First Mile Access Networks and Enabling Technologies

Design Rules for CWDM Networks in Metro Access

As a general guideline, when implementing a CWDM network, as in any optical network, we measure the optical power at the receiver and the transmitter end. We also ensure that the transmitter power is sufficient to support the required transmission distance. We also ensure that the power at the receiver is within the specification of the receiver—that is, conforming to receiver sensitivity (greater than –31 dB and less than –7 dB). If the power is above the specified range (greater than –7 dB), it needs to be attenuated or the receiver will be damaged due to excess photons hitting the p-n junction at the receiver. If the power is under the specified minimum level (less than –31 dB), the receiver cannot ...