The study, which was not peer reviewed before publication, described a technique, which minimized the effect of rain fade, and which trended positively higher with frequencies, namely 12 GHz, 20 GHz and 30 GHz. The major concept behind site diversity is that rain seldom happens concurrently on two spatially separated slant path as compared to rain along an independent propagation path, the researchers said. Some concepts appear to have been floated in ITU-R to update guidance this year, and to involve FSS and BSS experts.