Content for TS 28.062 Word version: 18.0.0

1 Scope p. 11

The present document contains the service description for the in-band signalling protocol for the support of Tandem Free Operation of the Half Rate, Full Rate, Enhanced Full Rate, Adaptive Multi Rate narrowband and Adaptive Multi Rate Wide-Band speech codec types in GSM and GSM-evolved 3G systems.

2 References p. 11

The following documents contain provisions, which, through reference in this text, constitute provisions of the present document.

References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1]

TS 22.053: "Digital cellular telecommunication system (Phase 2+); Tandem Free Operation (TFO); Service Description; Stage 1".

[2]

TS 23.053: "Digital cellular telecommunication system (Phase 2+); Tandem Free Operation (TFO); Service Description; Stage 2".

[3]

TS 48.060: "Digital cellular telecommunication system (Phase 2+); Inband control of remote transcoders and rate adaptors for full rate traffic channels".

[4]

TS 48.061: "Digital cellular telecommunication system (Phase 2+); In-band Control of Remote Transcoders and Rate Adaptors for half rate traffic channels".

[5]

TS 46.010: "Digital cellular telecommunications system (Phase 2+); Full rate speech transcoding".

[6]

TS 46.020: "Digital cellular telecommunications system (Phase 2+); Half rate speech transcoding".

[7]

TS 46.060: "Digital cellular telecommunications system (Phase 2+); Enhanced Full Rate (EFR) speech transcoding".

[8]

TS 26.090: "Mandatory Speech Codec speech processing functions AMR Speech Codec - Transcoding functions".

[9]

TS 45.009: "Digital cellular telecommunications system (Phase 2+); Link Adaptation".

[10]

TS 48.008: "Digital cellular telecommunications system (Phase 2+); Mobile-services Switching Centre - Base Station System (MSC - BSS) interface; Layer 3 specification".

[11]

TS 48.054: "Digital cellular telecommunication system (Phase 2+); Base Station Controller - Base Transceiver Station (BSC - BTS) interface; Layer 1 structure of physical circuits".

[12]

TS 48.058: "Digital Cellular telecommunications system (Phase 2+), "Base Station Controller - Base Transceiver Station (BSC - BTS) interface; Layer 3 specification".

[13]

ITU-T Recommendation G.711: "Pulse code modulation (PCM) of voice frequencies".

[14]

TS 44.018: "Mobile radio interface layer 3 specification; Radio Resource Control Protocol".

[15]

TS 23.153: "Out of Band Transcoder Control; Stage 2".

[16]

TS 29.232: "Media Gateway Controller (MGC) - Media Gateway (MGW) Interface; Stage 3"

[17]

TS 25.415: "UTRAN Iu interface User plane protocols"

[18]

TS 26.171: AMR-WB Speech Codec; General Description

[19]

TS 26.190: AMR-WB Speech Codec; Transcoding Functions

3 Definitions and abbreviations p. 12

3.1 Definitions p. 12

For the purposes of the present document, the following terms and definitions apply:

Transcoder:

device that converts the encoding of information from one particular scheme to a different one

Tandem Free Operation:

call configuration where a transcoder device is physically present in the signal path, but the transcoding functions are bypassed

Transcoder Free Operation:

call configuration where no transcoder device is physically present and hence no control or conversion or other functions associated with it are activated

Compressed Speech Samples:

speech samples coded according to one of the Speech Codec Types supported by the TFO specification

PCM Samples:

speech samples coded according to ITU-T Recommendation G.711 A-Law or μ-Law at 64 kbit/s

Speech Codec Type:

speech Codec among those supported by this TFO specification: GSM_FR, GSM_HR, GSM_EFR, FR_AMR, HR_AMR, OHR_AMR, UMTS_AMR, UMTS_AMR_2, FR_AMR-WB, UMTS_AMR-WB, OFR_AMR-WB, OHR_AMR-WB

AMR Speech Codec Type:

one of the following Speech Codec Types: FR_AMR, HR_AMR, UMTS_AMR, UMTS_AMR_2, FR_AMR-WB, UMTS_AMR-WB, OFR_AMR-WB, OHR_AMR-WB

AMR-NB Speech Codec Type:

one of the following Speech Codec Types: FR_AMR, HR_AMR, UMTS_AMR, UMTS_AMR_2, OHR_AMR.

