Patent ID: 7155127
Filing Date: 2006-12-26
Classification: H04B,H04J

Abstract:
1. An optical communication system, comprising: a plurality of subscriber side optical communication units that each has a subscriber side bi-directional network interface in which a physical bit rate of transmission signals and a physical bit rate of reception signals are identical, a subscriber side optical transmitter, a subscriber side optical receiver, and a subscriber side physical bit rate down-converter that lowers a physical bit rate of a transmission signal that is input from the subscriber side bi-directional network interface, and outputs the transmission signal to the subscriber side optical transmitter; a center side optical communication unit having a center side bi-directional network interface in which a physical bit rate of transmission signals and a physical bit rate of reception signals are identical, a plurality of center side optical transmitters and a plurality of center side optical receivers that correspond respectively to the plurality of subscriber side optical communication units, a wavelength multiplexing and demultiplexing section that performs wavelength-division multiplexing on optical signals output from the plurality of center side optical transmitters, the optical signals having different wavelengths from each other and each of the optical signals having a single wavelength, and transmits the multiplexed optical signals as downstream wavelength-division multiplexed optical signals, and demultiplexes into respective wavelengths input upstream wavelength-division multiplexed optical signals and causes the demultiplexed upstream signals to be received in the plurality of center side optical receivers, and a center side physical bit rate up-converter that raises a physical bit rate of a reception signal that is received by the center side optical receiver, and outputs the reception signal to the center side bi-directional network interface; and an optical splitter unit that is connected via at least one optical fiber to both the plurality of subscriber side optical communication units and the center side optical communication unit, and multiplexes optical signals from the plurality of subscriber side optical communication units and transmits the multiplexed optical signals to the center side optical communication unit as the upstream wavelength-division multiplexed optical signals, and that demultiplexes into respective wavelengths the downstream wavelength-division multiplexed optical signals from the center side optical communication unit and transmits the demultiplexed downstream signals to the plurality of subscriber side optical communication units, wherein each of the subscriber side optical transmitters is provided with a broadband light source that generates spontaneous emissions, and transmits modulated broadband light obtained by modulating the spontaneous emissions using transmission signals that are input via the subscriber side physical bit rate down-converter and that are at a lower rate than transmission signals output from the subscriber side bi-directional network interface, and wherein the optical splitter unit spectrally slices the modulated broadband light using respectively different wavelengths that correspond to the subscriber side optical communication units, and performs wavelength-division multiplexing on the spectrum-sliced light of each wavelength and transmits the multiplexed light to the center side optical communication unit.