Noise in Wireless Systems Produced by Solar Radio Bursts

We have carried out an investigation of 40 years of solar radio burst data in a wide range of frequencies that have been reported by observing stations around the world during 1960-1999. The data were compiled by the NGDC of NOAA. This period covers three full and two partial solar cycles. We find that the number of bursts per day with amplitudes of > 10 sup 3 solar flux units (SFU) falls as an approximate power law with increasing flux level for the frequency bands investigated (1-10 and 10-20 GHz). Also, the number of events with peak flux density > 10 sup 3 SFU varies, as expected, with the solar cycle in the bands investigated (1-2, 2-4, and 4-10 GHz). We discuss the event (> 10 sup 3 SFU) occurrence rate in the context of the noise levels in typical wireless communications systems. We find that statistically, there are likely to be several solar events per year that could cause severe interference in a given cell site during solar maximum periods.