In addition to the speed results, you can see the results of our "behavioral" tests, which are meant to closely approximate the wireless usage of real people. At each of our testing locations, our field researcher loaded a 100KB static Web page and viewed a 1-minute video while connected to each of the 3G and 4G services of the carriers. For each one, the researcher logged the time the Web page took to load, as well as the time necessary to stream the video.
In Video: Demystifying Spotty Cell Phone Coverage
You can see a lot of variance in the performance scores from location to location within our testing cities. The same service may deliver radically different results in two locations in the same part of town. Or two different wireless services might produce very different connection speeds and call quality at the same location.
That’s because a number of variables are constantly affecting the quality of the wireless service you get--factors such as nearby physical structures, your distance from a cell tower, whether you're connecting from indoors or outdoors, the time of day, and the total number of users connecting to a nearby cell tower at the same time.
Such variables are important to remember when you're selecting a cell service. Keeping them in mind is also key when you're choosing a device, because some phones and tablets do much better than others in challenging cellular environments.
Quick Facts by City
Atlanta: T-Mobile had a strong showing in Atlanta on the 3G side, with average download speeds at 4.53 mbps and uploads at 1.93 mbps. In 4G, AT&T showed the fastest average download speed of any carrier in any city we tested, at 11.60 mbps. Verizon had its next-to-worst 4G download showing in Atlanta, at 6.24 mbps on average.
Boston: T-Mobile clocked the fastest 3G speeds in Boston, while AT&T won on the 4G side. Both AT&T and Verizon delivered solid download averages, at 8.60 mbps and 7.24 mbps, respectively. Sprint's WiMax service performed unusually well in Boston, averaging 3.90 mbps for downloads.
Photograph by Robert CardinChicago: AT&T finished first in average 3G download speed (3.45 mbps), despite the fact that its 3G numbers weren't great in Chicago compared with its performance in other cities. AT&T also had the fastest average 4G download speed (9.70 mbps).
Dallas: AT&T's best numbers came in Dallas, with an average 3G download speed of 3.73 mbps and an average 4G download speed of 10.22 mbps. Meanwhile, T-Mobile's HSPA+ 21 service registered 13-city worsts for average download rate (2.62 mbps) and average upload rate (0.45 mbps).
Denver: Verizon had the top marks in average 4G download speed (6.68 mbps) and average upload speed (3.70 mbps). T-Mobile's HSPA+ 21 service rolled past its rivals on the 3G side, with solid averages for downloads (3.59 mbps) and uploads (1.53 mbps).