Section: 5.2.1.5 Alerting
Content: Having entered the "mobile originating call proceeding" state, upon receiving an indication that user alerting has been initiated at the called address, the call control entity of the network shall: send an ALERTING message to its peer entity at the calling mobile station and enter the "call delivered" state. When the call control entity of the mobile station in the "call initiated" state or "mobile originating call proceeding" state receives an ALERTING message then, the call control entity of the mobile station shall stop timer T303 and T310 (if running) and shall enter the "call delivered" state. In this state: - for speech calls: an alerting indication should be given to the user. If the mobile station has not attached the user connection then the mobile station shall internally generate an alerting indication. If the mobile station has attached the user connection then the network is responsible for generating the alerting indication and the mobile station need not generate one; and - for multimedia calls: if the mobile station has not attached the user connection then the mobile station may internally generate an alerting indication. If the mobile station supports multimedia CAT during the alerting phase of a mobile originated multimedia call establishment, the network may request the mobile station to attach the user connection and setup a H.324 call and generate multimedia CAT as specified in subclause 5.3.6.4, in which case the mobile station need not generatean alerting tone. Abnormal cases: On the mobile station side, if timer T303 or T310 expires, the call control entity of the mobile station shall initiate call clearing as described in subclause 5.4. Figure 5.4/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  Call confirmation at mobile originating call establishment