A method that may include receiving a block of signals from a certain wavelength division multiplex (WDM) channel out of a set of WDM channels; analyzing at least a first sub-block of signals of the block of signals to provide analysis results indicative of interferences that affect the first sub-block of signals and result from transmissions over other WDM channels of the set of WDM channels; and mitigating interferences that affect the block of signals in response to the analysis results.