AMR-WB speech Codec Type:

one of the following Speech Codec Types: UMTS_AMR-WB, FR_AMR-WB, OFR_AMR-WB, OHR_AMR-WB

Non-AMR Speech Codec Type:

one of the following Speech Codec Types: GSM_FR, GSM_HR, or GSM_EFR

Speech Codec Configuration:

set of parameters defining the operational conditions of a Speech Codec Type

EXAMPLE: The Speech Codec Configuration of an AMR Speech Codec Type defines the ACS, the SCS…

TRAU Frame or TRAU Speech Frame:

refer to a Speech Frame carried over the Abis/Ater Interface in a GSM network

TFO Frame or TFO Speech Frame:

refer to the Speech Frames exchanged between the Transcoders when Tandem Free Operation is active

Abis/Ater:

applies to a GSM network where either the GSM Abis or Ater interfaces are used, depending on the location of the Transcoder and Rate Adaptor Units

Other definitions are contained in [1] and [3].

3.2 Abbreviations p. 13

For the purposes of the present document, the following abbreviations apply:

ACS

Active Codec Set

ACT

Active Codec Type

AMR

Adaptive Multi-Rate

ATVN

AMR-TFO Version Number

BSC

Base Station Controller

BSS

Base Station Sub-system

BTS

Base Transceiver Station

CACS

Common Active Codec Set

CSCS

Common Supported Codec Set

DACS

Distant Active Codec Set

DSCS

Distant Supported Codec Set

EFR

Enhanced Full Rate

FQI

Frame Quality Index

Full Rate

HOM

Hand-Over-Mode

Half Rate

IACS

Immediate Active Codec Set

ICM

Initial Codec Mode

IPE

In Path Equipment

LACS

Local Active Codec Set

LSB

Least Significant Bit

LSCS

Local Supported Codec Set

MACS

Maximum number of Codecs Modes in the Active Codec Set

MGw

Media Gateway

Mobile Station

MSB

Most Significant Bit

MSC

Mobile Switching Centre

Narrow-Band

OACS

Optimised Active Codec Set

Optimal or Distant Configuration requested

Optimisation Mode supported

PCM sample

8-bit value representing the A_Law or μ_Law coded sample of a speech or audio signal; sometimes used to indicate the time interval between two PCM samples (125μs).

PCM

Pulse_Coded_Modulation

PCM_Alaw_Idle

PCM sample with value 0x54

PCM_Alaw_Idle

PCM sample with value 0x54.

PCM_Alaw_Silence

PCM sample with value 0xD5

PCM_Alaw_Silence

PCM sample with value 0xD5.

PCM_Idle

either PCM_Alaw_Idle, or PCM_μLaw_Idle, dependent on application

PCM_Silence

either PCM_Alaw_Silence, or PCM_μLaw_Silence, dependent on application

PCM_μLaw_Idle

PCM sample with value 0x00

PCM_μLaw_Idle

PCM sample with value 0x00.

PCM_μLaw_Silence

PCM sample with value 0xFF

PCM_μLaw_Silence

PCM sample with value 0xFF.

PDU

Packet Data Unit

PLMN

Public Land Mobile Network

RAN

Radio Access Network

RATSCCH

Robust AMR Traffic Synchronised Control Channel

RIF

Request Indication Flag

RNC

Radio Network Controller

SCR

Source Controlled Rate

SCS

Supported Codec Set

T_Bits

Time Alignment Bits

Tbfh

Time delay Bad Frame Handling

Transcoder

TCME

TFO Circuit Multiplication Equipment

TFO

Tandem Free Operation

TFO

Tandem Free Operation

TFO_ACK

TFO Acknowledgement Message

TFO_DUP

TFO (Half) Duplex Mode Message

TFO_DUP

TFO (Half) Duplex Mode Message

TFO_FILL

TFO Fill Message

TFO_NORMAL

TFO Normal Mode Message

TFO_REQ

TFO Request Message

TFO_SYL

TFO Sync Lost Message

TFO_TRANS

TFO Transparent Mode Message

TRAU

Transcoder and Rate Adaptor Unit

TrFO

Transcoder Free Operation

TSM

TFO Setup Mode

Tultfo

Time delay UpLink TFO

User Equipment

WideBand