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
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
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Technically, operating a cellular phone in-flight is also illegal. (FCC rule, not FAA. FAA says if you have permission of the Pilot-In-Command you're okay, and the vast majority of U.S. Flagged Air Carriers have rules against their pilots being allowed to offer that permission. Non-U.S. Carriers have their own rules. But the FCC rule overrides the FAA rules.)
Nate WY0X
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Michael Heim Sent: Wednesday, February 04, 2009 12:48 PM To: Tony Langdon; AMSAT-BB@amsat.org Subject: [amsat-bb] Re: Cell Phone in Spce
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
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Only if you're in the US.
Nate Duehr wrote: But the FCC rule overrides the FAA rules.)
Duh.
-----Original Message----- From: Nigel Gunn G8IFF/W8IFF [mailto:nigel@ngunn.net] Sent: Wednesday, February 04, 2009 5:39 PM To: Nate Duehr Cc: AMSAT-BB@amsat.org Subject: Re: [amsat-bb] Re: Cell Phone in Spce
Only if you're in the US.
Nate Duehr wrote: But the FCC rule overrides the FAA rules.)
When I drive my Ercoupe or Cessna around I have no problems using the cell phone in flight...but when I drive the Boeing or the Fighter...it is a different thing. Aside from link margins at the flight levels...one just moves through the cells far to rapidly in the Boeing or the fighter.
In the light planes it is no problem, particularly with the external antenna
Robert WB5MZO
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participants (5)
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Michael Heim -
Nate Duehr -
Nigel Gunn G8IFF/W8IFF -
Rocky Jones -
Tony Langdon