Patent ID: 8681782

Claim:
A method of setting up an emergency services call between a mobile client device and a corresponding one of a plurality of public safety answering points according to a current geographic location of the mobile client device, wherein the mobile client device roams over a voice-over-packet network comprised of a plurality of wireless access points each having a respective wireless coverage area, comprising the steps of: one of the wireless access points to which the mobile client device has roamed on the network receiving a request for an emergency services call from the mobile client device, wherein the request identifies the call as being for emergency services but does not identify any public safety answering point; the wireless access point parsing the request to determine whether it is for emergency services; in response to detecting the emergency services request, the wireless access point inserting a location identifier into the request and forwarding a modified request to a proxy server coupled to the voice-over-packet network, wherein the location identifier is comprised of one of a wireless access point identifier or a public safety answering point identifier that is stored in the respective wireless access point receiving the request; the proxy server receiving the modified request and determining if the location identifier is a public safety answering point identifier; if the location identifier is not a public safety answering point identifier, then the proxy server using the location identifier to retrieve a corresponding public safety answering point identifier from a public safety answering point coverage database; the proxy server using the public safety answering point identifier to retrieve a routing address from a routing database; and the proxy server setting up the emergency services call between the mobile client device and the public safety answering point located at the retrieved routing address.