If the question is:

Do higher radio frequencies have a greater range than lower radio frequencies?

The answer is a no. In fact, if using equal transmitter power, the exact opposite is true for the frequencies we use in our R/C hobby.

For example, under the right circumstances, signals in the 27 MHz band (used by some R/C planes) can travel around the world. Signals is this band are readily refracted by the ionosphere, making the potential range very long, indeed.

Signals in the 72 MHz band (most popular band for R/C in the USA) will seldom travel so far but can travel up to 2,000 miles or so at relatively modest power levels.

Signals in the new 2.4 GHz band (used by the new Spektrum radios) are essentially line of sight and so do not usually travel beyond the horizon.

Higher transmitter power, more sensitive receivers, and better antennas can all increase range, no matter what the frequency.

- Jeff