A recursive solution for improving the synchronization accuracy in wireless sensor networks

A two-way message exchange mechanism is at the core of many clock synchronization protocols. The basic concept of this method has been designed for symmetrical links, otherwise, depending on the level of asymmetric delays, large synchronization errors may occur. Many estimation based methods have been proposed so far for estimating the degree of asymmetry and reducing this error. However, many of them are solved for a specific distribution of link random delays. Moreover, imposing a high level of computational complexity upon network nodes is another problem of them. In this paper we introduce a recursive solution for improving the performance of the basic two-way message exchange mechanism. The advantage of this method is that it keeps the protocol simple and therefore easily implementable. The proposed method does not make any specific assumption about the distribution of the random delays. It also provides the network designer with some deployment flexibility, trading off convergence speed against stability.