AT&T Blames 'Software Defect' for Slow iPhone Upload Speeds

One day after mobile phone blogs lit up with accusations that AT&T had begun capping upload speeds for the iPhone 4, the iPhone's exclusive network partner is moving to dispel the rumors, saying instead that it found a minor software problem in its network equipment and a fix is in the works.

As well-received as the iPhone 4 has been with the public, selling 1.7 million iPhone 4 units in the first three days of release, it's had some real headaches when it comes to signal reception. First came reports of the "death grip," where radio signal strength would drop when the iPhone was held a certain way. Apple (NASDAQ: AAPL) has since said the "death grip" problem is a software issue and plans to issue a fix shortly.

Just days later, however, new reports of trouble began on the MacRumors forums, where users noticed their upload speeds were capped at about 100 kilobytes per second. That would have been slow for an EDGE network, not to mention the 7.2 megabits-per-second 3G network AT&T (NYSE: T) has.

In response to the reports, which were soon picked up around the blogosphere, people around the country began benchmarking their iPhone 4 with a bandwidth speed tester called Speedtest, which can measure both 3G and Wi-Fi download and upload speeds. A number of users from major metropolitan areas posted screen shots demonstrating sub-100kbps upload speeds, although download speeds seemed relatively unaffected.

Meanwhile, other users have reported seeing no trouble with their upload speeds, posting Speedtest screen captures to prove their point. (InternetNews.com's own tests in our Foster City, Calif. offices about 30 miles south of San Francisco showed download speeds on par with normal behavior).

However, while initial response to the reports had centered largely on speculation that AT&T had begun capping users' upload speeds, the company -- along with AT&T's wireless equipment provider Alcatel-Lucent -- pointed the finger squarely at a technical problem while downplaying its severity.

"AT&T and Alcatel-Lucent jointly identified a software defect -- triggered under certain conditions – that impacted uplink performance for Laptop Connect and smartphone customers using 3G HSUPA-capable wireless devices in markets with Alcatel-Lucent equipment," AT&T said in a statement. "This impacts less than 2 percent of our wireless customer base. While Alcatel-Lucent develops the appropriate software fix, we are providing normal 3G uplink speeds and consistent performance for affected customers with HSUPA-capable devices."

Apple, which has not commented publicly on the issue, did not respond to a request for comment.

Will Stofega, program manager for mobile device technology and trends at industry researcher IDC, takes AT&T and Alcatel-Lucent at their word for the software problem being the culprit. However, he thinks the outcry reveals a bigger problem: smartphone users' mentality that because they have a device with the power of computer in their hands, it should be expected to perform like one.

"There's a finite limit to what we can put over the air. Even with technical improvements, at the end of the day, you can't have people watching YouTube videos all day on their phone," Stofega told InternetNews.com. "It's similar to the broadband situation. Once the genie is out of the bottle, try to put it back in. Everyone's been taught, especially in the U.S., is you are entitled to [unlimited bandwidth] and you can get as much as you want. That's not feasible from an economic standpoint or a physics standpoint. There's going to come a day of reckoning sooner or later."

Andy Patrizio is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.


iPhone, Apple, 3G, AT&T, mobile device