scope:

The present document describes the protocol between the Base Transceiver Station (BTS) and the remote Transcoder/Rate Adaption Unit (TRAU) for speech and data on half rate traffic channel (TCH/H). For Half Rate speech and half rate data the protocol is specified for 8 kbit/s and 16 kbit/s submultiplexing scheme. For Adaptive Multi-Rate speech the present document specifies the 8 kBit/s submultiplexing, both for the full and the half rate traffic channels (TCH/AFS and TCH/AHS). The specification for 16 kBit/s submultiplexing is given i Rec GSM 08.60, both for the full and the half rate traffic channels (TCH/AFS and TCH/AHS). The present document should be considered together with the GSM 06 series, GSM 04.21 (Rate Adaption on the MS-BSS Interface) and GSM 08.20 (Rate Adaption on the BTS/MSC Interface).