Patent ID: 8280244

Claim:
An optical ring network system comprising: a first optical transmission line on which optical signals are transmitted in a first direction, being formed to a ring; a second optical transmission line on which optical signals are transmitted in a second direction of an opposite direction as the first direction, being formed to the ring; a first optical transmission apparatus connecting to the first optical transmission line and the second optical transmission line, being operable to transmit a first optical signal including a transmission source identifier indicating a transmission source of a transmitted signal, the first optical signal being on a first wavelength, transmitted to a first communication path formed on one of the first optical transmission line and the second optical transmission line; and a second optical transmission apparatus connecting to the first optical transmission line and the second optical transmission line, being operable to determine whether the transmission source identifier included in the first optical signal received over the first communication path matches a pre-stored reception expectation optical path identifier indicating an optical transmission apparatus of a communication partner; wherein the second optical transmission apparatus is operable to transmit a second optical signal including a switch request signal to request that the transmitted signal from the first optical transmission apparatus is transmitted to a second communication path in an opposite direction as the first communication path, the second optical signal being on the first wavelength, transmitted to the first communication path formed on the other one of the first optical transmission line and the second optical transmission line, and operable to receive a third optical signal on a second wavelength over the second communication path transmitted from the first optical transmission apparatus, in case of one of that the transmission source identifier differs from the reception expectation optical path identifier and that the transmission source identifier is not detected in the first optical signal.