scope:

The present document defines rate adaptation functions to be used in PLMN Base Station Systems (BSS) transcoders and IWF

- for adapting radio interface data rates to the 64 kbit/s used at the A-interface in A/Gb mode and

- for adapting radio interface data rates to the Iu interface in GERAN Iu mode in accordance with 3GPP TS 43.010.

The number of Base Station System - Mobile-services Switching Centre (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, shall conform to this specification.

NOTE: This specification should be considered together with 3GPP TS 44.021 to give a complete description of PLMN rate adaptation.