Position Information for VoIP Emergency Calls - Originating from a Wireless Metropolitan Access Network

This article describes a mechanism to provide location info rmation about users of a wireless metropolitan access network to trusted and authorized third parties. A ca se of particular interest is that of providing emergency centers with the location of the VoIP caller. The locat ion information is obtained from the wireless access points using SNMP polling, and stored in a location se rver. The outbound SIP proxy server requests the user’s location and includes it in the SIP invite message wh n the callee is an emergency center.