At 01:33 PM 2/4/2009, Kelly Martin wrote:
Cell phones need about -95 dBm received to work at all (and really at -95 dBm about all you get is network beaconing, with no ability to actually place a call). Typical cell transmit powers rarely go past one watt, and I think the cell base stations rarely go much over ten watts (per channel). I think you'll find that there's too much path loss for that to work to even LEO, notwithstanding the fact that cell tower antennas typically have radiation patterns that send virtually all the signal into terrain, that being where the cell phones are.
Some systems (GSM being the main example) have a distance limitation, of how far you can go from the base station, without losing sync due to propagation delay. Suffice to say this is well short of any LEO, even the ISS.
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