Whose Wireless is the Fastest of Them All?

As mobile streaming grows, data speeds are increasingly the biggest measure for wireless carrier performance. AT&T (NYSE:T) and T-Mobile were the respective winners of 4G and 3G download speeds in a recent country-wide test that ranked Sprint (NYSE:S) the poorest for both network levels. AT&T’s 4G network download average was found to be the fastest, though Verizon’s (NYSE:VZ) LTE network was slightly better in upload speeds, according to the tests conducted by PCWorld indoors and outdoors and at multiple locations in 13 major American cities.

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T-Mobile won both uploading and downloading tests when it came to 3G. Sprint fell short of its competitors in 3G and 4G and for uploads as well as downloads. In fact, its 4G network, which runs on WiMax, was even slower than 3G speeds for some of the other carriers.

AT&T clocked average download speeds of 9.12 megabytes per second on 4G LTE, while Verizon came in at 7.35 mbps and T-Mobile averaged 5.53 mbps. Sprint, which is now in the process of transferring its WiMax network to LTE, fell way short at barely 2.81 mbps. Among 3G download averages, T-Mobile did the best with 3.84 mbps. AT&T was second at 2.62 mbps and Verizon came in next at 1.05 mbps. Sprint only managed a shoddy average of 0.59 mbps.

While AT&T beat Verizon in the two most important categories, the problem remains that Verizon has a larger network with wider 4G coverage. That may be why Verizon sold the vast majority of new 4G iPads. If AT&T can expand its network while keeping up speeds — that’s what it was trying to do with its failed T-Mobile buy — then it might be able to steal back some smartphone customers it has lost to Verizon.

The Washington, D.C. area best reflected the nationwide averages for 4G speeds. The tests also found that average 3G speeds had gone up across the board from last year. Led by Apple (NASDAQ:AAPL) iPhones and Google (NASDAQ:GOOG) Android-powered devices, data-consuming smartphones now account for half of all mobile phones in the country, according to data by Nielsen.