| 摘要 |
The prior art is an optical subscriber access network with an end exchange (1) whose exit is connected to the entrance of a cable distributor (6) via a transmission line (5). An additional control signal with a control wavelength ( lambda c) is transmitted in order to monitor the transmission line (5) and in the event that the transmission line (5) fails, the end exchange (1) and the cable distributor (6) are switched over to a fallback circuit (12). This switchover requires so-called DOS: digital optical switches. These are active components and have to be supplied with a current for local heating. The aim of the invention is to configure a purely passive network structure in the cable distributor (6) so that a current is no longer necessary. The exits of the transmission line (5) and the fallback circuit (12) are connected to a wavelength router (8) in the cable distributor (6) by means of the series connection of a passive power divider (13) and a UV-induced grating (7) which corresponds to the control wavelength ( lambda c). |
