Enabling coder selection and rate adaptation for UTRAN and E-UTRAN for load adaptive applications; Stage 2
The system enhancements to enable codec rate adaptation at voice call setup over E-UTRA was standardized in Rel-9 in TS 23.401 [2].
The scope of this document is to study and specify enhancements to existing codec selection and codec rate adaptation based on network loading conditions and operator policies over UTRA and E-UTRA. Potential enhancements are definition of the signalling and interfaces enabling:
- To perform codec selection based on network loading conditions and operator policies during call establishment phase over both UTRA and E-UTRA;
- To perform codec data rate adaptation (if possible for the selected codec and needed by the service) based on network loading conditions during call establishment phase over UTRA;
- To perform codec data rate adaptation (if possible for the selected codec and needed by the service) for non-voice RTP-based services based on network loading conditions at call setup over E-UTRA;
- To perform codec data rate adaptation (if possible for the selected codec and needed by the service) based on network loading indications during an on-going call over both UTRA and E-UTRA;
- Support of codec rate adaptation by IMS Core Network entities (e.g., MGCF/MGW, IBCF/TrGW, etc.);
- Setting of Maximum Bit Rate (MBR) to be greater than the Guaranteed Bit Rate (GBR) over E-UTRA.
The solutions can be moved to normative specifications independently of each other once the study on the particular solution has been concluded.