WO1993025017A1 - Methode pour transferer des informations auxiliaires dans un systeme multiplexeur temporel de base - Google Patents
Methode pour transferer des informations auxiliaires dans un systeme multiplexeur temporel de base Download PDFInfo
- Publication number
- WO1993025017A1 WO1993025017A1 PCT/FI1993/000176 FI9300176W WO9325017A1 WO 1993025017 A1 WO1993025017 A1 WO 1993025017A1 FI 9300176 W FI9300176 W FI 9300176W WO 9325017 A1 WO9325017 A1 WO 9325017A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bits
- transferred
- ancillary information
- timeslot
- channel
- Prior art date
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/12—Arrangements providing for calling or supervisory signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
Definitions
- the invention relates to a method for trans- ferring ancillary information, such as channel- associated signalling, in a basic time-division multiplex system, where ancillary information is transferred in a predetermined timeslot of each frame, and where information associated with more than one channel is transferred in at least one timeslot of the basic system.
- ancillary information is transferred in a predetermined timeslot of each frame, and where information associated with more than one channel is transferred in at least one timeslot of the basic system.
- the method according to the invention is especially intended for use in connection with the European 2048 kbit/s 30-channel basic multiplex system, but it is not restricted to this standard only.
- channel- associated signalling CAS is transferred in a timeslot TS16 by grouping successive frames into larger multi- frames containing 16 frames.
- the timeslots TS16 of successive frames in the multiframe are assigned one at a time to a signalling channel corresponding to two separate speech channels. Accordingly, there are four bits available for each signalling channel in the timeslot.
- the signalling channels occupy the timeslots TS16 of fifteen frames contained in the multiframe.
- the timeslot TS16 of the remaining frame 0 contains e.g. a multiframe synchronizing signal, as will be described below.
- the basic system described above allows the transfer of 30 speech channels having a capacity of 64 kbit/s.
- the CCITT specification G.761 defines a 32 kbit/s ADPCM transcoder with accurately specified fixed timeslot mapping, signalling transfer and alarms handling. This transcoder cannot, however, be connect ⁇ ed to the 2048 kbit/s basic system as the bits it employs for alarm transfer are reserved for national use in the specification G.704. A reliable transfer of alarms cannot therefore be guaranteed.
- the specification G.761 also defines alarms, such as forward and backward AIS (Alarm Indication Signal) alarms.
- AIS Alarm Indication Signal
- the approach defined in the specification is not feasible when using a 16 kbit/s codec as the number of available bits is not suffi ⁇ cient for the transfer of alarms. This is because the network management also utilizes free bits available in the timeslot TSO, wherefore they are not available for the purpose specified in G.761.
- the object of the present invention is to pro ⁇ vide a method which avoids the above-mentioned short ⁇ comings and allows the transfer of ancillary informa- tion, especially the transfer of signalling and alarms, in a conventional basic multiplex system up to a capacity of 120 speech channels.
- This is achieved by means of a method according to the invention which is characterized by assembling a superframe having a length of several multiframes, at least part of the ancillary information being transferred in said predetermined timeslot so that the number of the multiframe is transmitted in addition to said ancil ⁇ lary information, the number indicating with which channel the ancillary information is associated.
- the basic idea of the invention is to employ a lower signalling rate and to utilize the "extra" bits remaining in the timeslot transferring channel- associated ancillary information as "address bits" indicating which one of the transfer connections is being served.
- part of the ancillary information is trans ⁇ ferred by changing the sequence of the multiframe numbers.
- the idea is thus to utilize the sequence of the multiframe numbers or a change in the sequence for transferring part of the ancillary information, such as alarms.
- part of the ancillary information such as alarms.
- super-frame will be used in the text below to illustrate the operation of the method to the reader, the operation of the method as such does not require a single superframe sync in all timeslots but the phase or sequence of the multiframe numbers may vary from one timeslot to another.
- the solution according to the invention is also compatible with n x 2048 kbit/s networks as the "address bits" used in the invention eliminate delay deviations (the delay varies from one timeslot to another) occurring in cross-connect devices.
