Patent ID: 9641242
Date: 2017-05-02
CPC Classifications: H04B,H04J

Claim:
1. A network device for an optical network comprising: a first port coupled with a first optical fiber link, the first port being an output port of said network device, the output port configured to transmit an outgoing signal from said network device to a second network device of the optical network; a second port coupled with a second optical fiber link, the second port being an input port of said network device, said input port configured to receive an incoming signal from said second network device via said second optical fiber link, said outgoing and incoming signals travelling in opposite directions; wherein the first port and the second port, which are substantially uncoupled with each other such that no or only a negligible part of the outgoing signal is launched into the second port under normal operation, are configured to be coupled with respect to each other in case a failure of the first optical fiber link or in case a failure of the second optical fiber link is detected, such that lost channels of the incoming signal are replaced by the outgoing signal having a same propagation direction at the second port as the lost channels under the normal operation.