A METHOD AND A CIRCUIT FOR THE TRANSFER OF DATA INFORMATION

摘要

A method of transferring relatively low frequency data information on a data channel for relatively high frequency data transmission comprises modulating the data rate of the relatively high frequency data channel in accordance with the low frequency data information. The phase variation generated thereby is controlled so as to be within a range which is defined upwardly by a predetermined value and defined downwardly by the phase variation which occurs in the data channel at an unmodulated data rate. This ensures that additional data information may be transferred in a network in which a determined phase variation (jitter) requirement (34, fig. 5) is to be observed. A circuit in the form of a buffer (22) and a multiplexer (23) controlled by a phase-locked loop (25, 26, 27) to restrict phase variations (jitter) out of a transmitter (20) additionally comprises a circuit (29) so that the multiplexer (23) depends on a signal (DATA).