Mile high signals

Brian

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The question is simple: has anyone received a signal from a commercial
airliner 6 miles high, for more than 10 seconds? Particularly an all digital
signal.

Comments how the signal that high in the sky and in a tin can is?
 
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Brian <no@spam.com> wrote:
> The question is simple: has anyone received a signal from a commercial
> airliner 6 miles high, for more than 10 seconds? Particularly an all digital
> signal.
>
> Comments how the signal that high in the sky and in a tin can is?

It doesn't matter. If you're flying 200-500 miles per hour you won't
be able to acquire a tower and hold on to its signal for more than a second
anyhow.


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Brian wrote:
>
> The question is simple: has anyone received a signal from a commercial
> airliner 6 miles high, for more than 10 seconds? Particularly an all digital
> signal.
>
> Comments how the signal that high in the sky and in a tin can is?

I frequently fly on a private aircraft and lose a signal somewhere
between 10,000 and 15,000 feet.

Larry
 
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"Brian" <no@spam.com> wrote in message
news:bNSsc.11119$j24.3939@twister.nyroc.rr.com...
> The question is simple: has anyone received a signal from a commercial
> airliner 6 miles high, for more than 10 seconds? Particularly an all
digital
> signal.
>
> Comments how the signal that high in the sky and in a tin can is?

As a pilot I can tell you, no.
 
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In addition to the many other fine answers you'll get telling you it's not
possible (because of speed of aircraft, distance or such)...and not to
mention it's currently illegal (at least in the states) - there's a
technical reason as well:

Most cell sites undoubtedly use some type of directional antenna (probably
sectional or panel type, not beam type) to help reduce interference and
boost the signal. While all antenna's bleed, they tend to have very sharp
attenuation in the directions they are not pointed towards. Since most cell
traffic is expected to be terrestial bound, they tend to be pointed at a
down angle from the tower (i.e. pointed towards the cell phones below it)
and thus there's not much signal escaping up. Sure, high frequency signals
tend to "expand" as they traverse a certain distance - but undoubtedly the
points at which you run through these apexs in a commercial airline are far
an few between....

And even if they did use an omnidirectional antenna, again, the properties
of such an atenna are that the signal is strong in the plane of the
direction (so typically in some sort of donut shape around the vertical
element) and attenuated perpendical to the plane (so no up and down signal).
Now, an omnidirectional antenna on it's side might give a better signal -
but that wouldn't be so useful to cell phones on the ground as now the
polarization of the signal is wrong (so there'd be a severely diminished
signal).



"Brian" <no@spam.com> wrote in message
news:bNSsc.11119$j24.3939@twister.nyroc.rr.com...
> The question is simple: has anyone received a signal from a commercial
> airliner 6 miles high, for more than 10 seconds? Particularly an all
digital
> signal.
>
> Comments how the signal that high in the sky and in a tin can is?
>
>
 
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Archived from groups: alt.cellular.verizon (More info?)

Steven J Sobol <sjsobol@JustThe.net> wrote in message news:<XbadnaNvMt--mindRVn-vA@lmi.net>...
>
> It doesn't matter. If you're flying 200-500 miles per hour you won't
> be able to acquire a tower and hold on to its signal for more than a second
> anyhow.

But the radio horizon is massively expanded at 35,000 feet. And path
loss is greatly diminished. W/ completely unobstructed line-of-sight,
a signal w/ a Rician distribution (i.e. a dominant LOS path) will
attenuate 6 dB for every doubling of path distance. As such, the
signal attenuation at 128 miles from a BTS is only 6 dB greater than
at 64 miles from the BTS...only 12 dB greater than at 32 miles...only
18 dB greater than at 16 miles...only 24 dB greater than at 8 miles...

At cruising speed & altitude on commercial flights, I have acquired
CDMA 1900 forward-link PNs from sites more than 100 miles distant. Of
course, Ec/Io was heavily degraded -- too many uncorrelated distant
sites corrupting orthogonality. And reverse-link power was
insufficient to complete a network registration let alone originate an
outgoing call. But, on the forward-link, individual PN offsets could
be identified & the sync channel could be successfully decoded. On
one particular hour-long flight, I logged Sprint PCS SIDs from the
Chicago MTA, Minneapolis-St. Paul MTA, Des Moines MTA, St. Louis MTA,
& Kansas City MTA.

Of course, all of the above were conducted for educational &/or
investigational purposes only... :)

Andrew
--
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cinema@ku.edu
cinema@sprintpcs.com
http://www.wirelesswavelength.com/
 
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On 29 May 2004 21:20:01 -0700, cinema@ku.edu (Andrew Shepherd) wrote:

>Steven J Sobol <sjsobol@JustThe.net> wrote in message news:<XbadnaNvMt--mindRVn-vA@lmi.net>...
>>
>> It doesn't matter. If you're flying 200-500 miles per hour you won't
>> be able to acquire a tower and hold on to its signal for more than a second
>> anyhow.
>
>But the radio horizon is massively expanded at 35,000 feet. And path
>loss is greatly diminished.

I subscribe to Alltel and have a Startac with the debug mode enabled.
I flew with a friend in a 182 from Greenville SC (GMU) to Augusta GA
several months back with it in debug mode. As we climbed (to 5500, I
think), I watched the signal fall from -65dB to -115dB ... in view of
4 Alltel towers.

I attribute that, perhaps wrongly, to a highly directional
omnidirectional antenna <g>(pattern flat like a pancake or frisbee).
I did not sync at all while in the air. As we approached the Augusta
airport, signal strength come up, and I obtained sync as we were on
final.

He has Sprint; his experiences are similar, but he doesn't try to use
it in the air .. something about "first, fly the airplane"

>Of course, all of the above were conducted for educational &/or
>investigational purposes only... :)
>
>Andrew

Exactly the same .... I never tried to make a call. Had I, things may
have changed. I do note that when roaming, I will often register with
a different system after I hit "send".

George
 
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I Don't have a clue what you just said. I thought using a cell phone
on an airplane was not allowed?

Dan

On Sun, 30 May 2004 09:08:09 -0400, GeorgeB <nospam@att.net> wrote:

>On 29 May 2004 21:20:01 -0700, cinema@ku.edu (Andrew Shepherd) wrote:
>
>>Steven J Sobol <sjsobol@JustThe.net> wrote in message news:<XbadnaNvMt--mindRVn-vA@lmi.net>...
>>>
>>> It doesn't matter. If you're flying 200-500 miles per hour you won't
>>> be able to acquire a tower and hold on to its signal for more than a second
>>> anyhow.
>>
>>But the radio horizon is massively expanded at 35,000 feet. And path
>>loss is greatly diminished.
>
>I subscribe to Alltel and have a Startac with the debug mode enabled.
>I flew with a friend in a 182 from Greenville SC (GMU) to Augusta GA
>several months back with it in debug mode. As we climbed (to 5500, I
>think), I watched the signal fall from -65dB to -115dB ... in view of
>4 Alltel towers.
>
>I attribute that, perhaps wrongly, to a highly directional
>omnidirectional antenna <g>(pattern flat like a pancake or frisbee).
>I did not sync at all while in the air. As we approached the Augusta
>airport, signal strength come up, and I obtained sync as we were on
>final.
>
>He has Sprint; his experiences are similar, but he doesn't try to use
>it in the air .. something about "first, fly the airplane"
>
>>Of course, all of the above were conducted for educational &/or
>>investigational purposes only... :)
>>
>>Andrew
>
>Exactly the same .... I never tried to make a call. Had I, things may
>have changed. I do note that when roaming, I will often register with
>a different system after I hit "send".
>
>George