Re: Headset & FCC
Mike Perry <dmperry1012@...>
Several comments re cell phones:toggle quoted messageShow quoted text
1) My first flight instructor always carried a cell phone and said she had
used it exactly once to land in controlled airspace with radios out. I
don't remember the details.
2) "cell phones" include both analog and digital; digital includes at
least a couple of protocols. The protocol Verizon uses is called CDMA; in
this system every tower sends out a brief time signal several times per
second; the cell phone decides which signal is best and sends out a signal
each second "this is who I want to talk to." The system routers then
decide which signals to ignore. The problem with signals hitting too many
towers is system overload: the system knows which signals to pay attention
to and which to ignore but you still have to filter out the extraneous
signals. However, this is far easier with digital than analog signals.
3) One problem with digital cell phones is that they will revert to analog
under some conditions. This "feature" allows you to get some signal in
areas that only have analog service (eg: some resort areas here in
California have a single analog cell tower just for the town or
resort). See Craig Steffen's comments below re analog cell phones in the
My son once worked on a software project for a cell phone system; I picked
up bits and pieces of info on the protocols.
At 08:55 AM 11/2/2006 -0600, you wrote:
Quoting FR Jones <<mailto:seabeevet%40gmail.com>seabeevet@...>:Shooting from the hip on this, two issues come to mind. First, why wouldAs has already been pointed out here: