| 摘要 |
PURPOSE: An OADM(Optical Add-Drop Multiplexing) system in a ring-type WDM(Wavelength Division Multiplexing) network and a method for protecting/recovering optical signals are provided to divide WDM optical signals into a working channel group and a protection channel group using optical splitters having a channel selection characteristic and to connect the two group using a pair of optical switches so that each channel group can execute an optical switching function independently in the event of network failure. CONSTITUTION: An OADM system consists of optical splitters(21,30), wide-area multiplexing parts(22,31), optical multiplexing parts(26,35), and optical couplers(29,38). The optical splitters(21,30) divide a ring-type WDM optical signal, inputted through an optical line, into a working channel group and a protection channel group. Each wide-area multiplexing part(22,31) separates the optical channels of each channel group individually. The optical multiplexing parts(26,35) binds the passed and added individual optical channels into the working channel group and the protection channel group again. The optical couplers(29,38) combine the bound channel groups into one WDM optical signal again and outputs it through the other optical line. Each wide-area multiplexing part(22,31) is composed of an optical switch(23,32) and a wide-area multiplexing element(24,33). Each optical multiplexing part(26,35) is composed of an optical multiplexing element(27,36) and an optical switch(28,37). |
