Design and evaluation of flow handoff signalling for multihomed mobile nodes in wireless overlay networks

With the increasing deployment of wireless overlay networks, a mobile node with a range of network interfaces can be connected to multiple heterogeneous or homogeneous access networks simultaneously. Such host multihoming technology can be exploited to distribute (or hand off) application flows among the most appropriate interfaces and access networks dynamically to achieve end-to-end seamless, robust and even quality-of-service-aware communications for mobile users. It is essential that an efficient and effective flow handoff signalling scheme be in place. Nevertheless, little prior work has addressed this problem sufficiently in a systematic way and little performance evaluation is readily available. We propose a set of signalling procedures for a comprehensive, flexible yet standard-oriented flow handoff solution. Two candidate schemes are designed by extending and optimising related IETF work based on Mobile IPv6 or Network Mobility (NEMO). Theoretical analyses are performed and numerical results are then presented with a focus on signalling loads to compare the two proposals and to demonstrate that the designs can largely meet the requirements on desired signalling performance. Preliminary implementations and experimental results are also reported to validate the concepts of the designs, investigate the flow handoff signalling delays and verify the effectiveness of the policy-based flow handoff support for typical real-time and non-real-time applications.