European Digital Cellular Telecommunications System (Phase 2); Rate Adaption on the Base Station System - Mobile-Services Switching Centre (BSS - MSC) Interface (GSM 08.20)
This specification defines rate adaptation functions to be used in GSM PLMN Base Station Systems (BSS) and transcoders for adapting radio interface data rates to the 64 kbit/s needed at the MSC in accordance with GSM 03.10. The number of BSS-MSC traffic channels supporting data rate adaptation may be limited. In this case some channels may not support data rate adaptation. Those that do must conform to this specification. Note: This specification should be considered together with TS GSM 04.21 to give a complete description of PLMN rate adaptation.