Research On DHT-Based Routing Protocol For MANET

Since peer-to-peer computing (P2P) has no centralized control point and can avoid the server bottleneck problem of C/S model, as a typical distributed computing technology, P2P becomes the research hot spots in distributed computing. P2P is pursuing of an uncontrolled Internet environment, enables different users to exchange information directly. With the developing and maturing of mobile application environment, more and more researchers start to focus on the MANET network, which set up the network conveniently. In order to solve route searching problems of MANET, people start to introduce P2P technical thought and produce a new research field: MP2P--Mobile peer-to-peer network. With the mainstream of Internet applications expanding to mobile devices, especially the far-ranging deployment of 3G technology, MP2P network has broad prospects for development.In MP2P network, the resource sharing is a very important application. However, because of the limited resources and the dynamic characteristic of nodes in MP2P system, when the routing protocols of traditional P2P network applied to MANET network, it has many problems. Therefore, it becomes an important task to design an efficient route searching algorithm for MP2P network.In this thesis, through deeply study the characteristics of P2P and MANET network, and analysis existing main routing protocols of MP2P network, an overlay routing algorithm Tapestry which is applicable for MANET network is proposed, then a DHT-based routing protocols for MANET--ACT (AODV Combined with Tapestry Routing Protocol) is presented. The main research work is as follows:A overlay routing algorithm Tapestry applicable for MANET is presented, which makes full use of the characteristics of node physical adjacent to cluster the network, so that the overlay and physical layer topology inconsistencies can be avoided, then the unnecessary middle nodes in physical links and the communication overhead of nodes can be reduced. Further more, by sharing object pointer between the nodes in the clusters, the search process can be speeded up. Simulation results show that the improved Tapestry overlay routing can effectively reduce the costs of network traffic.By constructing a P2P overlay on the top of MANET physical topology, and seamlessly combining the improved P2P overlay routing Tapestry with MANET network routing protocol AODV, a DHT-based routing protocol ACT for MANET is proposed. The routing process, routing discovery, routing table maintenance process, as well as the node's join and departure approach are designed in detail. The simulation results show that the comprehensive performance of ACT routing model is greatly improved. Even though node move fastly, a relative low routing delay and network overhead can still be maintained, at the same time a high searching success rate is holded.