Unified Mobility Manager -- Enabling Efficient SIP/UMTS Mobile Network Control

This paper proposes the Unified Mobility Manager (UMM) that achieves efficient interworking between traditional wireless networks and Internet-telephony networks. The main characteristic of the UMM is that it combines UMTS HLR and SIP proxy functionality in one logical entity, which helps eliminate the performance degradation due to interworking between SIP and UMTS. This paper identifies seven potential network architectures with and without the UMM and the varying degree of IP penetration in the wireless core networks, and performs comparative analysis in terms of their call setup signaling latency.