Patent ID: 8254877

Claim:
A method operable on a user equipment for making an emergency voice call, comprising: transmitting a request for an emergency call to a first serving core network via a wireless access network; and establishing the emergency call with a second serving core network different from the first serving core network based on: the first serving core network determining: an alternative serving core network, and the user equipment being located outside of a first emergency serving area of the first serving core network, and the first serving core network forwarding the request for the emergency call to the alternative serving core network based on a correspondence between a user equipment location and a second emergency serving area of the alternative serving core network, wherein the establishing at least comprises establishing the emergency call with a public safety access point having a serving geographic location that includes the user equipment location based on a location retrieval function (LRF) of the first serving core network obtaining user equipment location information corresponding to the user equipment location.