GB2321160A - Adaptive TDMA communication system - Google Patents
Adaptive TDMA communication system Download PDFInfo
- Publication number
- GB2321160A GB2321160A GB9625538A GB9625538A GB2321160A GB 2321160 A GB2321160 A GB 2321160A GB 9625538 A GB9625538 A GB 9625538A GB 9625538 A GB9625538 A GB 9625538A GB 2321160 A GB2321160 A GB 2321160A
- Authority
- GB
- United Kingdom
- Prior art keywords
- slot
- mobile station
- format
- uplink
- downlink
- 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
- 230000003044 adaptive effect Effects 0.000 title 1
- 230000005540 biological transmission Effects 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 8
- 230000001413 cellular effect Effects 0.000 claims description 5
- 241000269799 Perca fluviatilis Species 0.000 description 6
- 239000000969 carrier Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2643—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA]
- H04B7/2656—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA] for structure of frame, burst
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Time-Division Multiplex Systems (AREA)
- Small-Scale Networks (AREA)
Abstract
Downlink communication between a base station and a mobile station occurs in a first format of more than one time slot of a time division multiplexed frame or a second format of one slot per frame when the mobile station performs an uplink transmission using the second format. Single or multiple slot per frame formats can be selected by the mobile station according to whether a high or low rate of data transmission is required. The uplink communication channel may be of the common access type, and both the uplink and downlink slots may be spaced in frequency and spaced in time by less than the duration of one slot.
Description
PACKET DATA
The present invention relates to packet data communication in a telecommunication system, especially but not exclusively the RCR-27 personal digital cellular system.
In a cellular telecommunication system comprising base stations and subscriber mobile stations, many packet transactions between the subscriber mobile stations and the base stations make very heavy use of the downlink but relatively light use of the uplink between the base stations and the mobile stations. Internet applications exemplify this since most data flow takes place from the Internet to the subscriber via the downlink.
With this consideration in mind, the present invention provides a method, and a telecommunication system, in which the format of a channel for packet communication is varied according to the nature of the packet transaction.
Within the confines of a given system protocol and the specific hardware of a system, this allows the telecommunication system to manage the characteristics of the packet channel to best suit its need.
Exemplary embodiments of the invention are hereinafter described with reference to the accompanying drawings, in which:
Figure 1 illustrates the frequency allocation in the 800 MHz frequency band in the
RCR system;
Figure 2 illustrates the structure of a superframe in the RCR system;
Figure 3 shows the structure of an I-frame or layer 2 unit; and
Figure 4 shows an example of a packet transaction between a base station and a mobile station.
The Japanese RCR-27 personal digital cellular system is a Time Division Multiple
Access (TDMA) system. An overview of the RCR-27 system is given below to facilitate understanding of the invention. For more details of how the system operates, the following standards specifications should be consulted: reference 1
RCR STD-27D (Packet ver. Revisions) Layer Standards, and reference 2 - RCR
STD-27D (Packet ver. Revisions) Layer3 Standards.
Communication between a base station BS and a mobile station MS takes place via two discrete frequency bands, one reserved for communications from the base station BS to the mobile station MS, the downlink, and one reserved for communication from the mobile station MS to the base station BS, the uplink, as illustrated in Figure 1. In the example in Figure 1, the downlink accommodates 641 physical carriers between 810 MHz and 826 MHz at 25 kHz intervals. For each physical carrier in the downlink, there is a corresponding physical carrier in the uplink. In the uplink, the physical carriers are also at 25 kHz intervals located between 940 MHz and 956 MHz.
Each physical carrier has data transmitted on it in the form of a supenframe.
Referring to Figure 2, each superframe 100 consists of 36 (0 . . 35) frames of 20 ms duration and each frame 102 consists of three slots 104 (0 . . 2) each of 6.6 ms duration. A superframe lasts 720 ms. Each frame can be assigned the role of either a user traffic channel TCH or a control channel CCH. The superframes in the uplink and downlink are transmitted with a small offset in time. The uplink control channels are common access whereby any mobile station MS can apply to the base station to use the channel at any opportunity.
In order to register with the base station BS, the mobile station MS scans a subset of the downlink physical carriers, which have been predefined by the network operator, as being perch channels. The signal strength on each perch channel is ascertained and arranged in signal strength order. Starting with the perch channel having the strongest received signal strength, the mobile station MS attempts to synchronise and decode the data in slot 2 of the perch channel. This slot is assigned to a control channel, more particularly the broadcast control channel
BCCH. The broadest control channel BCCH contains information about the cell or zone including, for example, the control channel structure, network identity, location area, neighbouring zones, restrictions on use and the like. The BCCH information also includes information indicating which slots have been reserved for the role of the user packet channel UPCH. This UPCH information is in the form of data indicating the physical carrier and the slot of the superframe transmitted on that physical carrier.
