OPTICAL TRANSMISSION NETWORK SYSTEM, OPTICAL SIGNAL TRANSMISSION PATH SELECTION METHOD, AND OPTICAL TRANSMISSION DEVICE

It is an object to enable an NE to autonomously select a transmission path for optical signal transmission. An optical transport network system includes a plurality of NEs 200, each transmitting wavelength-multiplexed optical signals. Each NE includes a routing information DB 226 that is used to store reachable area information, which contains identifiers of other NEs in a range within which the optical signals can be transmitted from the own NE without using an REG 211. A FROM NE includes a path candidate searching unit 222-1 that searches for a plurality of path candidates for transmitting optical signals from the FROM NE to a TO NE. The TO NE includes a path selecting unit 222-2 that selects a path for transmitting optical signals from among a plurality of path candidates. Based on the reachable area information stored in the routing information DB 226 of the FROM NE and the routing information DBs 226 of intermediate NEs, the path selecting unit 222-2 obtains the number of times for which the REG 211 is used for each of the plurality of path candidates; and, based on each number of times that is obtained, selects a path for transmitting the optical signals.