| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a passive optical communication network of a wavelength division multiplex system capable of reducing costs of a subscriber side device by efficiently accommodating up optical signals even when the transmission capacity thereof is increased. <P>SOLUTION: A central station 200 which communicates with a subscriber side device 310 by utilizing a wavelength division multiplexed optical signal demultiplexes multi-wavelength light inputted to a fourth multiplex port R1 into a plurality of channels, amplifies, multiplexes and outputs the channels from a first multiplex port L1, demultiplexes and outputs an up optical signal inputted to a third multiplex port LN. Further, a device 30 includes a routing part 210 which multiplexes and outputs a channel comprising a down optical signal via a second multiplex port RN, and a branch part 250 which is located in an optical waveguide loop 220 linking the first and fourth multiplex ports of the routing part, outputs a part of the multi-wavelength light inputted to the first port from the second port and outputs the remaining parts from the third port to the fourth port. Besides, the central station 200 includes a circulation part 260 which transmits the multi-wavelength light inputted from the second port of the branch part to the subscriber side device and outputs the up optical signal from the subscriber side device to the third multiplex port of the routing part. <P>COPYRIGHT: (C)2004,JPO |