If the BCCH information is not decodable from the perch channel with the highest received signal strength, the mobile station MS tries the perch channel with the next highest received signal strength and so on.
Having decoded the BCCH information, the mobile station MS is able to make a request to be registered in the cell or zone. Having been registered with the base station BS, the MS station enters standby mode. In standby mode, the MS station wakes up only during those slots of the control channel CCH superframe which have been assigned the role of paging channels PCH in order to monitor whether it is being paged by the base station BS for a packet or voice transaction.
A packet transaction can be either initiated from the mobile station MS ('mobileoriginated transaction') or initiated from the base station ('mobile-terminated transaction').
A mobile-originated packet transaction is initialised as follows. The mobile station
MS synchronises to one of the dedicated user packet channels UPCH in the downlink (as previously decoded from the BCCH information). Via the corresponding uplink slot, the mobile station MS makes a request for packet communication. As part of the request the mobile station MS indicates whether it is seeking a high or low speed packet channel and whether it is capable of supporting full duplex communication. In a high speed packet channel, 2 or 3 slots (0..2) of the 3-slot frame allocated for the user packet channel UPCH are used to carry packet data ('multi-slot'). In a low speed packet channel, a single slot of the frame allocated for the user packet channel UPCH is used to carry packet data ('singleslot'). Via the assigned downlink slot, the mobile station MS can receive approval for either a multi-slot or a single-slot channel.
A mobile-terminated packet data transaction is initialised when the mobile station
MS detects that it is being paged via a paging channel PCH, as previously described. Thereafter, the procedure for initialising the transaction is the same as for the mobile-originated transaction.
Packet data is transmitted as a sequence of Frames or layer 2 (of the standard OSI seven layer model) LAPDm units. As shown in Figure 3, each frame 50 comprises a head unit 52, an end unit 54 and any number of intermediate units 53. Each unit occupies a single slot of the user packet channel UPCH.
Figure 4 shows an example of a packet transaction in which both a multi-slot and a single-slot user packet channel UPCH format are employed.
Initially, in frames 0-4, the base station BS sends three I-frames Idi, ld2 and ld3 via the downlink. The mobile station MS is not transmitting during this interval and is receiving in continuous reception mode (see section 4.1.10.2.2.2.2 of reference 1).
Idi comprises a head unit 52, 2 intermediate units 53a, 53b and an end unit 54 and is transmitted on slot 0. ld2 comprises a head unit 52, 1 intermediate unit 53a and an end unit 54 and is transmitted on slot 1. ld3 comprises a head unit 52, intermediate unit 53a and an end unit 54 and is transmitted on slot 2. In these initial frames when packet data is being sent in one direction via the downlink, a multi-slot user packet channel UPCH format is employed - the maximum number of 3 slots per frame are allocated to carry packet data.
On slot 0 of frame 4, a unit 60 not destined for the mobile station MS appears and so gives the mobile station MS the opportunity to attempt uplink access. Because the uplink control channels, including the user packet channel UPCH, are common access, a collision control mechanism (between the mobile stations) needs to be employed. The mobile station MS decodes (arrow 62) the idle/busy flag associated with slot 0 in the current frame of the downlink which indicates whether the corresponding uplink slot is currently in use. If it is 'idle', as it is in this case, the mobile station MS transmits on the corresponding uplink slot the head unit 52 of an
I-frame Iti. The MS station then waits on slot 0 of frame 5 for a response from the base station BS. The base station BS transmits a partial echo PE and a receive/not receive or R/N flag (arrow 64). The partial echo is a CRC check sum. If the partial echo PE matches that for the head unit 52 which was transmitted and the R/N flag indicates that the head unit 52 was successfully 'received', as it is in this case, the mobile station MS assumes that it has been allocated slot 0 for uplink transmission of further units of the frame It1 in subsequent frames and switches to a single-slot user packet channel UPCH format. On receiving a decodable head unit 52 from the mobile station MS the base station BS assumes that the mobile station MS has switched to a single-slot user packet channel UPCH format and acts accordingly. In the case (not illustrated) where uplink access is not gained, because of, for example, collision with another mobile station MS, the mobile station MS continues with multi-slot user packet channel UPCH format for the random retransmission interval specified in Figure 4.1.1 3.1-2 of reference 1. In subsequent frames, the intermediate units 53a, 53b, 53c and the end unit 54 of I-frame 1t, are transmitted on slot 0. From frame 5 onwards, the downlink user packet channel is in single-slot format, whereby only slot 0 is used. At frames 5 and 6, an I-frame ld4 comprising a head unit 54 and an end unit 56 are transmitted to the mobile station MS. Next on
9, an I-frame IdS comprising only a head/end unit 54/56 is transmitted to the mobile station MS.
