Anyone remember SXSWi? AT&T's cellular network in Austin was so overwhelmed by the huge number of iPhone users during the conference that it pretty much crashed. In response, AT&T opened up its 3G network across the 850MHz spectrum holdings it owns in Austin to boost capacity during the conference. It's about to do the same thing in NYC, Los Angeles and San Francisco.iPhone users in major cities have complained about the device's poor network reception pretty much since the device first became available. As AT&T continues to make improvements to its network, this has slowly gotten better.

The SXSWi incident must have taught AT&T a valuable lesson. Now that the new iPhone 3GS and its million or so users are signed up and using AT&T's network, the company needs to be able to serve them and their phones.

AT&T is prepared to open up its 850MHz spectrum in New York City, Los Angeles, and San Francisco to relieve the pressure its network is feeling from bandwidth-hogging iPhone users, reports Gearlog. The 850MHz spectrum was heretofore used for AT&T's older cellular systems, but is now being outfitted for 3G action. Once this spectrum goes live in the cities named above, all AT&T users in those areas should see much better performance.

Other steps AT&T is taking is to add some 2,100 new cell sites to areas across the country. These will be used to increase coverage and capacity where it is needed. The company also plans to overhaul its backhaul. That is to say, it's going to make the wired connections that feed traffic from its cell towers to the internet faster and more capable.

I have to wonder if this has anything to do with AT&T's choice to keep MMS inactive on the iPhone 3GS. Will MMS magically go live at the same time these network improvements are lit up? We'll have to make sure we're paying attention...