WO1995001072A1 - Method for monitoring a connection between a base station and a transcoder in a cellular radio network - Google Patents

Method for monitoring a connection between a base station and a transcoder in a cellular radio network Download PDF

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Publication number
WO1995001072A1
WO1995001072A1 PCT/FI1994/000280 FI9400280W WO9501072A1 WO 1995001072 A1 WO1995001072 A1 WO 1995001072A1 FI 9400280 W FI9400280 W FI 9400280W WO 9501072 A1 WO9501072 A1 WO 9501072A1
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WO
WIPO (PCT)
Prior art keywords
bits
check value
frame
transcoder
calculated
Prior art date
Application number
PCT/FI1994/000280
Other languages
French (fr)
Inventor
Vesa Koivu
Original Assignee
Nokia Telecommunications Oy
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nokia Telecommunications Oy filed Critical Nokia Telecommunications Oy
Priority to AU70746/94A priority Critical patent/AU7074694A/en
Publication of WO1995001072A1 publication Critical patent/WO1995001072A1/en

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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]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/18—Service support devices; Network management devices
    • H04W88/181—Transcoding devices; Rate adaptation devices

Definitions

  • the invention relates to a method for monitoring a connection between a base station and a transcoder in a cellular radio network, said method comprising transmitting digital speech and/or data in TRAU (Transcoder/Rate Adaptor Unit) frames according to GSM Recommendation 8.60, said frames being 320-bit speech and data frames containing synchronization bits, synchronization check bits, control bits and traffic bits.
  • TRAU Transcoder/Rate Adaptor Unit
  • the GSM Global System for Mobile Communica ⁇ tions
  • GSM Global System for Mobile Communica ⁇ tions
  • Figure 1 shows the basic structural elements of the GSM system in a simplified manner without a detailed description of their properties or the other parts of the system.
  • a mobile exchange MSC switches incoming and outgoing calls. Its functions are similar to those of an exchange in a public switched telephone network. In addition, the mobile exchange has functions typical of only mobile communications, such as subscriber location management.
  • Mobile stations MS are connected to the exchange MSC by means of base station systems.
  • a base station system comprises a base station controller BSC and base stations BTS.
  • a base station controller BSC is used for controlling a plurality of base stations BTS.
  • the GSM system is entirely digital; even speech and data transmission are carried out entirely digital ⁇ ly.
  • speech encoding is needed for speech transmission.
  • TRCU Transcoder/Rate Adaptor Unit
  • the TRCU may have several alternative locations in the system, depending on the choices made by the manufacturer.
  • TRAU frames There are four different types of frames, classified by the information they contain: speech frames, operation and maintenance frames, data frames, and so-called idle speech frames.
  • the trans ⁇ mission link often a fairly long one - between a base station BTS and a transcoder TRCU is hardly secured at all against bit errors.
  • the control and synchronization bits of the TRAU frames are checked in some way at the reception end, but the actual "traffic bits" (speech/data) are not protected.
  • the transmission link usually goes through a conventional public switched telephone network, in which a certain small number of bit errors is allowed, and thus even traffic bits are inevitably distorted.
  • the quality of speech decreases (e.g. clinking sounds or other side- tones), and in the case of data transmission, at least the number of retransmissions increases.
  • the object of the present invention is to obviate the drawback described above.
  • the method according to the invention is characterized by calculating a check value at the transmission end on the basis of at least the most significant traffic bits in the frame to be transmitted, using a given calculation algorithm, inserting the calculated check value in such control bit locations of the frame for which no other use has been defined, monitoring transmission errors caused by the connection between the base station and the transcoder by means of said check value at the reception end.
  • GSM Recommendation 8.60 defining the format of TRAU frames, the use of given bits in the frame is left undefined. In the present invention, these un- defined bits in the TRAU frames are used for monitoring the traffic between a base station and a transcoder unit.
  • the base station and the transcoder calculate, in a suitable manner, a check value, which is inserted in these undefined bits.
  • a corresponding check value is calculated and compared with the one calculated at the transmission end. If the reception end, on the basis of the check value, detects that a bit error has occurred, it can perform the procedures necessary for minimizing the effect of the error on the quality of the connection.
