Cell phone regulation on airlines?
 

"DaveC" wrote in message
al.net...
Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

The regulation against using electronic devices that have not been
determined by the operator to be harmless pre-dates the invention of
cellular phones. The text of the regulation is:

§ 121.306 Portable electronic devices.
(a) Except as provided in paragraph (b) of this section, no person may
operate, nor may any operator or pilot in command of an aircraft allow the
operation of, any portable electronic device on any U.S.-registered civil
aircraft operating under this part.

(b) Paragraph (a) of this section does not apply to-

(1) Portable voice recorders;

(2) Hearing aids;

(3) Heart pacemakers;

(4) Electric shavers; or

(5) Any other portable electronic device that the part 119 certificate
holder has determined will not cause interference with the navigation or
communication system of the aircraft on which it is to be used.

(c) The determination required by paragraph (b)(5) of this section shall be
made by that part 119 certificate holder operating the particular device to
be used.


The FCC prohibits using cellular phones on aircraft, but that applies only
to cellular phones, few of which exist any more. Most modern 'cellular'
phones are in fact PCS phones, which are not subject to that regulation.
This ban was created when the regulations for cellular phones were first
written and was not included in the regulations for PCS phones.

Anyway, cellular phones are specifically banned by the FCC and few flight
attendants are probably willing or able to verify whether a particular phone
is covered by the regulation or not, while all portable electronic devices
are banned by the FAA unless the air carrier has determined that they will
not be harmful. Few air carriers are probably willing to test every type and
model of electronic device for radio interference, but most of them have no
problem with pocket calculators, laptop computers, and the like, even though
a laptop computer or PDA with Bluetooth or WiFi would seem to be a potential
problem.

DaveC wrote:
Cell phone usage is restricted on all domestic commercial flights by the FAA,
so the flight attendant keeps telling me.

Nope. The FAA rules have not changed on this, nor have the FCC ones.
You can't use Advanced Mobile Phone Service (i.e., traditional cellular)
airborne. That is an FCC rule.

The FAA rule is just that the airline (i.e., the operator) must
determine when electronic devices are safe to use. The only thing that
has really changed is the "conventional wisdom" on the FAA's part got a
little tighter after some supposed interference issues (primarily blamed
on laptops) a few years back.

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

Yes, all airborne use is prohibited. On cell phones permanently
installed on private jets, there has to be a warning label attached to
prohibit it's use in the air. (FCC rule).

So my question... what is the technical reason for restriction of cell phone
us on commercial flights? Is this reason valid, technically? Or is it simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

Forcing you to use the Airphones is the least of the FAA's or the FCC's
concern.

The real reason is that the cellular phone industry does not want you
to. Their bread and butter is the ground based caller, and their
systems are not designed to work with callers that have some altitude on
the system (there are techncial deficiencies in this that I won't go
into unless you really want to know). As a matter of fact, the cellular
industry fought a company who wanted to share the spectrum
tooth-and-nail over airborne use.

Oddly, this prohibition is NOT written into the rules for the newer
wireless services (PCS, NEXTEL, etc...) that operate outside the AMPS
(800MHz) band. However, most of the carriers with these services still
discourate airborne use.

C J Campbell wrote:


The FCC prohibits using cellular phones on aircraft, but that applies only
to cellular phones, few of which exist any more. Most modern 'cellular'
phones are in fact PCS phones, which are not subject to that regulation.

Actually, they are subject to the regulation when they operate inside
the AMPS band regardless of the technology used. Many of the PCS
services fall back to AMPS. Some of the other wireless providers do
digital service in the AMPS band as well.

PCS is a marketing term invented by cellular
carriers. Both 800 and 1900 Mhz are still
"cellular." PCS originally meant Personal
Communications Services which was a term
used even with old analog via touch-tone
before there ever existed 1900 Mhz "Cellular."
The system could not operate with just one cell because
if everyone was on the same site they would
interefere with one another. More profound
than that, but a cell-phone is still cellular
whether on so-called "PCS" or 800 Mhz
bands.

