Reserch On Energy-Efficient Coverage Algorithm In Wireless Sesor Networks

Wireless sensor networks(WSN) has become a hotspot of research field as its unique value and advantages in many fields. It consists of a large number of nodes which integrate sensor module, data processing unit and short distance wireless communication module. The network is a kind of wireless Ad hoc networks with a distinct data-centric property. Its objective is to sense, collect and process the information of various environments and the detected objects in the coverage area, and then send the sensing information to the user.WSN has a wide range of applications in military, environment science, health care and other areas. Because it involves many disciplines and fields, there are some problems need to be solved. Coverage is one of the fundamental issues in the research of WSN. In this paper, coverage of the nodes has been reasearched. Because of the limited node energy, this paper focuses on the energy-efficient covering problems in wireless sensor networks.First, studing a lot of literatures related to coverage algorithms in WSN, and then this paper classifies these algorithms. Then it studies various groups of the classical covering algorithms and then summary the advantages and disadvantages of various types of algorithms.Second, using computational geometry methods to simplify the regional of nodes deployment in matrix form, a matrix-based coverage algorithm is proposed. In order to find the redundant nodes and sleep it, the algorithm deploys a sensor node at each matrix point and then tries to remove each node and then evaluates whether the area still maintain coverage. In order to assess the performance of the algorithm effectively, this paper presents two indicators:energy consumption rate and the coverage rate. The simulation results show that compare to normal circle coverage algorithm the algorithm has advantage in coverage rate. Moreover, it can save the node energy effectively.Third, considering the random deployment, an energy-efficient and self-adjusting of the circle coverage protocol(SCCP) is proposed. Based on the circle coverage algorithm, the protocol can enhance the time-to-live(TTL) of network through sleeping the redundant nodes without affecting the network coverage rate. The simulation results show that the SCCP has the similar performance in the network coverage with the circle coverage algorithm, but it can save the node energy effectively and extend the TTL of WSN significantly.Prior description of the coverage algorithms dependent on some location schemes to obtain the node's location information. In order to reduce more cost of the nodes, a location-independent coverage protocol based on residual energy is proposed. In the neighbor set, comparing residual energy with its neighborhood, the maximum energy node becoming a working node, and the other nodes turn off to sleep. The simulation and analysis demonstrate that the protocol not only provides a high quality of area caverage, but also provides better performance in the energy efficiency.