A reassessment of satellite communications in the 20 and 30 GHz bands

Some alternative approaches to the use of 30/20 GHz bands for satellite data communications are suggested. The next available frequency bands at 20/30 GHz were allocated by the World Administrative Radio Conference in 1971, when knowledge of propagation phenomena and their effect on satellite communication systems was fragmentary. Data are presented which show that even with corrective means such as diversity and coding, the service reliability of systems with up-links at 30 GHz and down-links at 20 GHz could not reach 99.99 percent at the lower frequencies and could be as low as 98.0 percent in certain parts of the world. Among the alternatives to operation in the 20/30 GHz bands are: placing both up- and down-links aroung 20 GHz and redistributing the spectrum available at 20 GHz; and postponing the use of frequencies around 30 GHz until the 20 GHz bands become saturated. In this way, when the 30 GHz band finally is used there would be no imbalance between up- and down-links.