Research On Cooperative Caching In Mobile Peer-to-peer System Based On Ad Hoc Network

It is expected that new P2P application systems can be configured and developed based on Ad Hoc network, making use of the features of Ad Hoc network and P2P system. Because of the feature of Ad Hoc network, the cooperating among mobile nodes is very important. The most common cooperating mechanism among mobile nodes is cooperative caching. That is, mobile nodes caching some important data or other resources, which can be used by other mobile nodes. Cooperative caching play a very important role in traditional networks for data access and information distribution and it will be very important in wireless Ad Hoc networks. Because of some restrictions in mobile environment, cooperative caching technologies used in traditional network are not suitable in mobile P2P systems.In this dissertation, some problems of cooperative caching that should be considered in mobile P2P environment are analyzed, including cache access control, cache preload control, and cache consistency maintaining, etc. Aimed at Ad Hoc based mobile P2P system, an algorithm of cache consistency maintaining, an algorithm of cache replacement, an algorithm of cache preloading, and an algorithm of admission controlling are given. Simulation experiments demonstrate that the data request delay in Ad Hoc network can be reduced and the network performance can be improved, with the using of admission controlling algorithm and cache preloading algorithm given in this paper to select the data in cache. Finally, an application environment is given, with which the cooperative caching technology can be verified.