7.2Mbps AT&T wireless coming to six cities by end of 2009

Wireless network speeds have been improving about as slowly as wired network speeds have, but progress is finally on the horizon. The latest news: AT&T will be rolling out High Speed Packet Access 7.2 (aka HSPA 7.2) in six cities this year, with a rollout to "90 percent of its existing 3G footprint" by the end of 2011.

HSPA 7.2 is an upgrade to existing 3G networks that allows for -- theoretically -- a doubling of the speed of the network, to a 7.2Mbps download speed. In the real world you won't get performance this extreme, but you should see a healthy bump if you access the network on your existing 3G device if it supports the 7.2 standard -- such as the iPhone 3GS. Note that the previous model iPhone is limited to the slower 3G network.

The six lucky cities to get HSPA 7.2 this year will be Charlotte, Chicago, Dallas, Houston, Los Angeles, and Miami, and service will be limited at first as upgrades are completed. AT&T also says it will be offering more HSPA 7.2-compatible equipment by the end of the year, including both cell phones and laptop data cards.

In a nutshell, HSPA 7.2 is a stopgap technology on the road from 3G to 4G. AT&T has thrown its lot in with a 4G technology called LTE, which could theoretically offer download speeds in the hundreds of megabits per second (though that's unlikely in its finished format). But while LTE is promising, it's still likely years off (2011 at the earliest) as far as real-world deployments go. By comparison (and to set expectations), LTE's major competitor, WiMax, has faced roadblock after roadblock, and while it has crept onto the market in a few cities, real-world performance has not proven much better than existing 3G technologies.

HSPA 7.2 is probably the end of the line for 3G technology before some form of 4G technology like LTE hits the market, so if you're considering an AT&T handset -- particularly if you have heavy data requirements -- you're well advised to hold off a month or two until HSPA 7.2-compatible gear arrives.

Or, of course, get an iPhone 3GS.