Subscribe to the::unwired's RSS Feedthe::unwired at Twitterthe::unwired on Facebookthe::unwired on Google Plus
the::unwired Article
THOUGHT: The use of Pocket PC Phone Edition on Airplanes
Posted by Arne Hess - on Thursday, 22.08.02 - 21:04:00 CET under 09 - Thoughts - Viewed 7131x
Not Tagged

Several sites like Pocket PC Thoughts and discussed the FAA announcement from USAToday that you are allowed to use PDAs on aircrafts, however I think the FAA missed the point here:

Thought 1: I don't see that that the wireless part of a Pocket PC Phone Edition is/should be allowed to use. The reason is pretty simple; we are talking about a radio module which - and it doesn’t matter if it is used for voice or data - (could) interfere the on-board electronic.

Thought 2: GSM will not work above the clouds. GSM and its antennas is designed to cover the ground. I’ve never seen a BTS which covers the air. You can see this even on skyscrapers in Manhattan. While you have a perfect coverage on ground you are out of coverage on the top levels, if no repeaters are installed. I saw this phenomena even in Hong Kong which is (I think so far) the best covered city in the world. Maybe near windows you will catch the one or the other signal but if you walk into the building you are out of any coverage which doesn’t happens on the ground floors.
So how we could believe that the area in 10.000 meters height is covered?

Thought 3: GSM has speed limits, not only for transferring data but also for transferring the waves. If I remember right, the speed limit for a GSM 900 MHz network is something around 400 km/h while it is something around 250 km/h for GSM 1800 MHz networks and even less for GSM 1900 MHz networks.
As far as I remember from my many flights a Boeing or Airbus fly faster than 400 km/h but for sure faster than 250 km/h only. So even if there would be coverage the handover between the BTS’ wouldn’t work anymore.

When I flew two weeks ago to Paris for a meeting, I’ve used my xda on the way to Paris as well as back to Munich (you might remember my thoughts about Vodafone GPRS roaming in Paris ;-) the flight attendees to Paris was relaxed when I was typing on my Pocket PC. However on the flight back to Munich a flight attendee asked me (more or less rude) to switch of my cell phone and she was right. She was a German woman who saw the TV commercials from o2 that the xda is (also) a mobile phone. And therefore she thought that I’m using my mobile phone during the flight. Also my explanation that the phone part is switched off and I’m using the PDA part only wasn’t clear for her but no attack here from my side because how should she knew what I was doing.

Also I have to confess that one time I forgot to switch off my mobile phone on a domestic flight in Germany. My mobile phones are always configured for manual network search and as you might know, Germany is a pretty good covered county.

So when I’ve arrived that time, the mobile phone asked me to select a new network which means it lost the connection to the original network. This is an indicator for me that there was no coverage available in the sky.

So I would like to ask to switch off your GSM enabled Pocket PC before you entering an aircraft because:

1st: It could interfere the electronic.

2nd: There is no coverage anyhow.

3rd: You would fly faster than the handover/signal works.

4th: I might be in the same aircraft and I would like to arrive safely!

So even if GSM wouldn't interfere the aircraft electronics your GSM device will not work above the clouds. GSM/GPRS is a different technology than Blackberry or Palm VII but a good approach could be "Connexion by Boeing" which I've wrote about some month ago.

Cheers ~ Arne