Telemetry
From NPrize
Telemetry
An introduction to RF telemetry systems, by Gale Allen (pdf link, 11 pages).
To summarize, with the same type of antenna, the higher the frequency the lower the range. We should prefer a 500MHz band to a 2.4GHz for example. However directive antennas with higher gain are more practical in higher frequencies because the wavelength is shorter and antennas are sized to the wavelength. They may also be cheaper. With a high gain antenna, a higher frequency link can reach the same range as a lower frequency link with a unity gain antenna.
A more complete reading is the Telemetry Systems Radio Frequency Handbook, US military document, 2008 (pdf link, 133 pages).
