US 11,811,448 B2
Optical communication system, optical communication apparatus and optical communication method
Hirotaka Ujikawa, Musashino (JP); Shin Kaneko, Musashino (JP); Rintaro Harada, Musashino (JP); and Jun Terada, Musashino (JP)
Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (JP)
Appl. No. 17/908,416
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Mar. 2, 2020, PCT No. PCT/JP2020/008585
§ 371(c)(1), (2) Date Aug. 31, 2022,
PCT Pub. No. WO2121/176490, PCT Pub. Date Sep. 10, 2021.
Prior Publication US 2023/0088621 A1, Mar. 23, 2023
Int. Cl. H04B 10/03 (2013.01); H04J 14/02 (2006.01)
CPC H04B 10/03 (2013.01) [H04J 14/0287 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An optical communication system in which an optical communication device and a plurality of optical transmission devices are loop-connected via a transmission line, wherein
the optical communication device includes:
an optical signal transmission unit configured to output, when no communication interruption occurs in the transmission line, an optical signal addressed to a communication destination device being another optical communication device that communicates with an own device to the transmission line connected to either one optical transmission device of two neighboring optical transmission devices, and output, at the time of communication interruption occurring in the transmission line, the optical signal addressed to the communication destination device to both of transmission lines connected to respective two neighboring optical transmission devices, and
the optical transmission device includes a branch unit configured to branch an optical signal input from a neighboring device that is a neighboring optical communication device or another optical transmission device, and output branched optical signals to both of the transmission line connected to a neighboring device different from the neighboring device that transmitted the optical signal and a transmission line connected to a subordinate communication destination device of the own device,
wherein the branch unit is configured to branch an optical signal input from a subordinate communication destination device and output the branched signals to both of transmission lines connected to respective two neighboring devices, and
wherein the optical communication device further includes an optical signal reception unit configured to receive respective signals transmitted by a plurality of communication destination devices, when no communication interruption occurs in the transmission line, from either one optical transmission device of the two neighboring optical transmission devices, and receive respective signals transmitted by the plurality of communication destination devices, at the time of communication interruption occurring in the transmission line, from either one of the two neighboring optical transmission devices depending on the communication destination device.