In optical DWDM networks, the spectrum is classically divided into several 50 or 100 GHz channels.
So, let's assume some channel ranges from x to x+50 GHz. On which frequency/frequencies is the signal sent?
It would be a reasonable choice to use x+25 GHz as a frequency to transmit the signal on, however, I was wondering whether one could also use x+12.5, x+25 and x+37.5 for instance, or even more frequencies simultaneously.
How is this usually handled in DWDM networks?