Optimization and Evaluation of an Energy-Efficient MAC Protocol for WASNs

A Wireless Ad hoc Sensor Network (WASN) is an autonomous collection of low cost devices that communicate over wireless links. This devices are often powered by limited energy resources, and it is expensive and sometimes infeasible to recharge or replace them. Hence, energy efficiency is the main design concern for such a network. In literature, several energy-efficient Medium Access Control (MAC) protocols have been proposed, because the primary sources of energy waste are collision, overhearing, idle listening and overhead. %Nevertheless, most of these works In this paper, we propose a novel adaptive MAC layer protocol, which uses a model-based duty-cycle adaptation strategy based on traffic load predictions. Specifically, a stochastic model is used by a state estimator to predict the network´s future conditions. The predicted network conditions are then used by an optimizer to derive an optimal wake-up time schedule which reduces the end-to-end latency while saving energy. The performance of our protocol is then compared to the most widely duty-cycle MAC protocols such are S-MAC and T-MAC. Our experimental results on a simulated WASN reveals that under heavy as well as light traffic conditions our solution results in an improvement in the balance between end-to-end latency and energy consumption.