Planes & Cell phones

Jay Honeck opined

I think you have too much time on your hands...
cheers ... denny

Actually, I think it's a cool topic.

I'd be willing to fly slower than 200 knots if it meant I could legally use
my cell phone in the air!

:-)

Cirrus 1234A: XXX Center, Cirrus 34A would like to slow to 190.

XXX Center: Cirrus 34A, why?

Cirrus 1234A: I need to phone home.



-ash
Cthulhu for President!
Why vote for a lesser evil?

Dylan Smith wrote in
:

I doubt they blow up gas tanks or the other evil things, but I have
first hand personal experience of a mobile phone intefering with
either the intercom or the COM radio of an aircraft (see earlier post
in this thread).

The "Mythbusters" (see Discovery Channel, TV) tried. Never even got close
to blowing up a service station... well, not with the cell phone. G

That OWT started as a more "modern" version of the older two-way mobile
radios. [And I've known some hams that ran a California Kilowatt out of
their cars.] Demolition crews would put up big signs around the area they
were using explosives, saying "Please turn off all two-way radios."

The problem there was explosives, wired through thousands of feet back to
the detonator. Made a great antenna. G

So people just naturally assumed that if a 1000+ watt transmitter would do
it, than naturally so would a cell phone. G

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

Elwood Dowd wrote in
:

Thanks very much for a comprehensive answer! Not many of those are to
be found on usenet.

Unfortunately, the one "practical" thing that wasn't mentioned - although
the regs may allow the newer PCS and GSM types in the air, at altitude much
above around 2000 AGL they start not working. The design of the ground-
based cell-site antennas degrade the signals badly (even though the raw
signal strength may still show okay on your phone).

Multi-mode models may then try reverting to "cell" technology - but then
theoretically you are back in conflict with the FCC regs.

If someone can solve this "last mile" (or so) problem, with a solution that
doesn't require a LONG phone cord, there sure are a lot of interesting
things that could then be done in our cockpits.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

Greg Copeland writes:

They almost certainly are not cell phones. Probably PCS.

I'm using layman's terminology, which would cover PCM, GSM, etc, etc, etc...

Oh, surely not! NOBODY (except me) calls those "cell phones".
http://groups.google.com/groups?hl=e... earthlink.net

Good thing we still have George around to explain this to us. I think we've
lost the brilliant educator Jerry Bransford.
http://groups.google.com/groups?selm...&output=gplain

--kyler

I'm tryint to speed-read all this excellent information, and I still don't
think I have an answer to my question:

By leaving my phone switched on, but *not making an outgoing call*, am I
doing no harm, or negligible harm, to the system?

Assume also that nobody calls me.

-- David Brooks

"G.R. Patterson III" wrote in message
...


Greg Copeland wrote:

The general theory on modern cell phones in flight, goes like this:
The FCC also has a ban because when you're in flight, you're always at
least 6-8 miles away from the nearest cell tower. You end up
communicating
with too many towers and bogging down the network.

No, you could be right beside the nearest tower. In general, any tower
within about
20 miles of you will be able to receive you when you're on the ground
(unless
something's blocking the signal). To eliminate conflict between calls,
towers that
are neighbors use different frequency sets. When you make a call, the
control system
polls all of the towers that can "hear" you and tells the closest one to
accept the
call. That tower tells your phone what frequency pair to use. After that,
only that
tower can "hear" your phone. If you move too far away, the control system
will poll
all the towers again and have your phone switch frequencies.

Unfortunately, there aren't enough radio frequencies to allow every tower
to use a
unique set, so there will probably be several towers between 30 and 60
miles from you
that use the same set of frequencies that your phone is using. They can't
hear you
'cause they're too far away.

Now take off. As soon as you get 500' up, some of these towers can hear
your phone.
If these towers are using the same frequency pair for other calls that
your phone is
using, your call will bleed into those conversations. Some hardware
systems can
detect conflicts like this and have other phones change frequencies. This
hardware,
however, will log the ID of the phone that's causing the trouble, and you
may get a
service termination notice.

The system designers carefully design the network to prevent call conflict
due to
things like skyscrapers. Skyscrapers rarely move, however.

George Patterson
This marriage is off to a shaky start. The groom just asked the band
to
play "Your cheatin' heart", and the bride just requested "Don't come
home
a'drinkin' with lovin' on your mind".

"David Brooks" wrote in message
...
I'm tryint to speed-read all this excellent information, and I still don't
think I have an answer to my question:

By leaving my phone switched on, but *not making an outgoing call*, am I
doing no harm, or negligible harm, to the system?

