A Concentric Data Aggregation Model in Wireless Sensor Network

The wireless sensor network (WSN) is composed of a collection of sensor nodes. Sensor nodes are small energy constrained devices, so the main focus is to be as energy effective as possible. The focus should be on minimizing the transmitting and receiving of data, because these axe expensive operations. If the base station does not need access to individual sensor readings, in-network data aggregation offers an alternative that significantly reduces the energy consumption when collecting data. The PEGASIS (Power-Efficient GAthering in Sensor Information Systems) protocol is a chain-based protocol, which presents twice or more performance in comparison with the LEACH (Low Energy Adaptive Clustering Hierarchy) protocol in data gathering. The PEGASIS protocol, however, has two critical problems that the redundant transmission and the latency of the data are occurred. The causes of these problems axe that there is no consideration of the base station's location when one of nodes is selected as the head node and there is only on head nodes in network. In this paper, a concentric data aggregation model is proposed to solve the problems. The main idea of the model is to consider the location of the base station, and divide the whole WSN into several concentric and hierarchical zones refer to the location of the base station, each zone is also divided into some areas, nodes in every area axe organized as PEGASIS. Data collected by sensor nodes goes through proper areas belong to different level zones towards the base station and aggregated in each hop, the last area's head node which is one of the nearest nodes of the base station transmits the aggregated data to the base station. As simulation results, the concentric data aggregation model performs better than the current PEGASIS in transmission delay and energy efficiency.