基于连通支配集的无线传感网Top-k查询最优支撑树研究

摘要

Constructing underlying logic trees can effectively reduce the large communication overhead for centralized top-k query.In this paper,an energy-balanced optimal support-tree is proposed to solve the problem of earlier death for nodes near sink in sensor networks without fixed sink.This method aggregates node energy,degree and communication overhead,and nodes with low energy cost are chosen to be dominating nodes for data processing based on connected dominating set.In each query,nodes take turns to be root by location-based ID,which effectively balances the energy cost.The simulation experiment shows that top-k query based on support-tree outperforms the existing trees by similar query time,but lower average energy cost per round and balanced consumption among all sensor nodes after continuous top-k queries,which effectively prolong the network lifetime.%构建底层逻辑树能有效降低集中式top-k查询带来的巨大通信开销,针对现有逻辑树都以固定汇聚节点为根节点,导致其附近节点能耗太大、过早死亡的问题,本文在无固定汇聚节点的网络背景下,基于连通支配集,提出一种能耗均衡的top-k查询最优支撑树构建方法,综合节点能量、度数以及与邻节点通信开销,选取能量代价小的作为支配节点负责查询中间数据处理,在每次查询中,节点基于地理位置ID轮流作为根节点,有效均衡节点的能耗.仿真实验表明,与其他逻辑拓扑树相比,基于最优支撑树的top-k查询具有相近的查询时间,但其平均每轮查询能耗更小,多次查询后各节点能耗达到均衡,有效延长了网络生命周期.