An SS7-based call protocol conversion gateway that translates between circuit-switched SS7 protocols and session initiation protocol (SIP) oriented protocol, allowing an E911 call initiated over a switched network to be routed by a VoIP network. The SS7-based call protocol conversion gateway provides...http://www.google.de/patents/US20070263610?utm_source=gb-gplus-sharePatent US20070263610 - SS7 MAP/Lg+ to SIP based call signaling conversion gateway for wireless VoIP E911
