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Cell phones to take flight

FAQ Consensus is building to relax rules that since 1991 have banned cell phone use on U.S. commercial flights.

FAQ Air travelers beware: Cell yell at 30,000 feet is coming.

As shown by the flurry of comments filed with the Federal Communications Commission in the past few days, there's a consensus building to relax rules that since 1991 have banned cell phone use on U.S. commercial flights.

Now the hard work begins--deciding to what extent to ease the rules. U.S. law enforcement, which doesn't like the idea at all, and lobbyists at the Cellular Telecommunications & Internet Association represent the two extremes of the argument. The questions and answers here focus on when the rules will be relaxed, the technology that'll make it happen and why there's a ban in the first place.


What's new:
Consensus is building to relax rules that since 1991 have banned cell phone use on U.S. commercial flights.

Bottom line:
These questions and answers focus on why the rules exist, when they will be relaxed and what technology will be at the center of it all.

More stories about cell phone use on planes.

When will I be able to make a cell phone call on an airplane?
Don't expect the rules to be relaxed until December 2006 at the earliest, and it'll more likely be early 2007. The Federal Aviation Administration has the ultimate say, and it's waiting for the second phase of a study being conducted by an advisory agency, the RTCA, or Radio Technical Commission for Aeronautics. The private, nonprofit company was organized under the Federal Advisory Committee Act. The second phase of the RTCA's report, to include its recommendations, is due by December 2006.

Will my cell phone call cause interference?
Maybe by then the industry will have found the answer to nagging interference issues the FCC believes are now clearly still in evidence. The commission noted in the Feb. 16, 2005, order that began its investigation of easing the cell phone rules that "while some assert that the technology exists that will allow cell phones...we are not prepared to take this step...without further development of the record on possible technical solutions."

The FCC continued: "While some say phones can be used on aircraft without causing unwanted interference, no party has provided sufficient detail explaining how eliminating the ban would actually work."

Can I make a call on board a plane?
There are a number of ways. One involves the familiar seat-back phones. Another involves the relatively new tandem of more broadband-enabled airplanes, and the voice over Internet Protocol, or VoIP, software to let Internet connections double as a phone line.

Why the cell phone ban?
The cell phone ban went into effect in 1991, mostly to eliminate the possibility that cell phone calls on airplanes would interfere with cell conversations on the ground, as well as with the airplane's radio communications.

The FCC cited effects of "frequency re-use," which is a fundamental cell phone principle that's helped mobile phones proliferate worldwide. The signal from a cell phone doesn't go on forever; the energy to propel it dissipates after a number of miles, and it dissipates more quickly if it bounces off buildings, hills and other obstacles. This allows the same frequencies to be re-used by operators in different markets sometimes just a few miles apart.

A cell phone signal falling to Earth from a phone aboard a plane encounters no significant obstacles to slow it down, so it's strong enough to reach the ground and find a network on its particular frequency. But if the airwaves belong to a different operator, there's likely to be "noise" and other forms of interference for everybody, the FCC believes.

Ban, what ban?
The 1991 ban hasn't kept people from using their cell phones while in flight, whether it's to secretly scroll through office e-mail, or to respond to far more dire circumstances, as was the case with Chicago resident Matthew Downs on Sept. 11, 2001.

Downs, a software salesman, learned of the terrorist attacks while on a commercial flight returning home from South America. The captain explained that "terrorist attacks on airplanes" meant they were making an emergency landing. People on board using cell phones soon discovered the true nature of the day's events.

"We found out from people using their phones that the World Trade Center was hit, and some unspecified area in Washington," Downs recalls.

Why do the Federal Aviation Administration and the FCC think they can ease restrictions?
For one, there's a lot of interest among cell phone operators to sell calls on board a flight. Just as they are on trains, in cars, buses, subways and on ferries, an operator's audience is trapped for anywhere from a few minutes to--in a transcontinental flight--12 hours.

Verizon Airfone, for instance, which operates seat-back phones on scores of planes, has indicated that in order to meet the needs of consumers on commercial aircraft, it plans solutions that would use Wi-Fi and Bluetooth, which are both wireless Internet technologies found in a growing number of cell phones.

What's changed since 1991?
Since the ban went into effect, cellular infrastructure has changed greatly, and promising technical innovations have taken place in areas of power control, as well as signal filter and antenna design. The advent of smart antennas, which are much more efficient at broadcasting signals, mean cell phones can operate on the very low-power threshold the FCC has tentatively set.

Pico Cells emerge as one of the new technology alternatives. A pico cell is, in effect, a low-power cellular base station installed on an aircraft to steer cell phone conversations to passengers and crew. The signal travels from the handset to the pico cell, which then relays it to the ground via a separate air-to-ground link, typically a satellite band.

In theory there's no threat of interfering with signals below, because the conversations are limited to the aircraft. Even better, pico cells can limit just how much power someone's cell phone signal has. Qualcomm performed a proof-of-concept flight in July 2004, with much fanfare. Other in-flight tests have been conducted by mobile network specialist AIRINC and Norwegian phone operator Telenor.

What are the drawbacks of pico cells?
Pico cells have some dangers; one well-known one has to do with if they should fail while in flight. There's significant risk of airborne cell phones beginning to search for a terrestrial base station and causing interference.

How does U.S. law enforcement view the cell phone ban?
U.S. law enforcement officials believe terrorists might have an easier time remotely detonating bombs and coordinating hijackings with accomplices on the ground, inside other airborne craft, or on the same flight, according to comments from the Department of Justice, the FBI and the Department of Homeland Security. Collectively, the group objects to any loosening of the FAA rules.

What personal electronic devices can you use on an airplane?
You use any electronic device on any aircraft, except for portable voice recorders, hearing aids, heart pacemakers and electronic shavers, according to FAA guidelines.

There is a big caveat, said FAA spokesman Les Dorr. If an airline can show the FAA that an electronic device does not interfere with aviation, then it's allowed on board. Laptops, not part of the FAA guideline, are one example. Most airlines remain conservative, however, in the technology they allow on board. American Airlines does not, for instance, allow Global Positioning System, or GPS, devices.