HF interference temporal and spectral characteristics over the eastern Mediterranean

In the frames of the Cyprus Ionospheric Forecasting Service (CIFS) which provides near-real time information on HF propagation conditions over the island there is a component for systematic measurement and analysis of HF spectral occupancy. The incentive for this initiative stems out of the well known fact that interference from legitimate users is one of the most common problems encountered in the use of the HF spectrum due to its long range transmission properties. With the congested nature of the HF spectrum, where users with differing requirements compete for diminishing available bandwidth within the International Telecommunications Union (ITU) frequency allocations, there is strong motivation for developing an understanding for spectrum usage characteristics. In this paper preliminary results of HF spectrum occupancy measurements over the eastern Mediterranean are presented and briefly discussed in accordance to ionospheric variability.