Method for routing emergency calls during busy interface channel conditions

摘要

A method for routing enhanced 9-1-1 (E9-1-1) calls from a mobile emergency user to a Public Safety Answering Point (PSAP). The method is directed specifically for use in a wireless communication system which includes a plurality of base stations each of which is operative to communicate with corresponding mobile units within its coverage area over air interface channels. When all interface channels of the corresponding base stations of the mobile emergency user are busy, the location of the emergency mobile user will determined in cooperation with a Location Adjunct Processor (LAP). All other mobile units communicating with the corresponding base stations will be identified. Predetermined uplink and downlink RF measurements for each of these mobile units will thereafter be extracted and by reference to the same it may be determined which of the mobile units are also within the coverage areas of neighboring base stations. It may further be determined which of the neighboring base stations can support additional mobile units. Once provided with this information, automatic link transfers/handoffs/handovers will be initiated so as to open an interface channel with a currently blocked E9-1-1 call.