I noticed on the evening news the other night that someone is trying to get
a modular mobile "cell tower" approved that would be installed in commercial
aircraft so that passengers can use their own mobile phones. It will be
interesting to see how the FCC and FAA handle this one.

--
Bob (Chief Pilot, White Knuckle Airways)

I don't have to like Bush and Cheney (Or Kerry, for that matter) to love
America

"Ron Natalie" wrote in message
m...
DaveC wrote:
Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

Nope. The FAA rules have not changed on this, nor have the FCC ones.
You can't use Advanced Mobile Phone Service (i.e., traditional cellular)
airborne. That is an FCC rule.

The FAA rule is just that the airline (i.e., the operator) must
determine when electronic devices are safe to use. The only thing that
has really changed is the "conventional wisdom" on the FAA's part got a
little tighter after some supposed interference issues (primarily blamed
on laptops) a few years back.

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

Yes, all airborne use is prohibited. On cell phones permanently
installed on private jets, there has to be a warning label attached to
prohibit it's use in the air. (FCC rule).

So my question... what is the technical reason for restriction of cell
phone
us on commercial flights? Is this reason valid, technically? Or is it
simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

Forcing you to use the Airphones is the least of the FAA's or the FCC's
concern.

The real reason is that the cellular phone industry does not want you
to. Their bread and butter is the ground based caller, and their
systems are not designed to work with callers that have some altitude on
the system (there are techncial deficiencies in this that I won't go
into unless you really want to know). As a matter of fact, the cellular
industry fought a company who wanted to share the spectrum
tooth-and-nail over airborne use.

Oddly, this prohibition is NOT written into the rules for the newer
wireless services (PCS, NEXTEL, etc...) that operate outside the AMPS
(800MHz) band. However, most of the carriers with these services still
discourate airborne use.

"DaveC" wrote in message
al.net...
Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

I seem to recall that this wasn't so, early in cellular history. Weren't
we
able to use cell phones on flights, long ago?

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

So my question... what is the technical reason for restriction of cell
phone
us on commercial flights? Is this reason valid, technically? Or is it
simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

Thanks,
--
Please, no "Go Google this" replies. I wouldn't
ask a question here if I hadn't done that already.

DaveC

This is an invalid return address
Please reply in the news group


No you cannot use your phone, But you can use their phone at $3.00 a min.

"Ron Natalie" wrote in message
m...
DaveC wrote:
Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

Nope. The FAA rules have not changed on this, nor have the FCC ones.
You can't use Advanced Mobile Phone Service (i.e., traditional cellular)
airborne. That is an FCC rule.

The FAA rule is just that the airline (i.e., the operator) must
determine when electronic devices are safe to use. The only thing that
has really changed is the "conventional wisdom" on the FAA's part got a
little tighter after some supposed interference issues (primarily blamed
on laptops) a few years back.

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

Yes, all airborne use is prohibited. On cell phones permanently
installed on private jets, there has to be a warning label attached to
prohibit it's use in the air. (FCC rule).

So my question... what is the technical reason for restriction of cell
phone
us on commercial flights? Is this reason valid, technically? Or is it
simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

Forcing you to use the Airphones is the least of the FAA's or the FCC's
concern.

The real reason is that the cellular phone industry does not want you
to. Their bread and butter is the ground based caller, and their
systems are not designed to work with callers that have some altitude on
the system (there are techncial deficiencies in this that I won't go
into unless you really want to know). As a matter of fact, the cellular
industry fought a company who wanted to share the spectrum
tooth-and-nail over airborne use.

Oddly, this prohibition is NOT written into the rules for the newer
wireless services (PCS, NEXTEL, etc...) that operate outside the AMPS
(800MHz) band. However, most of the carriers with these services still
discourate airborne use.

Later this month an industry group is going to announce standards and an
icon that will come on to show that a device that is not in a transmit mode,
even if it is turned on for other uses.

"Spike" wrote in message
...
PCS is a marketing term invented by cellular
carriers. Both 800 and 1900 Mhz are still
"cellular."

Nevertheless, the FCC rule applies only to the 800 Mhz band.

On Mon, 11 Oct 2004 14:01:15 -0700, "NW_PILOT"
wrote:

No you cannot use your phone, But you can use their phone at $3.00 a min.

