Patent ID: 8270574
Filing Date: 2012-09-18
Classification: H04L,H04M,H04W

Abstract:
1. A computing device-implemented method, comprising: receiving, by the computing device, an emergency call invite generated by a user device associated with an Internet protocol (IP) multimedia subsystem (IMS) media gateway; forwarding, by the computing device, the emergency call invite to a location resource function/route determination function (LRF/RDF) device for determining public safety answering point (PSAP) routing information; receiving, by the computing device and from the LRF/RDF device, the PSAP routing information based on the emergency call invite, the PSAP routing information including one of legacy PSAP routing information or IP PSAP routing information, when the PSAP routing information includes the legacy PSAP routing information, the PSAP routing information includes an emergency service routing key (ESRK) and an identifier or address for a transcoder free operation mobile switching center (TrFO MSC), the identifier or address for the TrFO MSC including a session initiation protocol (SIP) uniform resource identifier (URI) of the TrFO MSC; routing, by the computing device, the emergency call invite to a legacy PSAP when the PSAP routing information includes legacy PSAP routing information; and routing, by the computing device, the emergency call invite to an IP PSAP when the PSAP routing information includes IP PSAP routing information.