GB2356322A - Method of determining communications mode - Google Patents
Method of determining communications mode Download PDFInfo
- Publication number
- GB2356322A GB2356322A GB0104514A GB0104514A GB2356322A GB 2356322 A GB2356322 A GB 2356322A GB 0104514 A GB0104514 A GB 0104514A GB 0104514 A GB0104514 A GB 0104514A GB 2356322 A GB2356322 A GB 2356322A
- Authority
- GB
- United Kingdom
- Prior art keywords
- trunked
- direct mode
- mobile
- mode
- mobile station
- 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.)
- Granted
Links
- 238000004891 communication Methods 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000011664 signaling Effects 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 description 14
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000010267 cellular communication Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/12—Frequency diversity
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
- H04W36/302—Reselection being triggered by specific parameters by measured or perceived connection quality data due to low signal strength
-
- 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
- H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/04—Large scale networks; Deep hierarchical networks
- H04W84/08—Trunked mobile radio systems
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
A method of determining whether to communicate or handover between direct mode and trunked mode in a communications system having a base station for trunked communications and a first mobile station and a second mobile station communicating in a direct mode. The method includes receiving a first transmitted signal from the first mobile station at the second mobile station, receiving channel control information from the base station at the first and second mobile station, and determining to communicate in trunked mode based on a signal strength of the first transmitted signal and the channel control information.
Description
2356322 METHOD OF DETERMINING COMMUNICATIONS MODE
Field of the Invention
This invention relates to a method of determining a communications mode and optimising the quality of a communication link in a communications system.
Specifically, a method of determining a communications mode and handover in a trunked communications system involving direct mode communications.
Background of the Invention
A trunked communications system typically comprises a base station and a plurality of mobile stations. The mobile stations may communicate in trunked mode, via the base station, or in direct mode. A problem with allowing both trunked and direct mode communications in the same system is effectively managing such communications. Mobile stations in direct mode may still need to receive messages from the base station and the base station needs to know where the mobile stations are.
Furthern-lore, mobiles in direct mode may need to switch to trunked mode and vice versa.
A mobile radio operating in a trunked radio system may communicate with other radios in the system via the base station using two-frequency half-duplex operation. In contrast, a radio may also communicate directly with another radio using single frequency simplex operation. This is also known as direct mode communication.
It may be desirable for two radios communicating in trunked mode to hand over to direct mode communication if they are within direct mode range. This would have the advantage of releasing a trunked channel for other communications which may be beneficial, particularly when the trunked system is heavily loaded.
Conversely, it may also be desirable for two radios communicating in direct mode to hand over to trunked mode communications if the radios are about to move out of direct mode range and are within the coverage of a trunked system.
Handover is a well-known technique used in trunked and cellular communication systems to transfer a mobile radio communication from one base station to another as that mobile radio moves between base station coverage areas.
The invention proposes a method for handover from the base station of a trunked system to direct mode where radios communicate without the need for a base station.
There is a need to effectively move mobile radios from trunked mode to direct mode and vice versa in communications systems that allow the different operating modes. Such capability will allow the efficient use of the communications resources as well as improve the quality of the communications.
CM00458PDOI/CT/GB/Aitkenhead -2- Summary of the Invention
According to the present invention, a method of determining whether to communicate in a trunked mode in a communications system having a base station for trunked communications and a first mobile station and a second mobile station communicating in a direct mode. The method includes the steps of receiving a first transmitted signal from the first mobile station at the second mobile station, receiving channel control information from the base station at the first and second mobile station, and determining to communicate in trunked mode based the received channel control information.
A preferred embodiment of the invention is now described, by way of example only, with reference to the drawings.
Brief Description of Drawings
FIG. 1 shows a communications system including a base station 14 and mobile stations 10,12.
FIG. 2 shows a flowchart of a method performed in the system of figure 1.
FIG. 3 shows a flowchart according to an embodiment of the invention.
FIG. 4 shows a frame and timeslot structure for signalling according to an embodiment of the present invention.
Detailed Description of the Drawings
FIG. I shows a block diagram of a radio communications system having a central controller or base station 14 for trunked communications. The communications system of FIG. 1 also includes a first mobile station 10 and a second mobile station 12 capable of communicating in trunked mode or direct mode. In trunked mode communications, the mobile stations communicate to each other via the base station. In practice, the transmitting radio 10 transmits a signal on a first frequency, uplink, to the base station which then communicates the signal on a second frequency, downlink, to the receiving radio, downlink. In direct mode, the mobile stations may communicate directly to each other without communicating via the base station.
