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

摘要

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.

主权项

1. A passive optical network (PON) system in which a station-side terminal apparatus and a subscriber-side terminal apparatus are connected by using an optical line, wherein:
the subscriber-side terminal apparatus includes:
an optical transmitter that transmits an optical signal to the station-side terminal apparatus, andan upstream-data processor that performs processing on upstream data that is to be transmitted to the station-side terminal apparatus via the optical transmitter, the upstream-data processor including an upstream memory that stores upstream data that is to be transmitted from the optical transmitter; the subscriber-side terminal apparatus is operable in power-saving modes including a first power-saving mode and a second power-saving mode and in a normal mode, wherein
in the first power-saving mode, the optical transmitter is in a power-saving state,in the second power-saving mode, transmission and reception of a control message to and from the station-side terminal apparatus are possible, operation is performed in accordance with a control message received form the station-side terminal apparatus, and the upstream-data processor is in a power-saving state, andin the normal mode, transmission and reception of data are possible; and the station-side terminal apparatus includes:
a control-message transmitter that transmits a control message to the subscriber-side terminal apparatus, anda controller that controls, by using the control message that is transmitted via the control-message transmitter, transition of the subscriber-side terminal apparatus between the normal mode and the power-saving modes.