AT&T network not ready yet for all Apple iPhone 3G S functions

NEW YORK -- AT&T's wireless network is having a hard time keeping up with the Apple iPhone, a top wireless analyst says.

But when the list of global carriers offering the features was unveiled, AT&T wasn't on it. AT&T is the exclusive U.S. distributor.

AT&T says it plans to offer MMS "by the end of the summer," but it has so far declined to say when tethering might become available. As of Tuesday, that was still the case. The 3G S goes on sale Friday.

"Tethering will be available at some point," AT&T spokesman Mark Siegel told USA TODAY.

Meantime, iPhone users are gobbling up AT&T's network capacity at a record clip.

According to Entner, the average iPhone user eats up around 400 megabytes of capacity each month. Average smartphone usage is 40 to 80 megabytes.

Entner says the high usage is a testament to the power and popularity of the iPhone. "People really love that device and are using it intensively."

And network demands are only going to increase as pricing on the current iPhone 3G drops to $99, he says.

Part of the problem is due to iPhone's engineering. The device constantly checks back with the AT&T network, he says, making adjustments as necessary. The iPhone's "chatty" nature is one reason it performs so well. But the back and forth also eats up a lot of network capacity.

AT&T has more than 7 million iPhone users, Entner estimates, more than any other carrier in the world.

As a result, he says, "No other wireless network, in the United States or elsewhere, is nearly as loaded" as AT&T's.