| 摘要 |
The invention relates to a method for protecting a passive optical transmission network comprising an optical line terminal (OLT) connected to at least one remote node having a plurality of optical networking units (ONU) connected thereto. A bidirectional optical signal transmission can be established between each ONU and the OLT, wherein the connection between the OLT and the at least one RN occurs by means of a first bidirectional optical transmission route, by means of which an optical wavelength multiplex signal is transmitted in the downstream direction from the OLT to the at least one RN and the upstream direction from the at least one RN to the OLT. According to the invention, a second bidirectional optical transmission route is provided between the OLT and the at least one RN, wherein the wavelength multiplex signal is fed in the at least one RN in the upstream direction by means of a passive optical splitter unit both to the first optical transmission route and to the second optical transmission route, and wherein upon detecting a fault state in the OLT indicating an impairment of the first or the second transmission route, an optical switching unit for transmitting the wavelength multiplex signal in the downstream direction and/or for receiving the wavelength multiplex signal in the upstream direction switches to the other optical transmission route. Said principle can also be applied according to the invention in an analogous manner to a ring-shaped connection of a plurality of RNs to an OLT. The invention further relates to a passive optical transmission network wherein said method is implemented. |
