Patent ID: 6839515

Claim:
A method for at least one of laser safety switch-off and fiber standby switching in optical transmission devices, the method comprising the steps of: jointly transmitting, via a working optical fiber, from a first terminal to a second terminal, a working signal and an associated control signal; jointly transmitting, via a protection optical fiber, from the first terminal to the second terminal, a protection signal and an associated control signal; jointly transmitting, via a further working optical fiber, from the second terminal to the first terminal, a further working signal and an associated control signal; jointly transmitting, via a further protection optical fiber, from the second terminal to the first terminal, a further protection signal and an associated control signal; evaluating at least one of a working signal, a protection signal and a control signal at a respective receiving end; making a switchover, if one of the working or protection signals is disturbed or absent, to the respectively associated undisturbed signal; transmitting, if one of the working signals including its associated control signal or protection signals including its associated control signal is not received in the respectively corresponding first and second terminals, one of a changed control signal and a remote laser switch-off signal to the respectively corresponding first or second terminal to prevent the transmission of the respective working signal or the respective protection signal, but with the respectively associated control signal continuing to be transmitted with a low permissible level; and ending, upon a respective connection being switched on, signaling of one of the changed control signal and the remote laser switch-off signal by reception of the respectively corresponding control signal.