Research On Event-driven Data Aggregation Algorithm In Wireless Sensor Network

With the rapid progress made in the improvement of sensor, integrated circuit, wireless communication and network technologies in recent years, it begin to appear nodes capable of sensing, data processing and radio communication all over the world. More and more people pay tremendous attention to wireless sensor networks composed of such nodes. Due to its wide application in military, medical, agriculture, industrial,transportation and service industrial, it has already become one of the most active research branches of computer science. A few achievements have been acquired, but on some key techniques, there are also a lot of problems in need of resolution.In wireless sensor network, sensor nodes with limited battery power, communications and computing capability are usually numerous and work at remotely poor or dangerous environment, where humans even can not get close. Hence, it is hardly to replace batteries, so compared with other aspects, energy saving is an urgent problem to be solved. Due to its advantage performance in energy-saving, data aggregation now has become a focus in wireless sensor networks. In this paper, a research on data aggregation is performed oriented the WSN application which monitoring emergencies. Firstly the basic concept of wireless sensor network and main characteristics are introduced. Applications in wireless sensor network data aggregation are also been analyzed and summarized. Then the methods of how to use aggregation technique based on the event-driven are discussed. Due to the shortage of existed data aggregation algorithms in the network layer, a balanced energy consumption aggregation approach is presented with linear programming based on LEACH.In LEACH protocol, cluster heads and base station communicate in the process of using hop direct transmission, so that energy is wasted and it can not meet the practical requirements of large-scale networks. But LEACH protocol with fast response time is very suitable for wireless sensor networks monitoring emergencies, so the proposed algorithm BECA first cluster the network like LEACH. By changing the transmission means to multi-hop communication from cluster heads to base station, and involving the energy balance consumption theory to the routing algorithm, the energy saving in network increases greatly. In the data aggregation process, BECA divide the data aggregation into tow aspects, which are local aggregation and area aggregation. Local aggregation aggregates the cluster data in its cluster heads, and area aggregation aggregates data on the cluster head selected on the route to base station when data are transmitted between cluster heads. This two-level aggregation could remove more redundant data so that it reduce the energy consumption. As the search from a cluster heads to the base station with an optimal routing is a NP problem, this paper uses linear programming to reduce the computing flexibility.Experiment result shows that, the BECA is a fast, reliable and effective method, with a wide range of practical significance by reducing the whole network energy consumption, the complexity of the algorithm and the aggregation delay.