C.3A UICC access to IMS

24.2293GPPIP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Release 18Stage 3TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

If the UE supports the UICC access to IMS USAT feature defined in 3GPP TS 31.111 [15D] the following procedures in addition to the UE procedures in this specification apply.

If the EF_UICCIARI contains a list of IARIs associated with active applications installed on the UICC in either the USIM or the ISIM, then when performing the user-initiated registration procedure as described in subclause 5.1.1.2 the UE shall include in the REGISTER request the list of IARIs associated with active applications installed on the UICC in addition to any IARI values for active applications installed on the ME in g.3gpp.iari-ref media feature tag(s) in the Contact header field of the REGISTER request as defined in subclause 7.9.3 and RFC 3840 [62].

If the UE receives from the UICC an initial request for a dialog or a standalone transaction then after decapsulating the request as specified in 3GPP TS 31.111 [15D] the UE shall send the request to the IM CN subsystem as specified in subclause 5.1.2A. When the UE receives from the UICC subsequent requests or responses related to dialogs or transactions already established for UICC applications then after decapsulating the request or response as specified in 3GPP TS 31.111 [15D] the UE shall send the request or response to the IM CN subsystem as specified in subclause 5.1.2A.

NOTE: The encapsulated requests and responses transferred between the UICC and UE are complete and valid SIP requests and responses compliant with RFC 3261 [26].

When sending requests or responses received from the UICC to the IM CN subsystem the UE shall modify or include any header fields necessary (such as Route, Via, Contact) in order to conform with the procedures in this specification.