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.