An optimized time synchronization protocol for WSANs

Today, wireless sensor and actuator networks (WSANs) are used in diverse applications, including environmental monitoring, precision agriculture, and intrusion detection. The sensors and actuators in WSANs are equipped with quartz clocks. These are synchronized with a reference clock using time synchronization protocols. Indeed, Synchronizing the clocks is essential for coordinating the sensors and actuators’ operations. In this paper, we propose a new time synchronization protocol for WSANs. This latter combines the advantage of two approved protocols, namely SANSync and FCSA, which considerably improve time synchronization accuracy. Additionally, the proposed protocol can use multiple reference clocks simultaneously to synchronize the clocks. This makes it more robust and efficient. Simulation results show that the proposed protocol exceeds the performance of FCSA and SANSync in all the simulated networks, especially when the network diameter is large.

I. Introduction

A Wireless Sensor Network (WSN) is a set of inexpensive and autonomous sensor nodes equipped with wireless transmission interfaces. Usually, these sensors are deployed in hundreds or thousands to cover a given territory and take measurements of their environment. A wireless sensor and actuator network (WSAN) is a WSN with several actuators that can act on their environment. Compared to sensors, actuators are expensive and have more resources. Indeed, they have more energy capacity and transmission range [1].