Section: 4.5.1.9 MM connection establishment due to Dual Radio Voice Call Continuity (DRVCC) access transfer
Content: The MM Connection establishment procedures for a dual radio voice call continuity (DRVCC) access transfer follow the procedures described in subclause 4.5.1.1 with the following additions: Upon request from the upper layers to set up a DRVCC call, the MS shall initiate the MM connection establishment and send a CM SERVICE REQUEST message. The MS shall include the Additional update parameters information element indicating "DRVCC call". If the MS determines that it is in a different location area than the stored location area, the MS shall first initiate a normal location updating procedure regardless of Network Mode of Operation. The MS shall indicate "follow-on request pending", shall include the Additional update parameters information element indicating "DRVCC call", and shall not include the MS network feature support information element in the LOCATION UPDATING REQUEST message. The network may use the "DRVCC call" indication to decide whether to initiate any of the MM common procedures. If the MS and the network have an established GSM security context or UMTS security context, the MS and the network may take the key(s) of the established security context into use as specified in subclause 4.3.2.7a.