Enhancement of Seamless mobility in Nested Network Mobility

Mobile networks consist of one or more mobile IP-subnets and is viewed as one connected unit to the internet via one or more Mobile Router (MR). When MR is connecting to the other MR in the other mobile network, it makes a structure known as Nested Mobile Network. In this structure each level of connected router has a Bi-directional tunnel between each pair of MR and its Home Agent (HA) must be established. By this way the message size will increase, because of IP-in-IP header encapsulation. This leads to bad network performance in term of high tunneling overhead. In this paper we investigate on the current route optimization techniques that deal with nested network mobility problem. The main objective of this paper is to develop new a route optimization scheme that enhances the overall network performance by reducing the tunneling overhead, handoff latency, and packet transmission delay. This is accomplished using a hybrid approach between Proxy MIPv6 protocol and SD-TLMR scheme using pre-registration of SD-TLMR of each sub domain in advance with short time update in binding update extensions message format. Analytical model has been used to evaluate the performance analysis and the performance is benchmarked with NEMO protocol, BUL+ and SD-TLMR approaches. The obtained results showed that the proposed hybrid approach has improved the performance of the network when using the packet delay and handoff latency measures compared to the other techniques.