Abstract: The limited node energy, high node redundancy and other characteristics of Wireless Sensor Network (WSN) make working-in-round mechanism one of the basic policies in solving the network coverage problem. In this paper, the authors investigated the network characteristics of stochastic scheduling model, analyzed the relationship between the number of effective nodes and rotation cycles, and finally provided an adaptive algorithm to adjust the node work probability according to the effective node number in the network. The algorithm can solve the performance problem in the later periods of the network, which is caused by reduction of effective nodes and static work probability, and thus guaranteeing the network performance in each round. Simulation verifies the effectiveness and correctness of the novel algorithm.

Key words: Wireless Sensor Network (WSN), stochastic scheduling model, working-in-round mechanism, number of effective nodes

摘要： 无线传感器网络(WSN)具有节点能量有限、节点冗余度高等特点，这使得轮换成为解决网络覆盖问题的基本工作机制之一。基于轮换工作机制对随机调度模型下的网络特性进行了研究，分析了网络中有效节点总数与轮换周期数的关系，并提出了根据网络中有效节点总数来动态调节节点工作概率的算法。该算法能很好地解决网络因有效节点数目减少、工作概率固定所造成的网络运行后期网络性能无法满足网络需求的问题，保证每轮中的网络性能基本一致。仿真实验证明了所提算法的有效性及分析的正确性。

关键词: 无线传感器网络, 随机调度模型, 轮换工作机制, 有效节点数目