HF broadcasting service standards for service quality, and methods to maintain quality with the increasing use of telecommunication systems such as PLT

ITU-R Recommendations and the international agreements for HF broadcasting have specified the minimum usable field strengths to achieve a satisfactory quality of service. Other telecommunication systems, such as power line telecommunications, also use the same frequency ranges for their networks and may give rise to increased background noise levels for broadcasting due to unwanted emissions from such networks. A technique of adaptive frequency notching is described.