| 摘要 |
PURPOSE:To avoid a transmission speed from rising too high by converting broad band electric signals of plural kinds into optical signals respectively at the information source, sending the optical signals through an optical fiber bundle and branching the optical signal to each subscriber by a star.coupler. CONSTITUTION:Three kinds of broad band signals offered from information source companies 1, 4, 7 are sent through an optical fiber.ribbon 10 in which 3 optical fibers are bundled. Then 3 kinds of optical signals sent from a station 9 to an optical coupler.box 11 installed at a location parted from the station and branched into 3 directions and sent to subscribers 49-51 through optical fiber.ribbons 15-17 and required information is selected by using spatial split optical switches 40, 43, 46 at the subscribers 49-51. Thus, the transmission speed is not too high different from the usual time division multiplex. |
