EMERGENCY CALLS IN INTERNET PROTOCOL MULTIMEDIA SUBSYSTEM (IMS) OVER EVOLVED PACKET CORE (EPC) NETWORKS

摘要

A device receives an emergency call invite generated by a user device associated with an Internet protocol (IP) multimedia subsystem (IMS) media gateway, and forwards the emergency call invite to a location resource function/route determination function (LRF/RDF) device for determining public safety answering point (PSAP) routing information. The device receives, from the LRF/RDF device, the PSAP routing information based on the emergency call invite, and routes the emergency call invite to a particular PSAP based on the PSAP routing information. If the emergency call invite is routed to a legacy PSAP, the emergency call is routed to the legacy PSAP via legacy mobile switching center (MSC) direct trunks. If the emergency call invite is routed to an IP PSAP, the emergency call is routed to the IP PSAP via an IP connection.