Section: 5.2.2.1 Call indication
Content: After the arrival of a call from a remote user, the corresponding call control entity in the network shall: initiate the MM connection establishment according to clause 4 and enter the "MM connection pending" state. The request to establish the MM connection is passed from the CM sublayer to the MM sublayer. It contains the necessary routing information derived from the SETUP message. Upon completion of the MM connection, the call control entity of the network shall: send the SETUP message to its peer entity at the mobile station, start timer T303 and enter the "call present" state. The SETUP message shall contain the multicall supported information in the network call control capabilities in the case where the network supports multicall and there are no other ongoing calls to the MS. Mobile stations supporting multicall shall store this information until the call control state for all calls returns to null. Mobile stations not supporting multicall shall ignore this information if provided in a SETUP message. If the multicall supported information is not sent in the SETUP message, the mobile station supporting multicall shall regard that the network does not support multicall. Upon receipt of a SETUP message, the mobile station shall perform compatibility checking as described in subclause 5.2.2.2. If the result of the compatibility checking was compatibility, the call control entity of the mobile station shall enter the "call present" state. An incompatible mobile station shall respond with a RELEASE COMPLETE message in accordance with subclause 5.2.2.3.4. If there are no bearer capability IEs in the SETUP message, the network may provide information about the requested service in the backup bearer capability IE. If no response to the SETUP message is received by the call control entity of the network before the expiry of timer T303, the procedures described in subclause 5.2.2.3.3 shall apply. Figure 5.6/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  Mobile terminating call initiation and possible subsequent responses.