The Research Of High Performance Routing Protocols For Wireless Ad Hoc Network

Wireless ad hoc networks are one of the international research focuses, due to their potential applications in both military and civilian fields resulted from their flexibility and no infrastructure. As the mobile terminals in wireless ad hoc networks usually use battery, the energy consumption is very sensitive, and it is of significance to prolong the lifetime by reducing the energy consumption of nodes. The routing discovery flooding in wireless ad hoc networks can lead to huge amont of energy consumption, so flood control becomes very important for extending lifetime of networks.This thesis aims to achieve high performance routing protocols by mainly study on energy-efficient routing and direction routing in wireless ad hoc networks. Based on analysis and research of classical routing algorithms, some improved algorithms are proposed, and corresponding simulations are undertaken to analyze the performance of our improved algorithms. The main contributions of this thesis are as following:1. An improved MBCR algorithm, IM_MBCR, is proposed by improving MBCR. MBCR may causes some nodes died early and shorten the lifetime of networks, because it only concentrates on reducing the whole energy consumption and regardless of available energy of nodes of path. IM_MBCR algorithm monitors the real-time energy consumption of nodes, and re-establishes route once the available energy of nodes of path are lower than given threshold, thus can balance the energy consumption of every nodes and extend the whole lifetime of networks.2. Applying IM_MBCR algorithm to AODV protocol, an improved AODV protocol, IM_AODV, is implemented. By extending the structure of RREQ packet in IM_AODV, the number of nodes which available energy is in the range of alarm, and the total energy consumption of path, can be recorded by RREQ packets. According to those recorded information, the destination node can determine the more path and announce it to the source, then the global optimal energy-efficient route is maintained.3. Aiming to the problem in LAR algorithm which may select non-optimal route caused by effectively reducing routing flooding, an improved LAR algorithm, IM_LAR, is presented. By extending the request area of LAR scheme 1 to including all nodes of existed paths, the optimal route can always be found together with reducing the flooding effectively.4. The performances of improved algorithms and protocols are simulated through experiments on the OPNET simulation platform. The experimental results show that the proposed algorithms and protocols can effectively not only reduce the energy consumption but also delay the node death and prolong the lifetime of the whole network.