On Boundary Detection of 2-D and 3-D Wireless Sensor Networks

A novel method of identifying boundaries of wireless sensor networks deployed on 2D and 3D surfaces is presented. It does not require costly, error prone localization algorithms or physical locations of nodes. Instead, a Virtual Coordinate System (VCS) is used in which each node is characterized by the hop- distances to a set of randomly selected nodes known as anchors. To use geometric relationships for boundary detection, it transforms the VCS to a Topology Preserving Map (TPM). A TPM generation scheme for networks deployed on 3D surfaces is derived as well. The boundary detection scheme proposed is simple, not computationally intensive, energy efficient, and can be used with physical coordinates as well. Five representative example networks show the proposed scheme to be effective, with 100% of boundary nodes identified correctly with no erroneous identification of non-boundary nodes as boundary nodes. Use of TPM based boundary detection scheme for detecting dynamic event boundaries, such as those of plumes, in a distributed manner is also illustrated.