Nippon Telegraph and Telephone Corporation

Kazuhisa Furusawa

Takahiro Kubo

Shinichi Yoshihara

Yoshitaka Enomoto

Hideo Kawata

Yutaka Watanabe

Ayako Iwaki

An object of the present invention is to provide a communication system and a communication method that can suppress an increase in the total fiber distance even if the number of secondary devices increases and that can make complex processing for band allocation for uplink optical signals unnecessary. The configuration of the communication system according to the present invention is a mixture of a ring type and a branch type, in which an optical fiber cable (primary path) from a communication station to each user's home is arranged in a ring (loop) shape, and the primary path is branched and laid to the user's home. Furthermore, unidirectional communication is enabled by a ring-type primary path, and the transmittable amount can be made uniform by further combining time division multiplexing.

Communication system and communication method

A communication apparatus according to an aspect of the present invention is a communication apparatus that is able to be connected to a different communication apparatus via a network including three or more paths, the communication apparatus including a processing circuitry configured to measure a network state for each of the three or more paths, calculate an evaluation value based on a result of measuring the network state for each of the three or more paths, select at least two paths to be used for communication from among the three or more paths based on the calculated evaluation value, generate a packet for transmission through duplication of an input packet, and transmit the generated packet to the different communication apparatus through the selected paths.

Communication apparatus and communication method

An object is to provide a monitoring device capable of acquiring ONU-specific information and connection information even in the case of an optical communication system with the MC system, and enabling optical fiber cable switching work to be finished in a short time. The monitoring device according to the present invention is a monitoring device that monitors an optical communication system in which an OLT and an ONU are connected by a communication optical fiber, and includes: an optical receiver for receiving a signal beam transmitted by the ONU from the communication optical fiber; and an OAM frame analysis unit for extracting, from the signal beam received by the optical receiver, an OAM frame at a MEG level at which the ONU and the OLT are set as monitoring end points, and acquiring a transmission source address and a MEG-ID that identifies a MEG in the OAM frame.

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Musashino, Japan

Kazuhisa Furusawa