Patent ID: 6608829
Filing Date: 2003-08-19
Classification: H04J,H04L

Abstract:
A closed-loop synchronisation arrangement for a data transmission system, which arrangement includes a central data switch including a clock generator and a plurality of data ports each connecting the data switch to a separate one of a plurality of transceivers, each data port comprising a data transmitter, a data receiver, phase discrimination means connected between the data port receiver and the data port transmitter and operable to detect phase differences between the signals received by the data port receiver and those generated by the switch clock generator to generate a synchronising code pattern for transmission to a transceiver, each transceiver comprising a data transmitter and a data receiver; and a reference oscillator operable to provide a frequency reference signal to each part of the data transmission system, characterized in that each transceiver also includes separate transmit and receive clocks, first synchronising means responsive to the synchronising code pattern received by the receiver of the transceiver to adjust the phase of the receive clock so that synchronisation between the data transmitter of the data switch port and the data receiver of the transceiver is established and maintained and second synchronising means responsive to the synchronisation between the data receiver of the data switch port and the data transmitter of the transceiver is established and maintained.