When a fault occurs on a working ligthpath,the traffic can′t be immediately switched to the protecting lightpath until the protecting ligthpath is activated by an activation signaling.This causes an unacceptable amount of recovery time which becomes a critical factor limiting the application of shared protection and 1∶1 protection.This paper proposes a fast bidirectional activation signaling scheme for decreasing the recovery time,which is the extension of the unidirectional scheme.The novel sch..