When Apple Chief Operating Officer Tim Cook discussed the company's

When Apple Chief Operating Officer Tim Cook discussed the company's just-announced estimate-busting earnings, he spent a moment defending one of Apple's less popular partners, AT&T.

The very first question during this afternoon's analyst conference call addressed AT&T's continuing deal to serve as the exclusive carrier for iPhone owners in the United States. Since AT&T's network service is the subject of frequent complaints, Piper Jaffray analyst Gene Muenster asked what Apple is getting out of that deal. Cook answered by arguing that AT&T is handling "more mobile broadband usage than any other carrier in the world."

"In the vast majority of locations, we think that iPhone customers are having a great experience," Cook said, adding that AT&T has committed to improving its network. "We have personally reviewed these plans and we have very high confidence that they'll make significant progress towards fixing [the problems]."

Cook's remarks don't rule out the possibility that Apple will move away from AT&T exclusivity this summer (when there are rumors that the iPhone will join Verizon's network as well), but they're certainly more diplomatic that the barely-veiled swipes that Apple representatives made at AT&T on-stage at the Worldwide Developers Conference last year.

[Burning cell tower via weepnews.]