FIG. 2 shows a method of determining whether to communicate in direct mode in a communications system (FIG. 1) having a first mobile station 10 and a second mobile CM0045 8PDO 1/CT/GB/Aitkenhead -3- station 12 communicating via the base station 14. Referring to FIG. 2, a second mobile station 12 is receiving a signal from the first mobile station 10 via the base station on a second frequency (downlink frequency) in trunked mode, step 20. The second mobile station switches to the trunked mode uplink channel, a first frequency, as in step 22. The second mobile station then monitors signals on the first frequency, from the first mobile station, measures the received - signal strength and averages as in step 24. A determination may be made as to whether the signal strength average is sufficient, for example, greater than a predetermined threshold, as in step 26.
If the signal strength is below a threshold value the mobile stations continue to communicate in trunked mode and the second mobile may periodically monitor the uplink frequency for signals of sufficient signal strength, thus returning to step 20.
If the signal strength or signal strength average is determined to be greater than the threshold then the second mobile station transmits to the first mobile station, or transmit mobile, via the base station that they may communicate in direct mode, step 28.
The first mobile station, or transmit radio, may then scan for an available direct mode channel, step 30. If there is no direct mode channel available as determined in step 32 the first and second mobile station continue to communicate in trunked mode, step 20. If a direct mode channel is available the first mobile station may signal to the second mobile station to change to direct mode on the available direct mode channel, step 34. A signal may also be transmitted to the base station to inform the base station that the first and second mobile station have left truriked mode communication and are communicating in direct mode on the available direct mode channel. The mobile stations then continue communicating in direct mode, step 36.
FIG. 3 shows an embodiment of the present invention. Specifically a method of determining whether to communicate in a trunked mode is shown for a communications system having a base station for trunked communications and a first mobile station and a second mobile station communicating in a direct mode.
Referring to FIG. 3, a first mobile station and a second mobile station communicating in direct mode may monitor the trunked control channel average received signal strength, trunked signal RSSI, as in step 40. In step 42, the second mobile station, or receiving radio, measures the average received signal strength from the first mobile station, or transmit radio, in direct mode communication, direct mode RSSI.
If the direct mode RSSI is not less than a predetermined threshold value as determined in step 43 then the mobile stations continue communicating in direct mode and continue to monitor the trunked signal RSSI as in steps 40, 42.
CM00458PDOI/CT/GB/Aitkenhead -4- If the direct mode RSSI is less than a predetermined threshold as determined in step 43, a determination is made in step 44 as to whether the trunked signal RSSI, as measured in step 42, is greater than a first predetermined threshold.
If the trunked signal RSSI is not greater than the predetermined threshold as determined in step 44, then the mobile stations continue communicating in direct mode and continue to monitor the trunked signal RSSI as in steps 40, 42.
If the trunked signal RSSI is greater than the predetermined threshold the receive radio transmits to the transmitting radio to change to trunked mode as in step 46. The transmit radio must be able to detect the trunked signals, or the trunked RSSI must be greater than a second predetermined threshold as determined in step 48. The second predetermined threshold may be similar to the first predetermined threshold.
If the trunked RSSI is not greater than a second predetermined threshold, then the mobile stations continue communicating in direct mode and continue to monitor the trunked signal RSSI as in steps 40, 42.
If the trunked RSSI is greater than the second predetermined threshold the transmit radio signals to the receive radio on the direct mode channel that it is about to change to trunked mode, step 50. The transmit radio then sets up the call on the trunked system, step 53. The mobiles then continue to communicate in trunked mode, step 54.
Thus, by receiving a first transmitted signal from the first mobile station at the second mobile station, receiving channel control information from the base station at the first and second mobile stations, and making a determination whether to communicate in trunked mode based on the received channel control information, the mobile stations are making effective use of the communications resources. The determination of whether to communicate in trunked mode may be based on the received channel control information and the received transmitted signals.
The arrangement of figure I provides a method for detecting the possibility for handover between trunked mode and direct mode enabled by the use of time division multiplexing in the trunked mode and time burst transmission in direct mode. In this arrangement, there may be a signalling exchange to ensure that continuous communications can be maintained as the radios move between the two modes of operation.
A mobile to mobile communication in a trunked system is conveyed via a base station. A first mobile transmits on an uplink frequency, fl, to the base station. The base station then repeats this transmission on a downlink frequency, f2, which is then received by a second mobile. In a TDMA trunked system, the uplink and downlink frequencies are divided into timeslots and thus, a mobile transmitting or receiving only does so for the duration of a single timeslot. Hence transmission and reception is discontinuous.
