station being arranged to transmit said different parts of said information in said common channel, wherein said different parts of said information intended for different user terminals are transmitted at different power levels, said base station being arranged to receive information as to the power to be used for said different parts of said information.
25. A network comprising a first station and a plurality of second stations, said first station being arranged to transmit different parts of user data intended for different second stations on a common channel, said first station having a mode of operation in which said first station is arranged to transmit said different parts of said user data intended for different second stations on the common channel at different power levels, wherein a second mode of operation is provided in which the first station sends user data to said second stations with substantially the same power level, one of said first and second modes being selected.
Applications Claiming Priority (3)
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| GBGB9912846.4A GB9912846D0 (en) | 1999-06-02 | 1999-06-02 | A method of controlling power |
| GB9912846.4 | 1999-06-02 | ||
| PCT/EP2000/004230 WO2000076083A1 (en) | 1999-06-02 | 2000-05-09 | A method of controlling power |
Publications (2)
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| CA2375696A1 CA2375696A1 (en) | 2000-12-14 |
| CA2375696C true CA2375696C (en) | 2009-07-21 |
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| CA002375696A Expired - Lifetime CA2375696C (en) | 1999-06-02 | 2000-05-09 | A method of controlling power |
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| EP (1) | EP1181783B2 (en) |
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| US20020172186A1 (en) * | 2001-04-09 | 2002-11-21 | Peter Larsson | Instantaneous joint transmit power control and link adaptation for RTS/CTS based channel access |
| US10355825B2 (en) * | 2004-07-21 | 2019-07-16 | Qualcomm Incorporated | Shared signaling channel for a communication system |
| JP4513974B2 (en) * | 2005-06-27 | 2010-07-28 | 日本電気株式会社 | Wireless communication network that broadcasts high-priority information, method for changing the same, and wireless communication network design tool |
| US7664091B2 (en) * | 2005-10-03 | 2010-02-16 | Motorola, Inc. | Method and apparatus for control channel transmission and reception |
| CN101426254B (en) | 2007-10-31 | 2010-12-08 | 华为技术有限公司 | Method, apparatus and system for information transmission implementation |
| CN101426253B (en) | 2007-10-31 | 2013-08-07 | 华为技术有限公司 | Method, apparatus and system for information transmission implementation |
| US8774105B2 (en) * | 2008-11-10 | 2014-07-08 | Qualcomm Incorporated | Communications methods and apparatus related to partitioned traffic segments |
| US8208459B2 (en) * | 2008-11-10 | 2012-06-26 | Qualcomm Incorporated | Partitioned traffic segment communications methods and apparatus |
| US8923910B2 (en) * | 2010-02-25 | 2014-12-30 | Qualcomm Incorporated | Methods and apparatus for communicating information using various transmission power levels |
| US20120236953A1 (en) * | 2011-03-14 | 2012-09-20 | Markus Dominik Mueck | Base Station |
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| US5267262A (en) | 1989-11-07 | 1993-11-30 | Qualcomm Incorporated | Transmitter power control system |
| GB2296625B (en) * | 1994-12-23 | 1999-04-14 | Nokia Mobile Phones Ltd | Apparatus and method for data transmission |
| CA2188455C (en) | 1995-02-23 | 2003-07-15 | Yukihiko Okumura | Variable rate transmission method, transmitter and receiver using the same |
