Method of phase-synchronising a transit exchange in a digital telecommunication network

Abstract From the Canadian patent

A method and apparatus are disclosed for synchronising the phase of a transit exchange in a digital communication network. The transit exchange has a signal-controlled oscillator with an output signal which depends on the collectively weighted phase difference between the local exchange clock and the clock of the other exchanges. To avoid phase jumps a signal, corresponding to the phase difference is sampled the sampled, values differentiated, the differentiated values compared with a limit value employing a phase jump when exceeded and when, this value is exceeded a signal with the control signal's highest value but with opposite sign is added to form a compensation signal, this …