The company told newswire Reuters that the problem, which caused some users to not be able to surf the Web on their phones, was fixed just before noon on Wednesday. The problem did not affect phone calls, text messages or mobile e-mail from devices such as Research In Motion's BlackBerry.
A company spokesman told the news service that it was a "routing issue" that affected how data is delivered to and sent from devices. The spokesman declined to provide more details about the cause of the service issues.
AT&T subscribers in the Midwest and Southeast experienced similar problems accessing 3G (third-generation) and EDGE data services on AT&T's network in January. And there were reports in July 2007 of trouble accessing 3G and EDGE data services.
Since the iPhone 3G was launched in July some subscribers have complained of poor reception. At first, neither Apple nor AT&T would admit to any problems. But after persistent complaints on blogs around the world, Apple finally relented and released a software update for the iPhone 3G that was supposed to fix the problems.
While it's difficult to pinpoint the precise cause of these issues, many industry experts have hypothesized that it's likely a combination of the iPhone's hardware and software and how it interacts with the various 3G networks it operates on throughout the world.
AT&T is the exclusive carrier for the iPhone in the U.S. And although it boasts that it has the fastest 3G network in the nation, its coverage footprint is not as extensive as that of competitors such as Verizon Wireless and Sprint Nextel. This means that 3G phones such as the iPhone 3G likely switch between the 3G HSPA network and the 2.5 EDGE network more frequently than on some other 3G networks. And problems are more likely to occur during these handoffs, industry experts say.