Which of the four major carriers has the fastest LTE service in the U.S.?

Wall Street Journal tech scribe Walt Mossberg decided to run his own tests to see which of the four major stateside carriers had the fastest 4G LTE service. Mossberg himself admits that this was far from a scientific study as it consisted of Mossberg testing data speed from one coast to the other with four different versions of the Apple iPhone 5s. Each of the four units was connected to one of the top four U.S.mobile operators: Verizon, Sprint, AT&T and T-Mobile. Mossberg ran the test in three locations. One was a Maryland suburb near Washington D.C. The second test location was in Manhattan while the third was in Silicon Valley.

The winner of Mossberg's informal testing was...drum roll please...AT&T. The mobile operator managed to produce an average download speed during the three tests of 19.7 Mbps. But it was the test in New York City that helped AT&T take the crown. In the Big Apple, the nation's second largest carrier blew away the other three with a 34.8 Mbps speed test. Outside of that one area, AT&T finished third in Maryland and dead last in Silicon Valley.

The most consistent performer was the one that finished second as Verizon averaged 16.7 Mbps. Big Red didn't finish first in any of the three locations, but managed to stay between 15 Mbps and 18.6 Mbps during the testing. T-Mobile finished third with an average score of 13.5 Mbps and even finished first in Maryland with a 19.5 Mbps tally. Mossberg found that his T-Mobile branded iPhone 5s took the longest of the four to find and lock onto an LTE signal.

Sprint finished last with an average speed of 10.4 Mbps. Had the operator not won in Silicon Valley with a reading of 20.7 Mbps, the average speed would have been much lower. Mossberg relates that in two cities, he had to travel away from the testing area to find a Sprint LTE signal. But this could soon change as Sprint has started slowly testing its tri-band LTE service called Sprint Spark. With the tri-band LTE service, the circuitry on the user's handset decides in the blink of an eye, which of the three LTE bands is perfect for a particular task.
 
Because LTE data speed can vary depending on the amount of traffic in the area at a certain time, we really can't take away too much from Mossberg's test, especially when  the winner relied on one high scoring city to bail it out. Ironically, AT&T's signal in New York was called "crap" earlier this year during CES in Las Vegas, by none other than T-Mobile CEO John Legere.
source: WSJ