Monitoring optical wide band subscriber lines

摘要

The monitoring takes place between an optical fibre coupler, such as an exchange side subscriber coupler (LT), and a defined, passive, optical interface (PNT1), as part of an optical wide band subscriber linking line (OAL). A rectangular, pseudo-noise, random signal is transmitted together with the information signal from the optical fibre subscriber coupler in the downstream direction over the optical wide band coupling line. A small part of the optical downstream signal is fed back from the passive interface in the upstream direction to the coupler, where it is converted into an electric signal by an optical receiver.