What in the world is going on over at AT&T with HSUPA service on smartphones? The network is clearly capable of such feats, as evidenced by the iPhone taking advantage of the enhanced upload speeds, yet other phones aren’t able to pull the same kind of bandwidth. Engadget talked to an unnamed source with knowledge of AT&T’s technical infrastructure, and offers an explanation of why some smartphones get HSUPA speeds, why others that seem capable don’t, and when we might expect the situation to be taken care of.

According to the tipster, the problem lies with the protocols AT&T mandates phones use when setting up a wireless network connection. The version of the 3GPP standard being used for nearly all its phones, including the latest Android smartphones like the Inspire 4G, includes HSDPA but not HSUPA. Supposedly, the iPhone is the only AT&T smartphone using the next revision of 3GPP, adding HSUPA support.

That would explain the lackluster upload speeds, but it doesn’t address why AT&T would do such a thing. Either it’s worried about the strain that more upload bandwidth would place on its infrastructure, or maybe it’s really trying to emphasize the iPhone’s performance above that of other smartphone offerings.

Now, for some good news, that same source thinks that AT&T is in the process of upgrading its procedures to call for phones to use a more recent 3GPP revision, adding the missing HSUPA for hardware that supports it. The source estimates that the change could go down within a month or two. Presumably, then AT&T would update affected phone firmware to let the devices perform at full speed.

AT&T hasn’t made any official statement regarding these accusations.

Source: Engadget