A context-aware handoff scheme and all-ip mobile multicast service for heterogeneous wireless networks

With rapid development of wireless technologies, current user mobile devices can support to access various wireless networks such as Wi-Fi 802.11 Wireless LANs, 3G cellular networks, etc. Due to requirements of multicast mobility for multimedia services, the convergence of wired and wireless network has been a necessary trend in Next Generation Networks (NGN). The issues of multicast and mobility in the heterogeneous networks are very significant. Thus, the paper proposes an integrated framework for mobile nodes (MNs) and core networks to provide a seamless multicast mobility service according user contexts, i.e. user states and network states. The context-aware handoff process including the operations of system discovery, handoff decision, and handoff execution are designed for MNs. In addition, multicast agents (MAs) in the core networks are designed to deal with multicast connection management, which supports all IP multicast connection for multicast supported and non-multicast-supported networks. The prototype of the proposed framework has been implemented and tested. The performance measurements and system evaluation are shown, and the service disruption time during context-aware handoff can be minimized.