“Switching more spectrum to the 3G network lets AT&T carry more calls and transfer more data. The ‘3G on 850’ upgrade is designed to improve voice and data call quality in areas where AT&T’s network was overloaded with heavy users (mostly on iPhones) or where higher-frequency 1,900-MHz radio waves have trouble penetrating buildings. In New York, San Francisco and many other places, AT&T owns a large 25 MHz chunk of valuable 850-MHz spectrum,” Segan reports.
AT&T is also “upgrading its 3G network to a faster version called HSDPA 7.2 that should provide higher data speeds. That upgrade will start at the end of this year and run through 2011,” Segan reports. “Currently, the iPhone 3GS is the only AT&T phone that supports HSDPA 7.2.”
Full article here.