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Reliable rainfall rate complementary cumulative distributions are critical for the design of microwave communications systems operating above around 8 GHz. This Letter presents the results of the analysis of more than 5 years of 1-minute integrated rainfall accumulation data for 12 stations. This new dataset will prove useful considering the sharing analyses that must be executed for IMT services in the 24.25–27.5, 37–43.5, 45.5–47, 47.2–48.2 and 66–71 GHz spectrum bands. The resulting statistics can complement the entries in the database of ITU-R Study Group 3 for the region. [ABSTRACT FROM AUTHOR]

When 1-minute integrated rainfall rate statistics are not available for microwave system design, the conversion from rain rate cumulative distributions with a longer integration time T can be envisaged. A new set of global coefficients for the current ITU-R method of rain statistics conversion is proposed and tested against a comprehensive database. Results are compared with those provided by the currently recommended ITU-R method. Moreover, the method's applicability is extended to include 60-minute integration time conversions. Tests show that the new set of coefficients performs better than the ITU-R one over its applicability range. [ABSTRACT FROM AUTHOR]

This communication presents an improved approximate method for the estimation of water vapor attenuation along Earth-space slant paths, over the 1–350-GHz frequency range. Evaluated against a large set of radiosonde data, the proposed method provides more accurate results than those delivered by the current alternative approximation methods included in Annex 2 of recommendation ITU-R P.676-10. This result is important as it sheds light on which approximate water vapor attenuation model should be selected for predictions along Earth-space slant paths. [ABSTRACT FROM AUTHOR]

At frequencies above 10 GHz, cloud attenuation in equatorial climate is one of the components that need to be characterised for low-availability satellite links. In addition to annual and worst month cumulative cloud attenuation, the statistics of seasonal and diurnal variations are required for providing detailed insights into system design. The authors present the cloud occurrences observed during different months, seasons and cloud attenuation results obtained from Penang, Malaysia, for a period of 5 years. A comparison of the present results with the results obtained from the existing models is also presented. [ABSTRACT FROM AUTHOR]