AT&T looks like it doesn’t want to let T-Mobile gain any ground on it, and now AT&T has finished the software upgrade of all its 3G cell sites across the US. The deployment was mainly to improve the consistency of data access to subscribers, and adding support for 7.2Mbps 3G, a step up from the current 3.6Mbps, though the carrier will need to complete a series of backhaul hardware upgrades before subscribers will actually see realistically faster speeds. Hopefully these upgrades will help AT&T cope with the demand on the network that is chalked up by iPhone users, though we’ll have to check and see if subscribers feel any difference.