METHOD AND APPARATUS FOR PROCESSING EMERGENCY CALLS

摘要

A method and apparatus are described for processing emergency calls by simplifying call setup procedures and minimizing call setup delay. In one scenario, a system information (SI) broadcast may include emergency services support information that conveys various emergency call network support levels and setup procedures. The SI broadcast is decoded to retrieve system parameters used to process an emergency call. The SI broadcast may include a bitmap or at least one information element (IE), that indicates the various emergency call network support levels. In another scenario, an extended service request message indicating circuit switched fallback (CSFB) for an emergency call is transmitted to a packet switched (PS) radio access technology (RAT) network during a PS session. An inter-system change is performed from the PS RAT network to a circuit switched (CS) RAT without a PS handover, and a CS emergency call is initiated via the CS RAT network.