CM0045 8PDO I/CT/GB/Aitkenhead -5- In contrast, a mobile may operate in direct mode. In direct mode, a first mobile transmits on a direct mode frequency and a second mobile receives on that same frequency. In a communications system such as TETRA, the first mobile station transmission and the second mobile station reception is discontinuous.
Before being able to hand over a trunked mode communication to direct mode, the communicating mobiles must first establish that they are in direct mode range, as referenced in the discussion of FIG. 2. Such operation is made possible by a TDMA frame structure as used in TETRA which is shown in FIG. 4.
Thus, the operation of the method of FIG. 2 is easily implemented with a TDMA frame structure. Such frame and time slot structure may be used to detect if the mobiles are in direct mode range. The TDNIA slot structure is such that there are four slots per frame with a two slot offset between slots transmitted on the uplink frequency and those transmitted on the downlink frequency, FIG. 4. This means that a mobile receiving traffic 'on a traffic channel by receiving the downlink slots assigned to that channel can also switch to the uplink frequency and monitor the uplink slot of the same traffic channel. In this way, the receiving mobile, as well as receiving the traffic channel transmissions from the base station, can also monitor the transmissions of the transmitting radio. It can determine the signal strength or signal quality of these uplink transmissions in order to determine whether or not the transmitting radio is in direct mode range. Generally, the receiving radio may monitor several uplink transmissions over a period of a few seconds in order to average out any fluctuations in the signal level due to fading. The receiving radio may also attempt to decode the uplink transmissions and compare them with the downlink transmissions to ensure that the signal strength being measured on the uplink is indeed as a result of the transmitting mobile and not interference from some other source.
An advantage of the present invention is that by receiving both the uplink and downlink transmissions, a receiving radio has the opportunity to perform diversity combining of the two slots containing the same information which may improve the overall quality of the received signal. This improvement may be useful if either of the mobiles have a poor communication link to the trunked system base station but the mobiles are within direct mode coverage.
According to the arrangement of Fig. 1, and as described with respect to Fig. 2, the receiving radio records the direct mode signal strength and when it reaches a level which would support adequate direct mode communications the receiving radio can inform the transmitting mobile.
Thus, having ascertained that the transmitting radio is in direct mode range, the receiving radio can inform the transmitting radio via the base station by using the slow associated control channel (SACCH). This control channel allows a mobile transmitting CM00458PDOI/CT/GB/Aitkenhead -6- or receiving on a traffic channel to exchange signalling information with the base station approximately once per second. Using this channel, the receiving radio sends a signalling message to the base station which is then passed onto the transmitting mobile also using the SACCH. The signalling message has a parameter which can have one of 5 the following values:
I - Receiving mobile is in direct mode range; 2 - Receiving mobile is out of direct mode range; 3 - Receiving mobile is about to lose system range and is inside direct mode range.
Using such signalling the receiving radio can inform the transmitting radio that it is able to switch to direct mode if necessary or that it has moved out of direct mode range. This allows the transmitting mobile to make the decision as to whether or not to switch over to direct mode. Such a decision may be made automatically or by the user of the radio. If the receiving mobile is about to lose system range, then it can inforni the transmitting mobile in order to initiate a handover to direct mode. In all cases, the transmitting mobile initiates any change to direct mode.
Thus, the transmitting mobile can change to direct mode if it has been informed by the receiving mobile that this is possible. As also described with reference to FIG. 2, the transmitting mobile can scan direct mode channels in between uplink transmissions in order to find a direct mode channel that is free. The transmitting mobile then signals to the receiving mobile to change to the direct mode channel by stealing signalling capacity from the traffic channel. This signalling also informs the system that the communication is about to be dropped as the mobiles change to direct mode. The communication then continues on the direct mode channel using the same frame timing to ensure that synchronisation is not lost. In this way, seamless handover can be achieved and communication can be maintained.
In accordance with the present invention, and as described with reference to FIG.
3, a direct mode to trunked mode handover may also be performed. In order to initiate a handover to trunked mode, the radios must be inside system coverage. In between uplink transmissions, the transmitting mobile can monitor the trunked system control channel frequency and measure the received signal strength in order to ensure that it is inside range of the system. The receiving mobile can also perform such measurements in between receiving bursts on the direct mode channel. In this way both mobiles can ensure that they are inside system coverage before initiating handover.
CM00458PDOI/CT/GB/Aitkenhead -7- The receiving mobile may use the reverse signalling channel on the direct mode frequency in order to inform the transmitting mobile that it is inside system coverage and that direct mode range may be failing.
