Time synchronization and system support for energy efficient wireless sensor networks

Abstract

This thesis presents a design of a Wireless Sensor Network (WSN) and the implementation of an original time synchronization algorithm. The complete system support for energy efficient WSNs was developed. The new time synchronization algorithm called Sliding Clock Synchronization employs a simple, yet very effective algorithm to compensate for static and dynamic drifts in the frequencies of crystal oscillators used in the WSN nodes. As power is a very scarce and critical resource in most WSN s, a tight synchronization algorithm can reduce power consumption thereby increasing the life of a WSN. An accurate and reliable synchronization algorithm also enables the WSN to be used for applications that require a tight synchronization for data correlation. A hardware and software interface for an embedded web server has been provided so that the WSN can be monitored and controlled over the Internet. An interface for a GPS module enables the network to incorporate GPS time stamps in recording network events. A sensor node emulator has been developed so that a single node can emulate multiple nodes without additional hardware, thus providing a simple and cost, effective means to test the network performance with large number of nodes.