5 UE and network capabilities

22.2433GPPRelease 17Speech recognition framework for automated voice servicesStage 1TS

In addition to the capabilities required for IMS Basic Voice session (such as the default voice codec that will be used for the downlink audio prompt stream), the following SRF-based automated voice service-specific capabilities shall be required in the UE and network:

• A default uplink codec (conventional codec or DSR optimized codec).
• A downlink conventional codec and downlink streaming capabilities (simultaneous with uplink).
• The capability to transmit keypad information from the client to the server (e.g., either DTMF or the keypad string).
• The capability to reconstruct encoded speech. The reconstruction requirement does not apply to the UE.

It shall be possible to enable application specific information exchanges between the client and the server (e.g. client events (e.g. barge-in events), display information, etc…), in the form of speech meta-information. It shall be possible to enable these exchanges with conversational QoS.

SRF shall be supported by an uplink channel available in GERAN and UTRAN networks for the transport of the codec payload and with QoS (Quality of Service) for conversational class, streaming and interactive QoS services as specified in TS 22.105 [4].

It shall be possible for the network to distinguish a SRF session from a basic voice session (e.g. for charging purposes).