- a further advantage of the invention is that the bits of the timeslot TSO normally used for the network management are not utilized but they are still avail ⁇ able for the network management purposes, as distinct from e.g. the above-mentioned specification G.761, where they are used for another purpose.
- Figure 1 illustrates the assembly of superframes from multiframes
- Figure 2 illustrates the transfer of ancillary information in the timeslot TS16 in successive multi- and superframes
- Figure 3 is a block diagram illustrating a transmitter section in a codec applying the method according to the invention.
- FIG. 4 is a block diagram illustrating a receiver section in a codec applying the method according to the invention.
- a 2048 kbit/s basic multiplex system transferring 120 speech channels by a 16 kbit/s speech coder will be used as an example.
- Each speech channel timeslot (the timeslots TS1...TS15 and the timeslots TS17...TS31) thus contains 4 coded speech channels.
- FIG. 1 shows a frame 10 in a basic multiplex system.
- the frame 10 comprises 32 timeslots TSO... TS31.
- the timeslot TS16 of the frame is used by two signalling channels so that there are four bits abed available for each channel.
- sixteen successive frames F0...F15 form a multiframe 11 having a length of 2 ms.
- service can thus be offered for 30 speech channels.
- the number of signalling bits actually transferred per channel can be reduced to two (the bits a and b hereinbelow).
- the other bits (the bits c and d hereinbelow) are typically connected to a fixed state, and so it is not normally necessary to send them at all.
- a superframe struc ⁇ ture of four multiframes and having a length of 8 ms is assembled from the 16-frame multiframes 11.
- the above-mentioned bits c and d are used in such a manner that the transmitter unit always sends not only the actual signalling bits a and b but also the bits c and d indicating the number (1...4) of the multiframe in the superframe. This number indicates which one of the speech channels is being served currently, that is, the receiver employs the "address bits" c and d to update the signalling data of the appropriate speech channel.
- the signalling data of only one of the four speech channels is updated during the multiframe, and so the signalling of all speech channels will be up ⁇ dated once only after the superframe.
- the updating sync is thus reduced from the normal value of 2 ms (multiframe sync) to 8 ms. (When using a 32 kbit/s coder, the updating sync is correspondingly 4 ms. )
- the reduction of the sync even to one quarter of the original has no detrimental effects, as even a slower rate is adequate for normal telephone network sig ⁇ nalling.
- Figure 2 illustrates channel-associated sig ⁇ nalling for the timeslot TS1. This is done by showing the content of the timeslots TS16 (there are 64 such timeslots in the superframe 12) in those of the successive frames where the signalling data of the timeslot TS1 is transferred.
- the third and fourth bit in the timeslot TS16 in the second frame FI of each multiframe 11, that is, the above-described bits c and d indicate by the number (00, 01, 10 or 11) of the multiframe 11 to which speech channel of the timeslot TS1 the corresponding bits al and bl are assigned.
- Figure 2 further shows the first four bits abed of the timeslot TS16 of the first frame FO of each multi ⁇ frame. These bits form the synchronizing signal, being all zeros.
- the bits c and d (not shown) following the bits al7 and bl7, for instance, indicate to which one of the four speech channels of the timeslot TS17 the bits are assigned.
- the bits cd form a sequence 00, 01, 10, 11, as described above.
- the superframe structure according to the invention may be incoherent, that is, the phase of the respective "1-4 counter" may be different in each timeslot.
- the cyclically changing bits c and d are used for the transfer of alarms so that a certain normal cd bit sequence, such as the above-described normal-state sequence 00, 01, 10, 11, is replaced with another sequence in an alarm situation.
- a certain normal cd bit sequence such as the above-described normal-state sequence 00, 01, 10, 11, is replaced with another sequence in an alarm situation.
- Some alarms, such as the forward AIS alarm can be given so that the bits c and d become fixed (e.g. 10). In other words, the number of the multiframe stops rotating intermittently. In such a case the signalling does not, of course, take place as described above; in an alarm situation, however, this is not significant.
- Figures 3 and 4 show one way of realizing a codec so as to apply the method according to the invention. These embodiments correspond to the Applicant's ADPCM codec, which is a member of the product family sold under the name DYNACARDTM.
