Cell phones work on planes!!!

I was under the impression that most modern aircraft that fly domestic routes and some international routes actually have a type of cell site repeater equipment in the planes aviation electronics package. Its part of the system the FAA uses for tracking and control of the aircraft, the higher bandwidth allows handoff data to be streamed back and forth from the aircraft.

By using a cell phone on the plane at the same time as an active transmission during a handoff could delay the intercept data to the new ground center causing a momentary "loss of position" of the aircraft until the signal is received clear enough. A long converstation that prolongs the intercept of the position data to the new control center could put the plane and passengers in harms way if the new controller can not pinpoint its converging location with another aircraft.

At least that is what I thought the main reason why Cell phones were not allowed in flight. The skytel system uses a dedicated transmission channel that is at a different feq then the ground tracking channel.

Fetzer claimed it again tonite on C-span, along with some other questionable claims !!!!! Cell phones were impossible!! This guy has gotta be doing a stand up routine. You can't be that wrong, or funny , by accident. Can you ??????

Originally posted by robertfenix
I was under the impression that most modern aircraft that fly domestic routes and some international routes actually have a type of cell site repeater equipment in the planes aviation electronics package. Its part of the system the FAA uses for tracking and control of the aircraft, the higher bandwidth allows handoff data to be streamed back and forth from the aircraft.

By using a cell phone on the plane at the same time as an active transmission during a handoff could delay the intercept data to the new ground center causing a momentary "loss of position" of the aircraft until the signal is received clear enough. A long converstation that prolongs the intercept of the position data to the new control center could put the plane and passengers in harms way if the new controller can not pinpoint its converging location with another aircraft.

At least that is what I thought the main reason why Cell phones were not allowed in flight. The skytel system uses a dedicated transmission channel that is at a different feq then the ground tracking channel.

Uhm, no they don't. There is no control equipment on planes. They're designing cell antennas for planes, but as of now there is no repeater or cell antenna. The reason that you can't use a cell is because, as was stated, it could interfere with navigation electronics and cause a problem with the plane. Nothing to do with tracking or control or anything else.

The FAA use a transponder system to track planes. It sends out a code that is received by radar that displays on a radar screen.

Hi,

Just from a technical view point and having been a system engineer for Vodafone here in the UK, I can confirm cellphones work on aircraft, only if the basestation repeater can 'hear' the cellphone and vice versa.....but..

Due to the way cellphones are 'multiplexed' digitally there is a maximum range that a cellphone has with the basestation, this range is NOT governed by 'RF' constraints, i.e. how strong the signal is from the cellphone to the basestation, but where the cellphones 'timeslot' is within the 'multiplex-chain' of the data being send/received.

I believe the current maximum distance of GSM cellphones-Basestations is 32Kms.

If the cellphone is further away from the basestation than 32Kms, then the time taken for the radio waves to travel to the basestation is too long and the cellphone misses it's 'timeslot' within the multiplexed-chain, i.e. 'No-Service'.

Doppler effects with regard to RF on aeroplanes is not a factor due to the small 'error difference' of frequency.


If your cellphone is within 'RF' range and you are within 32Kms of a basestation then you will have cellphone service and voice and data calls work.

Just my input,

Best Regards,


TimeSlice.

All , I am trying to get across is ,they work ! While CT "experts" like Jim Fetzer , see C- Span Debacle, keep claiming it is impossible! MYTH BUSTED !!! LOL LOL !!!

Originally posted by Zaphod58

The FAA use a transponder system to track planes. It sends out a code that is received by radar that displays on a radar screen.

exactly. it also sends out the aircraft's speed and altitude data which the radar correlates with its own to give the altitude and speed display that we see on the scope.

once again an excellent job by zaphod.