Patent ID: 6973267

Claim:
An autoprotected optical communication system, comprising: a first optical carrier configured to transport optical signals in a first direction; a second optical carrier configured to transport optical signals in a second direction that is opposite to the first direction; and a plurality of nodes connected along the first optical carrier and the second optical carrier to form bidirectional links, the plurality of nodes communicating in pairs, one of the pairs defining a working link associated with a portion of the first optical carrier and a portion of the second optical carrier and being configured to exchange optical signals using a first wavelength on the first optical carrier and a second wavelength that is different from the first wavelength on the second optical carrier during a normal condition, the one pair of nodes being configured to exchange optical signals using the first wavelength on the second optical carrier and the second wavelength on the first optical carrier during a failure condition, wherein a response to the failure condition is executed on a channel level, and wherein each of the plurality of nodes includes a plurality of transmitting and receiving transponders, and wherein the plurality of transmitting transponders includes a first transmitting transponder optically coupled to the first optical carrier and configured to modulate a signal at the first wavelength, a second transmitting transponder optically coupled to the first optical carrier and configured to modulate a signal at a second wavelength, and a third transmitting transponder optically coupled to a second optical carrier and configured to modulate a signal at the first wavelength, the plurality of receiving transponders including a first receiving transponder optically coupled to the second optical carrier and configured to demodulate a signal having the first wavelength, a second receiving transponder optically coupled to the second optical carrier and configured to demodulate a signal having the second wavelength, a third receiving transponder optically coupled to the first optical carrier and configured to demodulate a signal having the second wavelength, and wherein, under the normal condition, optical switches in an optical switch unit are configured to optically connect an optical transmitter to the first transmitting transponder, to optically connect the first receiving transponder to the third transmitting transponder, to optically connect the second receiving transponder to an optical receiver, and to optically connect the third receiving transponder to the second transmitting transponder.