Research On Data Collection In Wireless Sensor Networks

Data collection is a main application of wireless sensor networks. In a large-scale sensor network, numerous sensor nodes constitute multi-hop wireless ad hoc network. Sensor nodes sample local sense data and transmit results to the base station. Then the base station transfers them to outside users. System lifetime is one of the most important design factors in wireless sensor network. Battery energy of sensor node directly determines system lifetime. This paper studies three key parts that affect system lifetime of data collection problem: data collection protocol, sensor node deploying and sensor node scheduling, and proposes corresponding resolving scheme. Present studies all aimed at wireless sensor networks of plane model. But many applications are linear model. So this paper proposes resolving schemes of data collection in wireless sensor networks of both plane model and linear model.Data collection protocol is a network layer protocol. It studies how sensor nodes transmit data to the base station. Sensor node consumes great energy while idle listening. So reducing idle listening nodes may reduce system energy consumption and prolong system lifetime. Most present protocols were to construct a backbone by which sensor nodes transmit data to the base station. Constructing minimum backbone makes idle listening nodes least. But energy of nodes in backbone constructed by present protocols may be too little that brings blind point and reduces system lifetime. And path that node transmit data by backbone may be too long that increases energy consumption of transmitting data. This paper proposes a breath-first search based data collection tree algorithm that taking in account size of backbone, energy of node and path. The data collection tree is maintained locally. Simulation results show system lifetime of this algorithm is improved by 15% of present algorithms and delay is reduced by 23%. For linear model, this paper proposes a linear path based backbone algorithm. Simulation results shows system lifetime of this algorithm is improved by 12% of algorithm of plane model.Optimum sensor node deploying may prolong system lifetime effectively. Because wireless sensor network is multi-hop, data stream densities of different regions aren't same. The region closer to the base station must transfer more data. Its data stream density is bigger and energy consumption is faster. Present schemes all deployed sensor nodes evenly that may cause sensor nodes close to the base station use up energy rapidly and invalid. The network becomes unconnected that reduces system lifetime. By studying energy consumption rate of region, this paper proposes a...