Where will T-Mobile launch LTE first? Probably in these eight cities

T-Mobile will launch its much-anticipated LTE network next week, but thanks to OpenSignal we’ve gotten what is probably an early preview of T-Mo’s launch markets. OpenSignal collects crowdsourced signal and speed test data from phones all over the country, and a lot of T-Mobile LTE data points have started popping up on its map.

OpenSignal has recorded more than 1,500 signal strength readings in eight metropolitan areas from devices connected to T-Mobile’s network: Denver, Kansas City, Las Vegas, New Orleans, New York City, San Diego, Seattle and the Bay Area. OpenSignal has mapped those signal readings on its blog, though it represents multiple signal readings as single data points, largely to respect the privacy of the testers.

OpenSignal T-Mo LTE test

Though the network isn’t commercially launched, OpenSignal CEO Brendan Gill told me that its crowdsourced app is popular with engineers at all of the carriers for ad hoc network measurements. What we’re most likely seeing, Gill said, is a bunch of technical workers from T-Mobile and its vendor partners that have the OpenSignal app loaded and running on their test devices. A good indication of this is that one of the devices sending data is a Samsung Galaxy S4, which isn’t yet available to the general public.

T-Mobile CTO Neville Ray has already confirmed that its LTE network is complete in Las Vegas and Kansas City, so test data from those cities is hardly a surprise. We’ve also seen evidence of the network in NYC: A GigaOM reader mapped out a cluster of cells in Astoria, Queens, and T-Mobile has given several live 4G demos to reporters in Manhattan.

The other five areas are new, but because of their importance you would expect them to show up early on T-Mobile’s national rollout schedule. OpenSignal recorded the biggest concentrations of tests in San Jose, Calif., and surrounding Bay Area cities like Mountain View, Santa Clara and Sunnyvale. OpenSignal even tracked tests in the East Bay, but recorded none in San Francisco proper.

T-Mobile motorcycle girlThe Seattle area had the second highest concentration of readings, many of them around Bellevue, which just happens to be the location of T-Mobile’s national headquarters. Las Vegas yielded many data points as well, though the signal readings in Denver, Kansas City, New Orleans, New York and San Diego were much more sparse.

OpenSignal also recorded about a dozen speed tests on T-Mobile’s LTE network, averaging an impressive 25 Mbps on the downlink and 8 Mbps on the uplink (though keep in mind that the network is largely empty so there’s no congestion). The speed tests were so few because they must be manually initiated, while OpenSignal’s app takes signal strength readings automatically on a regular basis.

Gill said that he’s fairly convinced that these eight markets will be among the first to launch based on the activity OpenSignal is tracking, though he cautioned that his conclusions don’t constitute a scientific study. The results are dependent on a fairly limited pool of people using OpenSignal’s app, so there are likely many more cities with live LTE networks that the company couldn’t track.