CEO admits AT&T wasn't ready for Apple iPhone

Sounds like AT&T (T) has been fairly criticized by its Apple (AAPL) iPhone customers for poor network performance.

The telecom giant wasn't quite ready when the iPhone launched, AT&T CEO Randall Stephenson told the audience today at the "D: All Things Digital" conference in Carlsbad, California.

"We're improving," he told The Wall Street Journal's Walt Mossberg, during on onstage interview at the conference. Specifically, he said AT&T is improving network quality and reducing churn.