An optical transmission system controls an ALS (Automatic Laser Shutdown) function using a message. The optical transmission system includes first and second optical repeaters. The first optical repeater monitors a plurality of optical lines incoming from the second optical repeater to detect a line...http://www.google.com/patents/US6194707?utm_source=gb-gplus-sharePatent US6194707 - Automatic laser shutdown method and apparatus in optical transmission system
