ABSTRACT
This chapter describes the 'cognitive frequency exclusion' concept in detail, specified in European Norm (EN) 50561–1. After an overview of the standardisation history, the high-frequency (HF) radio transmissions, the influence on the power line communication (PLC) spectrum are shown. 'Cognitive frequency exclusion' is an adaptive process which automatically excludes all frequencies – from PLC – being used by receivable radio services, without any user or network operator interaction. Reports about interference from PLC to HF radio broadcasts were published quite early by Stott and Salter. The new high-bitrate PLC modems using multiple communication carriers at various frequencies with adaptive constellations enable the realisation of the cognitive frequency exclusion concept. Of initial interest is a comparison of the signals measured when connected to the mains and the field measured with an antenna in the air. Comparing the signal strength of an HF radio broadcast station at two locations at once is very difficult.
