A new scheme for synchronization of inactive nodes in a sender-receiver protocol

This paper targets the problem of clock synchronization for a set of receivers lying within the broadcast range of two nodes implementing a general sender-receiver protocol using a wireless channel. The maximum likelihood estimate of the clock offset of the inactive node (and mean link delay) hearing the broadcasts from both the master and slave nodes was derived in assuming symmetric exponential link delays. In this paper, the minimum variance unbiased estimate for the clock offset of such nodes is derived by applying the Rao-Blackwell-Lehmann-Scheffe theorem. The result is important in the realm of wireless sensor networks, where a tight network synchronization along with a conservative energy utilization plays a major role in network performance.