Assume also that nobody calls me.


Probably not. Digital phones have unique identifiers and are actually
supposed to be picked up by more than one tower at a time. If too many
towers pick up the phone then they electronically assign that phone to just
one tower and the others reject it. Since it is a digital stream, each
frequency can handle many cellular phones. It would be very difficult to bog
down the system with digital phones.

The problem is that the digital signals tend to be too weak, so the phone
frequently switches to analog when you start using it in an airplane. At the
very least, your phone will keep switching from one tower to another,
constantly searching even when you are not talking on it, and that will run
down the battery.

I recall reading somewhere that FCC regulations against using cellular
phones in flight do not apply to digital phones.

"C J Campbell" wrote in message
...

I recall reading somewhere that FCC regulations against using cellular
phones in flight do not apply to digital phones.



Nevertheless, I don't find any exception in this part:


§ 22.925 Prohibition on airborne operation of cellular telephones.
Cellular telephones installed in or carried aboard airplanes, balloons or
any other type of aircraft must not be operated while such aircraft are
airborne (not touching the ground). When any aircraft leaves the ground, all
cellular telephones on board that aircraft must be turned off. The following
notice must be posted on or near each cellular telephone installed in any
aircraft:

“The use of cellular telephones while this aircraft is airborne is
prohibited by FCC rules, and the violation of this rule could result in
suspension of service and/or a fine. The use of cellular telephones while
this aircraft is on the ground is subject to FAA regulations.”

"C J Campbell" wrote in message
...

"C J Campbell" wrote in message
...

I recall reading somewhere that FCC regulations against using cellular
phones in flight do not apply to digital phones.



Nevertheless, I don't find any exception in this part:


§ 22.925 Prohibition on airborne operation of cellular telephones.
Cellular telephones installed in or carried aboard airplanes, balloons or
any other type of aircraft must not be operated while such aircraft are
airborne (not touching the ground). When any aircraft leaves the ground,
all
cellular telephones on board that aircraft must be turned off. The
following
notice must be posted on or near each cellular telephone installed in any
aircraft:

“The use of cellular telephones while this aircraft is airborne is
prohibited by FCC rules, and the violation of this rule could result in
suspension of service and/or a fine. The use of cellular telephones while
this aircraft is on the ground is subject to FAA regulations.”

Of course, PCS phones are operated under Part 24 of the FCC regulations,
which have no prohibition against use in aircraft.

On Wed, 21 Apr 2004 08:10:57 -0700, David Brooks wrote:

I'm tryint to speed-read all this excellent information, and I still don't
think I have an answer to my question:

By leaving my phone switched on, but *not making an outgoing call*, am I
doing no harm, or negligible harm, to the system?

Assume also that nobody calls me.


It's probably safe to say that it is disturbing the the network, even if
you are not actually on a call. Having said that, in a slower GA plane
(130kts or less; number pulled from my tail pipe), in a rural area, the
impact *probably* is minimal. Especially considering the more rural you
are, the less the capacity demands on the towers, from other users in the
area, are likely to be.

On the other hand, imagine a commercial plane full of people and
the majority of them have a cell phones on. I think we've pretty well
established that it can very disturbing to the networks and their capacity.

On Wed, 21 Apr 2004 08:59:34 -0700, "C J Campbell"
wrote:


"C J Campbell" wrote in message
...

I recall reading somewhere that FCC regulations against using cellular
phones in flight do not apply to digital phones.



Nevertheless, I don't find any exception in this part:


§ 22.925 Prohibition on airborne operation of cellular telephones.
Cellular telephones installed in or carried aboard airplanes, balloons or
any other type of aircraft must not be operated while such aircraft are
airborne (not touching the ground). When any aircraft leaves the ground, all
cellular telephones on board that aircraft must be turned off. The following
notice must be posted on or near each cellular telephone installed in any
aircraft:

“The use of cellular telephones while this aircraft is airborne is
prohibited by FCC rules, and the violation of this rule could result in
suspension of service and/or a fine. The use of cellular telephones while
this aircraft is on the ground is subject to FAA regulations.”

Here's the FCC site on cellular telephones:

http://wireless.fcc.gov/services/cellular/

Here's the FCC site on PCS telephones:

http://wireless.fcc.gov/services/broadbandpcs/

The prohibition is in the first (Part 22). There is no corresponding
prohibition in the second (Part 24).

Don