| 摘要 |
<p>A passive optical network (PON) using an optical fiber and an optical coupler. A central unit (10) includes a hub (16), a plurality of modulators/demodulators (17), a mixer (18), and a branching filter (19). A carrier of a predetermined frequency is assigned for the plurality of modulators/demodulators (17) and consumers (60). In the downlink direction, the hub (16) selects each modulator/demodulator (17) (i.e., each consumer (60)) and generates a modulation signal of a carrier assigned. The modulation signals are mixed by a mixer (18) to become a frequency multiplexing signal and transmitted via a first optical coupler (52) to the consumer (60). Each of the consumers (60) demodulates the signal by the assigned carrier frequency. In the uplink direction, the first optical coupler (53) frequency-multiplexes the modulation signal of each consumer (60) and transmits the signal to the central unit (10). In the central unit (10), the branching filter (19) braches each carrier for which the branching filter (19) is assigned and the resultant signal is demodulated by each modulator/demodulator (17). This realizes the passive optical network (PON).</p> |
