Mid-band spectrum for 5G growing, with fits and starts

A new auction for enormously valuable mid-band spectrum and a rollback of availability for a different piece of it illustrates the uneven progress of 5G rollouts in the U.S. and represents a challenge for enterprises looking to take advantage of 5G technology.

The mid-band is valuable because it’s in a “Goldilocks” zone of the wireless spectrum—its frequencies are high enough to support higher throughput, while also being low enough to propagate effectively across relatively large areas.

The major wireless network providers are desperate to acquire as much of it as they can, to deploy 5G as widely as possible. While there’s plenty of spectrum available in the millimeter-wave range above 30GHz, those frequencies don’t travel as far, meaning that orders of magnitude more base stations would be required to cover a given area.

The problem for carriers is that large parts of the mid-band aren’t available at auction yet, although the FCC has been auctioning off other important parts of the airwaves specifically to speed 5G deployment.

The latestmidrange auction , which began Oct. 5, will see 100MHz of spectrum in the 3.45GHz-to-3.55GHz range auctioned off in 10MHz blocks within FCC designated geographical regions known as Partial Economic Areas, which vary widely in size and population

“There’s no question that the last several auctions that the FCC has run have all been centered on 5G,” said Dan Hays, principal at PwC. The largest was the C-band auction  in the 3.7GHz range, which took in more than $81 billion.

“[The C-band auction] completely blew out everyone’s expectations for what they might be able to raise, and there are high hopes for this auction as well, but the industry is really crying for more mid-band spectrum to accelerate the rollout,” said Hays.

Yet it’s not full speed ahead for the FCC. Earlier this month it rescinded a rule made under the previous administration that would have opened 50MHz in the 4.9GHz band for commercial auction and use. That band is currently designated for use by public safety, and municipalities objected to the earlier decision to open it to shared use. The objections centered on concerns that sharing the spectrum would cause interference with networks used by police and fire departments, and that could delay response times.

“Mid-band is tough because it’s already crowded,” said Forrester research director Glenn O’Donnell. “With modern radios and data equipment it’s possible to avoid interference, so in a sense [former FCC Chairman] Ajit Pai’s administration was correct that you can avoid the issues that are being discussed, but having a dedicated space for public safety, there’s some logic to that as well.”

All this adds up to a scenario where big wireless providers are eager to build out their 5G networks. The big three—AT&T Mobility, T-Mobile, and Verizon Wireless—have been marketing their 5G networks widely,nand enterprises are that much more interested in trying it out, according to Hays.

“A lot of enterprises are starting to think about the art of the possible with 5G use cases,” he said. “So just getting a handle on what is possible is a really important first step, and that’s where we see a lot of enterprises out there.”

That said, once businesses start to experiment with 5G, they butt up against the reality of 5G networks in the US: it’s spotty and not that widely available. Nor is it merely a question of putting up a sufficient number of new base stations, Hays added. Features are lagging. Network slicing—dynamically carving a piece of spectrum into multiple virtual networks to meet varying customer demand—and 5G’s much-vaunted low latency have yet to make their way into most commercial offerings.

“We don’t see a lot of commercial offers of network slicing just yet, [and] we don’t see anyone out there saying, “Hey, we can offer you truly low-latency 5G end-to-end solutions for a premium price,’” he said.