A Comprehensive Study on Handover Performance of Hierarchical Mobile IPv6

Recently, IETF has standardized Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6) for supporting IPv6 mobility. Even though existing literatures have asserted that HMIPv6 generally improves MIPv6 in terms of handover speed, they do not carefully consider the details of the whole handover procedures. In this paper, based on the current IETF standards of both MIPv6 and HMIPv6, we conduct a comprehensive study of all IP-level handover procedures. We also provide a mathematical analysis on MIPv6 and HMIPv6 performance in terms of handover speed, and reveal that the average HMIPv6 handover latency is not always lower than the average MIPv6 handover latency. A vital finding of our analysis is that some optimization techniques for movement detection and duplicate address detection are essential to increasing the benefit of HMIPv6.