AT & T is hitting the Windy City like a hurricane. At several sites in downtown Chicago, we tasted 537Mbps with a Samsung Galaxy S9.
We used a regular retail phone, standing on an ordinary street using the public network. This is not a test site. Our AT & T experience makes for a single T-Mobile LAA site in midtown Manhattan, and it shows that high-speed competition is heating up in major US cities.
LAA, or Licensed Assisted Access, let wireless carriers use 5GHz unlicensed spectrum (considered by most people to be Wi-Fi spectrum) as part of their LTE networks. It's being installed by AT & T, T-Mobile, and Verizon, and slowly spreading across the most congested parts of major cities.
This is an urban solution, because the LAA spectrum does not travel very far. The four-cells we checked out in Chicago had radiuses of about 150 feet to 400 feet, which is on par with some of the big public Wi-Fi solutions we've seen. Also, like Wi-Fi, it is not very good at penetrating walls.
AT & T is rolling out LAA and gigabit-class 4G technologies in several cities. LA, in the at least 24 cities in 2018.
We achieved our smashing result by the aggregation of 15MHz of LTE Band 2 spectrum , the old 1900MHz band, with 60MHz (three 20MHz carriers) of LAA.
The LAA small cell sites in downtown Chicago (above) fit on light poles. Made primarily by Ericsson, they consisted of a black cylinder at the antennas, and a larger black box about halfway down holding the radio equipment.
The four sites in Chicago showed different performance based on their level of congestion. According to AT & T, they're part of a C-RAN setup, which links together a bunch of small cell sites. That's much easier to set up than if you had to give every site to the Internet, but it can be spread across a whole C-RAN unit.
At Kinzie and Dearborn in River North, we averaged 273Mbps down. At the second site, by the Merchandise Mart, a little ways away, we hit an average of 424.2Mbps. The third site, in the South Loop, averaged 468.6Mbps (including that one 537Mbps result), and the final site, also in the South Loop area, showed 290Mbps.
Above: Our Ookla Speedtest.net results on our Galaxy S9; a service mode screen showing the LAA Band 46 connection.
LAA improves downloads a lot. Uploads still run on the dedicated LTE spectrum: we got between 33 and 43Mbps down on all of the sites. The LAA sites also showed better latency than most LTE sites, by a few milliseconds.
Who needs 537Mbps on their cell phone? No one. In this case, the speeds are a proxy for capacity. If our single device could get 537Mbps, that means 10 devices will chug along at a happy 50Mbps each without choking up the cell or the spectrum.
You'll need an LAA-compatible phone to run in this fast lane. That means a Samsung Galaxy S8, Note 8, or S9, their variants, a Motorola Z2 Force Edition, or an LG V30. Most notably, no iPhone has LAA.
Speedtest results on an iPhone X.
With iPhones, AT & T, we have an unlocked (Qualcomm model) iPhone X in the same locations. We got 92Mbps, 93Mbps, 201Mbps, and 173Mbps downloads, respectively. The fastest single result was 205Mbps. That's all pretty fast, but it's a fraction of the speed and capacity of LAA brings. So as these sites build out, iPhones without LAA can appear on the network more quickly than LAA-compatible phones. We expect this year's upcoming iPhones will support LAA.
We will be looking for LAA as we drive around with Galaxy S9 phones on our Fastest Mobile Networks trip in May, which will take in several of AT & T's target cities.