AU2004307535B2 - A method and a device for reducing impact of interference on a control channel - Google Patents
A method and a device for reducing impact of interference on a control channel Download PDFInfo
- Publication number
- AU2004307535B2 AU2004307535B2 AU2004307535A AU2004307535A AU2004307535B2 AU 2004307535 B2 AU2004307535 B2 AU 2004307535B2 AU 2004307535 A AU2004307535 A AU 2004307535A AU 2004307535 A AU2004307535 A AU 2004307535A AU 2004307535 B2 AU2004307535 B2 AU 2004307535B2
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- AU
- Australia
- Prior art keywords
- control channel
- wireless communication
- communication unit
- control channels
- replicated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K3/00—Jamming of communication; Counter-measures
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K3/00—Jamming of communication; Counter-measures
- H04K3/20—Countermeasures against jamming
- H04K3/22—Countermeasures against jamming including jamming detection and monitoring
- H04K3/224—Countermeasures against jamming including jamming detection and monitoring with countermeasures at transmission and/or reception of the jammed signal, e.g. stopping operation of transmitter or receiver, nulling or enhancing transmitted power in direction of or at frequency of jammer
- H04K3/226—Selection of non-jammed channel for communication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
- H04W48/10—Access restriction or access information delivery, e.g. discovery data delivery using broadcasted information
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K2203/00—Jamming of communication; Countermeasures
- H04K2203/10—Jamming or countermeasure used for a particular application
- H04K2203/16—Jamming or countermeasure used for a particular application for telephony
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
- H04W24/04—Arrangements for maintaining operational condition
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/541—Allocation or scheduling criteria for wireless resources based on quality criteria using the level of interference
Description
WO 2005/041606 PCT/EP2004/051692 A METHOD AND A DEVICE FOR REDUCING IMPACT OF INTERFERENCE ON A CONTROL CHANNEL Field of the Invention The present invention relates to wireless communication systems, in general, and reducing impact of interference on a control channel, in particular.
Background of the Invention Wireless telecommunication systems provide voice and data transmission from places where communication based on Public Switched Telephone Network (PSTN) or other wired networks is not possible. Quality of communication link in radio transmission can be affected by interference and jamming. It is important to highlight that the term "jamming" is used in situations where an interfering signal is generated intentionally and for unintentional signals the same phenomenon is called interference. However in both situations the physical phenomenon is the same and is known as interference, thus each time herein below when the term "interference" is used it covers both intentional and unintentional signals that cause interference unless otherwise stated. For systems operating in trunking mode, with a base station serving in one cell the interference on the main control channel might make the cell unusable to legitimate subscribers' wireless communication units.
The impact of the interference on a control channel frequency can be reduced in such a way that the cell shall still remain operational and continue the expected WO 2005/041606 PCT/EP2004/051692 2 service, with a possible reduction in capacity efficiency of the cell.
The term a "jamming device" herein below refers to a transmitter that intentionally transmits radio waves (interferences) at the same frequency which system transmitters (mobile and base station) work on. That signal corrupts some of data exchanged between the wireless communication unit and the base station (BS), and makes it impossible for these terminals to decode the information.
A jamming device might make a whole cell useless by generating an interfering signal on that control channel. Once it happens, all the wireless communication units that are camped on that control channel and listen to the broadcast on that channel, lose the connection to the BS, and leave the cell.
The jamming signal is considered to be generated on either downlink or uplink frequencies of a main carrier to corrupt the received information to the wireless communication units or BSs. If the interference source succeeds in this, the entire cell would be useless to the subscribers using the wireless communication units.
Jamming of downlink signalling is easier due to the fact that the downlink signal is always present and therefore is more vulnerable to analysis and selective attack.
There is known in the prior art a solution to the problem of jamming and interference defined in a standard for TErrestrial Trunked RAdio (TETRA) system, as defined by the European Telecommunications Standards Institute (ETSI). A primary focus for TETRA equipment is the emergency services, as TETRA provides a dispatch and control operation. Each wireless communication unit is able to transmit and receive control, voice and data information. The system infrastructure in a TETRA system is generally referred to as a switching and management infrastructure (SWMI), which substantially contains all of the system elements apart from the wireless communication units.
