GSM vs CDMA
There are many situations were the use of a mobile phone in an aircraft in flight is possible, permitted, plausible, and otherwise OK.
On practicality however, my own experience has shown that it may not always be possible.
I have a GSM mobile, and have discovered that it is possible to send and recieve text messages, and make phone calls, but only up to about 4000 feet.
My understanding of how the GSM network works, is that above that height the poor phone can 'see' too many towers, and panicks. I see a full strength signal, but it doesnt work.
Now, if I were to use a CDMA phone, which likes the more towers the better, would I theoretically have a much higher usage ceiling for the phone?
Does anyone have any experience with the two systems at altitude?