Analysis of Synchronization Algorithms with Time-Out Control Over Networks with Exponentially Symmetric Delays

We study the performance of a family of slave-to-master clock-offset synchronization algorithms based on ping-ponging timing cells over symmetric uplink/downlink of a master-slave pair. We analyze the total number of tries and synchronization time using an exponential model for the Cell Delay Variation (CDV). For this analysis we implement a time-put control function for cell acknowledgment/reception with a maximum number of tries per sample and an option of time-out with wait or no wait. We show that the maximum likelihood (ML) phase offset estimator doesn't exist for the exponential likelihood function. Then we analytically provide RMS error results and comparative analysis for five different ad-hoc estimation algorithms: the Median Round Delay (MdRD), the Minimum Round Delay (MnRD), the Minimum Link Delay (MnLD), the Median Phase (MdPh) and the Average Phase (AvPh). We conclude that the MnLD algorithm can achieve the highest phase estimation accuracy without having to impose a strict time-out control, which would substantially increase the speed of the algorithm.