Some notes on the synchronization of low-power wireless nodes

The problem of device synchronization in a distributed measuring system can present a designer with a range of choices and solutions, depending on technical specifications, cost, feasibility, robustness and other requirements. In wireless sensor networks (WSNs), synchronization mechanisms often have to be run on lean resources and, in particular, the active and “sleep” time schedules of low-power nodes introduce specific constraints which impact, for instance, on the rate of exchange of timing messages. Loss of timing packets could also be particularly critical. In this paper we analyse how clock instability, timestamp uncertainty and the particular implementation of a servo clock affect the performances of a synchronization algorithm, assuming relevant information are received at a low rate (and, occasionally, missing). An accurate study based on the effect of measurement uncertainty will evaluate the performance of a low-power synchronization mechanism and its robustness to information loss.