Supported by the Key Program of National Natural Science Foundation of China under Grant No.60533110 (国家自然科学基金重点项目); the National Natural Science Foundation of China under Grant No.60473075 (国家自然科学基金); the National Grand Fundamental Research 973 Program of China under Grant No.2006CB303000 (国家重点基础研究发展计划(973)); the Program for New Century Excellent Talents in University of China under Grant No.NCET-05-0333 (新世纪优秀人才支持计划); the Key Program of the Natural Science Foundation of Heilongjiang Province of China under Grant No.ZJG03-05 (黑龙江省自然科学基金重点项目); the Heilongjiang Province Scientific and Technological Special Fund for Young Scholars of China under Grant No.QC06C033 (黑龙江省青年科技专项资金)
The traditional data centric storage method has a serious problem named hotspot problem, which appears near the sink and home node. Hotspot problem causes the nodes near the hotspot consume much more energy than other nodes, which seriously shortens the lifetime of the sensor networks. In this paper, a method distributing multiple sink nodes around the sensor networks is proposed to solve the hotspot problem around the sink. A load balance data storage method based on ring and a query processing algorithm for such a kind of data storage method are proposed to solve the hotspot problem around the home node. First, the ring based load balance data storage method divides the sensor networks into a lot of rings and stores data among all nodes within a ring. Second, different rings alternatively work during the working time of the network, which avoids the hotspot problem further. Finally, the query processing algorithm based on the load balance data storage method makes all nodes within a ring cooperatively answer the user’s query. Although the ring based load balance data storage method and the query processing algorithm consume more energy than the traditional method when answering a user’s query, the method makes all nodes within the network consume energy evenly, which avoids the hotspot problem of the traditional method, so the lifetime of sensor networks can be extended. Experimental results also show that the ring based load balance data storage method and the query processing algorithm can solve the hotspot problem and prolong the lifetime of the sensor networks.