Mobility Management Alternatives for Migration to Mobile Internet Session-based Services

In this paper we address seamless roaming for SIP-based services across current cellular telecommunications networks and emerging all-IP wireless networks, such as those using 3G and WiFi networks. We present an abstract mobility model, and map this model to three basic approaches for supporting seamless mobility: A master-slave network approach, a federated system, and a unified approach. We discuss the challenges and implementation of an instance of the unified mobility management approach, called the Unified Mobility Manager, and then compare the trade-offs of the three systems using a comparative performance analysis. We conclude that unified mobility management is most efficient if a great deal of internetworking is required, and as more users invoke IP-based services; the federated approach is efficient when a single network technology is dominant and data access is limited, but requires sharing of data across networks; the master-slave approach is the least efficient, but is easy to introduce if the number of network types is small.