We put AT&T's new LTE network head to head against Verizon Wireless's network in Houston, TX and found that AT&T's new system is really, really fast.

Watch out, Verizon. There's a new fastest network in town: AT&T's LTE.

AT&T in five cities on Sunday, and PCMag.com junior analyst David Pierce went to Houston, Texas to compare the network to the Verizon Wireless 4G LTE system.

We did eight rounds of testing and found that AT&T's Houston network is even faster than Verizon's. Of course, we're comparing a loaded Verizon network full of Droid Bionics and HTC Thunderbolts to a brand-new AT&T system just out of the wrapping paper. But the results still show that if AT&T takes good care of its LTE system, it's going to be downright screaming crazy fast.

The AT&T network averaged out with about 24Mbps downloads and peaked at 42.85Mbps, the fastest cellular connection we've ever seen. Just as exciting as the sheer download speeds were the connection quality results: Pingtest.net generally rated the network an A or a B, good enough for video chat or gaming.

How We're Testing

We tested in eight locations in central Houston, some of which we pre-checked with AT&T for coverage and some of which we left for surprises. You can see a map of the locations at right (Click to expand).

We're using three tests on a Dell Inspiron Windows 7 laptop to check out the networks. Speedtest.net, which we also used in our feature, gives a solid number for uploads, downloads and the time it takes to reach a testing server (ping). Its sibling Pingtest.net focuses on the streaming experience: whether a connection is good enough for video streaming, VOIP calling, or gaming. That's an area where LTE should do a lot better than other forms of 3G and 4G. Finally, we downloaded the home pages of five different Web sites using the "curl" command-line tool and averaged out both the time until the first byte of the site arrived, and the total download time.

Currently, AT&T has two USB modems (the Momentum 4G by Sierra Wireless and the Adrenaline by LG), a hotspot (the Elevate 4G by Sierra) and a tablet (the HTC Jetstream) able to run on its LTE network. The carrier has no LTE phones yet. And no, you can't use AT&T, Verizon, and MetroPCS LTE devices on each others' networks, as the companies spec out their radios to exclude each others' frequencies. Apparently, they don't want roaming.

LTE service plan prices are the same as 3G, for now.

Why LTE Matters

All the wireless carriers say they have 4G; heck, AT&T said it had 4G before this. But some 4Gs are more "4" than others. LTE is the true next-generation technology all the major carriers are headed towards. It's at least twice as fast as other forms of 4G, and it's one of the major reasons, if not the primary reason, AT&T says it wants to merge with T-Mobile.

To see the difference between LTE and other networks, check out our 21-city tests. It's striking. AT&T's previous 3G network averaged 2.44 Mbps down in our nationwide tests, with a peak of 12.97 Mbps. That's respectable, and that's broadband, but we got more than nine times that average speed in our AT&T LTE tests in Houston.

That enables new uses, like reliable high-definition video calling and streaming. The faster response times mean a lot for social networking and multiplayer gaming. But one thing you can't do is use this as a primary home Internet connection; AT&T's data caps, like Verizon, are just too severe to handle the gigabytes of data home users typically go through in a month. AT&T has said the average user of its home DSL system consumes 18GB per month. At current rates, that would run $180/month for LTE wireless service.

One of AT&T's crowning arguments for the merger is that if it's allowed to merge with T-Mobile, it can cover 97 percent of the country with LTE. If it isn't, it'll only cover 80 percent of the country. Opinions differ rather sharply about what AT&T is actually capable of covering with LTE in its current state, with merger opponents saying that AT&T has more options than it lets on.

For its part, AT&T has put coverage maps on its pro-merger Web site showing what it's pledging to cover with LTE with and without the merger. Almost all of the southern half of Georgia, for instance, only gets LTE if the merger goes through, AT&T says.

Continue Reading: LTE Coverage Maps and More>

Who's Stronger in AT&T's Cities?

This leaves AT&T in an interesting bind with its 4G LTE launch. The carrier insists that it's rolling out LTE as fast as it can, but you can't help wondering if the rollout would be more aggressive if the . After all, if AT&T could easily blanket the USA with LTE all on its own, why should the government approve the merger?

AT&T has just launched five cities, promising to have 15 metro areas covering 70 million people by the end of the year. Verizon, of course, already covers 160 million people—more than half of the U.S. population. Sprint covers 120 million people with its slower 4G WiMAX, and T-Mobile covers over 200 million with its HSPA+ 42 network.

Big Blue's 4G is backstopped by faster 3G than Verizon's, though. AT&T's 3G system is on average three times faster than Verizon's 3G, according to our Fastest Mobile Networks tests, so drops from 4G LTE to 3G won't feel quite as hard on AT&T as on Verizon. Later this week, we'll look more into the current state of AT&T's pseudo-4G, kinda-3G HSPA+ network in New York City.

Comparing AT&T's and Verizon's 4G LTE coverage maps plays pretty neatly into stereotypes of where each carrier is stronger. Texas is AT&T's homeland. The current AT&T grew out of the former Southwestern Bell, headquartered in Dallas. If you look at AT&T's maps for Dallas, Houston and San Antonio, they cover more of those metro areas with LTE than Verizon does.

Atlanta is the headquarters of the former BellSouth, another AT&T component. There, too, AT&T embraces more of the metro area than Verizon does.

AT&T's weakest market so far is Chicago, the former haunt of AT&T component Ameritech. There, Verizon smacks down AT&T's coverage, with Verizon's 4G network extending seamlessly well into Wisconsin and Indiana.

There's a difference in speed and capacity between the AT&T cities, too, a company rep told us: in Chicago it's running on half of the spectrum Verizon is, using paired 5-MHz rather than 10-MHz blocks. (The company has paired 10-MHz blocks in Houston.) AT&T's solution for increasing capacity? Merging with T-Mobile, of course.

Full Reviews Coming

Later this week, we'll have full reviews of the first two AT&T modems as well as the LTE network's speed and pricing. Keep checking back at PCMag.com for more on AT&T's brand-new network.