Performance of a System of Mutually Synchronized Clocks
James Porter Moreland · Bell System Technical Journal · 1971
This paper is concerned with mutual sychronization — a scheme for synchronizing a nationwide network of clocks for an integrated digital transmission and switching communications system. Described is an approach to the problem of determining values for the design parameters of a one-sided, linear phase averaging scheme with no filters. Two different sets of performance objectives are considered. The primary results concern the bounds which the effects of delay change force on the parameters which describe the inherent clock stability. Specifically, if a performance objective is no slips, and a limit is imposed on the amount of buffer storage, then an upper bound is forced on the allowable random drift in the free-running frequencies of the clocks. Alternatively, if an objective is that the slip rate not exceed some specified rate, again with a limited buffer size, then an upper bound is forced on the rate of random drift. Both bounds depend on the network configuration with the so called “dumbbell” configuration representing the worst case. A numerical example is included.