Patent ID: 7050450

Claim:
A telecommunications system comprising: devices to provide output clock signals that are synchronous to at least one source clock signal, at least one of the devices comprising an interface card to a transmission network; and a main clock generator comprising a selector to select one of the output clock signals, the main clock generator generating a main clock signal for the telecommunications system based on a selected one of the output clock signals; wherein each of the devices comprises a quality detector (i) to detect a quality of the at least one source clock signal, and (ii) to interrupt providing an output clock signal in response to a decrease in quality of the at least one source clock signal; wherein the main clock generator comprises an interrupt detector to detect an interruption in an output clock signal provided by at least one of the devices; and wherein the selector selects a different output clock signal if the interrupt detector detects that the selected one of the output clock signals is interrupted.