Abstract: The receive power of an optical data signal is converted into an electrical data signal by a photodiode. The electrical data signal is then amplified and supplied to a scanning circuit. The receive power (useful signal and noise) is measured in a measurement and control device and the adjustable scanning threshold is set as a function of the receive power corresponding to a predetermined function.

Abstract: The invention relates to a device and a method for parallel signal dividing and signal processing in multiplex devices with a high ordinal number. The advantage of the inventive nth level multiplex device lies in the fact that n transmission-end signals are divided cyclically among n/m mth level multiplex devices at a second multiplex device level, said second multiplex device level enabling the n/m mth level multiplex devices to be processed parallel to n/m partial signals and these n/m partial signals to be cyclically and sequentially processed into one signal by a parallel serial converter at a first multiplex device level. The resulting signal already has the arrangement of channels and bytes prescribed by the SDH format. The sorting process at the first multiplex device level, which is demanding in terms of memory, is therefore no longer necessary.