| JP3098180B2 (en) | 1995-10-09 | 2000-10-16 | キヤノン株式会社 | Cordless phone system |
| US6067446A (en) * | 1996-07-11 | 2000-05-23 | Telefonaktiebolaget Lm Ericsson | Power presetting in a radio communication system |
| FI105866B (en) | 1996-12-04 | 2000-10-13 | Nokia Networks Oy | The method produces a general channel carrier and radio system |
| US6347083B1 (en) * | 1997-02-24 | 2002-02-12 | Oki Electric Industry Co., Ltd. | Transmission power control apparatus for a CDMA system |
| CA2278755A1 (en) | 1997-04-16 | 1998-10-22 | Ntt Mobile Communications Network Inc. | Code division multiple access communication method |
| CN1783754A (en) | 1997-04-17 | 2006-06-07 | Ntt移动通信网株式会社 | Base station apparatus of mobile communication system |
| CA2485891A1 (en) | 1997-04-17 | 1998-10-22 | Ntt Mobile Communications Network Inc. | Base station apparatus of mobile communication system |
| US6259927B1 (en) * | 1997-06-06 | 2001-07-10 | Telefonaktiebolaget Lm Ericsson | Transmit power control in a radio communication system |
| FR2766316B1 (en) * | 1997-07-17 | 1999-09-24 | Alsthom Cge Alcatel | NON-CONSTANT POWER BCCH CARRIER AND CORRESPONDING METHOD FOR MEASURING THE SIGNAL LEVEL RECEIVED BY A MOBILE STATION ON SUCH A CARRIER |
| US6498785B1 (en) * | 1998-10-02 | 2002-12-24 | Nokia Mobile Phones Ltd | Method and apparatus for power control on a common channel in a telecommunication system |
| US6628956B2 (en) * | 1999-03-15 | 2003-09-30 | Telefonaktiebolaget Lm Ericsson (Publ) | Adaptive power control in a radio communications systems |
| EP1047206A1 (en) | 1999-04-20 | 2000-10-25 | Alcatel | A power control method implemented in a base station of a CDMA type transmission network, and corresponding apparatus and base station |
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1999
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2000
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- 2000-05-09 AT AT00931178T patent/ATE320677T1/en not_active IP Right Cessation
- 2000-05-09 WO PCT/EP2000/004230 patent/WO2000076083A1/en active IP Right Grant
- 2000-05-09 US US09/980,377 patent/US7797012B1/en not_active Expired - Fee Related
- 2000-05-09 CN CN2007101619019A patent/CN101159453B/en not_active Expired - Lifetime
- 2000-05-09 PT PT00931178T patent/PT1181783E/en unknown
- 2000-05-09 JP JP2001502244A patent/JP2003501938A/en active Pending
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- 2000-05-09 CN CN00809632A patent/CN1358356A/en active Pending
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- 2000-05-09 CA CA002375696A patent/CA2375696C/en not_active Expired - Lifetime
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2005
- 2005-11-10 JP JP2005326567A patent/JP2006115532A/en active Pending
Also Published As
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| CA2375696A1 (en) | 2000-12-14 |
| EP1181783B2 (en) | 2009-10-28 |
| EP1181783A1 (en) | 2002-02-27 |
| DK1181783T3 (en) | 2006-07-24 |
| JP2006115532A (en) | 2006-04-27 |
| KR20020006052A (en) | 2002-01-18 |
| WO2000076083A1 (en) | 2000-12-14 |
| CN1358356A (en) | 2002-07-10 |
| US7797012B1 (en) | 2010-09-14 |
| DE60026699T2 (en) | 2006-12-14 |
| ES2260013T5 (en) | 2010-03-03 |
| ES2260013T3 (en) | 2006-11-01 |
| PT1181783E (en) | 2006-06-30 |
| CN101159453A (en) | 2008-04-09 |
| EP1181783B1 (en) | 2006-03-15 |
| ATE320677T1 (en) | 2006-04-15 |
| DE60026699D1 (en) | 2006-05-11 |
| CN101159453B (en) | 2013-08-21 |
| BR0011099A (en) | 2002-03-05 |
| AU4919800A (en) | 2000-12-28 |
| DE60026699T3 (en) | 2010-02-25 |
| GB9912846D0 (en) | 1999-08-04 |
| DK1181783T4 (en) | 2010-01-18 |
| JP2003501938A (en) | 2003-01-14 |
| KR100729418B1 (en) | 2007-06-18 |
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