Wavelength standards in fibre-optic systems

In multi-channel wavelength multiplexing (WDM) systems, just randomly transmitting the signal is almost certain to cause interference with the other channels, therefore defined frequency intervals will be needed in this type of system. Considerations of how to define and fix such frequency intervals are already underway, and the aim of the author is to present a short overview of the requirements and then briefly outline some of the ideas being considered to develop and propose standards for in-band transmission frequencies that could be adopted by international regulatory bodies