An Analytical Model for Wireless Sensor Networks with Sleeping Nodes

We consider a wireless sensor network whose nodes may enter the so-called sleep mode, corresponding to low power consumption and reduced operational capabilities. We develop a Markov model of the network representing: 1) the behavior of a single sensor as well as the dynamics of the entire network, 2) the channel contention among sensors, and 3) the data routing through the network. We use this model to evaluate the system performance in terms of energy consumption, network capacity, and data delivery delay. Analytical results present a very good matching with simulation results for a large variety of system scenarios, showing the accuracy of our approach.