An Asynchronous and Adaptive Quorum Based MAC Protocol for Wireless Sensor Networks

The extension of the lifespan of sensor network is greatly reliable on sensor node‟s battery power. Scheduling and tuning sensor node‟s wake up and sleep duration plays an important role in minimizing the energy consumption. Hence, a new asynchronous, adaptive, heterogenous quorum based Medium Access Control protocol called Connected Dominating Tree Medium Access Control (CDT-MAC) is introduced, that tunes and dynamically adjusts the duty cycle of selected sensor nodes called dominators, based on the inter arrival time of the packets, and, assigns fixed duty cycle to the remaining sensor nodes in the network. These dominator nodes selection is accomplished during virtual backbone construction in which a subnet of Wireless Sensor Networks called Connected Dominating Tree (CDT) is created that consists of minimum number of dominators and connectors for aggregating and forwarding the data to the sink node. A new Quorum system called HiQuorum is also introduced that provides minimum quorum ratio and network sensibility and maximum rendezvous compared with existing dygrid system. Simulation results prove that CDT-MAC when applied with HiQuorum in CDT leads to high throughput and less delay, and thereby, improving the reliability and energy conservation of the sensor networks.