scope:

This ETS describes all the functions associated with the TETRA speech codec, excepted the specification of the codec by itself which is entirely defined in ETS 300 395-2 [2]. Clause 4 of this ETS provides a description of the funtions associated with the speech encoder, while clause 5 is its counterpart for the speech decoder. Clause 6 describes the contents and the format of the signalling data block included in a stolen frame when used for transferring information relevant to the codec in a U-plane signalling message.