Patent ID: 6332022
Filing Date: 2001-12-18
Classification: H04M,H04Q,H04W

Abstract:
A method of handling emergency services calls from calling parties in an intelligent network having a plurality of emergency services operator stations (PSAPs), at least one Service Control Point (SCP) equipped with software for providing service features and having access to databases including routing data for said plurality of emergency services operator stations and a plurality of Service Switching Points (SSP) equipped with call processing software having point-in-call triggers for interrupting processing of a call and exchanging signalling messages with the Service Control Point (SCP) to obtain instructions for further processing of the call, the Service Switching Points and Service Control Point (SCP) being interconnected by a data communication signalling system, the Service Switching Points being interconnected by trunks for calls therebetween, and the plurality of emergency services operator stations being each connected by trunks or lines to at least one of said Service Switching Points, the said routing data comprising routing numbers each identifying a network location for a respective one of said plurality of emergency services operator stations, the routing data associating with each calling party a primary emergency services operator station and at least one alternative emergency services operator station, the method comprising the steps of:(i) at a particular Service Switching Point, presetting a point-in-call trigger to operate at a predetermined point in a call for emergency services,(ii) subsequently, when said particular Service Switching Point is processing an emergency services call, interrupting processing of the call and transmitting to the Service Control Point (SCP) a query signalling message requesting routing information,(iii) at the Service Control Point (SCP), upon receipt of the query signalling message, accessing said routing data in dependence upon parameters in the query signalling messages, and selecting a routing number corresponding to said alternative emergency services operator station for that calling party, forming a response signalling message including the selected routing number and returning such response signalling message to said particular Service Switching Point,(iv) at said particular Service Switching Point, upon receipt of said response signalling message, detecting the selected routing number, and routing the call to the network location corresponding to the selected routing number for completion to said alternative emergency services operator station.