A backup control channel as defined in the TETRA standard, replaces the main control channel, once the main control channel goes off. A jamming device which is capable of jamming the control channel, may switch to the backup channel and to jam it as well once it detects that the SWMI has switched to the backup. There is no need to a more powerful jamming device for that. Besides, the wireless communication units are always on the same channel, so all of them are affected, by jamming a single channel.
A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.
Summary of the Invention There is a need for a method of reducing the impact of an interference of a control channel and for a wireless communication unit and base transceiver station which are able to operate according to the method and which alleviate the disadvantages of the prior art.
According to a first aspect of the present invention there is provided a method of reducing impact of interference on a first downlink control channel used by a base transceiver station in a digital wireless communication system, wherein the first control channel is replicated into a plurality of further control channels when interference on the first control channel is detected, availability of the further control channels is transmitted to wireless communication units on a broadcast control channel and each of the wireless communication units operating on the first control channel selects a different control channel from the further control channels to receive downlink information from the base station, wherein each of the replicated control channels delivers the same downlink W VmanGA8NODEL\IRN769755 ,ep4aced pags JI 07 doc information to all wireless communication units served by the base transceiver station so that each wireless communication unit is able to receive the same downlink information on any selected one of the further control channels.
According to a second aspect of the present invention there is provided a wireless communication unit operable in the method as described above.
The wireless communication unit may comprise receiver circuitry, transmitter circuitry, a signal processor operably coupled to the receiver circuitry and/or the transmitter circuitry and a memory coupled to the signal processor, wherein the receiver circuitry and the signal processor are adapted to receive and decode information about replicated downlink control channels sent by a base transceiver station following detection of interference on a first downlink control channel, to store the information in the form of a table in the memory, to select, using data stored in the memory, a control channel from the replicated control channels to receive downlink information from the base station and to switch the current control channel to the selected replicated control channel to receive downlink information.
According to a third aspect of the present invention there is provided a base transceiver station adapted for use in the method described above, the base transceiver station being operable to replicate a first downlink control channel into a plurality of downlink control channels when interference on the first downlink control channel is detected, and to transmit information about the replicated control channels to wireless communication units served by the base transceiver station over a broadcast control channel, and to deliver the same downlink information on each of the replicated downlink control channels whereby communication units which select any of the replicated channels will receive the same downlink information.
The present invention may beneficially allow for minimizing the effect of interference by the fact that the communication devices may be distributed over different control channels and jamming one of the channel affects only part of the wireless communication units operating in the cell. As there are other WVane GABNOOEL\IRN769755. eo acd ,ages -2 Ju 1070 oc control channels the wireless communication units from the jammed or affected by interference control channel can switch to another one. Jamming of all control channels is difficult as it requires more powerful jamming device. To jam all the control channels the jamming device needs N times power, assuming that there are N control channels.
Brief description of the drawings The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: FIG. 1 is a flow chart illustrating a method of reducing impact of jamming of a control channel in one embodiment of the present invention, FIG. 2 is a block diagram of a mobile station in one embodiment of the present invention.
Detailed description of an embodiment of the invention Referring to FIG. 1 one embodiment of a method of reducing impact of interference on a control channel according to the present invention is shown.
W Vnane1GABNOOEL\IRN76Q755 replaced pages. 2 Jul 07 doc WO 2005/041606 PCT/EP2004/051692 The impact of interference on a control channel is reduced by replication 104 of the first control channel into plurality of control channels and switching communication devices to the replicated control channels. Each of these replicated control channels comprises exactly the same downlink information as the first control channel. The first control channel is replicated after detection 102 of interference on the first control channel. Once the base transceiver station detects the interference the replication is performed by the base transceiver station. When the first control channel is replicated a base transceiver station transmits 106 over a broadcast control channel a list of available, replicated, control channels.
