Robust hierarchical mobile IPv6 (RH-MIPv6): an enhancement for survivability and fault-tolerance in mobile IP systems

In wireless networks, system survivability is one of the most important issues in providing quality of service (QoS). However, since failure of home agent (HA) or mobile anchor point (MAP) causes service interruption, the hierarchical mobile IPv6 (HMIPv6) has only weak survivability. In this paper, we propose robust hierarchical mobile IPv6 (RH-MIPv6), which provides fault tolerance and robustness in mobile networks. In RH-MIPv6, a mobile node (MN) registers primary (P-RCoA) and secondary (S-RCoA) regional care of addresses to two different MAPs (primary and secondary) simultaneously. We develop a mechanism to enable the mobile node or correspondent node (CN) to detect the failure of primary MAP and change their attachment from the primary to secondary MAP. By this recovery procedure, it is possible to reduce the failure recovery time. Analytical evaluation indicates that RH-MIPv6 has faster recovery time than HMIPv6 and we also show through simulation as like analytical result. Consequently, RH-MIPv6 shows about 60% faster recovery time compared with HMIPv6.