Soon-to-be-Released Technical Report Could Permit Cell Phones to Fly

The 400-word Radio Technical Commission for Aeronautics report does not advocate the use of cell phones on planes, but rather details what tests airlines should conduct to determine whether a plane is at risk of interference.

On the ground, a cell phone regularly connects to the nearest cellular antenna to let the system know where it is and that it is available to receive calls. As the cell phone moves, say, in a vehicle, the signal is handed off from one antenna to the next. A cell phone thousands of feet overhead could contact numerous antennas, potentially disrupting calls and confusing the system.

When the FCC said in 2004 that it was considering lifting its ban on the use of cell phones on airplanes, it received more than 7,800 comments from the public. The commission has not made a decision and has not set a date to do so.

The Cellular Telecommunications Industry Association said it is not advocating the use of cell phones aboard planes. Spokesman Joe Ferren said if the FAA and FCC decide that it is safe, then the trade group would defer to the airlines.

"Our view is it would be up to the airlines," he said. "It's not something we're pushing or advocating."

Qualcomm, a developer of wireless technology and maker of chips that power cell phones, has been working on the cell phone issue from several angles.

In July 2004, the San Diego company and American Airlines conducted a successful "proof of concept" test using cell phones aboard an MD-80 aircraft over Dallas. The two-hour test, done with the permission of the FCC and the FAA, involved phones using Qualcomm's patented CDMA -- code division multiple access -- technology. Calls were made over Sprint's network.

To eliminate the problem of a phone contacting numerous cell towers on the ground, Qualcomm installed a small cell phone antenna -- called a pico cell -- on the plane that linked the calls to a satellite system and then to the Sprint network on the ground.

As many as 15 calls at once were made, and no interference with the aircraft's equipment was found, said Guckian, the Qualcomm vice president. From 2003 to 2004, Qualcomm used a corporate business jet to measure cell phone activity over 10 flights. Qualcomm collected logs from the phones during all phases of flight. The data were used to help the company understand the behavior of CDMA cell phones and to establish power levels necessary to prevent interference with ground networks.

Qualcomm conducted research with Boeing beginning in 2004 to see if a pico cell system on a plane would interfere with wireless networks on the ground. Guckian said that CDMA cell phones, which can operate at lower power levels than rival GSM phones, showed no interference with terrestrial networks. He said GSM phones showed a greater possibility of interference with networks on the ground.

Guckian said he believes cell phones will be allowed on airplanes -- someday.

"I think it may happen under much more controlled scenarios," he said. "You'll see some trials going on, but in terms of a widespread deployment, that's several years away."

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