A 3GPP-SIP Media Gateway for the IP Multimedia Subsystem

3GPP aims to leverage the flexibility and robustness of the Internet protocol in the 3G telecommunication networks. The IP multimedia subsystem (IMS) is founding element in the process of 3GPP migration from the traditional audio/video platforms to more flexible multi-modal environments. The IMS, further embraced by ETSI and other telecommunication standardization bodies, extends its application not only to the cellular world, but also to wire-line telephony and broadband Internet services. In this paper we introduce a media gateway (MG) between the conventional telephony infrastructure and the 3GPP-IMS plane. Our approach was to extend the capabilities of an existing PBX system to meet the signalling and media requirements of the 3GPP-IMS. Our 3GPP-IMS media gateway is a major element of the IMPULSE platform and integrates the IMS with the residential telecommunication environment.