- the input of the transmitter section 30 comprises a line interface circuit 31 where a data signal and a clock signal are separated from the incoming PCM signal PCM in .
- the data and clock signal are then transferred to corresponding inputs in a demultiplexer unit 32.
- the signalling bits to be transferred in the timeslot TS16 are separated and applied to a copying unit 35.
- data is applied from the demultiplexer unit to a coder unit 33, and a frame synchronizing signal is applied to a coder control unit 36 which informs the coder of the coding rate (64/32/16 kbit/s) used in the system.
- the c and d bits of the incoming signal are eliminated in the copying unit 35.
- Coded data (speech) and signalling data from the copying unit are connected to a cross-connect circuit 34 which rearranges the timeslots to an outbound bus TX BUS.
- the signalling output of the cross-connect circuit comprises a sequence changing means 38 for the bits cd in which new signalling bits c and d are added to the signalling data.
- the sequence changing means changes the normal sequence of the cd bits to another sequence (under the control of a processor unit 37) if an alarm has to be transferred.
- the sequence changing means is controlled by a cd bit sequence generator which is a counter stepping forward at intervals of one multiframe (and being reset at intervals of one superframe). The sequence generator derives the multiframe sync from the bus.
- each received speech channel is ADPCM decoded into a normal PCM speech channel. This requires channel-associated control data which is so generic that the internal cross-connect data of the timeslot can also be disassembled on the basis of it. This also produces local c and d bits.
- the comparison block 45 compares the locally generated c and d bits with the received c and d bits. If they match, the comparison block applies an enable signal to the multiplexer. The enable signal updates the signalling memory in the memory of the multiplexer unit 43 for this particular channel. If the received cd bits and the locally generated cd bits do not match, the signalling of the channel is maintained unchanged until the comparison indicates that the cd bits match. The comparison block also determines whether the sequence of the cd bits is normal or whether it indicates an alarm. The processor unit 47 selects the timeslot to be monitored.
- the re ⁇ DC uses received signalling bits to update the signalling information of the appropriate speech channel.
- a conventional PCM signal PCM out where the bits c and d are fixed can again be produced at the output of the receiver unit.
- the processor unit 47 assigns the multiplexer unit 43 with fixed cd bits cd out .
- the c and d bits can be connected forward.
- the method according to the invention can, of course, be realized by various different device con- figurations. However, only some minor modifications are required in existing devices, mainly means for providing a freely rotating two-bit multiframe counter in the transmitter section for the signalling bits.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Time-Division Multiplex Systems (AREA)
Abstract
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9423241A GB2282509B (en) | 1992-05-22 | 1993-04-23 | Method for transferring ancillary information in a basic time-division multiplex system |
AU39558/93A AU671631B2 (en) | 1992-05-22 | 1993-04-23 | Method for transferring ancillary information in a basic time-division multiplex system |
HK98105799A HK1006618A1 (en) | 1992-05-22 | 1998-06-19 | Method for transferring ancillary information in a basic time-division multiplex system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI922354A FI94694C (fi) | 1992-05-22 | 1992-05-22 | Menetelmä sivuinformaation siirtämiseksi aikajakokanavoidussa peruskanavointijärjestelmässä |
FI922354 | 1992-05-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993025017A1 true WO1993025017A1 (fr) | 1993-12-09 |
Family
ID=8535337
