On Tue, 20 Apr 2004 20:59:28 -0500, FUji wrote:

Even though it is theoretically possible to overload the processing
capability, I doubt that it is really a significant problem in the real
world.

It happens on the time. Capacity planning is part of their job. It's
just that proper planning by the various carriers tend to hide this fact.


For example, a group of people standing at the top of the CN Tower using
their phones would be line-of-sight to almost every cell tower in the
Toronto area. The system would select the best tower and lock on.

Right, which means they are not changing towers and are only using the
resources of a single tower.


A better example that includes moving: People on their phones driving
through downtown NYC. A densely populated area would need more towers with
closer spacing. With all the buildings acting as giant reflectors we now
have multipath signals from many towers as well as phones. If the system
can lock onto thousands of phones under these conditions, a couple of 747's
with about half of the people on phones would be minor.

That's really part of a capacity planning issue, IMO. If you were to
figure out the average call density, it would probably be fairly sparse.
After all, only so many cars can fit in a given area. Now then, if you
have a plane with 250 people and half those are using their phone, that's
an extra 125 calls on each tower that is now suddenly passing from tower
to tower. That's a HUGE difference in capacity in a very short period of
time.


As some pilots who used their phones in the air have reported, they have to
lower their altitude to get a signal. Regardless of what the reports say,
hitting twenty towers with such a low wattage is highly unlikely.

If it's reasonable to assume a ground based user can get two to three
towers at any given time, I don't think it's hard to easily imagine two,
three or even four times that since you're in the air with much fewer
obstructions (less scatter, direct, and father los), especially since
there is a much higher chance that your phone is operating at or near its
maximum output. Granted, chances are you not in a rural area if you're
hitting that many towers. But, just for the sake of argument, let's say
it's less. Is using use two or three times your normally alloted capacity
fair on the carriers? With enough phones in use at any given time, I can
easily imagine it playing heck with their capacity planning.