When the information transmitted 106 over the broadcast control channel is received by the communication device said information is further decoded and stored 108 in a form of a list of the available control channels in a memory of said wireless communication unit. The list is dynamically updated as the base transceiver station transmits the new lists with available control channels. Some of the control channels can be closed 124 due to necessity of allocation of bandwidth to other services.
To provide good quality of service, in one embodiment, if said list of available control channels contains more than one control channel the communication device measures quality 110 of the available control channels. In one embodiment the measure of quality can be a ratio of good packets to bad packets received on the control channel by the communication device. However for those skilled in the art it is clear that other methods of measuring quality could also be applied.
WO 2005/041606 PCT/EP2004/051692 6 As the result of measuring of the quality of the control channels they are being prioritized according to their quality 112 and the ones with the quality below a predefined value are not selected by the wireless communication unit 114 for switching. The communication device switches 118 to one of the control channels with quality equal or above the predefined control level.
In one embodiment the wireless communication unit switches 118 to one of the replicated control channels after predefined period of time of operation on a current control channel 126, 128. Selection of the control channel for switching 118 is done randomly.
Random selection has the advantage that the communication devices are equally distributed over the control channels and additionally makes jamming more difficult as it is not possible to predict on which control channel operates and will operate particular communication device. However switching to other control channels according to a predefined pattern is also possible.
If the jamming device continues its operation also on the replicated control channels or interference appears on any of the replicated control channels the wireless communication units operating on the control channel affected by the interference switch to other of the replicated control channels when the interference is detected on their current control channel. The wireless communication unit always switches to other control channel once it detects interference on its current control channel.
In one embodiment the replicated control channels are closed and their bandwidth is freed for other WO 2005/041606 PCT/EP2004/051692 7 services if the interference or jamming signal disappeared.
In one embodiment the base transceiver station transmits the information on the available control channels in repetitions and for the repetitions different broadcast control channels are used.
With reference to Fig. 2 an embodiment of a wireless communication unit 200, which is capable to operate according to the above described method is shown. The wireless communication unit 200 comprises an antenna 206, a Radio Frequency (RF) switch 204 and a receiver section 208, which together form a receiver circuitry. A transmitter section 202, the RF switch 204 and the antenna 206 form together a transmitter circuitry. A signal processor 210 is operably coupled to the receiver and/or transmitter circuitries as well as to a memory 212. The communication device comprises also an audio output section 224 and 226 as well as a microphone 220. A keypad 216 and a display 218 form a user interface that allows controlling the communication device 200.
In operation, when the base transceiver station transmits over the broadcast control channel information on available, replicated, control channels, the receiving circuitry and the signal processor 210 receives and decodes that information and stores in a form of a table in the memory 212. The communication device 200 switches the current control channel to one of the replicated control channels.
The wireless communication unit 200 switches to one of the replicated channels after predefined period of WO 2005/041606 PCT/EP2004/051692 8 time of operation on a current control channel.
Selection of the control channel to switch is performed in a random manner. However in alternative embodiment the control channel to switch is selected in accordance with a predefined pattern.
In one embodiment the signal processor 210 of the communication device 200 calculates a ratio of good packets to bad packets received on each of the control channels. The calculated ratio is a measure of quality of each of the control channels and is used for prioritization of the control channels. The control channels with the quality measure below a predefined value are not selected for switching.
It is obvious for those skilled in the art that the embodiments described above may be equally used for reducing impact of both unintentional and intentional (jamming) interference.
It is worth to emphasize that the information on all control channels is identical, and a wireless communication unit may switch from one control channel to another without missing any broadcast information. In one embodiment of the present invention, the wireless communication unit switches to a control channel for a predefined period of time, and then picks up another control channel randomly from the pool of the available control channels in the cell, and switches over. This mechanism also overcomes a smart jamming device that tries to chase after a specific wireless communication unit.
