Sorry Syd, your conspiracy theorist friends have led you astray again. Gawd I wish you'd research non-conspiracy websites.
Above you referenced the following: "According to AT&T spokesperson Alexa Graf, cellphones are not designed for calls from the high altitudes at which most airliners normally operate. It was, in her opinion, a “fluke” that so many calls reached their destinations."
Unfortunately, you failed, once again I might add, to include the WHOLE statement from Ms. Graf which stated in its entirety:
"Because wireless networks are designed for terrestrial use, the fact that so many people were able to call from the sky brings into question how the phones worked from such altitudes.
Alexa Graf, AT&T spokesperson, said systems are not designed for calls from high altitudes, suggesting it was almost a fluke that the calls reached their destinations.
“On land, we have antenna sectors that point in three directions — say north, southwest, and southeast,” she explained. “Those signals are radiating across the land, and those signals do go up, too, due to leakage.”
From high altitudes, the call quality is not very good, and most callers will experience drops. Although calls are not reliable, callers can pick up and hold calls for a little while below a certain altitude, she added.
Brenda Raney, Verizon Wireless spokesperson, said that RF signals actually can broadcast fairly high. On Sept. 11, the planes were flying low when people started using their phones. And, each call lasted 60 seconds or less.
“They also were digital phones, and there's a little bit more leeway on those digital phones, so it worked,” she said.
It helped that the planes were flying in areas with plenty of cell sites, too. Even United Airlines 93, which crashed in rural Pennsylvania, was supported by several nearby cell sites, Raney added."http://connectedplanetonline.com/wirele ... l_contact/
And second, here's this:
Making Calls From The Air
By Brad Smith
September 24, 2001
c 2003, Reed Business Information, a division of Reed Elsevier Inc. All Rights Reserved.
When several passengers aboard the hijacked airliners made calls to family and spouses from their wireless phones on the now-infamous Sept. 11, it came as a surprise to many that the calls actually were completed.
Although airline passengers are warned against using their mobile phones in flight, it's fairly well-known that private airplane pilots often use regular cellular and PCS phones, even if it is illegal. Not quite as well-known, however, is that people have used their wireless phones to make surreptitious calls from the bathrooms of airliners.
The technology is there to support such airborne mobile connections. Take the Colorado company Aircell Inc., which uses FCC-approved equipment for wireless phone service.
But how does a terrestrial technology work in the sky?
First, altitude in itself is not a problem. Earthbound wireless phones can talk to base stations up to 10 miles away, depending on the terrain, while a typical passenger jet flies at an altitude of about six and a half miles. Since cell site antennas are configured to pick up signals horizontally and not from overhead, performance is usually compromised in calls from above. Nevertheless, cell sites can pick up signals from the air from great distances.
Toby Seay, vice president of national field operations for AT&T Wireless, says the technological limits to using a cell phone aboard a plane include the signal strength, potential signal inhibitors and "free space loss" as the signal gradually loses strength. The frequency used can make a difference, too. A signal using an 800 MHz cellular frequency can travel farther than a 1900 MHz PCS signal because of the different propagation characteristics of the two wavelengths.
The biggest problem with a phone signal sent from the air is that it can reach several different cell sites simultaneously. The signal can interfere with callers already using that frequency, and because there is no way for one cell site to hand off calls to another that is not adjacent to it, signals can become scrambled in the process. That's why wireless calls from jetliners don't last long, says Kathryn Condello, vice president of industry operations for CTIA. The network keeps dropping the calls, even if they are re-established later.
The phones on the back of the seats in most airplanes work similarly to a regular wireless phone. The major differences are that the antennas at the ground base stations are set up to pick up the signals from the sky, and there are far fewer stations handing off signals from one to another as a plane crosses overhead.
Also, Seay says, the airplane phones operated by AT&T Wireless and the GTE subsidiary of Verizon Communications send signals through wires to an antenna mounted on the outside of the plane. That is done to prevent interference with the plane's own radio communications, as well as to eliminate signal loss caused by the airplane's metal fuselage.
Syd, please stop posting half-told stories to make it fit your agenda. It's the lazy way out.