数据融合是降低无线传感器网络的冗余能耗、延长网络生存期的有效手段之一.传输延时的分配是数据融合中的重要问题,它对网络融合的效果和数据分组的传输延迟具有很大影响.提出了一种基于融合贡献的传输延时分配算法ACDA(aggregate contribution baseddelay—time allocation),量化了路由树中不同位置的节点对融合效果的影响,并依此按比例分配融合等待时间.算法充分考虑到了各节点在路由树中的位置差异性和节点间的相互影响.仿真结果表明,同现有的几种延时分配算法相比,ACDA能够更加有效地改进数据融合效果,提高网络实时性。
A primary goal in the design of wireless sensor networks (WSNs) is lifetime maximization, constrained by the energy capacity of batteries. By introducing in-network processing technology, data aggregation has been recently proved to be an effective method to reduce the redundant energy consumption and prolong the network lifespan. Data aggregation can also improve the data accuracy and reliability. When applying specific aggregation schemes to reality, it is necessary to take into account the aggregation time factor, whose increase will improve the aggregation efficacy but deteriorate network transmission performance. And how to allocate the entire delay-time along each route to attain a balance between these two factors is significant. In this paper, a novel aggregate contribution based delay-time allocation algorithm (ACDA) is proposed, in which the impact on aggregation efficacy of different positions in the route tree is quantified first, then the aggregate contribution is gradually refined through an iterative update process, and finally the aggregation time of every node at sink is proportionally allocated. Since this scheme takes into full consideration of location discrepancy and interaction between nodes, The simulation results show that the ACDA achieves a better performance in both aggregation gain and transmission real-time property when compared with other present schemes, just shown in the simulation results.