What is also worth to emphasize is that the present invention allows for dynamic change of number of control WO 2005/041606 PCT/EP2004/051692 9 channels depending on the available bandwidth. If there is a free bandwidth in the cell it can be used for the replicated control channel. If there is a plurality of control channels in the cell and there is a demand for a bandwidth, some of the control channels can be closed and the bandwidth can be made available for other services.
In case of a cell with multiple control channel the wireless communication units that operate on the jammed control channel are affected, but the ones that listening to the other control channel are getting full service from the base transceiver station.
Claims (21)
1. A method of reducing impact of interference on a first downlink control channel used by a base transceiver station in a digital wireless communication system, wherein the first control channel is replicated into a plurality of further control channels when interference on the first control channel is detected, availability of the further control channels is transmitted to wireless communication units on a broadcast control channel and each of the wireless communication units operating on the first control channel selects a different control channel from the further control channels to receive downlink information from the base station, wherein each of the replicated control channels delivers the same downlink information to all wireless communication units served by the base transceiver station so that each wireless communication unit is able to receive the same downlink information on any selected one of the further control channels.
2. The method according to claim 1, wherein the information transmitted on the broadcast control channel is decoded and stored in the form of a list of available control channels in a memory of each of the wireless communication units.
3. The method according to claim 1 or 2, wherein each of the wireless communication units switches to one of the further control channels after a predefined period of time of operation on a current one of the further control channels.
4. The method according to claim 1 or 2, wherein the further control channels are prioritized by each communication unit according to their quality, and the control channels having a quality below a predefined value as detected by any given communication unit are not selected by the wireless communication unit.
The method according to claim 4, wherein each of the wireless communication units continuously monitors the quality of the control channels W V ane\GABNODELIRN769755 replaced 2ages J 107 oc I and scores the quality based upon a ratio of good packets to bad packets 0 received.
6. The method according to any one of the preceding claims, wherein each wireless communication unit switches from one control channel to another control channel in a random manner.
7. The method according to any one of claims 1 to 5, wherein each wireless q communication unit switches from one control channel to another control S 10 channel in accordance with a predefined pattern. (Ni
8. The method according to any one of the preceding claims, wherein all of the communication units switch back to one downlink control channel and the remaining, replicated, control channels are closed when the interference is detected to have disappeared.
9. A wireless communication unit operable in the method according to any one of the preceding claims.
10. A wireless communication unit according to claim 9 comprising receiver circuitry, transmitter circuitry, a signal processor operably coupled to the receiver circuitry and/or the transmitter circuitry and a memory coupled to the signal processor, wherein the receiver circuitry and the signal processor are adapted to receive and decode information about replicated downlink control channels sent by a base transceiver station following detection of interference on a first downlink control channel, to store the information in the form of a table in the memory, to select, using data stored in the memory, a control channel from the replicated control channels to receive downlink information from the base station and to switch the current control channel to the selected replicated control channel to receive downlink information.
11. The wireless communication unit according to claim 10 adapted to detect interference on its current control channel. W ~nnexGAHNODELIRN76975S replacod pages 2JuI07 dec 12
12. The wireless communication unit according to claim 10 or 11 which is adapted to switch to one of the replicated channels after a predefined period of time of operation on a current control channel.
13. The wireless communication unit according to claim 10 or 11, wherein the signal processor is adapted to calculate a ratio of good packets to bad packets received on each of the replicated control channels to determine a quality of the control channels.
14. The wireless communication unit according to any one of claims 10 to 13, wherein the signal processor is adapted to switch operation of the communication unit from one control channel to another randomly selected control channel.
15. The wireless communication unit according to any one of claims 10 to 13, wherein the signal processor is adapted to switch the operation of the communication unit from one control channel to another control channel in accordance with a predefined pattern.
16. A base transceiver station adapted for use in the method according to claim 1, the base transceiver station being operable to replicate a first downlink control channel into a plurality of downlink control channels when interference on the first downlink control channel is detected, and to transmit information about the replicated control channels to wireless communication units served by the base transceiver station over a broadcast control channel, and to deliver the same downlink information on each of the replicated downlink control channels whereby communication units which select any of the replicated channels will receive the same downlink information.