  • the check value may be generated either on the basis of all bits of a TRAU frame, i.e. the control and the traffic bits, or on the basis of the traffic bits only. If desired, it is also possible to check only those traffic bits that are the most significant and the most essential for the quality of speech.
  • the way in which the check value is generated is not essential to the invention. For this purpose, it is possible to use any suitable error correction or error indication algorithm.
  • FIG. 1 illustrates the basic elements of the GSM radio system
  • Figure 2 illustrates a TRAU speech frame according to GSM Recommendation 8.60
  • Figure 3 illustrates a TRAU data frame accord ⁇ ing to GSM Recommendation 8.60
  • Figure 4 illustrates a TRAU operation and main ⁇ tenance frame according to GSM Recommendation 8.60.
  • TRAU frames 320 bits.
  • TRAU frames There are four different types of TRAU frames, classified by the information they contain: speech frames (Figure 2), data frames ( Figure 3), operation and maintenance frames ( Figure 4), and so- called idle speech frames.
  • the first two octets in each frame contain 16 syn- chronization bits.
  • the first bit of the 16-bit words (two octets) that form a frame is a syn ⁇ chronization check bit.
  • all frames comprise control bits, which transmit information on the type of the frame and a varying amount of other frame-type-specific information.
  • Figure 2 illustrates a speech frame which comprises 21 control bits C1-C21 and in which the last four bits T1-T4 are reserved for timing alignment.
  • the bits carrying actual speech information are located in octets 4 to 38.
  • the speech information that is transmitted consists of LAR, RPE and LTP parameters of the RPE-LTP (Regular Pulse Excitation - Long Term Prediction) speech encoding method.
  • An idle speech frame is identical with the speech frame of Figure 2, except that all traffic bits of the frame are in logical state "1".
  • GSM Recommendation 8.60 defines control bits C17, C18, C19, C20 and C21 as spare bits. According to the invention, these control bits C17-C21 or some of them are used for monitoring the traffic between a base station BTS and a transcoder unit TRCU during speech transmission. In other respects, the frame and its processing are fully compatible with the GSM. According to the invention, a check value is calculated at the transmission end (BTS or TRCU) on the basis of the bits in the frame, using a suitable calcu ⁇ lation algorithm. It is not essential to the invention which calculation algorithm is used. Those skilled in the art know several error correction or error detection algorithms suitable for this purpose, for example the Reed-Solomon algorithms.
  • the check value is generated on the basis of all bits of the TRAU frame, i.e. the control and the traffic bits, or merely on the basis of the traffic bits. If desired, it is also possible to check only those traffic bits that are the most significant and the most essential for the quality of speech.
  • the check value calculated at the transmission end is inserted in all or some of the control bit locations C17-C21 of the speech frame shown in Figure 2.
  • the check value is calculated on the basis of the same bits in the received frame, using the same algorithm as at the transmission end.
  • the calcu- lated check value is compared with the one calculated at the transmission end, and if the comparison indicates a bit error, the error is corrected or its effect on the quality of the connection is minimized.
  • Figure 3 shows a TRAU data frame according to GSM Recommendation 8.60, comprising 15 control bits Cl- C15.
  • the recommendation defines bits C7, C8, C9, CIO, Cll, C12, C13, C14 and C15 as spare bits, for which no use has been assigned.
  • the check bit according to the invention can be inserted in all or some of these control bit locations C7-C15.
  • Figure 4 shows an operation and maintenance frame according to GSM Recommendation 8.60, comprising 15 control bits C1-C15, which are all defined as spare bits, for which no use has been assigned.
  • the six last bits S1-S6 in the frame are also defined as spare bits.
  • the check value according to the invention can also be inserted in all or some of the control bit locations C5-C15, or alternatively, in all or some of the spare bit locations S1-S6.

Abstract

The invention relates to a method for monitoring a connection between a base station (BTS) and a transcoder (TRCU) in a cellular radio network. Digital speech and/or data is transmitted in TRAU (Transcoder/Rate Adaptor Unit) frames according to GSM Recommendation 8.60, said frames being 320-bit speech and data frames containing synchronization bits, synchronization check bits, control bits and traffic bits. At the transmission end, a check value is calculated on the basis of at least the most significant traffic bits in the frame to be transmitted, using a given calculation algorithm. The calculated check value is inserted in such control bit locations for which no other use has been defined. At the reception end, transmission errors caused by the connection between the base station and the transcoder are monitored by means of said check value.

