SPACC: A Simple Positioning and Coverage Control Solution for Wireless Sensor Networks

A category of wireless sensor networks consists of lots of autonomous sensor nodes with limited power and few base stations with theoretically unlimited power. A number of redundant nodes are usually deployed densely in these types of networks in order to provide redundancy for sensing and communications. There is a challenge though of which nodes must be active and which ones must be asleep, without compromising the coverage and network connectivity. To get round this challenge, each node should somehow know the position of its immediate neighbors. Previous researches have impractically assumed the existence of a GPS module in each node, which is in direct contradiction with the main constraints of low cost and size of sensor nodes. This paper proposes an energy saving solution without requiring the nodes to possess any physical GPS. The goal is to minimize the number of active sensors with respect to coverage and connectivity. Each node decides locally by itself whether to be active or not. There is no need for any global synchronization between nodes. Simulation results show that the higher density of nodes in our proposed solution leads to better coverage, higher energy saving and longer network lifetime.