Apple introduced its new 3G iPhonethis week, and at least one commentator is questioning whether the AT&T infrastructure will be able to handle the increase in data traffic that is sure to follow.

Well-known blogger Om Malik had an interesting post Sunday where he points out that last year's introduction of the 2G iPhone caused traffic to swell on AT&T's network. He notes that iPhone users are more likely to use the data capabilities of their smartphones than other smartphone users are.

Malik goes into more detail, but basically he reasons that 3G will give those iPhone users less incentive to wait until they can get a Wi-Fi connection before using the Web. If traffic shifts to 3G instead, you could see a bit of "stress" on those networks.

On the back end, any carrier supporting the new phone is going to have to deploy robust backhaul infrastructure, possibly Ethernet microwave, Malik notes.

So, AT&T has its work cut out for it, though it maintains it is up to the task. Last week it announced it had upgraded its 3G network. And it has had plenty of time to prepare for it, since a 3G iPhone has been discussed for at least a year. So far, the company's 2G EDGE network has performed pretty well, with the occasional exception.

It's no wonder that Ethernet microwave is the fastest-growing metro Ethernet technology. It is used for 55% of the world's mobile backhaul connections, according to Infonetics. 

On a related note, Apple's U.K. partner was reported in February to be working on femtocell deployments to anticipate a 3G iPhone surge in traffic. 

Jeff Caruso is site editor at Network World.