Mitsubishi Electric Corporation

Koshi Sugimura

Hiroaki Mukai

Masaki Tanaka

Yukio Hirano

Yoshifumi Hotta

Jun Mizuguchi

Kaori Mie

A communication system in which a master station device is connected to a plurality of slave station devices by an optical transmission line and a plurality of wavelengths are used to perform at least one of downstream communication and upstream communication. The master station device includes: a control unit that assigns a wavelength to be used in communication to the slave station device, and that generates a control signal for notifying the slave station device of the assigned wavelength; and an optical transmitter that transmits the control signal generated by the control unit to the slave station device. The slave station device includes an optical receiver and an optical transmitter that carry out communication with the master station device using the wavelength based on the control signal received from the master station device.

Communication system, master station device, slave station device, control unit, and communication control method

A relay device that relays communication between a low-speed communication device performing uplink 1 G transfer and a high-speed communication device performing uplink 10 G transfer and a station-side optical communication device, wherein the relay device includes a low-speed reception unit that converts an optical signal received from the low-speed communication device to an electric signal, a buffer that buffers the electric signal, and a high-speed transmission unit that transmits, to the station-side optical communication device, a bandwidth allocation request requesting bandwidth allocation for communication from its own unit to the station-side optical communication device, and within a transmission permitted time period allocated by the station-side optical communication device, reads an electric signal stored in the buffer, converts the electric signal to an optical signal having a communication speed of 10 G, and transmits the optical signal.

Relay device, station-side optical communication device, communication system, and bandwidth allocation method

In a PON system, an ONU includes a receive buffer that stores therein a signal in a downstream direction transmitted from an OLT and a PON control unit that controls transition to a power-saving state and transition to a normal state for the reception buffer. The OLT includes a transmission buffer that stores transmission data to be transmitted to the ONU and the PON control unit that transmits the downstream power-saving-state transition request that requests the ONU to transition to the downstream power-saving state when it is determined that transmission data addressed to the ONU is not present in the transmission buffer. The PON control unit sets the reception buffer to a power-saving state for a predetermined downstream sleep time requested based on the downstream power-saving-state transition request.

PON system, subscriber-side terminal apparatus, station-side terminal apparatus, and power saving method

A logical-link management method to be executed in an optical communication system including a station side device (OLT) and a subscriber side device (ONU) that is capable of setting a plurality of logical links together with the OLT, in which the OLT transmits a signal for managing the ONU via a single logical link. The logical-link management method includes a status monitoring of the OLT monitoring whether there is a change in a connection status of the logical link between the OLT and the ONU and a link resetting of the OLT resetting, when a change of the connection status of the logical link is detected at the status monitoring, a device management logical link used for transmitting the signal for managing the ONU according to a predetermined procedure.

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Tokyo, Japan

Koshi Sugimura