0
$\begingroup$

I know for example that one of the reasons why our cellular phones need to be turned off in airplanes is that the navigation system of the plane (GPS and other systems) works on frequencies close to that of cellular phones, and that can effect the reading of the navigation equipment (the communication with the satelite goes bad). So my question is what is the technic reason for the wide-spread use of certain frequencies?

$\endgroup$
2
  • 1
    $\begingroup$ The FCC assigns the frequency bands to various industries and applications. The rationales will be in the detailed history of these allocations. $\endgroup$ May 12 '16 at 13:26
  • $\begingroup$ At the top level, the ITU (International Telecommunications Union) decides on broad allocations, with the various regions and national bodies making more detailed decisions. However, to get to the point, cell phones are relatively recent arrivals on the spectrum scene. This means their frequencies were shoehorned in wherever there was a little space. For some equipment, where the designer assumed there would not be nearby active transmitters on a neighboring frequency, this caused problems with sensitivity and frequency rejection. $\endgroup$
    – Jon Custer
    May 20 '16 at 13:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.