The transmitting mobile initiates the change to trunked mode by informing the receiving mobile to change to the control channel of the trunked system and then requesting a channel to continue the communication, similar to setting up a new call on the trunked system.
Alternatively, the transmitting mobile may attempt to set up the communication on the trunked channel by signalling in between direct mode communications and then informing the receiving mobile that it has changed to the trunked channel where communication may continue.
The arrangement of figure 1 provides a method to apply time diversity to combine a communication which is recieved in direct mode as well as in trunked mode a's well as to effectively and efficiently handover between trunked and direct modes of operation within the same communication system. By the use of time division multiplexing in trunked mode and time burst transmission in direct mode which allow such diversity and handover to be applied with minimal interruption of the ongoing communication, the integrity of the communications is increased. Thus, the above arrangements are of advantage for communications systems to implement different modes of operation effectively.
Claims (2)
1. A method of determining whether to communicate in a trunked mode in a communications system having a base station for trunked communications and a first mobile station and a second mobile station communicating in a direct mode, the method comprising the steps of:
receiving a first transmitted signal from the first mobile station at the second mobile station; receiving channel control information from the base station at the first and second mobile station; and deterTnining to communicate in tnanked mode based on a signal strength of the first transmitted signal and the channel control information.
2. The method of claim I further comprising the steps of the first mobile station and the second mobile station signalling in direct mode to coordinate transfer of communications to trunked mode.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9616296A GB2316271B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0104514D0 GB0104514D0 (en) | 2001-04-11 |
| GB2356322A true GB2356322A (en) | 2001-05-16 |
| GB2356322B GB2356322B (en) | 2001-07-25 |
Family
ID=10797944
Family Applications (3)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9616296A Expired - Lifetime GB2316271B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
| GB0104514A Expired - Fee Related GB2356322B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
| GB0104512A Expired - Fee Related GB2356532B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9616296A Expired - Lifetime GB2316271B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0104512A Expired - Fee Related GB2356532B (en) | 1996-08-02 | 1996-08-02 | Method of determining communications mode |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0853861A2 (en) |
| AU (1) | AU3770497A (en) |
| GB (3) | GB2316271B (en) |
| WO (1) | WO1998006228A2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5995500A (en) * | 1997-07-18 | 1999-11-30 | Telefonaktiebolaget Lm Ericsson | Method and apparatus for direct communication between mobile stations |
| US6484027B1 (en) | 1998-06-15 | 2002-11-19 | Sbc Technology Resources, Inc. | Enhanced wireless handset, including direct handset-to-handset communication mode |
| US6996088B1 (en) | 1998-09-18 | 2006-02-07 | Harris Corporation | Distributed trunking mechanism for VHF networking |
| EP1114542B1 (en) * | 1998-09-18 | 2008-03-12 | Harris Corporation | Distributed trunking mechanism for a vhf network |
| FR2786055B1 (en) * | 1998-11-16 | 2001-01-05 | Raoul Parienti | SHORT-RANGE COMMUNICATION DEVICE |
| JP3661481B2 (en) * | 1999-03-30 | 2005-06-15 | 富士通株式会社 | In-vehicle communication device |
| US6744750B1 (en) | 1999-09-28 | 2004-06-01 | Siemens Information & Communication Mobile, Llc | Replicating and recombinant networking systems and methods for wireless networks |
| US6470189B1 (en) * | 1999-09-29 | 2002-10-22 | Motorola, Inc. | Method and apparatus in a wireless transceiver for seeking and transferring information available from a network server |
| JP2001230723A (en) * | 2000-02-17 | 2001-08-24 | Matsushita Electric Ind Co Ltd | Mobile communication method |
| GB2362069A (en) * | 2000-05-03 | 2001-11-07 | Motorola Inc | Optimising communication wherein a transmission procedure is determined according to information about the environment in which a mobile station is located |
