OPEN: An Optimization Scheme of N-node Coverage in Wireless Sensor Networks

—Deployment is an important issue in wireless sensor networks(WSNs). Most of recent researches focus on the optimal deployment patterns for full-coverage WSNs. In practice, there are only finite number of nodes can be used in WSNs applications, which cannot guarantee that the entire region can be monitored; On the other hand, the information generated from monitored objects is distributed unevenly in the monitored region. How to get a reasonable network deployment with the finite number of sensors becomes a practical problem, which should not be neglected. From all above, we propose a new coverage problem in WSNs named N-node coverage, which refers to using the limited number of nodes to achieve maximum information acquirement. In this problem we use the information obtained from the monitored region as the new evaluation standard for network coverage. On the basis of this standard, we construct the N-node network coverage model and convert the deployment problem to a combinatorial optimization problem. we present a heuristic optimization deployment scheme, the OPEN, to solve the problem. Experimental results show that the OPEN can effectively improve the performance of sensor network coverage and provide practical guidance for deployment of WSNs. Wireless sensor networks (WSNs) have gradually been available for critical applications such as environmental monitoring , battlefield surveillance, industrial monitoring etc. In many practical sensor network deployments, the number of sensors is limited, the monitored regions are vast and the information generated from monitored object is usually distributed unevenly in the region. Due to these reasons above, it is challenging to achieve full coverage in the monitored region and it is not a reasonable choice to apply the uniform and random deployment as an effective deployment scheme for these applications. In order to illustrate these scenarios, we take the application of monitoring the waterfowls habitats as an example (see Fig.1). The wetlands as the habitats of the waterfowls have characteristics such as large area and complex geographical conditions. It is difficult or impossible to deploy a certain number of sensor nodes within the region to achieve full coverage and to obtain all information from the region. However, the waterfowls prefer living in groups and inhabiting relatively constant regions in wetlands. By using this character, it is better to place sensor nodes around the regions where the birds haunt rather than to deploy the nodes Fig. 1. Flocks of waterfowls exist in a vast wetland. The distribution of …