Emergency services calls may be alternate-routed in an intelligent network
having at least one Service Control Point (SCP) with access to a routing
table, a plurality of Service Switching Points (SSP) equipped with
point-in-call triggers and one or more emergency services stations (PSAP).
The routing table lists a routing number for each of the emergency
services stations. The alternate routing involves presetting a
point-in-call trigger at a Service Switching Point to operate at a
predetermined point in a call for emergency services. During subsequent
processing of an emergency services call, the trigger interrupts
processing of the call and and prompts transmission to the SCP of a query
signalling message requesting routing information. Upon receipt, the SCP
accesses the routing table in dependence upon parameters in the query
signalling message and obtains a routing number for a selected emergency
services operator station, forms a response signalling message including
the routing number and returns such response signalling message to the
SSP. Upon receipt of the response signalling message, the SSP detects the
routing number, and routes the call to the emergency services operator
station.
There is also provided a method of translating signalling message
parameters from a mobile protocol to an intelligent network protocol, and
vice versa, to enable emergency services calls from mobile users to be
routed to one or more PSAPs in the intelligent network.