2020/02/25 by Anantha K. Karthik, Karthik, Anantha K., Rick S. Blum +1 · 1 citation
Computer Science · Engineering · #FOS: Electrical engineering #Network Time Synchronization Technologies #Signal Processing (eess.SP) #Smart Grid Security and Resilience #Wireless Body Area Networks #electronic engineering #information engineering
paper · pdf · doi:10.48550/arxiv.2002.10858
openalex publication_date 2020/02/25 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
IEEE 1588, built on the classical two-way message exchange scheme, is a\npopular clock synchronization protocol for packet-switched networks. Due to the\npresence of random queuing delays in a packet-switched network, the joint\nrecovery of the clock skew and offset from the timestamps of the exchanged\nsynchronization packets can be treated as a statistical estimation problem. In\nthis paper, we address the problem of clock skew and offset estimation for IEEE\n1588 in the presence of possible unknown asymmetries between the colorblack\ndeterministic path delays of the forward master-to-slave path and reverse\nslave-to-master path, which can result from incorrect modeling or\ncyber-attacks. First, we develop lower bounds on the mean square estimation\nerror for a clock skew and offset estimation scheme for IEEE 1588 assuming the\navailability of multiple master-slave communication paths and complete\nknowledge of the probability density functions (pdf) describing the random\nqueuing delays. Approximating the pdf of the random queuing delays by a mixture\nof Gaussian random variables, we then present a robust iterative clock skew and\noffset estimation scheme that employs the space alternating generalized\nexpectation-maximization (SAGE) algorithm for learning all the unknown\nparameters. Numerical results indicate that the developed robust scheme\nexhibits a mean square estimation error close to the lower bounds.\n