关键词: 无线传感网, 汇聚, 能量有效, 分级

Abstract: Considering the distributions of node’s energy consumptions in Wireless Sensor Networks（WSN），a modified hierarchical data aggregation protocol is proposed.Firstly，this paper sets up a simple model to analytically evaluate the energy consumption in WSN by using aggregation mechanism.This paper also shows that energy consumption of an aggregation node increases so rapidly in the neighborhood of the sink node that these nodes will die and shorten the lifetime of the whole network.Secondly，a modified hierarchical data aggregation strategy in order to achieve balanced energy depletion by reduce the cluster head selection probability near the sink is proposed.Simulation results show that，this method can reduce the energy consumption efficiently for sensor networks.So，it can prolong the lifetime of the whole networks.

Key words: Wireless Sensor Network（WSN）, aggregation, energy-efficient, hierarchy