Maximizing network-lifetime in large scale heterogeneous wireless sensor-actuator networks

Abstract

Delay and energy constraints have a significant impact on the design and operation of wireless sensor-actuator networks. We cosider a wireless sensor-actuator network, consisting of large number of sensors and few actuators, in which both energy and delay are hard constraints and must be jointly optimized. Abstract In this paper, we propose that each sensor node must transmit its data to only one of the actuators. To maximize the network lifetime and attain minimum end-to-end delays, it is essential to optimally match each sensor node to an actuator and find an optimal routing scheme. We model the actuator selection and optimal flow routing as joint optimization problem, which is NP-hard in general. Therefore, we use a relaxation technique and provide a distributed solution for optimal actuator selection subject to energy and delay constraints. Further, once the destination actuators are fixed, we provide an optimal flow routing solution with the aim of maximizing network lifetime. We then propose to use a delay-energy aware TDMA based MAC protocol in compliance with the routing algorithm. The optimal routing and TDMA MAC schemes together guarantees a near-optimal lifetime. The proposal is validated by means of analysis and ns-2 simulation results.