17. The base transceiver station according to claim 16 adapted to transmit repeatedly over more than one broadcast control channel the information about the replicated control channels, wherein on each repetition a different broadcast control channel is used. W Vane\GABNODEL\lRN76G755 (epaced pages 2 Jul 07 doc 13
18. The base transceiver station according to claim 16 or 17 which is Sadapted to detect interference on the first downlink control channel.
19. A method according to claim 1 substantially as hereinbefore described with reference to FIG. 1 of the accompanying drawings. er
20. A wireless communication unit according to claim 10 substantially as hereinbefore described with reference to FIG. 2 of the accompanying drawings. O 10
21. A base transceiver station according to claim 16 and operable in the N method substantially as hereinbefore described with reference to FIG. 1 of the accompanying drawings. W VnaneMGABNCOELXIRN769755 replaced pages 2 JO 07 Odc
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0324625.3 | 2003-10-22 | ||
| GB0324625A GB2407455B (en) | 2003-10-22 | 2003-10-22 | A method and a device for reducing impact of interference on a control channel |
| PCT/EP2004/051692 WO2005041606A1 (en) | 2003-10-22 | 2004-08-02 | A method and a device for reducing impact of interference on a control channel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2004307535A1 AU2004307535A1 (en) | 2005-05-06 |
| AU2004307535B2 true AU2004307535B2 (en) | 2007-08-09 |
Family
ID=29595592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2004307535A Ceased AU2004307535B2 (en) | 2003-10-22 | 2004-08-02 | A method and a device for reducing impact of interference on a control channel |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP1680937A1 (en) |
| KR (1) | KR100827944B1 (en) |
| CN (1) | CN1868234A (en) |
| AU (1) | AU2004307535B2 (en) |
| CA (1) | CA2541818A1 (en) |
| GB (1) | GB2407455B (en) |
| WO (1) | WO2005041606A1 (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101480550B1 (en) * | 2008-03-26 | 2015-01-20 | 엘지전자 주식회사 | Method for Performing Intercell Interference Coordination |
| US8319615B2 (en) | 2009-12-21 | 2012-11-27 | Continental Automotive Systems, Inc. | Apparatus and method for detecting jamming of communications |
| US8896431B2 (en) | 2009-12-21 | 2014-11-25 | Continental Automotive Systems, Inc. | Apparatus and method for compromised vehicle tracking |
| US10027682B2 (en) | 2009-12-21 | 2018-07-17 | Continental Automotive Systems, Inc. | Apparatus and method for detecting a cloned base station |
| US8320872B2 (en) * | 2009-12-21 | 2012-11-27 | Continental Automotive Systems, Inc. | Apparatus and method for broadcasting the detection of RF jammer presence |
| US8639209B2 (en) | 2009-12-21 | 2014-01-28 | Continental Automotive Systems, Inc. | Apparatus and method for detecting a cloned base station |
| US8159336B2 (en) | 2009-12-21 | 2012-04-17 | Continental Automotive Systems Us, Inc. | Apparatus and method for maintaining communication with a stolen vehicle tracking device |
| US8884821B2 (en) | 2009-12-21 | 2014-11-11 | Continental Automotive Systems, Inc. | Apparatus and method for determining vehicle location |
| US8611847B2 (en) | 2009-12-21 | 2013-12-17 | Continental Automotive Systems, Inc. | Apparatus and method for detecting communication interference |
| US9102293B2 (en) | 2009-12-21 | 2015-08-11 | Continental Automotive Systems, Inc. | Apparatus and method for reducing false alarms in stolen vehicle tracking |
| US8175573B2 (en) | 2009-12-21 | 2012-05-08 | Continental Automotive Systems, Inc. | Apparatus and method for maintaining communications with a vehicle in the presence of jamming |