Description

Method for monitoring a connection between a base station and a transcoder in a cellular radio network
The invention relates to a method for monitoring a connection between a base station and a transcoder in a cellular radio network, said method comprising transmitting digital speech and/or data in TRAU (Transcoder/Rate Adaptor Unit) frames according to GSM Recommendation 8.60, said frames being 320-bit speech and data frames containing synchronization bits, synchronization check bits, control bits and traffic bits.
The GSM (Global System for Mobile Communica¬ tions) is a pan-European mobile telephone system which is evolving into a world-wide standard. Figure 1 shows the basic structural elements of the GSM system in a simplified manner without a detailed description of their properties or the other parts of the system. A mobile exchange MSC switches incoming and outgoing calls. Its functions are similar to those of an exchange in a public switched telephone network. In addition, the mobile exchange has functions typical of only mobile communications, such as subscriber location management. Mobile stations MS are connected to the exchange MSC by means of base station systems. A base station system comprises a base station controller BSC and base stations BTS. A base station controller BSC is used for controlling a plurality of base stations BTS.
The GSM system is entirely digital; even speech and data transmission are carried out entirely digital¬ ly. On account of capacity limitations on the radio path used, speech encoding is needed for speech transmission. In the network, various speech encoding and rate adaption functions are concentrated in one transcoder unit TRCU (Transcoder/Rate Adaptor Unit). The TRCU may have several alternative locations in the system, depending on the choices made by the manufacturer. When the transcoder TRCU is positioned apart from the base station BTS, information is transmitted between the BTS and the transcoder in so-called TRAU frames of 320 bits. There are four different types of frames, classified by the information they contain: speech frames, operation and maintenance frames, data frames, and so-called idle speech frames. Although the GSM recommendations define the structure of TRAU frames very accurately, the trans¬ mission link - often a fairly long one - between a base station BTS and a transcoder TRCU is hardly secured at all against bit errors. The control and synchronization bits of the TRAU frames are checked in some way at the reception end, but the actual "traffic bits" (speech/data) are not protected. The transmission link usually goes through a conventional public switched telephone network, in which a certain small number of bit errors is allowed, and thus even traffic bits are inevitably distorted. As a result of this, the quality of speech decreases (e.g. clinking sounds or other side- tones), and in the case of data transmission, at least the number of retransmissions increases. The object of the present invention is to obviate the drawback described above.
This and other objects and advantages of the invention are achieved with a method of the type described in the introduction for monitoring a connec- tion between a base station and a transcoder. The method according to the invention is characterized by calculating a check value at the transmission end on the basis of at least the most significant traffic bits in the frame to be transmitted, using a given calculation algorithm, inserting the calculated check value in such control bit locations of the frame for which no other use has been defined, monitoring transmission errors caused by the connection between the base station and the transcoder by means of said check value at the reception end.
In GSM Recommendation 8.60, defining the format of TRAU frames, the use of given bits in the frame is left undefined. In the present invention, these un- defined bits in the TRAU frames are used for monitoring the traffic between a base station and a transcoder unit. When assembling a TRAU frame, the base station and the transcoder calculate, in a suitable manner, a check value, which is inserted in these undefined bits. At the reception end, a corresponding check value is calculated and compared with the one calculated at the transmission end. If the reception end, on the basis of the check value, detects that a bit error has occurred, it can perform the procedures necessary for minimizing the effect of the error on the quality of the connection. The check value may be generated either on the basis of all bits of a TRAU frame, i.e. the control and the traffic bits, or on the basis of the traffic bits only. If desired, it is also possible to check only those traffic bits that are the most significant and the most essential for the quality of speech. The way in which the check value is generated is not essential to the invention. For this purpose, it is possible to use any suitable error correction or error indication algorithm. In the following, the invention will be described in more detail by means of embodiments and with reference to the accompanying drawings, in which
