8.46 SRVCC Preparation

25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling

8.46.1 General

The purpose of the SRVCC Preparation procedure is the reception of the security parameters from the PS CN domain needed for successful SRVCC operation as described in TS 23.216 [54].

The procedure uses connection oriented signalling.

8.46.2 Successful Operation

Figure 61: SRVCC Preparation procedure. Successful operation.

The RNC shall determine if the SRVCC operation as described in TS 23.216 [54] is required. In such case the RNC shall initiate the SRVCC Preparation procedure by sending an SRVCC CS KEYS REQUEST message to the source SGSN.

The SGSN shall respond to the RNC with SRVCC CS KEYS RESPONSE message containing the Integrity Protection Key IE, the Encryption Key IE and the SRVCC Information IE.

8.46.3 Abnormal Conditions

Not applicable.