3 Definitions and Abbreviations

08.623GPPInband Tandem Free Operation (TFO) of speech codecsService descriptionStage 3TS

3.1 Definitions

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

TRAU Frame: is used equivalent to "TRAU Speech Frame".

TFO Frame: is used equivalent to "TFO Speech Frame".

Abis/Ater: indicates that either the Abis or the Ater interface is used, depending on the location of the TRAU equipment.

3.2 Abbreviations

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

BSC Base Station Controller

BSS Base Station Sub-system

BTS Base Transceiver Station

EFR Enhanced Full Rate

FR Full Rate

GCME GSM Circuit Multiplication Equipment

HR Half Rate

IPE In Path Equipment

MS Mobile Station

MSC Mobile Switching Centre

PCM Pulse_Coded_Modulation

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

PCM_Silence either PCM_Alaw_Silence, or PCM_Law_Silence, dependent on application

PCM_Alaw_Silence PCM sample with value 0xD5.

PCM_Law_Silence PCM sample with value 0xFF.

PCM_Idle either PCM_Alaw_Idle, or PCM_Law_Idle, dependent on application

PCM_Alaw_Idle PCM sample with value 0x54.

PCM_Law_Idle PCM sample with value 0x00.

TFO_ACK TFO Acknowledgement Message

T_Bits Time Alignment Bits

TFO_FILL TFO Fill Message

TFO_TRANS TFO Transparent Mode Message

TFO_NORMAL TFO Normal Mode Message

TFO_DUP TFO (Half) Duplex Mode Message

TFO_REQ TFO Request Message

TFO_SYL TFO Sync Lost Message

TFO Tandem Free Operation

TRAU Transcoder and Rate Adaptor Unit

Other abbreviations used in this TS are listed in GSM 01.04.