Wireless Ad Hoc Network Topology Control Technology Research

There are two important problems for research and application of the Ad Hoc networks. The one is to establish the coverage model of target area, and another is to quantify the connectivity, stability, energy consumption and communication quality assessment. These two core problems are researched in this paper.In this paper, the history and characteristics of the Ad Hoc networks are introduced firstly. Then we focus on the basic concepts and the main problems on the topology control of Ad Hoc networks.Subsequently, the coverage optimization model of the Ad Hoc network has been proposed, which are based on the finite covering theorem and circle overlap rate. The model can reach K-coverage by adjusting overlap ratio of the circumference, and computer simulation methods have verified the correctness of the model.It is a core problem to measure the performance problems of Ad Hoc networks based on coverage optimization model in this paper. we firstly analyze the connectivity probability of network, and then simulation method which base on probability model are used. The theoretical and experimental results have shown that the coverage model based on the circumference has stronger connectivity and higher survivability. In the worst case, the connectivity probability can reach96.9%in theoretical analysis and98.5%in simulation computing. Then the four channel allocation scheme of Ad Hoc networks is proposed by means of Four-Color theorem. Taking into account the mobility of the nodes in the networks, mobile stability of the networks are simulated, under some reasonable assumptions. The simulation results show that the networks still has higher connectivity and connectivity probability can reach96.7%even though these node are static deployment. Lastly, energy consumption and communication quality assessment of coverage optimization model in the second chapter are analyzed and simulated.Because there are some impractical assumption for nodes and target area, two improved models are researched. Firstly, the improved model for the target area with obstacles and heterogeneous sensor nodes is studied, and the nodes deployment and channel allocation scheme are proposed for the new model. Secondly, we study the target area coverage problem from the view of nodes cluster coverage. Similar methods are used to research channel allocation and survivability performance of network in this situation. The results show that the asymmetric nodes deployment will affect network performance if we do not take into account the cost of deployment.Finally we summed up the achievements and contributions of this paper, and further research problems are pointed out.,...