| US20110222491A1 (en) * | 2010-03-09 | 2011-09-15 | Qualcomm Incorporated | Method and apparatus for sending control information with enhanced coverage in a wireless network |
| CN102437886A (en) * | 2011-10-14 | 2012-05-02 | 上海移为通信技术有限公司 | Method for detecting man-made interference |
| US9031538B2 (en) | 2012-02-16 | 2015-05-12 | Continental Automotive Systems, Inc. | Method and apparatus to determine if a cellular jamming signal is malicious or non-malicious based on received signal strength |
| US8982825B2 (en) | 2013-03-13 | 2015-03-17 | Motorola Solutions, Inc. | Method and device to support site activation using a hailing channel |
| CN105208614A (en) * | 2015-10-19 | 2015-12-30 | 上海斐讯数据通信技术有限公司 | Automatic switching device and switching method for wireless channels |
| US10243929B2 (en) * | 2016-03-30 | 2019-03-26 | Qualcomm Incorporated | Uplink control channel scheduling for jamming resilience |
| CN108834178B (en) * | 2018-06-25 | 2021-07-20 | 东方通信股份有限公司 | PDT cluster system auxiliary control channel design method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03125523A (en) * | 1989-10-11 | 1991-05-28 | Fujitsu Ltd | Duplicating system for control channel in mobile communication |
| US5778318A (en) * | 1994-01-14 | 1998-07-07 | Nokia Telecommunications Oy | Method for allocating channels in a radio system |
| US6301481B1 (en) * | 1998-12-28 | 2001-10-09 | Nortel Networks Limited | Optimum MACA-based channel allocation for TDMA call setup |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4434506A (en) * | 1980-12-23 | 1984-02-28 | Nippon Electric Co., Ltd. | Circuit arrangement for protecting a control channel from jamming waves in a radio communication system |
| DE3611301C2 (en) * | 1986-04-04 | 1997-09-25 | Philips Patentverwaltung | Mobile radio system with communication channel and organization channel |
| GB2293523B (en) * | 1994-09-21 | 1998-08-05 | Motorola Ltd | Radio base station equipment with non-constant offset duplex trunking |
| JPH0951291A (en) * | 1995-08-03 | 1997-02-18 | Fujitsu Ltd | Control channel changeover method |
-
2003
- 2003-10-22 GB GB0324625A patent/GB2407455B/en not_active Expired - Fee Related
-
2004
- 2004-08-02 CA CA002541818A patent/CA2541818A1/en not_active Abandoned
- 2004-08-02 AU AU2004307535A patent/AU2004307535B2/en not_active Ceased
- 2004-08-02 EP EP04766399A patent/EP1680937A1/en not_active Withdrawn
- 2004-08-02 KR KR1020067007737A patent/KR100827944B1/en not_active IP Right Cessation
- 2004-08-02 WO PCT/EP2004/051692 patent/WO2005041606A1/en active IP Right Grant
- 2004-08-02 CN CNA2004800306026A patent/CN1868234A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03125523A (en) * | 1989-10-11 | 1991-05-28 | Fujitsu Ltd | Duplicating system for control channel in mobile communication |
| US5778318A (en) * | 1994-01-14 | 1998-07-07 | Nokia Telecommunications Oy | Method for allocating channels in a radio system |
| US6301481B1 (en) * | 1998-12-28 | 2001-10-09 | Nortel Networks Limited | Optimum MACA-based channel allocation for TDMA call setup |
Non-Patent Citations (2)
| Title |
|---|
| PAJ & JP 03125523 A * |
| PAJ & JP 09051291 A * |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2407455A (en) | 2005-04-27 |
| KR20060073640A (en) | 2006-06-28 |
| GB2407455B (en) | 2006-08-23 |
| AU2004307535A1 (en) | 2005-05-06 |
| CA2541818A1 (en) | 2005-05-06 |
| EP1680937A1 (en) | 2006-07-19 |
| CN1868234A (en) | 2006-11-22 |
| GB0324625D0 (en) | 2003-11-26 |
| KR100827944B1 (en) | 2008-05-13 |
| WO2005041606A1 (en) | 2005-05-06 |
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