Research On Energy-Efficient Strategy In Wireless Sensor Networks

Recently advances in sensor, micro-electro-mechanical systems (MEMS) technology, nested computation and wireless communications have enabled the development of wireless sensor networks (WSNs) including a large number sensor nodes, which consistint of sensing, data processing, and communicating components. WSNs, which are data-centric and put emphasis upon information detection and cooperative processing, provide a novel technology about acquiring and processing information. WSNs is cpable of the detection, measurement, classification, recognition, location and track of interested target, and can be widely used in national defense, infrastructure security, environment monitoring, traffic management and industry control applicatins etc. But its characters of so many nodes, redundant data, complicated environments and limited resources, especially node energy and communication bandwidth, have presented great challenges for its basic theory and engineering technology. Netword protocol stack and collaborative signal and information processing (CSIP), which are the important components of key technologies in wireless sensor netword, have attracted more and more attentions.The research work and the main results are as follows:(1) By allowing intermediate sensors to process the images and combine the overlapping portions, the total energy spent on transmission is reduced subject to any degradation in image quality. The compromising between image quality and energy consumption of different routing is very important on wireless sensor networks.(2) The discrete graph algorithm that finds an approximate path by discreting the problem space to form a graph and searching a shortest path is introduced. Algorithm parameters that allow energy-saving paths to be searched at a certain time are found. The extended algorithm can facilitate other constraints in the problem.(3) Using a lossy link model, two new forwarding schemes named Single-Link and Multi-Link Energy-Efficient Forwarding that trade off delivery rate and energy costs best by maximizing energy efficiency are proposed. By mathematical analyses, extensive simulations, and experiment, the performance of this approach against other forwarding schemes is contrasted. The simulation results show energy-efficient forwarding schemes conserves energy efficiently.(4)A new scheme for data-centred multi-path routing in sensor networks using a fuzzy logic controller at each node is proposed. The basic idea of this scheme is as follows: During route discovery, each node comparing and correlating remaining energy and received data type based on the output of the fuzzy logic controller, a decision is made whether to return or forward the data packets. The simulation results show that the scheme can obviously reduce the packet returned rate, and doesn't add energy consumption or prolong the time of finding routing.