The iPhone has certainly had an impact on customer's wallets, on Apple's Mac OS release schedule [1] and on competitors like Nokia [2] and Motorola [3]. Now, it seems that the device has also had an impact on AT&T's cellular network. AT&T says that network upgrades go on all the time, but 20,000 new radios seems like a significant change for a single new device. The upgrades are having an impact beyond the iPhone, though--customer churn is low, and customer satisfaction is high. With results like these, the iPhone could prove important to AT&T for a long time to come.

For more on AT&T's network upgrades:
- read the business analysis [4] at WirelessWeek