It will be appreciated that the time offset between the uplink and downlink channels enables half-duplex communication to take place during the same logical slot via the uplink and the downlink, whereby a mobile station MS which is not capable of transmitting and receiving at the same time may be used.
In the Figure 4 example, the mobile station MS is receiving in continuous reception mode with a multi-slot user packet channel UPCH format. On switching to the single-slot user packet channel UPCH format, the mobile station MS continues with the continuous reception mode. Similarly, the mobile station MS would remain with the same reception mode on switching between the multi-slot and the single-slot user packet channel UPCH format when the mobile station is initially in intermittent reception, superframe intermittent reception or hyperframe intermittent reception as defined in section 4.1.1.10.2.2.2.2 of reference 1.
It will be appreciated that because the format of the user packet channel is switched in the way described, a half-duplex mobile station is able, if circumstances permit (i.e. if no uplink communication is required for a given interval) to maximise the downlink throughput (up to 28.8 kbps), while still being able to cope, albeit at a lower data rate, with communication via both the uplink and downlink. Further, because the change in user packet channel format has effects which are confined to a given frame, full and half-duplex mobile stations can easily co-exist on the same network.
Claims (6)
1. A method of carrying out a transaction between a mobile station and a base station in a cellular radio system using communication channels comprising a plurality of time-division multiplexed frames, each frame comprising a plurality of consecutive slots, the method including the steps of the base station performing downlink transmission in a first format of more than one slot per frame, and the base station performing downlink transmission in a second format of one slot per frame when the mobile station is performing uplink transmission in the second format.
2. A method as in Claim 1, wherein the base station switches from the first format to the second format to allow the mobile station to perform uplink transmission.
3. A method as in Claim 1 or Claim 2, wherein the mobile station initiates uplink transmission after the completion of a downlink transaction in the first format.
4. A method as in any preceding claim, wherein the mobile station comprises a transmitter for performing uplink transmission in the first format; a receiver for performing downlink reception in the first or second format; wherein, in the system, corresponding uplink and downlink slots are substantially spaced from one another in frequency and spaced from another in time by less than the duration of one slot, and wherein the mobile station further comprises means to attempt uplink access via an uplink slot and verify uplink access by a message via the corresponding downlink slot.
5. A mobile station for performing the method according to any of Claims 1 to 3.
6. A mobile station for a cellular radio system in which uplink communication is common access, comprising: a transmitter for performing uplink transmission in a single-slot format; a receiver for performing down link reception in a single-slot or a multipleconsecutive-slot format; wherein corresponding uplink and downlink slots are substantially spaced from one another in frequency and spaced from one another in time by less than the duration of one slot, wherein the mobile station is able to initiate uplink transmission via an uplink slot and then verify uplink access by a message on the corresponding downlink slot.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9625538A GB2321160B (en) | 1996-12-09 | 1996-12-09 | Packet data |
| JP33872797A JP3860652B2 (en) | 1996-12-09 | 1997-12-09 | Packet data communication method |
| JP33872897A JPH10257569A (en) | 1996-12-09 | 1997-12-09 | Communication method for packet data |
| JP2006192369A JP4272220B2 (en) | 1996-12-09 | 2006-07-13 | Packet data communication method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9625538A GB2321160B (en) | 1996-12-09 | 1996-12-09 | Packet data |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9625538D0 GB9625538D0 (en) | 1997-01-29 |
| GB2321160A true GB2321160A (en) | 1998-07-15 |
| GB2321160B GB2321160B (en) | 2001-05-16 |
Family
ID=10804160
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9625538A Expired - Fee Related GB2321160B (en) | 1996-12-09 | 1996-12-09 | Packet data |
Country Status (2)
| Country | Link |
|---|---|
| JP (2) | JP3860652B2 (en) |
| GB (1) | GB2321160B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001071945A1 (en) * | 2000-03-22 | 2001-09-27 | Rohde & Schwarz Gmbh & Co. Kg | Method for transmitting voice data packets |
| GB2366477A (en) * | 2000-08-24 | 2002-03-06 | Motorola Inc | Communication system supporting half-duplex calls via full-duplex connexions |
