The leap in sensitivity of the new generation telescopes and the intensifying commercial and public use of the spectrum warrant a new and innovative approach towards RFI Mitigation. An RFI Mitigation strategy using multiple layers of applications during the data-processing flow is found to be optimal. This approach can be partially implemented at the WSRT and will be used for LOFAR and also for SKA. We will consider the actual implementation of these schemes for these telescopes and review results from ASTRON activities.