SGsAP SGs Application Protocol
SGsAP is designed to facilitate mobility management and paging procedures on the SGs interface, as part of CSFB (Circuit Switched Fallback) operation. In addition, SGsAP permits the transfer of SMS delivery via the circuit switched core network when IP based messaging services are not available. Key capabilities of SGsAP include: Paging for non-EPS services, Location Updates for non EPS services, alerting procedures, IMSI detach from EPS services, Mobility Management procedures and failure conditions.