AHS: Advanced Handoff Scheme for Nested Mobile Networks

Network Mobility Basic Support protocol (NEMO Basic) that is designed to offer network mobility is not efficient to offer low latency handoff in the case of nested mobile networks since fairly sub-optimal routing is utilized. A mobile network is composed of Mobile Network Nodes (MNNs) and a Mobile Router (MR). Route optimization for MNNs in IPv6 mobile networks is performed with Hierarchical Prefix Delegation protocol (HPD) and Reverse Routing Header (RRH). However, when a mobile network that contains a lot of MNNs moves locally in a nested mobile network, problems such as handoff latency, signaling overhead and packet losses will occur. This paper proposes an Advanced Handoff Scheme (AHS) which overcomes the limitations in conventional solutions. Combining the HPD and the Hierarchical Mobile IPv6 (HMIPv6) functionality can enable the improvement to the micro-mobility problem, and the location address of MNNs is created in Hierarchical Mobile Network Prefix (HMNP) assignment. Furthermore, a Mobility Management Router (MMR) is allowed to update the binding information of all MNNs in a mobile network without getting Binding Update messages (BUs) from the MNNs as the MMR receives a BU from the MR in the mobile network. The simulation is done by NS-2. The results show that a significant improvement is achieved compared to conventional solutions in terms of handoff latency, signaling overhead, and transmission delay.