Originally Posted by sixmilehighclub
Why is that relevant CHD? It's not the phone ringing that causes interference (that affects electronics more than avionics). It's the handset searching for a signal that causes the inteference as it tries to communicate with any thing thats transmitting in range at the time.
Forgive me, sixmilehighclub, but that's a load of old toffee. Electronics, avionics, what's the diff?
Also the phone does NOT try to "communicate with any thing thats transmitting in range at the time" -- that really is absolute nonsense. It LISTENS.
Phones are operating on 850MHz through to 2.1 GHz. That means the transmit frequencies are well above that used for conventional avionics and aircraft communications. Harmonic products from these frequencies fall at higher frequencies.
Differing systems are used worldwide. GSM (as in the UK, Europe and much of the world) uses digital encoding time-division multiplexing on 900Mhz, 1800MHz and 1900MHz (in North America). Other systems use CDMA (code division multiple access) which is a low-power spread-spectrum system). 3G uses wide-band CDMA at 2.1GHz.
None of these systems is at all likely to interfere with aircraft systems such as VORs, ILS, ACARS or whatever. Doesn't screw up your laptop, digital watch, microwave oven, television or whatever does it? Doesn't even screw up the phone of the person next to you, even though that's using the same waveband. Not likely to screw up a $150m aircraft then, surely?
What happens when an airplane is autolanding within 100 yards range of several airport based 100 watt cellular towers carrying hundreds of calls? No problem. Why would a 500mW cellular phone make it crash and burn?
The answer, of course, is that it doesn't.
Now, before you all leap down my throat, I obey the rules and instructions given me by CC even though I know it's all complete nonsense.
But rules is rules.