Why is this important you may ask? I know a lot about cell phones because I was a Tier 2 tech support agent for T-mobile while I was going to University for a number of years in early 2000's and I can tell you at a high rate of speed and altitude a cell phone at that time would cut customers off or rarely if ever even connect. As the signal bounces to the first tower the plane would be at the 2nd tower or out of range because of its high rate of speed, and the call would get stuck because the signal would still be on the first tower. If by chance it did the connection would fail after a minute or less because the signal could not travel as fast or reach certain altitudes. Back then for those who remember when you were driving you would sometimes get static, missed, and dropped calls and it is also why all major phone providers would eventually build their towers near high ways so that there is less dropped calls for their cellular customers while driving. But remember planes do not travel along highways in a linear fashion and the signal begins to degrade past 2000 ft. I always fielded complaints from customers once they got on the ground as to why their cell phones would not connect when on a plane at higher than 2000 ft and if they landed while they had their phone on the entire time it would never work. They usually had to call from someone else’s cell phone or use a land line to fix the problem. I had to educate them as to how the signal and towers worked and the reason for why they could not get a reduction in their monthly bill for this reason.
I was much higher than 2000 feet when I received those cell phone calls and text messages. In addition, United 93 was at, and below, 5000 feet when those cell phone calls were made and I have posted phone records from the company as well.
Edited by skyeagle409, 06 November 2012 - 05:04 PM.