updated 03:45 pm EST, Wed February 23, 2011
ATT said allowing HSUPA only for iPhone 4 so far
AT&T's apparent disabling of HSUPA 3G on some of its phones may have been a temporary measure that didn't affect the iPhone 4, insiders suggested on Wednesday. The carrier so far reportedly requires just regular HSDPA, without the faster upload speeds, on its network and thus can't guarantee that the Atrix 4G, Inspire 4G or any other phone would connect properly. The iPhone 4, and most likely 3G modems, were given special exemption to the rule to run at full HSUPA rates, Engadget understood.
The motivation for the selective speed grants wasn't clear. AT&T may have been concerned about oversaturating the network and intentionally limited the faster speeds to those devices where the effect would be the most public or demonstrable. As the iPhone has been AT&T's most popular cellphone by a wide margin and has often been used for speed tests, showing a tangible improvement may have been more important than for someone using a Samsung Captivate.
No matter the reason, AT&T is expected to grant permission for all HSUPA-capable devices in a "month or two" and isn't thought to have given Apple special access in an attempt to make it look more favorable. Representatives from the carrier have occasionally told users that the '4G' network isn't live even in areas which directly support HSPA+ and may have been confused when told that the full specification wasn't available.
AT&T hasn't confirmed or denied the limitations.