| GB2368494B (en) * | 2000-10-23 | 2002-07-03 | Motorola Israel Ltd | Wireless communication system,wireless communication unit and method of call set-up |
| GB2377854B (en) * | 2001-07-18 | 2004-01-28 | Motorola Inc | Call set-up in a radio communication system |
| FI114074B (en) | 2001-12-07 | 2004-07-30 | Nokia Corp | Systems in a digital radio network system for disseminating information |
| DE10206698B4 (en) * | 2002-02-15 | 2013-12-12 | Definiens Ag | Apparatus and method for receiving data packets in wavebound signals for use in a remotely controlled communication network and a method for accessing a remotely controlled communication network |
| GB2390510A (en) | 2002-07-05 | 2004-01-07 | Nokia Corp | Direct mode communication between mobiles |
| TW200721738A (en) * | 2002-07-31 | 2007-06-01 | Interdigital Tech Corp | Wireless personal communicator and communication method |
| SE0202847L (en) | 2002-09-26 | 2004-03-27 | Lars Edman | Method and device |
| CN1527635A (en) * | 2003-03-07 | 2004-09-08 | 皇家飞利浦电子股份有限公司 | Method and system for establishing radio reciprocal communication |
| CN1322769C (en) * | 2003-09-19 | 2007-06-20 | 华为技术有限公司 | Method for backward transmitting message in digital honeycomb network group communication system |
| WO2005060300A1 (en) * | 2003-12-15 | 2005-06-30 | Philips Intellectual Property & Standards Gmbh | Wireless system comprising a first station and a second station system |
| GB2415864B (en) * | 2004-07-02 | 2007-04-25 | Motorola Inc | A communication unit,a cellular communication system and a method of operation therefor |
| WO2010005348A1 (en) * | 2008-07-07 | 2010-01-14 | Telefonaktiebolaget L M Ericsson (Publ) | Switching between modes of operation for mobile communications |
| US20110103240A1 (en) | 2009-10-29 | 2011-05-05 | Qualcomm Incorporated | Method for forwarding in peer-to-peer wireless communications |
| US8565803B2 (en) * | 2010-08-23 | 2013-10-22 | Motorola Solutions, Inc. | Method and apparatus for communicating amongst two-way radios |
| US9451419B2 (en) | 2013-07-25 | 2016-09-20 | Motorola Solutions, Inc. | Method and system for seamlessly switching between a trunked mode operation and a direct mode operation |
| CN105636217A (en) * | 2014-11-07 | 2016-06-01 | 北京三星通信技术研究有限公司 | Method and device used for accessing cellular network |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0723464A (en) * | 1993-07-01 | 1995-01-24 | Mitsubishi Electric Corp | Communication system |
| GB2287612A (en) * | 1994-02-25 | 1995-09-20 | Motorola Ltd | Communications system |
| WO1995034180A2 (en) * | 1994-06-02 | 1995-12-14 | Nokia Telecommunications Oy | A method of selecting the transmission to be received in a mobile radio system, and a mobile station |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5423055A (en) * | 1993-06-29 | 1995-06-06 | Motorola, Inc. | Trunked communication system with automatic repeater talk-around |
| GB2285723B (en) * | 1994-01-18 | 1997-09-10 | Motorola Ltd | Communications system |
| GB9411908D0 (en) * | 1994-06-14 | 1994-08-03 | John Heyer Paper Ltd | Web monitoring for paper machines |
| JPH08163636A (en) * | 1994-12-09 | 1996-06-21 | Sony Corp | Digital cordless telephone system |
-
1996
- 1996-08-02 GB GB9616296A patent/GB2316271B/en not_active Expired - Lifetime
- 1996-08-02 GB GB0104514A patent/GB2356322B/en not_active Expired - Fee Related
- 1996-08-02 GB GB0104512A patent/GB2356532B/en not_active Expired - Fee Related
-
1997
- 1997-07-21 AU AU37704/97A patent/AU3770497A/en not_active Abandoned
- 1997-07-21 WO PCT/EP1997/003965 patent/WO1998006228A2/en not_active Application Discontinuation
- 1997-07-21 EP EP97934520A patent/EP0853861A2/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0723464A (en) * | 1993-07-01 | 1995-01-24 | Mitsubishi Electric Corp | Communication system |
| GB2287612A (en) * | 1994-02-25 | 1995-09-20 | Motorola Ltd | Communications system |
| WO1995034180A2 (en) * | 1994-06-02 | 1995-12-14 | Nokia Telecommunications Oy | A method of selecting the transmission to be received in a mobile radio system, and a mobile station |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2356322B (en) | 2001-07-25 |
| GB0104512D0 (en) | 2001-04-11 |
| WO1998006228A3 (en) | 1998-03-19 |
| GB2316271A (en) | 1998-02-18 |
| GB2356532A (en) | 2001-05-23 |
| GB9616296D0 (en) | 1996-09-11 |
| EP0853861A2 (en) | 1998-07-22 |
| GB2356532B (en) | 2001-07-18 |
| GB2316271B (en) | 2001-04-18 |
| GB0104514D0 (en) | 2001-04-11 |
| AU3770497A (en) | 1998-02-25 |
| WO1998006228A2 (en) | 1998-02-12 |
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| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20120802 |