Patent ID: 7330464
Filing Date: 2008-02-12
Classification: H04M

Abstract:
1. A method for supporting emergency services provided by public safety access points (PSAPs) by locating a telephony subscriber that is using voice over internet protocol (VOIP) services in a telephone network, the method comprising the steps of: assigning a unique secondary telephone directory number (SDN) to each VOIP access port in addition to a telephone directory number; storing in a database for each VOIP access port a corresponding SDN and geographic location information; receiving a first request for emergency services where said first request includes identification of one SDN assigned to the VOIP access port from which the corresponding request for emergency services originated; determining, based on said one SDN, one PSAP to handle the first request for emergency services; transmitting to the one PSAP a second request based on the first request, the second request including the directory number of the requesting subscriber and the one SDN; the one PSAP generating a query to the database to obtain the corresponding geographic location information associated with the one SDN; the one PSAP receiving a reply to the query containing the geographic location information associated with the one SDN, thereby identifying the location of the requesting subscriber.