GSM-IP: A VoIP service for mobile networks

Based on media gateway control protocol (MGCP), this paper describes GSM-IP, a voice over IP service for GSM mobile network. With the signaling protocol translation mechanism provided by the MGCP signaling gateway, we demonstrate how to interwork the MGCP elements with the home location register, visitor location register and mobile switching center in the GSM network. Then we present the message flows for GSM-IP registration, call origination, call delivery, call release and inter-system handoff procedures. We show the feasibility of integrating GSM with the MGCP-based VoIP network without modifying the GSM network. Furthermore, our approach does not introduce new protocol primitives to MGCP.