June 1, 2005 4:00 AM PDT
Cell phones to take flight
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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.
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?
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.
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