EETS: AN ENERGY-EFFICIENT TIME SYNCHRONIZATION ALGORITHM FOR WIRELESS SENSOR NETWORKS

High precision and real-time communications are increasingly becoming important in Wireless Sensor Networks as such networks are required to support highly time-critical applications. The sensor nodes need to communicate data to each other at the correct time. However, the clocks of sensor nodes run at different speed and very often drift from the real time value. In this paper we are proposing EETS, an energy efficient time synchronization algorithm. Energy efficiency is achieved by synchronizing only nodes that are communicating with each other when an event occurs. EETS is performed in two phases namely the Level discovery phase and the Synchronization phase. A simulation study has been carried out and the results shows that EETS is more energy efficient than other existing algorithms. Particularly, EETS has been compared to Network Wide Time Synchronization (NWTS) which is a widely used algorithm for time synchronization in WSN. Simulation results have shown that NWTS uses about 10% more energy than EETS. NWTS synchronizes 90% of the network nodes but reduces the lifetime of the network considerably while EETS synchronizes only nodes that need to be synchronized and thus saving energy