| 20100189442 | METHOD FOR THE PROTECTION OF A PASSIVE OPTICAL TRANSMISSION NETWORK AS WELL AS A PASSIVE OPTICAL TRANSMISSION NETWORK WITH A CORRESPONDING PROTECTION MECHANISM - The invention relates to a method for the protection of a passive optical transmission network comprising an optical line terminal (OLT) that is connected to at least one remote node to which a plurality of network termination nodes (ONU) is linked. Between each ONU and the OLT, a bidirectional optical signal transmission can be established, wherein the connection between the OLT and the one or more RNs is realized via a first bidirectional optical transmission route by means of which an optical wavelength-multiplexed signal is transmitted in the downstream direction from the OLT to the one or more RNs and in the upstream direction from the one or more RNs to the OLT. According to the invention, a second bidirectional optical transmission route is provided between the OLT and the one or more RNs, wherein, in the one or more RNs, the wavelength-multiplexed signal is fed in the upstream direction by means of a passive optical splitter unit both to the first optical transmission route and also to the second optical transmission route, and wherein, in the OLT, in the case of the detection of a fault state that suggests a negative effect on the first or second optical transmission route, it is switched to the other corresponding optical transmission route by means of an optical switch unit for transmitting the wavelength-multiplexed signal in the downstream direction and/or for receiving the wavelength-multiplexed signal in the upstream direction. This principle could also be applied analogously, according to the invention, to a ring-shaped linking of several RNs to an OLT. In addition, the invention relates to a passive optical transmission network in which this method is realized. | 07-29-2010 |
