Realistically, most Americans won't have a chance to enjoy the full spoils of T-Mobile's shiny new 21Mbps HSPA+ network any time soon, but hey, at least they appear to be making solid progress. In a recent chat with GigaOM, T-Mobile's VP of engineering Dave Mayo has said that the requisite software for HSPA+ service is already rolled out to cell sites along the California coast and in major cities between Washington, DC and Boston, but like AT&T, it's not the software that's the concern -- it's the width of the backhaul pipe. The company says that it's got 20Mbps fiber connections to just 7 percent of its cells presently but plans to rapidly expand that to around 25 percent "within the next few weeks." Ultimately, that's going to be the key for every carrier around the world that's deploying 3.75 to 4G networks -- the cells themselves might be easy, but getting enough data piped to them is another story altogether.

[Thanks, Burnside]