Abstract: A wavelength-multiplexed passive optical network (WDM-PON) and a method are described herein for setting-up (e.g., wavelength tuning, power tuning) an ONT laser by establishing a communications channel on an optical layer between an optical line terminal (OLT) and an optical network termination (ONT). The communications channel is established by utilizing the OLT's laser shutdown function and the ONT's signal detection function.

Abstract: A threshold value is set in a decision circuit receiving a transmitted stream of binary symbols from a network link. The decision circuit uses the threshold value for detecting whether a 1 or a 0 is received to produce an output stream having a low bit error rate. Bit errors in the output stream of the detector are detected. The number of errors is counted when a transmitted 0 is detected as a 1 in the output stream. The number of errors is also counted when a transmitted 1 is detected as a 0 in the output stream. The counted numbers of errors are compared to each other. The threshold value is modified, if necessary, based on the result of the comparing, to e.g. make the probabilities of the two kinds of errors equal to each other. Extra predetermined bits can be inserted and used in determining bit errors.