I recall doing a broadcast remote where I was engineering the remote from a single engine aircraft. At about 5000 feet or so, I lost all cellphone functionality because I was getting into too many cell sites at the same time and the system locked me out (thats the best explanation I could come up with). Even if there was enough signal from that distance, I doubt it would work for that reason.
Michael Heim Chief Engineer, Forever Broadcasting New Castle PA WKST WJST WWGY 814-671-0666 ARS KD0AR
--- On Tue, 2/3/09, Tony Langdon vk3jed@gmail.com wrote:
From: Tony Langdon vk3jed@gmail.com Subject: [amsat-bb] Re: Cell Phone in Spce To: "Kelly Martin" kelly.lynn.martin@gmail.com, "Dave" dave@mynatt.biz Cc: AMSAT-BB@amsat.org Date: Tuesday, February 3, 2009, 9:51 PM 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.
73 de VK3JED / VK3IRL http://vkradio.com
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