Patent ID: 7778160

Claim:
A transmission device provided in a synchronous communication network to transmit signals, comprising: a bus; a reference signal generator to generate a reference signal; an active unit coupled to the bus and the reference signal generator, comprising: a first reference signal receiver to receive the reference signal, a first timing signal generator comprising a first counter to divide a frequency of the received reference signal and thereby generate a first timing signal for operation of the active unit, and a first count holder to hold a first count value of the first counter for access via the bus; and a standby unit coupled to the bus and the reference signal generator, comprising: a second reference signal receiver to receive the reference signal, a second timing signal generator comprising a second counter to divide a frequency of the received reference signal and thereby generate a second timing signal for operation of the standby unit, a count receiver to receive, via the bus, the first count value from the first count holder in the active unit, and a count updater to update a second count value of the second counter with the first count value received by the count receiver.