F.1 Avoidance of Codec Type Optimisation

28.0623GPPInband Tandem Free Operation (TFO) of speech codecsService descriptionStage 3TS

Depending on the call configuration on both sides of the connection a Codec Type Optimisation may follow after TFO has been established, because the full list of supported Codec Types is only available then. For this Codec Type Optimisation an intra-cell hand-over is required. In many call scenarios with a TFO Connection with HR_AMR the resulting communication quality may be sufficient. The benefits of a Codec Type Optimisation by an intra cell hand-over may be not obvious, but the signalling load may be too costly.

Guideline 1:

If the operator wants to avoid any Codec Type Optimisation, then the supported Codec List shall contain only one, the Active Codec Type.