AT&T just made a major upgrade to its nascent 5G network—one that suggests fast wireless speeds for many more people are around the corner.

In a brief statement Friday, AT&T said its Netgear Nighthawk 5G mobile hotspot had hit speeds of over 1Gbps on the company's live 5G NR network, which is available by invitation in 12 cities right now. The technical leap making that possible was an upgrade to allow four-carrier aggregation of 100MHz carriers, Igal Elbaz, AT&T's SVP of wireless technology, said in an exclusive interview with PCMag.

"It was just the evolution of the standards and the capabilities. The software had to evolve across all of the ecosystem," he said.

It sounds like AT&T's network and hotspots could go even faster as the carrier acquires more spectrum, too. Elbaz was very careful to say that speeds are now limited by AT&T's spectrum—the company has an average of 375MHz in most major cities—and not by the firmware any more.

This solves some 5G deployment mysteries I've been wondering about for months. AT&T launched its hotspot in December, but wouldn't let me test it, and the few test results I saw were quite disappointing. That's because the whole system could only use a single 100MHz carrier.

Back-of-the-envelope math provided to me by Qualcomm gave a 625Mbps theoretical speed for that original 100MHz mode; we're now looking at 2.4Gbps. Think of actual speeds as around half that, and you see where AT&T is getting its gig. With the single carrier, we weren't seeing much of an advantage over a good 4G LTE connection. Now we will see the difference.

As T-Mobile CTO Neville Ray explained to me in February, a new revision of the 5G standard last December left all the carriers waiting for firmware that supported the gigabit speeds everyone has been promising.

AT&T had committed to launching 5G in 2018, so it launched with very early firmware. The company implying that the new firmware is here probably also means that Verizon and T-Mobile will feel comfortable launching their millimeter-wave 5G soon. Verizon plans to launch in parts of Chicago and Minneapolis on April 11, with the Moto Z3 phone. Sprint plans to use different spectrum for 5G, which has different challenges, and expects to launch in May with the LG V50 phone.

"We are carrying and moving the whole industry with us," Elbaz said.

We will track the carriers' upgrades on our Race to 5G page as they launch.

Two More Major Boosts Coming

Elbaz and I discussed two more speed boosts AT&T's network will get this year. One will probably apply to the Netgear hotspot, and the other will require different consumer hardware.

Dual connectivity will further boost speeds by combining 4G LTE and 5G NR on the same connection. Qualcomm has shown off that feature in demos of the X50 chipset that's in the Netgear hotspot, and "it will be able to do that in the future," Elbaz said.

With gigabit-plus speeds, the 802.11ac (Wi-Fi 5) Wi-Fi on the hotspot starts to become a speed limit. In theory, 802.11ac allows speeds over a gigabit, but people rarely see those speeds in real life for a complicated set of reasons involving different 802.11ac router and client capabilities, interference, and signal attenuation. For now, you can tether your laptop via USB to get the full speeds, Elbaz said.

That Wi-Fi speed limit will rise later this year as 802.11ax (Wi-Fi 6) devices become available; the first one we've seen is the Samsung Galaxy S10, and the upcoming Galaxy S10 5G does in fact have 802.11ax, although I still need to check whether that applies to the S10's hotspot mode. AT&T plans to carry the Galaxy S10 5G, the company confirmed.

Still Many Mysteries

AT&T's Netgear hotspot is still available only by invitation, and AT&T's service plan strategy is still very odd; it's offering unlimited use for free at the moment, with a promise to slap down a 15GB limit and a $70 price point in the future. That's far too little data for too much money in an age of gig-plus speeds. Elbaz demurred on any talk of service plans.

Why aren't the hotspots going on sale to the public now? Elbaz wouldn't say, but I got a sense that the issue is now about availability of X50-based devices from Qualcomm and Netgear, not about what the network can handle.

"I don't think the network has a limitation. This is a journey," Elbaz said.

AT&T also won't give any clear idea of its 5G coverage areas yet. While Verizon has given us neighborhood names and Sprint has shown us maps, AT&T only says that 5G is available in "parts" of 12 cities.

Coverage is important because, for now, AT&T is using extremely short-range, millimeter-wave 39GHz spectrum, which requires a lot of small cell sites very close together. Using similar 28GHz spectrum, Verizon will be launching in Minneapolis only covering the downtown area. A recent study from analysis firm MoffettNathanson said Verizon has been having a hard time covering Sacramento with 5G because of the short range of its cell sites.

"Like any mmWave system it has limited range in terms of coverage, so you will probably see this in dense areas where we have people coming in and out. [But] we are surprised by the capabilities and the quality," Elbaz said.

Later this year, AT&T will spread 5G much more widely by reusing older 4G spectrum, which has much longer range but slower speeds. That will require newer devices based on the Qualcomm X55 modem; I expect the first one to be the Samsung Galaxy Note 10. The company is targeting nationwide coverage in 2020, Elbaz said.