| 摘要 |
PURPOSE:To simplify, a control station and a base station, to make the size of them small and to reduce the cost by arranging a light source only to a control station at a start point of a transmission line. CONSTITUTION:An optical fiber cable 25 forms a loop from a control station 5 and to the control station 5 via base stations 101-10n sequentially, and a light source for the optical fiber cable 25 is installed in an electrooptic converter 6 of the control station 5, each of the base stations 101-10n is provided with a photoelectric converter 11 converting an optical signal branched from the optical fiber cable 25 into an electric signal and with an optical modulator 39 modulating the optical signal through the optical fiber cable 25 with the electric signal, and the control station 5 is provided with an optoelectric converter 7 converting the optical signal coming circulated through the optical fiber cable 25 into an electric signal. Then the transmission reception wavelength of the optical signal for the control station 5 an each of the base stations 101-10n is allocated in wavelength division and he optical signals among the base stations 101-10n are not interfered with each other. |
