FoV-Clustering as a solution to a novel camera node activation problem in WVSNs

In Wireless Visual Sensor Networks (WVSNs), node selection and organization to realize applications is the title of some research fields known as network topology models that can be classified into two main categories of single-tier and multi-tier. According to the literature, only multi-tier topology model is able to provide a balance between WVSNs objectives such as low cost, maximum coverage, minimum energy consumption, high functionality, and good reliability. In a general architecture for this model, the lowest tier consists of scalar nodes that can activate camera nodes of upper tier only if necessary. However, regarding the inter-tier communication radio range and camera nodes´ covered area, in many cases the activated cameras do not detect any objects. The mentioned problem which wastes energy and processor time for doing unneeded image capturing and object detection operations is introduced for the first time in this paper. Besides, a new clustering method with the aim of determining the scalar nodes located inside the area covered by a camera node is proposed as a solution. As the simulation results indicate, this solution has succeeded in saving camera nodes´ energy and prolonging network lifetime.