Figure 1 illustrates the basic elements of the GSM radio system, Figure 2 illustrates a TRAU speech frame according to GSM Recommendation 8.60,
Figure 3 illustrates a TRAU data frame accord¬ ing to GSM Recommendation 8.60, and Figure 4 illustrates a TRAU operation and main¬ tenance frame according to GSM Recommendation 8.60.
The basic structural elements of the GSM system and the TRAU frame are described in the GSM recommenda¬ tions. As for a more accurate description of the GSM system, reference is made to the GSM recommendations and "The GSM System for Mobile Communications" by M. Mouly and M-B. Pautet, Palaiseau, France, 1992, ISBN: 2- 9507190-0-7.
As stated above, when the transcoder TRCU is positioned apart from the base station BTS (e.g. in connection with the base station controller BSC or the exchange MSC, as in Figure 1), information is trans¬ mitted between the BTS and the transcoder in so-called TRAU frames of 320 bits. There are four different types of TRAU frames, classified by the information they contain: speech frames (Figure 2), data frames (Figure 3), operation and maintenance frames (Figure 4), and so- called idle speech frames. To enable synchronization, the first two octets in each frame contain 16 syn- chronization bits. In addition, the first bit of the 16-bit words (two octets) that form a frame is a syn¬ chronization check bit. In addition to traffic bits con¬ taining actual speech, data or operation and maintenance information, all frames comprise control bits, which transmit information on the type of the frame and a varying amount of other frame-type-specific information.
Figure 2 illustrates a speech frame which comprises 21 control bits C1-C21 and in which the last four bits T1-T4 are reserved for timing alignment. The bits carrying actual speech information are located in octets 4 to 38. In practice, the speech information that is transmitted consists of LAR, RPE and LTP parameters of the RPE-LTP (Regular Pulse Excitation - Long Term Prediction) speech encoding method. An idle speech frame is identical with the speech frame of Figure 2, except that all traffic bits of the frame are in logical state "1".
GSM Recommendation 8.60 defines control bits C17, C18, C19, C20 and C21 as spare bits. According to the invention, these control bits C17-C21 or some of them are used for monitoring the traffic between a base station BTS and a transcoder unit TRCU during speech transmission. In other respects, the frame and its processing are fully compatible with the GSM. According to the invention, a check value is calculated at the transmission end (BTS or TRCU) on the basis of the bits in the frame, using a suitable calcu¬ lation algorithm. It is not essential to the invention which calculation algorithm is used. Those skilled in the art know several error correction or error detection algorithms suitable for this purpose, for example the Reed-Solomon algorithms. Neither is it essential whether the check value is generated on the basis of all bits of the TRAU frame, i.e. the control and the traffic bits, or merely on the basis of the traffic bits. If desired, it is also possible to check only those traffic bits that are the most significant and the most essential for the quality of speech. The check value calculated at the transmission end is inserted in all or some of the control bit locations C17-C21 of the speech frame shown in Figure 2. At the reception end (BTS or TRCU), the check value is calculated on the basis of the same bits in the received frame, using the same algorithm as at the transmission end. The calcu- lated check value is compared with the one calculated at the transmission end, and if the comparison indicates a bit error, the error is corrected or its effect on the quality of the connection is minimized.
Figure 3 shows a TRAU data frame according to GSM Recommendation 8.60, comprising 15 control bits Cl- C15. The recommendation defines bits C7, C8, C9, CIO, Cll, C12, C13, C14 and C15 as spare bits, for which no use has been assigned. The check bit according to the invention can be inserted in all or some of these control bit locations C7-C15.
Figure 4 shows an operation and maintenance frame according to GSM Recommendation 8.60, comprising 15 control bits C1-C15, which are all defined as spare bits, for which no use has been assigned. In addition, the six last bits S1-S6 in the frame are also defined as spare bits. The check value according to the invention can also be inserted in all or some of the control bit locations C5-C15, or alternatively, in all or some of the spare bit locations S1-S6. The figures and the associated description are intended merely to illustrate the present invention. In its details, the method of the invention can be modified within the scope of the appended claims.

