An Evaluation Framework for Time Synchronization in Lossy Links

Although wireless sensor networks have been widely studied, the special characteristics of these networks provide challenges from many points of view. One such challenge is time synchronization. The design and the performance of time synchronization protocols in wireless sensor networks have been examined analytically and using simulations for different network scenarios. However an empirical analysis of their performance under lossy conditions has not been carried out yet. In this work, a framework which consists of all components required to evaluate the performance of time synchronization protocols for multi-hop wireless sensor networks under lossy conditions is presented. The framework, which is built using Redwire Econotags and the Contiki operating system, is used for a show case evaluation of the two well-known synchronization protocols GTSP and FTSP. Both random packet losses and node failures are considered in order to provide some insights into the influence of lossy environments on the performance of time synchronization protocols for multi-hop communication.