Sensor-MAC with Dynamic Duty Cycle in wireless sensor networks

Abstract

Wireless sensor networks are designed to be deployed in the physical environment to monitor a wide variety of real-world phenomena. These networks are composed of various small sensor nodes deposited in a given area. In these networks, the battery replacement is unfeasible and thus the energy is a critical resource that must be considered by all protocols. In order to reduce the energy consumption, protocols for MAC layer use techniques that turn off the radio of sensor nodes. However, in many protocols, all sensor nodes operate on the same static schedule in which they wake up periodically at the same fixed interval of time. This scheme might not be appropriate in dynamic scenarios in which the traffic varies. In these situations, it is desirable to adjust the operation mode of sensor nodes according with the network traffic. In this work, we present the Sensor-MAC with Dynamic Duty Cycle (SMAC-DDC), a new MAC protocol that adjusts the duty cycle of sensor nodes according with the network traffic. Through a cross layer interaction, SMAC-DDC uses the information of the network layer to adjust the value of the duty cycle of sensor nodes. Simulations results show that the proposed protocol reduces the latency and the energy consumption of a network, keeping the delivery ratio.