Nested Mobile Network Routing Optimization Technology Research

As the demand for a ubiquitous connectivity increased, information access mode has changed a lot. It will be a common scenarios that a group of mobile terminals moving as a unit. This type of network is called Network Mobility (NEMO). Due to the complex topology of mobile network, it is very difficult to manage the mobility of every nodes, because it will waste too much wireless network resources. Then how to manage the complex mobility and evaluate the routing optimization scheme has become a hot issue in the network mobility research field.This paper first summarizes the background and reviews the actualities of NEMO. After clarifying the direction and significance of this paper, we will introduce the Mobile IPv6 and NEMO, and point out the shortcomings of NEMO Basic Support Protocol.After studying the scenarios of the nested mobile network, the reason that nesting may amplifies the sub-optimality of routing introduced by NEMO Basic Support Protocol was discussed. Then three typical route optimization solutions (RRH, ROTIO, FRO) were given, and compared them with NEMO Basic Support Protocol from packet overhead and the number of home agents crossed by packet. New route optimization solution called ERRHO is proposed to solve suboptimal routing problem caused by nested mobile networks. By adding a new slot recording the care-of-address of the mobile router at the top of the nested mobile network (TLMR) in the reverse route header, the corresponding node can set up a bi-directional tunnel with the TLMR, and then the route optimization between nested mobile network and corresponding node can be achieved.Based on analysis of amounts of routing optimization mechanisms, a model evaluating the routing optimization is provided, and then we make a comparison between ERRHO scheme and other schemes mentioned above on the total cost of transmission and memory. The analysis and simulation results show that ERRHO can improve routing performance of nested mobile networks in that it introduces lower memory and transmission costs while the nest level increasing.