By PETER SVENSSON, AP Technology Writer - Wed Sep 9, 2009 11:49AM EDT

Chicago, Dallas, Houston, Los Angeles, Miami and Charlotte, N.C., will be the first cities to see the benefits of AT&T's plans to double the data download speeds on its wireless network. The six cities will be upgraded before the end of the year, the carrier said Wednesday.

The iPhone 3GS is the only phone on the market now that will be able to take advantage of the speed increase. But AT&T pointed to five other "smart" phones and some USB dongles, which let laptops go online, that will go on sale before the end of the year. Those devices also will be able to take advantage of the new technology, known as HSPA, or High-Speed Packet Access.

IPhone users have complained of slow data service that appears to be the result of congestion on the wireless network, something the network upgrade could alleviate.

»tech.yahoo.com/news/ap/20090909/···at_t3g_2