6.9.5 UE Radio Capability Match Request

23.0603GPPGeneral Packet Radio Service (GPRS)Release 17Service descriptionStage 2TS

If the SGSN requires more information on the UE capabilities support to be able to set the IMS voice over PS Session Supported Indication (see clause 5.3.8), then the SGSN may send a UE Radio Capability Match Request to the RAN. This procedure is typically used during the Initial Attach procedure, during Routing Area Update procedure for the "first RAU following GERAN/E-UTRAN Attach" or for "UE Capability update" or when SGSN has not received the Voice Support Match Indicator (as part of the MM Context).

Figure 6.9.5-1: UE Radio Capability Match Request

1 The SGSN indicates whether the SGSN wants to receive Voice support match indicator.

2. Upon receiving a UE Radio Capability Match Request from the SGSN, if the RAN has not already received the UE capabilities from the MS the RAN requests the MS to upload the UE Capability information by sending the RRC UE Capability Enquiry.

3. The MS provides the RAN with its UE capabilities sending the RRC UE Capability Information.

4. Upon receiving a UE Radio Capability Match Request from the SGSN, the RAN checks whether the UE capabilities are compatible with the network configuration. The RAN provides a Voice Support Match Indicator to the SGSN to indicate whether the UE capabilities and networks configuration are compatible.

For determining the appropriate UE Radio Capability Match Response, the RAN is configured by the operator to check whether the MS supports certain capabilities required for IMS PS Voice continuity. In a shared network, the RAN keeps a configuration separately per PLMN.

NOTE: What checks to perform depends on network configuration, i.e. following are some examples of MS capabilities to be taken into account:

– the SRVCC, and UTRAN/E-UTRAN Voice over PS capabilities;

– the Radio capabilities for UTRAN/E-UTRAN FDD and/or TDD; and/or

– the support of UTRAN/E-UTRAN frequency bands.

The SGSN stores the received Voice support match indicator in the MM Context and uses it as an input for setting the IMS voice over PS Session Supported Indication.