Less than that with Verizon

http://www.verizonwireless.com:80/b2...fone/index.jsp

Evan
--
To reply, remove TheObvious from my e-mail address.

"Bob Chilcoat" wrote in message
...
I noticed on the evening news the other night that someone is trying to
get
a modular mobile "cell tower" approved that would be installed in
commercial
aircraft so that passengers can use their own mobile phones. It will be
interesting to see how the FCC and FAA handle this one.

--
Bob (Chief Pilot, White Knuckle Airways)


Still won't work. The frequency the cell in the air is on, will be hitting
dozens of towers on the ground, making them unable to use that frequency for
other users on the land.
--
Jim in NC


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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"DaveC" wrote in message
al.net...
Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

I seem to recall that this wasn't so, early in cellular history. Weren't
we
able to use cell phones on flights, long ago?

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

So my question... what is the technical reason for restriction of cell
phone
us on commercial flights? Is this reason valid, technically? Or is it
simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

Oh good. Let's list all the reasons why cell phones belong in airplanes:

1) Airlines in bankrupty which (and I say this with enormous sarcasm) has NO
effect on the morale of people who should be happy, like mechanics

2) A random selection of pilots who partied way too late the night before

3) Sky marshalls who saunter aboard like what's-his-name from Miami Vice,
thereby making it perfectly clear who to strangle if you're a hijacker and
need a gun.

4) Passengers who think flying is a convenient excuse to get plastered
within 15 minutes of takeoff and mouth off to the crew.

5) People who've lived on potato chips and cheesecake since birth, but think
they shouldn't have to buy two seats to contain their lard, and end up
flowing all over your for 4 hours.

6) Air traffic control computers which are, in many cases, antiques.

7) Morons who will look right at you while you're listening to quiet music
with your eyes closed and begin telling you their life story.

8) Fools who SLAM their seats backwards within seconds of the warning lights
being turned off, and pretend they're instantly asleep?

On top of all this, you think there should be lots of cell phones in use on
airplanes? I've got news for you: Do that, and it'll be more comfortable to
take a bus through a Central American jungle with goats & pigs roaming the
aisles. I don't know how old you are, but there was actually a time when
flying was comfortable and enjoyable.

Spike wrote:

PCS is a marketing term invented by cellular
carriers. Both 800 and 1900 Mhz are still
"cellular." PCS originally meant Personal
Communications Services which was a term
used even with old analog via touch-tone
before there ever existed 1900 Mhz "Cellular."
The system could not operate with just one cell because
if everyone was on the same site they would
interefere with one another. More profound
than that, but a cell-phone is still cellular
whether on so-called "PCS" or 800 Mhz
bands.

Not according to the FCC, and they (literally) make the rules and the definitions.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

On Tue, 12 Oct 2004 03:10:28 GMT, "Doug Kanter"
wrote:

I don't know how old you are, but there was actually a time when
flying was comfortable and enjoyable.

And expensive!

In 1958, I left my job in Frankfurt and looked at modes of
transportation home. I got a ticket on the Holland-America line for
$278. An airplane would have been $400--one-way!

To translate into millennium dollars, multiply by ten.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

Warbird's Forum www.warbirdforum.com
Piper Cub Forum www.pipercubforum.com
Viva Bush! www.vivabush.org

"Cub Driver" wrote in message
...
On Tue, 12 Oct 2004 03:10:28 GMT, "Doug Kanter"
wrote:

I don't know how old you are, but there was actually a time when
flying was comfortable and enjoyable.

And expensive!

In 1958, I left my job in Frankfurt and looked at modes of
transportation home. I got a ticket on the Holland-America line for
$278. An airplane would have been $400--one-way!

To translate into millennium dollars, multiply by ten.

I dunno....my dad paid for it when I was 12 years old. :-) About the only
negative thing I remember was that the airlines were silly enough to serve
peas, which made for a bit of a mess on bumpy flights.