| EP0901241A3 (en) * | 1997-09-08 | 2003-06-04 | Infineon Technologies AG | Digil mobil telecommunication system with TDMA |
| EP1575190A1 (en) * | 2004-03-12 | 2005-09-14 | Motorola, Inc. | Dynamically setting and changing a TDMA slotting structure to accomodate different call types |
| WO2007071694A1 (en) * | 2005-12-19 | 2007-06-28 | Siemens Home And Office Communication Devices Gmbh & Co. Kg | Method for transmitting subscriber-specific data |
| CN100417055C (en) * | 2002-06-28 | 2008-09-03 | 东方通信股份有限公司 | Synchronous channel framing method for CDMA mobile communication system |
| CN101562474B (en) * | 2008-04-15 | 2013-05-08 | 杰脉通信技术(上海)有限公司 | Method for detecting uplink synchronizing signals |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2195958A2 (en) * | 2007-09-27 | 2010-06-16 | Lucent Technologies Inc. | Method for half-and full-duplex subscriber station operation in frequency division duplex systems |
| CN101848031A (en) * | 2009-03-26 | 2010-09-29 | 京瓷株式会社 | Wireless base station and communication control method |
| EP3857760B1 (en) | 2018-09-28 | 2024-01-24 | Telefonaktiebolaget LM Ericsson (publ) | Overlapping multi-slot and single-slot control channel resources |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994010767A1 (en) * | 1992-10-26 | 1994-05-11 | Telefonaktiebolaget Lm Ericsson | A method of effecting random access in a mobile radio system |
| EP0644702A1 (en) * | 1993-09-17 | 1995-03-22 | Alcatel Bell-Sdt S.A. | Communication protocol for a mobile communication system |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE460749B (en) * | 1988-03-15 | 1989-11-13 | Ericsson Telefon Ab L M | PROCEDURE TO TRANSFER DATA INFORMATION IN A CELL-DIVIDED MOBILE RADIO COMMUNICATION SYSTEM |
| JP3212169B2 (en) * | 1993-01-06 | 2001-09-25 | 株式会社東芝 | Wireless communication system and base station |
| US5515379A (en) * | 1993-10-18 | 1996-05-07 | Motorola, Inc. | Time slot allocation method |
| GB9418780D0 (en) * | 1994-09-16 | 1994-11-02 | Ionica L3 Limited | Digital telephony |
| GB2324686B (en) * | 1994-09-30 | 1999-02-10 | Motorola Inc | Method for dynamically allocating wireless communication resources |
| FI106182B (en) * | 1996-11-27 | 2000-11-30 | Nokia Networks Oy | Procedure for Improving Connection Quality and System Capacity in Cellular Radio and Cellular Radio Systems |
-
1996
- 1996-12-09 GB GB9625538A patent/GB2321160B/en not_active Expired - Fee Related
-
1997
- 1997-12-09 JP JP33872797A patent/JP3860652B2/en not_active Expired - Fee Related
-
2006
- 2006-07-13 JP JP2006192369A patent/JP4272220B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994010767A1 (en) * | 1992-10-26 | 1994-05-11 | Telefonaktiebolaget Lm Ericsson | A method of effecting random access in a mobile radio system |
| EP0644702A1 (en) * | 1993-09-17 | 1995-03-22 | Alcatel Bell-Sdt S.A. | Communication protocol for a mobile communication system |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0901241A3 (en) * | 1997-09-08 | 2003-06-04 | Infineon Technologies AG | Digil mobil telecommunication system with TDMA |
| US6778510B1 (en) | 1997-09-08 | 2004-08-17 | Siemens Aktiengesellschaft | Digital telecommunication facility |
| WO2001071945A1 (en) * | 2000-03-22 | 2001-09-27 | Rohde & Schwarz Gmbh & Co. Kg | Method for transmitting voice data packets |
| US7436856B2 (en) | 2000-03-22 | 2008-10-14 | Rohde & Schwarz Gmbh & Co. Kg | Method for transmitting voice data packets |
| GB2366477A (en) * | 2000-08-24 | 2002-03-06 | Motorola Inc | Communication system supporting half-duplex calls via full-duplex connexions |
| GB2366477B (en) * | 2000-08-24 | 2004-03-31 | Motorola Inc | Communications system,base transmitter station and method for supporting half duplexcalls via full duplex connections |
| CN100417055C (en) * | 2002-06-28 | 2008-09-03 | 东方通信股份有限公司 | Synchronous channel framing method for CDMA mobile communication system |
| EP1575190A1 (en) * | 2004-03-12 | 2005-09-14 | Motorola, Inc. | Dynamically setting and changing a TDMA slotting structure to accomodate different call types |
| WO2007071694A1 (en) * | 2005-12-19 | 2007-06-28 | Siemens Home And Office Communication Devices Gmbh & Co. Kg | Method for transmitting subscriber-specific data |
| US7848344B2 (en) | 2005-12-19 | 2010-12-07 | Gigaset Communications Gmbh | Method for transmitting subscriber-specific data |
| CN101562474B (en) * | 2008-04-15 | 2013-05-08 | 杰脉通信技术(上海)有限公司 | Method for detecting uplink synchronizing signals |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006333502A (en) | 2006-12-07 |
| JP3860652B2 (en) | 2006-12-20 |
| GB9625538D0 (en) | 1997-01-29 |
| GB2321160B (en) | 2001-05-16 |
| JP4272220B2 (en) | 2009-06-03 |
| JPH10178682A (en) | 1998-06-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) |
Free format text: REGISTERED BETWEEN 20150910 AND 20150916 |
|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20151209 |