Alright I've been wondering this for a while, how does 3G work? Is it like a pool that each device take a piece of? Or does the number of users have no effect on your individual signal strength? The reason I ask is because I have a consistent 4 to 5 bar's on 3G. But I live in an area (Tulsa, Ok.) without alot of people walking around using BB or iPhone's. I know that sound's like a dumb question, but with all the problem's with the 3G I've been wondering that for a while.
Actually, yes, in the case of 3G, more users can have an effect on coverage, and a heavily loaded cell site will have an effectively reduced range. The effect is called
cell breathing.
It's kinda technical, but basically, the 3G works is all users (or at least large groups of them) share a common carrier signal. Think of it as a whole bunch of people talking in the same room. The more people that are talking, the louder the background noise and the harder it is to hear the person you're actually trying to talk to. Since everyone is trying to talk to the cell tower, at the center of the "room," the people closer to the cell site will be able to "hear" it a bit better in this noisy environment, and the cell site will hear them better, too.
It sounds chaotic, but in practice, you can actually fit more callers on a cell site using the 3G method than you can with 2G GSM. it's also why usually, having 2-3 bars is nothing to get annoyed about, because it's still pretty unlikely your call will drop. When you get down to one weak bar though, then things can go pear shaped, like the OP has figured out.
The other thing to note about this is that 3G was
meant to be well-built out to work properly. Cells are
supposed to shrink because there are supposed to be cells overlapping each other, and taking over for one another as cells shrink. This is a load balancing effect, and this is why Verizon works out really well for a lot of people: they use a similar technology and have spent a over a decade getting it right.
Unfortunately, AT&T is kinda in the same boat Apple is: everyone wants them to rush the product out
now, and then everyone raises a stink when the product is buggy because it's been rushed. AT&T rushed the network in a lot of places, and so it's spread extremely thin in the newer spots. The good news is, it DOES get better. Where I live, 3G was pretty horrid last year before I got my first iPhone. It's improved a lot a year later.