A performance study of hierarchical mobile IPv6 from a system perspective

We performed a simulative evaluation of standard Mobile IPv6 via ns-2 for a ´hot spot deployment´ scenario. The simulation scenario comprises four access routers and up to 30 mobile nodes that move randomly and communicate in accordance with IEEE 802.11 wireless LAN standard. The study collected the performance metrics of all mobile nodes from the system. As data traffic video, VoIP, and TCP sources were considered. The goal of the study was to obtain quantitative results of the improvements provided by HMIPv6 with respect to handoff latency, packet loss, signaling load and bandwidth per station as well as an indication of the number of users that could be accommodated depending on the traffic source. Moreover, we performed a ´stress-test´ of the protocol to investigate the behavior of the protocol in extreme cases, e.g. under channel saturation conditions. In addition to the quantitative results provided, the simulations taught us insights on the protocol performance not easily gained without performing simulations. For example, we learned that i) in our scenario a low HMIPv6 signaling load reduction outside of the micro-mobility domain implies a significant increase within it, ii) under high saturation conditions we can expect a better performance of HMIPv6 in latency terms but not in packet losses or bandwidth and iii) the consideration of network coverage user unawareness impact the performance results.