scope:

When 64 kbit/s traffic channels are used on the Abis interface, the speech shall be coded according to CCITT Recommendation G.711 and the data rate adaptation shall be as specified in 3GPP TS 44.021 and 3GPP TS 48.020.

In the case where 16 kbit/s traffic channels are used for full rate speech, enhanced full rate speech, Adaptive Multi-Rate speech, Adaptive Multi-Rate Wideband speech or full rate data service, then the present document shall apply for frame structure and for control of remote transcoders and additional rate adaptors.

For Adaptive Multi-Rate speech the present document specifies the 16 kBit/s submultiplexing, both for the full and the half rate traffic channels (TCH/AFS, TCH/AHS, TCH/WFS and O-TCH/WHS). The specification for 8 kBit/s submultiplexing is given in 3GPP TS 48.061, both for the full and the half rate traffic channels (TCH/AFS and TCH/AHS).

Additionally, the present document specifies the 32 kBit/s submultiplexing for Adaptive Multi-Rate Wideband speech. However it reuses the frame structure of the 16 kBit/s submultiplexing for Adaptive Multi-Rate speech.

The use and general aspects of the Abis interface are given in 3GPP TS 48.051.

NOTE: The present document should be considered together with the 3GPP TS 06 series of specifications, 3GPP TS 44.021 (Rate Adaptation on the MS-BSS Interface) and 3GPP TS 48.020 (Rate Adaptation on the BS/MSC Interface).