L-SYNC: Larger Degree Clustering Based Time-Synchronisation for Wireless Sensor Network

Abstract

In many existing synchronization protocols within wireless sensor networks, the effect of routing algorithm in synchronization precision of two remote nodes is not being considered. In several protocols such as SLTP, this issue is considered for local time estimation of a remote node. Cluster creation is according to ID technique. This technique incurs an increase in cluster overlapping and eventually the routing algorithm will be affected and requires more hops to move from one cluster to another remote cluster. In this article, we present L-SYNC method, which creates large degree clusters for wireless sensor networks synchronization. Using large degree clustering, L-SYNC can reduce path hops. Also, L-SYNC uses linear regression method to calculate clock offset and skew in each cluster. Therefore, it is capable to compute skew and offset intervals between each node and its head cluster and, in other words, it can estimate the local time of remote nodes in future and past. To estimate the local time for remote nodes, routing algorithm is used and conversion technique is performed in each time changing hop. The fewer L-SYNC hops could increase the precision. Simulation results illustrate that monotonous clustering formation can increase the precision in synchronization. However, more overhead and time period are needed for clustering formation