Bandwidth Efficient Algorithms And Routing Protocols For Tactical Mobile Ad Hoc Networks

Until now most research efforts in mobile ad hoc networks are focused on wireless LAN technology, which characterizes short range and high data rate transmission. But for tactical mobile ad hoc networks with some very unique characteristics such as large amount of users, long distance of transmission, continuous mobility of nodes, and low data rate, an important issue is the design of some bandwidth efficient network protocols. This dissertation presents some innovative bandwidth efficient algorithms in power control, location management and unicast-routing. Nodes usually move in groups in tactical networks as they are always organized. This feature can be utilized to design bandwidth efficient distributed network algorithms.A distributed location aided power control algorithm is presented which is easy for implementation. In the algorithm nodes estimate the number of their neighbors by location prediction, and adjust their transmitting power to maintain an optimal network connectivity, so as to improve the spatial reuse and the overall throughput of the network.A group-based location prediction theory is proposed, and with a theoretical analysis of the condition for its application. A group prediction based location update algorithm is presented, which estimates the motion of the group center, and then predicts location for each node. Only when the predicted location deviates from the true location over a given threshold, does the node trigger a new location update message. Thus total number of location update messages in the network is greatly reduced.Hierarchical location management techniques are investigated, and a group mobility based hierarchical location management algorithm is presented. In this algorithm, nodes are divided into clusters according to their group mobility. Location is updated by prediction of each node with the aid of the motion of their cluster center. Locations of the nodes in the lower cluster are distributed in the scope of their own cluster, and only cluster center information is exchanged among peer clusters, while location information is transfered from the lower hierarchy to the higher hierarchy with group mobility based update mechanism, so as to reduce the number of location messages in the whole network. Relations of the location error between all those hierarchies are analyzed.A new hierarchical routing protocol for mobile ad hoc networks is proposed. In this protocol, location based routing is run for intra-cluster nodes, while link state routing is run for inter-cluster nodes. Each node update and distribute their locations in the same cluster according to the aforementioned algorithm, and maintain a location table for all nodes in itscluster, and then compute the intra-cluster topology graph by location prediction. Shortest path first (SPF) algorithm is run to acquire the intra-cluster route. Thus the usual "void region" problem in the location-based algorithms is avoided. Inter-cluster topology is maintained instead of the concrete links, thus fewer topology update messages are generated compared with other routing protocols. In this protocol, location update message, which is also the control packet overhead of the protocol, can serve as the situation awareness (C2) information for the tactical networks. Therefore bandwidth is reserved for the most part for the transmission of the command and control (C2) data. We prove its correctness by mathematical methods, and also compare the performance of the protocol with other routing protocols via simulation, which demonstrates its efficiency.