Wireless network operator AT&T's 4G Long Term Evolution (LTE) network speed was clocked at 18.6 megabits per second, offering the fastest pure LTE download speed of any carrier and outpacing Verizon's mark of 14.3M bps for LTE-only downloads, according to a report by Root Metrics.
Across its LTE markets, AT&T averaged a maximum download speed of 57.7M bps and a maximum upload speed of 19.6M bps, according to Root Metrics, which based its study on more than 725,000 data samples gathered while visiting the top 77 U.S. markets in the second half of 2012.
Verizon recorded a speedy 14.3M bps for LTE-only download, complemented by a fast 8.5M bps for LTE-only upload. In their maximum speed tests, Verizon averaged 49.3M bps for maximum download speeds and an "extremely fast" 19.7M bps average for maximum upload speed.
"Verizon's advantage in being the first major carrier to market with LTE clearly shows when comparing the size of LTE footprints," the report said. "At 93.2 percent, we had a better than nine out of 10 chance of accessing their LTE service. If the likelihood of connecting to an LTE network is your primary concern, Verizon continues to be the leader at this point."
Sprint's LTE speeds lag those of AT&T and Verizon, averaging 10.3M bps for LTE download and 4.4M bps for LTE upload, but the report noted those speeds are faster than what Sprint publicly claimed they would be. However, Sprint's LTE coverage remains limited, both at a national level and within markets that are LTE-enabled.
"We were able to access Sprint's LTE service in 50.2 percent of download tests in the five cities in which we were able to test their LTE network," the report said. "Sprint's smaller footprint isn't a surprise for a carrier at the very beginning of an LTE rollout, and this limited footprint could increase substantially in 2013."
Of the four major network operators, T-Mobile is the only one that didn't offer LTE in 2012. However, the report noted T-Mobile's HSPA+ 42 network continues to turn in impressive download speeds, while they struggled with upload speeds.
"LTE, coupled with HSPA+ 42, could create the fastest combination around. We'll be very interested in seeing what speeds T-Mobile can offer with LTE and how long it will take for their footprint to catch up to the carriers who have a head start on LTE rollout," the report said.
Root Metrics also conducted what it calls "the bucket test," which shows how often a carrier's speed fell within three different buckets, representing three different consumer experiences. In the second half of 2012, AT&T and Verizon ran neck-and-neck when comparing results calculated over each carrier's LTE markets.
Verizon's extensive LTE footprint, though, once again helped the carrier pull away in the overall race. While Verizon offered LTE in all 77 of the survey's markets, AT&T provided LTE in 47 of those same 77 markets and their speed bucket results dipped considerably in their non-LTE markets.