  This paper addresses the problem of clock skew and offset estimation for the
IEEE 1588 precision time protocol. Built on the classical two-way message
exchange scheme, IEEE 1588 is a prominent synchronization protocol for packet
switched networks. It is employed in various applications including cellular
base station synchronization in 4G long-term evaluation backhaul networks,
substation synchronization in electrical grid networks and industrial control.
Due to the presence of random queuing delays in a packet switched network, the
recovery of clock skew and offset from the received packet timestamps can be
viewed as a statistical estimation problem. Recently, assuming perfect clock
skew information, minimax optimum clock offset estimators were developed for
IEEE 1588. Building on this work, we develop minimax optimum clock skew and
offset estimators for IEEE 1588 in this paper. Simulation results indicate the
proposed minimax estimators exhibit a lower mean square estimation error than
the estimators available in the literature for various network scenarios.
