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Communication technology has made astonishing achievements these years. A new decentralized self-organized wireless network within dynamic topology, Ad Hoc network, has attracted the world’s attention, within more and more applications in military, rescue, sensor network, and other scenarios.However, the lack of a fixed infrastructure in Ad Hoc networks implies that it is a tough task to ensure a high Quality of Service (QoS) such as connectivity, reliability, and network capacity. How to use the limited capacity of wireless nodes to provide a high QoS has become the key issue in Ad Hoc network technology.In this paper, a novel adaptive topology control method is proposed to handle this problem from the perspective of network topology, by introducing two adjustable parameters– adaptive topology parameter and the longest transmitting range, into existing proximity graph topology control algorithms. By tuning adjustable parameters, adaptive topology control can provide an optimized QoS, including connectivity, reliability, and network capacity.The main contents of this paper are as follows:1、Build the model of Ad Hoc network topology. Give a mathmetical description of optimization problem of the network connectivity, reliability, and capacity, from the perspective of network topology, based on this model.2、Proposed a novel adaptive topology control algorithm. By proposing a novel conception of exclusive area, classify different proximity graph topology control algorithms into one framework. Further, by introducing adaptive topology parameter and the longest transmitting range as two adjustable parameters, the open-loop topology control algorithm can be adapted into close-loop to suit different situation.3、Expand the conclusions about network connectivity in proximity graph topology to adaptive topology algorithm, and induce the parameter adjusting rule for network connectivity.4、Give the probability density function of SIR within interception by statistical inference. Furhter, induce the parameter adjusting rule for network reliability ensurence based on this density function.5、Analyse the network capacity considering network topology under protocol model. Prove the adjusting rule for network capacity optimization mathematically.6、Give the optimization solution for all three QoS indicators including network connectivity, reliability and capacity. Prove its validity by simulations, which show that the adaptive topology control can increase the reliability from 20~30% to 80%, improve capacity about 10%, within connectiviy reserved.
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