REVERSE 911 USING MULTICAST SESSION INTERNET PROTOCOL (SIP) CONFERENCING OF VOICE OVER INTERNET PROTOCOL (VoIP) USERS

Abstract

A reverse 911 system uses voice over Internet Protocol (VoIP)/Session Internet Protocol (SIP) conferencing. An emergency alert message may be a text, video, MMS, hyperlink and/or image communicated simultaneously to multiple VoIP users via a SIP conference. Multiple SIP conferences may be cascaded to communicate with a larger number of users in a relevant group of users to be communicated with.

What is claimed is: 
     
         1 . A reverse 911 emergency alert system, comprising:
 a SIP conference focus server to establish a SIP conference triggered by an appropriate reverse 911 trigger event; and   a Session Internet Protocol (SIP) conference bridge, initiated by said SIP conference focus server, to establish a listen-only SIP conference with said SIP conference focus server as host;   wherein said SIP conference focus server is adapted to issue a SIP INVITE to each of a plurality of user agent devices designated in a user agent database for listen-only participation in said listen-only SIP conference;   wherein said SIP conference focus server further establishes another listen-only SIP conference triggered by said appropriate reverse 911 trigger event, and issues a SIP INVITE to each of a plurality of user agent devices designated in said user agent database for listen-only participation in said another listen-only SIP conference;   wherein said SIP conference focus server cascades said listen-only SIP conference with said another listen-only SIP conference; and   wherein said plurality of user agent devices are provided listen-only access to said SIP conference bridge.