AT&T is blaming the iPhone 4's sluggish upload speeds in some areas of the country on 3G wireless gear from supplier Alcatel-Lucent.
On Wednesday, AT&T issued a statement saying a software glitch in the Alcatel-Lucent equipment is limiting data upload speeds from smartphones and data sticks using the latest version of 3G technology known as HSUPA. HSUPA is an acronym for High Speed Upload Packet Access. It increases upload speeds to between 500 kilobits per second and 1.2 megabits per second.
"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," said Jenny Bridges, a spokeswoman for the company./p>
Since the iPhone 4 is currently the only smartphone that AT&T offers that is using HSUPA, AT&T said that the problem only affects a small number of its wireless customers, which includes some laptop data stick users, who also use the HSUPA technology. AT&T said the company has come up with a temporary fix that should restore upload data speeds to regular 3G speeds. This means that upload speeds will likely have a maximum speed of 384Kbps until the problem is completely resolved.
"This impacts less than 2 percent of our wireless customer base," Bridges added in her statement. "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."
The problem surfaced over the weekend when iPhone 4 customers started noticing that their upload speeds had slowed to a crawl. People who were previously getting uploads of 1.7Mbps last week, reported that speeds dropped to under 100Kbps. The slowdown affected made it difficult for people to send e-mails and upload or send videos and pictures.
AT&T doesn't use Alcatel-Lucent gear in every part of its network, which explains why the problem only occurred in select regions of the country, such as, New York, Philadelphia, Washington D.C., Salt Lake City, and Seattle.
The upload problem is just the latest in a long line of performance issues that AT&T has faced since it became the exclusive carrier for the iPhone in the U.S. in 2007. AT&T has acknowledged that the heavy data usage from iPhone subscribers has put a strain on its network. Apple has also hit a few snags recently. After the iPhone 4 was released in June, customers complained of poor reception when the phone was gripped a certain way. Apple acknowledged the issue and told customers not to hold it that way. Then just last week, the company admitted that it has been miscalculating how it represents signal strength bars on all of its iPhones.