Research On Routing And Cross-Layer Technologies In Mobile Ad Hoc Networks

As the society becomes increasingly information-based and the digital communication, wireless communication and computer technology develops rapidly, wireless communication network has become a hot topic in research. Mobile Ad Hoc networks have drawn much attention. Ad Hoc is characterized by being no fixed infrastructure, temporary networking, dynamic network topology and self-organization. Network nodes can join or exit networks dynamically. Its advantages such as flexibility in organizing network, high robustness of the network, low cost in system make Ad Hoc suitable to be applied to conference and academic exchanges, disaster aid and recovery, home network and military command in war field. In such areas, Ad Hoc is irreplaceable and has broad prospect of application and development.In a mobile Ad Hoc network, there are some problems because of that dynamic topologies, bandwidth capacity, energy-constrained and limited physical security. To develop routing protocol with energy saving strategy, security-guarantee, multicast and support of QoS are both the key points and the difficult points in research. This thesis starts with the hot points in research of Ad Hoc and studies key issues like improvement of broadcast storm mechanism, optimization of routing protocol and cross-layer technology. The main contents and innovation of the thesis are as follows.1,In the first chapter, the history, characteristic, foreground of deployment, hot point of research and prospect in key technology of MANET are analysised, and then, research background, content and innovation of this dissertation are summarized.2,In order to avoid Broadcast Storm, the Energy Prediction Broadcast (EPB) algorithm is proposed. Based on prediction of the node's remainder energy, EPB dynamically adjusts the rebroadcasting probability and decides which nodes to rebroadcast. 3,Ant-colony optimization is applied to improving a routing selected algorithm which is based on bandwidth-limited and the remainder energy in Ad Hoc networks. This algorithm adaptively adjusts routing selected according the pheromone of ant-colony and achieves globally optimization.4,A dynamic traffic allocation algorithm based on packet delay and hops in Mobile Ad Hoc networks is proposed. The algorithm is based on the minimization product of delay and hops in each path and adjusts the traffic adaptively so as to make load-balanced which optimizes network resource utilization. Simulation demonstrated that the algorithm could dynamically balance the traffic allocation between paths. The aim of the minimum utilization of resource in mobile Ad Hoc networks can be achieved.5,A cross-layer design on traffic allocation algorithm based on delay in Ad Hoc networks is proposed. In the algorithm, the traffic allocation information from network layer is used in MAC layer, which can make the average delay to be minimized. Simulation demonstrates that the algorithm can distribute traffic according to delay of each path adaptively and achieve optimization of resource utilization.6,In the last chapter, the thesis is concluded and the succeeding work in the future researches is pointed on.