Best memory - 1987: My flight from Pittsburgh to Rochester NY was delayed by
an hour due to crazy summer weather. When we finally boarded, the pilot came
out of the cockpit and addressed the passengers. He said "Sorry about the
delay, but there were thunderstorms. They've passed, but it's still pretty
turbulent. I'll give you a choice. I can avoid 98% of the turbulence and
we'll be in Rochester around 8:30. Or, I can go through the bumps and it'll
be about 15 minutes quicker. The 2nd choice could be a little unnerving, but
nothing we're not trained for and the plane's not built for. How about a
show of hands - who wants choice A? And choice B?" Choice B won. We got home
faster. :-)

Spike wrote:
PCS is a marketing term invented by cellular
carriers. Both 800 and 1900 Mhz are still
"cellular.

Not when you are talking about FCC rules. For regulatory purposes,
cellular specifically refers to 47 CFR 22 Subpart H which covers the
800MHz (AMPS) band. PCS is governed by 47 CFR 24.

Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.

As I understand it that signal bar you see on you Cell phone is
dictates how much power the cell phone uses to transmit. So the closer
you are to the tower the less power it uses to transmit. This is why
you phone batteries probably last longer in town than the do out in
the boondocks.

By installing the tower in the aircraft you are only a few hundred
feet from the tower (at the most). The Cell phones will get an
excellent signal from it and will drop to the lowest transmit power
setting, Thus the interference with towers on the ground should be
minimal.

I am not an expert on these, I am just repeating how it was explained
to me.

Brian

"Morgans" wrote in message ...
"Bob Chilcoat" wrote in message
...
I noticed on the evening news the other night that someone is trying to
get
a modular mobile "cell tower" approved that would be installed in
commercial
aircraft so that passengers can use their own mobile phones. It will be
interesting to see how the FCC and FAA handle this one.

--
Bob (Chief Pilot, White Knuckle Airways)


Still won't work. The frequency the cell in the air is on, will be hitting
dozens of towers on the ground, making them unable to use that frequency for
other users on the land.

Brian Case wrote:


As I understand it that signal bar you see on you Cell phone is
dictates how much power the cell phone uses to transmit. So the closer
you are to the tower the less power it uses to transmit. This is why
you phone batteries probably last longer in town than the do out in
the boondocks.

The cellular phone does use an adaptive power control (it's not tied to
the signal strength bar).

The problem is that even at mimimal power, if you're sitting close to
the window, you can be heard equally well by a large number of cells
over the system. There's nothing magic that they can do to stop this
short of rf shielding the aircraft windows somehow.

"Brian Case" wrote in message
om...
Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.

As I understand it that signal bar you see on you Cell phone is
dictates how much power the cell phone uses to transmit. So the closer
you are to the tower the less power it uses to transmit. This is why
you phone batteries probably last longer in town than the do out in
the boondocks.

By installing the tower in the aircraft you are only a few hundred
feet from the tower (at the most). The Cell phones will get an
excellent signal from it and will drop to the lowest transmit power
setting, Thus the interference with towers on the ground should be
minimal.

I am not an expert on these, I am just repeating how it was explained
to me.

Brian
I could see the possibilities of strong enough signal not reaching the
ground to cause problems, but......

Which company (Of the multitudes) will you have to belong to, to get your
phone to work? How will the plane's system communicate with the ground? By
cell tower? g
--
Jim in NC


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.774 / Virus Database: 521 - Release Date: 10/7/2004

The only thing that I see wrong with this is that the cell "tower" needs
to connect to the wired phone system. We know that it can't be
hardwired, that would be one hell of a long cable! So, as the "tower"
needs to transmit and receive (transceiver) from other transceivers on
the ground that are hardwired to the phone system. You can put the
ground transceivers on a different frequency pairs, but that's a whole
new world wide system!

Brian Case wrote:

Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.

As I understand it that signal bar you see on you Cell phone is
dictates how much power the cell phone uses to transmit. So the closer
you are to the tower the less power it uses to transmit. This is why
you phone batteries probably last longer in town than the do out in
the boondocks.

By installing the tower in the aircraft you are only a few hundred
feet from the tower (at the most). The Cell phones will get an
excellent signal from it and will drop to the lowest transmit power
setting, Thus the interference with towers on the ground should be
minimal.