Claims

Claims
1. A method for monitoring a connection between a base station and a transcoder in a cellular radio network, said method comprising transmitting digital speech and/or data in TRAU (Transcoder/Rate Adaptor Unit) frames according to GSM Recommendation 8.60, said frames being 320-bit speech and data frames containing synchronization bits, synchronization check bits, control bits and traffic bits, c h a r a c t e r i z e d by calculating a check value at the transmission end on the basis of at least the most significant traffic bits in the frame to be transmitted, using a given calculation algorithm, inserting the calculated check value in such control bit locations of the frame for which no other use has been defined, monitoring transmission errors caused by the connection between the base station and the transcoder by means of said check value at the reception end.
2. A method according to claim 1, c h a r a c ¬ t e r i z e d in that the check value is inserted in all or some of the control bits C17, C18, C19, C20 and C21 of a speech frame according to GSM Recommendation 8.60.
3. A method according to claim 1, c h a r a c ¬ t e r i z e d in that the check value is inserted in all or some of the control bits C7 to C15 of a data frame according to the GSM Recommendation.
4. A method according to claim 1, c h a r a c ¬ t e r i z e d in that the check value is inserted in all or some of the control bits C5 to C15 of a use and maintenance frame according to the GSM Recommendation.
5. A method according to claim 1, c h a r a c ¬ t e r i z e d in that the check value is inserted in all or some of the spare bit locations SI to S6 of a use and maintenance frame according to the GSM Recommenda- tion.
6. A method according to any one of the preceding claims, c h a r a c t e r i z e d in that the check value is calculated on the basis of all traffic bits in the frame.
7. A method according to any one of claims 1 to 5, c h a r a c t e r i z e d in that the check value is calculated on the basis of all bits in the frame.
8. A method according to any one of the preceding claims, c h a r a c t e r i z e d by calculating a check value at the reception end on the basis of the same bits in the received frame, using the same calculation algorithm as at the trans¬ mission end, comparing the calculated check value with the check value calculated at the transmission end, when the comparison indicates a bit error, correcting the error or minimizing its effect on the quality of the connection.
PCT/FI1994/000280 1993-06-24 1994-06-22 Method for monitoring a connection between a base station and a transcoder in a cellular radio network WO1995001072A1 (en)

Priority Applications (1)

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AU70746/94A AU7074694A (en) 1993-06-24 1994-06-22 Method for monitoring a connection between a base station and a transcoder in a cellular radio network

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FI932964 1993-06-24
FI932964A FI93788C (en) 1993-06-24 1993-06-24 A method for checking the connection between a base station and a transcoder in a cellular radio network

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995026602A2 (en) * 1994-03-28 1995-10-05 Nokia Telecommunications Oy Decoding method
WO1997019571A1 (en) * 1995-11-24 1997-05-29 Telefonaktiebolaget Lm Ericsson (Publ) Transmission link supervision in radiocommunication systems
FR2743237A1 (en) * 1995-12-29 1997-07-04 Christophe Desseignes RADIO COMMUNICATION SYSTEM WITH ACCESS INTERFACE TO THE TELECOMMUNICATIONS NETWORK
DE19647630A1 (en) * 1996-11-18 1998-05-20 Siemens Ag Digital information transmission method between transcoder and base station
WO1998021840A1 (en) * 1996-11-14 1998-05-22 Telefonaktiebolaget Lm Ericsson (Publ) Transporting user data over a-bis and a-interfaces within a mobile telecommunications network
WO1998028936A1 (en) * 1996-12-05 1998-07-02 Nokia Telecommunications Oy Detection of speech channel back-looping
WO1998051033A2 (en) * 1997-05-07 1998-11-12 Nokia Networks Oy Method for correcting synchronization error and radio system
WO1999005871A2 (en) * 1997-07-22 1999-02-04 Nokia Networks Oy Identifying a trau frame in a mobile telephone system
WO1999026435A2 (en) * 1997-11-13 1999-05-27 Nokia Networks Oy Method for controlling a transcoder of a mobile communication system
US6633840B1 (en) * 1998-07-13 2003-10-14 Alcatel Method and system for transmitting data on a speech channel
CN1838585B (en) * 2005-03-23 2011-05-04 华为技术有限公司 Method for obtaining same block number data frame in multi chain circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0117595A2 (en) * 1983-02-25 1984-09-05 Philips Electronics Uk Limited Digital data transmission system
EP0471246A2 (en) * 1990-08-16 1992-02-19 Motorola, Inc. Digital cellular TDM system employing 6:1 packing of transcoded information
EP0535812A2 (en) * 1991-10-04 1993-04-07 Nokia Mobile Phones (U.K.) Limited TDMA burst-mode mobile radio communication system with forward error correction

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0117595A2 (en) * 1983-02-25 1984-09-05 Philips Electronics Uk Limited Digital data transmission system
EP0471246A2 (en) * 1990-08-16 1992-02-19 Motorola, Inc. Digital cellular TDM system employing 6:1 packing of transcoded information
EP0535812A2 (en) * 1991-10-04 1993-04-07 Nokia Mobile Phones (U.K.) Limited TDMA burst-mode mobile radio communication system with forward error correction

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
GSM RECOMMENDATION 08.60 ETSI/PT 12. *
PATENT ABSTRACTS OF JAPAN, Vol. 10, No. 20, E-376; & JP,A,60 182 230 (NIPPON DENSHIN DENWA KOSHA), 17 September 1985. *
PATENT ABSTRACTS OF JAPAN, Vol. 17, No. 386, E-1401; & JP,A,05 068 014 (NIPPON TELEGR & TELEPH CORP), 19 March 1993. *

