Experimental study of attenuation due to rain for an LMCS link at 29 GHz

The Communications Research Centre (CRC) Canada conducted a preliminary evaluation of an experimental 29 GHz LMCS point-to-point lint: in the fall of 1999. The objective was to evaluate the performance of an LMCS transmission system over time under various rainfall conditions and to compare the results with two prediction models. Specifically, the following parameters. have been monitored for two months during the fall of 1999: The received signal power; The radiowave attenuation due to rain (computed from the above signal power); The corresponding rain rate in mm/hour at three different locations along the path. The 2.88 km line-of-sight link was set up at Shirleys Bay, in the West End of Ottawa. Horizontal polarization was used. The most severe rain fade recorded during this measurement campaign was 49 dB, during the storm of November 2, 1999. However. most rain fades did not exceed 20 dB. Comparisons with predictions from empirical and theoretical models relating attenuation to rainfall rate based on the analysis of single events show a good agreement if we average readings from the three rain gauges, ie, using a path averaged rainfall rate.