Patent ID: 8412804

Claim:
A method for acquiring, at a first entity, public safety information related to a geographic location of the first entity, wherein the first entity is a communication unit in a Voice over Internet Protocol (VoIP) communication network, the method comprising: generating, by the first entity, a Dynamic Host Configuration Protocol (DHCP) message requesting the geographic location of the first entity; forwarding, by the first entity, the DHCP message to an external DHCP server; receiving, at the first entity, a DHCP response from the DHCP server that comprises a DHCP location configuration information (LCI) option representing the geographic location of the first entity, wherein the LCI option comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address of the first entity; generating a request at the first entity to a trusted source server for a Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the first entity wherein the request is a Session Initiation Protocol (SIP) SUBSCRIBE message and includes location information representing the geographic location of the first entity; forwarding the request to a trusted source server considered a trustworthy source of information by the first entity, wherein the trusted source server is configured to use the geographic location of the first entity to locate a PSAP and verify that the PSAP services the geographic location of the first entity; if the URI or URL of the PSAP is located by the trusted source server, receiving a SIP “200 OK” response message generated by the server containing the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit; and establishing a VoIP call with the PSAP using the received URI or URL.