Even though AT&T's already committed both carrier and backhaul upgrades
in an effort to buck the butt-of-the-joke trend it's been experiencing for the last couple years, there's some evidence that it's a recent trend in the way phone radios operate -- not a lack of overall capacity -- that should shoulder at least some of the blame for the issues. An O2 staffer (O2 carries the iPhone and has coincidentally experienced many of the same growing pains AT&T has in recent months) that reached out to Ars Technica
says that Apple's baby was one of the first widely popular phones to immediately drop data connections as soon as transfers were complete and re-establish them only when needed; that tactic saves battery power, but can overwhelm cell sites pretty easily if they're not configured to handle it -- even if there's plenty of spectrum and backhaul available. Other handsets now employ the same strategy, compounding the problem. This seems like an awfully odd thing to miss during carrier testing, but who knows -- we wouldn't put it past anyone to gladhand the iPhone through the toughest parts of the gauntlet.