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5940412A (en) * 1994-03-28 1999-08-17 Nokia Telecommunications Oy Decoding method
WO1995026602A3 (en) * 1994-03-28 1995-10-26 Nokia Telecommunications Oy Decoding method
AU687180B2 (en) * 1994-03-28 1998-02-19 Nokia Telecommunications Oy Decoding method
WO1995026602A2 (en) * 1994-03-28 1995-10-05 Nokia Telecommunications Oy Decoding method
WO1997019571A1 (en) * 1995-11-24 1997-05-29 Telefonaktiebolaget Lm Ericsson (Publ) Transmission link supervision in radiocommunication systems
US5757810A (en) * 1995-11-24 1998-05-26 Telefonaktiebolaget Lm Ericsson Transmission link supervision in radiocommunication systems
FR2743237A1 (en) * 1995-12-29 1997-07-04 Christophe Desseignes RADIO COMMUNICATION SYSTEM WITH ACCESS INTERFACE TO THE TELECOMMUNICATIONS NETWORK
WO1998021840A1 (en) * 1996-11-14 1998-05-22 Telefonaktiebolaget Lm Ericsson (Publ) Transporting user data over a-bis and a-interfaces within a mobile telecommunications network
CZ301170B6 (en) * 1996-11-14 2009-11-25 Telefonaktiebolaget Lm Ericsson (Publ) Communication system and method for communicating user data between a mobile station and a telecommunications network
AU720818B2 (en) * 1996-11-14 2000-06-15 Telefonaktiebolaget Lm Ericsson (Publ) Transporting user data over A-bis and A-interfaces within a mobile telecommunications network
DE19647630A1 (en) * 1996-11-18 1998-05-20 Siemens Ag Digital information transmission method between transcoder and base station
DE19647630C2 (en) * 1996-11-18 1998-12-17 Siemens Ag Method for digital information transmission between a transcoding unit and a base station in a mobile radio network
US6230120B1 (en) 1996-12-05 2001-05-08 Nokia Communications Oy Detection of speech channel back-looping
WO1998028936A1 (en) * 1996-12-05 1998-07-02 Nokia Telecommunications Oy Detection of speech channel back-looping
AU734814B2 (en) * 1997-05-07 2001-06-21 Nokia Networks Oy Method for correcting synchronization error,and radio system
WO1998051033A3 (en) * 1997-05-07 1999-03-11 Nokia Telecommunications Oy Method for correcting synchronization error and radio system
WO1998051033A2 (en) * 1997-05-07 1998-11-12 Nokia Networks Oy Method for correcting synchronization error and radio system
US6490704B1 (en) 1997-05-07 2002-12-03 Nokia Networks Oy Method for correcting synchronization error and radio system
WO1999005871A2 (en) * 1997-07-22 1999-02-04 Nokia Networks Oy Identifying a trau frame in a mobile telephone system
WO1999005871A3 (en) * 1997-07-22 1999-04-08 Nokia Telecommunications Oy Identifying a trau frame in a mobile telephone system
US6356750B1 (en) 1997-07-22 2002-03-12 Nokia Telecommunications Oy Identifying a TRAU frame in a mobile telephone system
AU745433B2 (en) * 1997-07-22 2002-03-21 Nokia Networks Oy Identifying a trau frame in a mobile telephone system
WO1999026435A3 (en) * 1997-11-13 1999-07-15 Nokia Telecommunications Oy Method for controlling a transcoder of a mobile communication system
US7096031B1 (en) 1997-11-13 2006-08-22 Nokia Networks Oy Method for controlling a transcoder of a mobile communication system
WO1999026435A2 (en) * 1997-11-13 1999-05-27 Nokia Networks Oy Method for controlling a transcoder of a mobile communication system
US6633840B1 (en) * 1998-07-13 2003-10-14 Alcatel Method and system for transmitting data on a speech channel
CN1838585B (en) * 2005-03-23 2011-05-04 华为技术有限公司 Method for obtaining same block number data frame in multi chain circuit

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Publication number Publication date
FI932964A (en) 1994-12-25
FI932964A0 (en) 1993-06-24
AU7074694A (en) 1995-01-17
FI93788B (en) 1995-02-15
FI93788C (en) 1995-05-26

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