I am not an expert on these, I am just repeating how it was explained
to me.

Brian

"Morgans" wrote in message ...

"Bob Chilcoat" wrote in message
...

I noticed on the evening news the other night that someone is trying to

get

a modular mobile "cell tower" approved that would be installed in

commercial

aircraft so that passengers can use their own mobile phones. It will be
interesting to see how the FCC and FAA handle this one.

--
Bob (Chief Pilot, White Knuckle Airways)


Still won't work. The frequency the cell in the air is on, will be hitting
dozens of towers on the ground, making them unable to use that frequency for
other users on the land.

DaveC wrote:

Cell phone usage is restricted on all domestic commercial flights by the FAA,
so the flight attendant keeps telling me.

I seem to recall that this wasn't so, early in cellular history. Weren't we
able to use cell phones on flights, long ago?

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

So my question... what is the technical reason for restriction of cell phone
us on commercial flights? Is this reason valid, technically? Or is it simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

The origin of the ban was due to concerns about cellphone transmissions
interfering with onboard avionics. This is more likely to be a concern with older
a/c. There is no hard data that I know of that substantiates the concern. There
is some anecdotal evidence of interference though.

As another poster has mentioned, cellphones don't work well at altitude.

Both Boeing and Airbus are now working on systems to enable airborne use of
cellphones.


Graham

Joseph wrote:

On Mon, 11 Oct 2004 11:38:10 -0700, DaveC wrote:

Cell phone usage is restricted on all domestic commercial flights by the FAA,
so the flight attendant keeps telling me.

I seem to recall that this wasn't so, early in cellular history. Weren't we
able to use cell phones on flights, long ago?

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

Restriction of cell phones from planes is not due to the interference
to avionics, but is more of concern that it will interfere with
land-based communications. When you're up at a height and you attempt
to use your phone you are hitting a whole lot of cell sites as once
and if lots of people did this it would make a real mess of land-based
cellular service. So it's more of an FCC mandate than it is of the
FAA.

I thought that the base station antenna patterns pretty much ignore any signal
greater than a few ( maybe ~10 ) degrees above the horizon.


Graham

Brian Case wrote:

Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.

Well, it would work well, but not if they actually used the cellular frequencies
(AMPS). If they installed a PCS processor in the plane, modern PCS phones would
communicate with it and not fall back on the AMPS frequencies.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

Pooh Bear wrote:

The origin of the ban was due to concerns about cellphone transmissions
interfering with onboard avionics.

The origin of the ban on cellphone usage at altitude was to prevent phones from
hitting multiple receivers which were using the same frequency. The designers of the
AMPS system counted on being able to have many "cells" use the same frequency set
because they were far apart. Put the phone in the air, and several of these stations
would receive the transmissions from the call.

The origin of the FAA ban on electronic devices is as you say, but it is not unique
to cell phones.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

"Pooh Bear" wrote in message
...
DaveC wrote:

Cell phone usage is restricted on all domestic commercial flights by the
FAA,
so the flight attendant keeps telling me.

I seem to recall that this wasn't so, early in cellular history. Weren't
we
able to use cell phones on flights, long ago?

Is cell phone usage also restricted on private jets, etc. for similar
reasons?

So my question... what is the technical reason for restriction of cell
phone
us on commercial flights? Is this reason valid, technically? Or is it
simply
an excuse to force anyone who needs to make a call to use the airline's
on-board phones (and pay their outrageous rates)?

The origin of the ban was due to concerns about cellphone transmissions
interfering with onboard avionics. This is more likely to be a concern
with older
a/c. There is no hard data that I know of that substantiates the concern.
There
is some anecdotal evidence of interference though.

Everyone's got a conspiracy theory. Here's another: The ban on cellular
phones is kept alive by the book publishing industry. Some in the evil cabal
may actually have the best intentions: Trying to get cell phone addicts to
shut the phuque up and try reading something for a change.

Pooh Bear wrote:

The origin of the ban was due to concerns about cellphone transmissions
interfering with onboard avionics. This is more likely to be a concern with older
a/c. There is no hard data that I know of that substantiates the concern. There
is some anecdotal evidence of interference though.

