Energy Efficiency Model of Network-Coded Cooperation in Wireless Sensor Networks

In Wireless Sensor Networks, designing energy efficient transmission protocols is a key requirement. Network-coded cooperation allows wireless nodes to exploit spatial diversity by relaying received messages, which reduces transmission energy or increases communication reliability. However, relaying redundant messages consumes considerable energy at transmitting and receiving nodes. In this work, we develop a comprehensive energy efficiency model of network-coded cooperation in Wireless Sensor Networks. The energy model takes into account both the energy spent (i.e., transmission, reception, and processing) at all cooperating nodes and the reliability of reception at a destination node. Based on the model, the impact of network geometry and system parameters such as code rate are investigated. The numerical results show the range of partner node locations and code rate in which the performance of network-coded cooperation outperforms point-to-point transmission. In a network of multiple nodes, the results give some clue on when to cooperate and how to select the partner node for cooperation.