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FI1993/000176 WO1993025017A1 (fr) | 1992-05-22 | 1993-04-23 | Methode pour transferer des informations auxiliaires dans un systeme multiplexeur temporel de base |
Country Status (6)
Country | Link |
---|---|
AU (1) | AU671631B2 (fr) |
FI (1) | FI94694C (fr) |
GB (1) | GB2282509B (fr) |
HK (1) | HK1006618A1 (fr) |
NZ (1) | NZ251727A (fr) |
WO (1) | WO1993025017A1 (fr) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0677930A1 (fr) * | 1994-04-15 | 1995-10-18 | Alcatel Mobile Communication France | Procédé AMRF à structure trame/multitrame et signal correspondant |
WO1997016917A1 (fr) * | 1995-11-02 | 1997-05-09 | Nokia Telecommunications Oy | Procede et appareil pour transmettre des messages dans un systeme de telecommunication |
US5663954A (en) * | 1994-10-31 | 1997-09-02 | Nokia Mobile Phones Ltd. | Frame timing control of time division multiple access |
GB2342013A (en) * | 1998-09-23 | 2000-03-29 | Sony Uk Ltd | Multiplexing digital signals |
DE10200201A1 (de) * | 2002-01-04 | 2003-07-24 | Daimler Chrysler Ag | Zyklusbasiertes zeitgesteuertes Kommunikationssystem |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4358845A (en) * | 1980-03-05 | 1982-11-09 | Societe Anonyme de Telecommunications Company | Process for the compression of signalling data or the like transmitted in a train of multiplexed PCM information |
-
1992
- 1992-05-22 FI FI922354A patent/FI94694C/fi active
-
1993
- 1993-04-23 NZ NZ25172793A patent/NZ251727A/en unknown
- 1993-04-23 AU AU39558/93A patent/AU671631B2/en not_active Ceased
- 1993-04-23 WO PCT/FI1993/000176 patent/WO1993025017A1/fr active Application Filing
- 1993-04-23 GB GB9423241A patent/GB2282509B/en not_active Expired - Lifetime
-
1998
- 1998-06-19 HK HK98105799A patent/HK1006618A1/xx not_active IP Right Cessation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4358845A (en) * | 1980-03-05 | 1982-11-09 | Societe Anonyme de Telecommunications Company | Process for the compression of signalling data or the like transmitted in a train of multiplexed PCM information |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0677930A1 (fr) * | 1994-04-15 | 1995-10-18 | Alcatel Mobile Communication France | Procédé AMRF à structure trame/multitrame et signal correspondant |
FR2718907A1 (fr) * | 1994-04-15 | 1995-10-20 | Alcatel Mobile Comm France | Procédé AMRF à structure trame-multitrame et signal correspondant. |
US5617412A (en) * | 1994-04-15 | 1997-04-01 | Alcatel N.V. | Frame/multiframe structure FDMA system and corresponding signal |
US5663954A (en) * | 1994-10-31 | 1997-09-02 | Nokia Mobile Phones Ltd. | Frame timing control of time division multiple access |
WO1997016917A1 (fr) * | 1995-11-02 | 1997-05-09 | Nokia Telecommunications Oy | Procede et appareil pour transmettre des messages dans un systeme de telecommunication |
US6208715B1 (en) | 1995-11-02 | 2001-03-27 | Nokia Telecommunications Oy | Method and apparatus for transmitting messages in a telecommunication system |
GB2342013A (en) * | 1998-09-23 | 2000-03-29 | Sony Uk Ltd | Multiplexing digital signals |
GB2342013B (en) * | 1998-09-23 | 2003-06-25 | Sony Uk Ltd | Multiplexing digital signals |
US6744788B2 (en) | 1998-09-23 | 2004-06-01 | Sony United Kingdom Limited | Multiplexing digital signals |
DE10200201A1 (de) * | 2002-01-04 | 2003-07-24 | Daimler Chrysler Ag | Zyklusbasiertes zeitgesteuertes Kommunikationssystem |
US7912080B2 (en) | 2002-01-04 | 2011-03-22 | Robert Bosch Gmbh | Cyclical time-based communication system, user in such a system and transmission method |
Also Published As
Publication number | Publication date |
---|---|
AU3955893A (en) | 1993-12-30 |
FI94694C (fi) | 1995-10-10 |
FI922354A (fi) | 1993-11-23 |
FI922354A0 (fi) | 1992-05-22 |
GB9423241D0 (en) | 1995-01-11 |
GB2282509B (en) | 1996-03-13 |
AU671631B2 (en) | 1996-09-05 |
HK1006618A1 (en) | 1999-03-05 |
GB2282509A (en) | 1995-04-05 |
FI94694B (fi) | 1995-06-30 |
NZ251727A (en) | 1995-08-28 |
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