Research On Medium Access And Routing Algorithm For Tactical Ad Hoc Networks

With the fast developments and advancements in wireless communication andcomputer networks technologies, mobile wireless communication networks isexpected to see increasingly wide-spread use and application. Now mobile ad hocnetworks is born from the situation and becoming the main research interest in mobilenetworks because mobile ad hoc networks can be widely used in both military andcivil area. There is no stationary infrastructure such as base station in mobile ad hocnetworks;each node acts as a router;the bandwidth of networks is limited and thetopology of networks is dynamic and changing. It is a central and pivotal problem toconstruct effective routing in mobile ad hoc networks. And it is a challenging task toensure the validity of the routing especially when the mobility of nodes is increasingand the topology of the networks is quickly changing. First, in the paper we analyzethe medium access control algorithm of mobile ad hoc networks, and propose adynamic slots assignment algorithm based on fixed TDMA. Second, we propose aposition based beaconless routing algorithm on the basis of analysis andsummarization of routing algorithms for mobile ad hoc networks, and compare theperformance of dynamic source routing (DSR) with that of position base beaconlessrouting algorithm proposed. Last, we propose a routing maintenance algorithm ofDSR by using position information, which improves the performance of DSR. Themain achievements are listed as follows:1. The detailed introduction and analysis of medium access control technologies areprovided. Many medium access control protocols for mobile ad hoc networks havebeen introduced and analyzed. In order to solve the existed drawbacks of MACprotocols, we propose a dynamic slots assignment algorithm based on fixedTDMA, analyze its performance, construct its model and simulate the algorithm.2. The detailed analysis and research of routing algorithm based on topology formobile ad hoc networks are provided. We have introduced and analyzed therouting algorithms for mobile ad hoc networks, and analyzed and compared theirperformance. Destination sequence distance vector (DSDV) is modeled andsimulated by OPNET based on the analysis in detail.3. The detailed analysis and research of routing algorithm based on position formobile ad hoc networks are provided. The existed several routing algorithms basedon position information for mobile ad hoc networks are introduced and analyzed.An improved progress is defined, which combines the traditional progress withdirection of greedy routing strategies in position based routing algorithms, and thecombination makes the routing has better performance in both progress anddirection. And an improved progress position based beaconless routing algorithm(I_PBBLR) is proposed, which is combined with the greedy routing strategies.4. The detailed analysis and research of dynamic source routing (DSR) are provided.First we compare DSR's performance with the improved progress position basedbeaconless routing (I_PBBLR) by simulations. And we improve the routingmaintenance algorithm of DSR by using the position based beaconless routingalgorithm, propose a kind of position information based routing maintenancealgorithm for DSR. This improvement not only enhances the performance of DSR,but also makes DSR more adapt to the dynamic ad hoc networks in which thenodes move fast.