Node Deployment Strategy for WSN-based Node-Sequence Localization Considering Specific Paths

In wireless sensor network (WSN) applications, information of detection location for sensing changes in the environment is very important. Sequence-based Localization (SBL) is a well-known localization mechanism for WSN that can be deployed quickly and utilized right after deployment. In our previous study, we have already designed and developed a deployment strategy for the sensor nodes that can effectively reduce location error in SBL. In this paper we further consider the condition when the target is used to moving in specific paths in the sensing environment. We can then deploy sensor nodes to optimize the location error along the paths. We propose (1) path division and (2) path bounding mechanisms to assist in sensor node deployment. In path division, the path is divided into several quasi-linear subpaths such that the subpaths can be easily processed using path bounding mechanism. In path bounding, three sensor nodes are first deployed for each subpath such that the area partition along the subpath can be as small as possible. After path-bounding processing, more sensor nodes can be deployed to further reduce the location error for multiple subpaths. For paths with single or multiple quasi-linear subpaths, we investigate the effectiveness that our proposed mechanism may achieve. The analysis results show that our proposed deployment mechanisms outperform the one with either random deployment, spacing keeping deployment, angle optimization deployment, or traditional cross-type deployment. Finally we utilize ns-2 network simulator to verify the usefulness of our mechanisms. The ns-2 simulation results show that considering the specific path the target used to take, our proposed mechanisms can indeed effectively reduce location errors in SBL localization mechanism.