Sorry, there are two issues. The FAA has it's own concerns about ANY
electronic devices. There's not hard and fast info on a lot of these
devices and the FAA has gotten more restrictive over time. However, the
AMPS regs specifically prohibit it without specifying the reason. It would
seem unlikely that a prohibition against airborn use however has anything
to do with air navigation because NOTHING ELSE the FCC regulates really
addresses that issue.


As another poster has mentioned, cellphones don't work well at altitude.

Wrong. AMPS / Analog cell phones, the ones the regulatory applies to, work
just fine from altitude. Actually too well. That was demonstrated on 9/11.
However some of the digital (PCS, for example) services, don't work at all
airborne (but they are not prohibited by regulation either).

G.R. Patterson III wrote:

Brian Case wrote:

Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.


Well, it would work well, but not if they actually used the cellular frequencies
(AMPS). If they installed a PCS processor in the plane, modern PCS phones would
communicate with it and not fall back on the AMPS frequencies.

It would be a real can of worms. If everybody had a GSM phone in the
US it might be doable. But every carrier these days tends to market
a multimode phone that bounces between CDMA, old style TDMA, analog AMPS,
GSM, and a couple of proprietary schemes like iDEN.

It's going to have to be a "only [insert carrier here]" phones work onboard
United's flights.

On Wed, 13 Oct 2004 12:16:13 -0400, Ron Natalie
wrote:

G.R. Patterson III wrote:

Brian Case wrote:

Actually it could work very well, and I have seen this proposal from
several different sources. The Idea is to install a low power cell
phone tower into the airliner.


Well, it would work well, but not if they actually used the cellular frequencies
(AMPS). If they installed a PCS processor in the plane, modern PCS phones would
communicate with it and not fall back on the AMPS frequencies.

It would be a real can of worms. If everybody had a GSM phone in the
US it might be doable. But every carrier these days tends to market
a multimode phone that bounces between CDMA, old style TDMA, analog AMPS,
GSM, and a couple of proprietary schemes like iDEN.

Given that it's no big deal these days to make a multi-mode,
multi-band phone, why do you think it'd be so tough to make a
multi-mode, multi-band base station in the A/C? Certainly would be
easier if all phones were CDMA, of course. ;-)

Klein

On Wed, 13 Oct 2004 12:13:36 -0400, Ron Natalie
wrote:

Pooh Bear wrote:

The origin of the ban was due to concerns about cellphone transmissions
interfering with onboard avionics. This is more likely to be a concern with older
a/c. There is no hard data that I know of that substantiates the concern. There
is some anecdotal evidence of interference though.

Sorry, there are two issues. The FAA has it's own concerns about ANY
electronic devices. There's not hard and fast info on a lot of these
devices and the FAA has gotten more restrictive over time. However, the
AMPS regs specifically prohibit it without specifying the reason. It would
seem unlikely that a prohibition against airborn use however has anything
to do with air navigation because NOTHING ELSE the FCC regulates really
addresses that issue.


As another poster has mentioned, cellphones don't work well at altitude.

Wrong. AMPS / Analog cell phones, the ones the regulatory applies to, work
just fine from altitude. Actually too well. That was demonstrated on 9/11.
However some of the digital (PCS, for example) services, don't work at all
airborne (but they are not prohibited by regulation either).

Actually, PCS and 800 MHz digital CDMA work just fine airborne
provided there are only a few CDMA base stations near the aircraft,
but flying over a city it is hopeless. The problem is that in CDMA
systems many base stations transmit on the same wideband channel,
interfering with each other. The phone will never attempt to transmit
because it never succeeds in acquiring the system.

Klein

Klein wrote:

Given that it's no big deal these days to make a multi-mode,
multi-band phone, why do you think it'd be so tough to make a
multi-mode, multi-band base station in the A/C? Certainly would be
easier if all phones were CDMA, of course. ;-)

That would be fine if there were some industry cooperation with the
people planning on offering the airborne service. But the plethora
of incompatible modulation schemes now sort of demonstrates that this
level of cooperation isn't likely .