Federated demo with DoD highlights benefits of shared spectrum

Federated Wireless recently led a demonstration for the U.S. Department of Defense (DoD) using Citizens Broadband Radio Services (CBRS) and millimeter wave spectrum, underscoring the importance of spectrum sharing between government and non-government entities.

What made this event especially significant was the spectrum normally wouldn’t have been used by the U.S. Marine Corps if it weren’t for the unique sharing paradigm implemented in the 3.5 GHz band, according to Federated Wireless. Federated had a significant hand in enabling the CBRS band in the U.S.

The demonstration, conducted at the U.S. Marine Corps Base Albany 5G Testbed, produced download speeds of 1.5 Gbps and sub-15 millisecond latency using 380 MHz of spectrum in the 3.5 GHz band and 37 GHz shared DoD bands. The hope is that it will be replicated at bases around the U.S.

“By using shared spectrum, the U.S. Marine Corps was actually able to use its own spectrum,” said Jennifer McCarthy, VP of legal advocacy at Federated Wireless. Thus, the DoD took advantage of the innovation that comes from sharing with the commercial sector — basically coat-tailing off commercial development, both in terms of equipment availability and use case/application support, she said.

“It was the perfect combination of spectrum, technology, American know-how and capabilities, and it really showcased the benefits of 5G technology that we think are going to be important for private wireless networking and smart logistics, smart manufacturing and smart automation – all of those things that will be real drivers of 5G deployments,” particularly in the enterprise sector, she said.

As one might imagine, the DoD doesn’t always get too specific about how it uses spectrum, but it’s pretty well understood that historically, one of the primary government uses for the 3.5 GHz spectrum has been when planes take off or land on ships. They need the spectrum during those times, but that isn’t happening all the time.

The prototype network was built using open radio access network (RAN) technology and was designed to comply with DoD specifications, according to Federated. It’s within the DoD’s “Tranche 1” of 5G projects, which is part of a more than $500 million DoD investment in advanced 5G. Once deployed, it will be used at the Marine Corps Logistics Base Albany, Georgia, as a private 5G network, where it can use up to 750 MHz of available shared spectrum bandwidth.  

Federated worked with partners Amazon Web Services (AWS), Cisco, JMA, Vectrus, Peraton Labs and Capstone Partners on the deployment. The network will be available to support a range of applications for the Marine Corps.

“I think this is really important for commercial private networks, for smart cities, smart manufacturing, agriculture” and other situations where the spectrum can be enhanced, McCarthy said.

That spat with Google

According to Federated, the demonstration showcased the capabilities of $12 million prototype smart warehouse technology. Federated provided the automated sharing framework for the 3.5 GHz CBRS spectrum band, including its Spectrum Controller and nationwide network of sensors.

Last year, Federated Wireless and Google clashed over how sensors are deployed in the CBRS framework. Both Federated and Google are operating as Spectrum Access System (SAS) administrators and they each use their own Environmental Sensing Capability (ESC) systems to ensure interference isn’t a problem.  

RELATED: Google, Federated clash over how spectrum gets managed in CBRS, other bands

McCarthy said Federated is “constantly optimizing” systems but it didn’t make any changes directly as a result of Google’s complaints about how its sensors were deployed.

“We haven’t changed them because of the issues that Google was complaining about, but we have been refining our network deployment to improve its ability to detect the Naval radar as efficiently as possible,” she said.

“We’re constantly upgrading and tweaking our network to make sure it’s operating as efficiently as possible,” she said, and to some extent, it addresses some concerns that Google brought up. “We’re constantly trying to improve.”  

What about other bands?

An area where both Federated and Google agree is they’d like to see more spectrum sharing going on, and they’ve told the FCC as much as the agency reviews spectrum in other bands.

“We think this is really good evidence of the benefits of shared spectrum,” McCarthy said of their latest demo with the DoD. “If we had tried to do this on any other fully licensed band, we never would have been able to get the throughput that we just demonstrated. It’s only through shared spectrum that a private wireless network of this sort could be deployed.”

The CBRS band features the General Authorized Access (GAA) portion of the band, which doesn’t require a license, and the Priority Access License (PAL) portion that does calls for licenses. Mobile carriers, including Verizon, bid on those PAL licenses during an auction last year. While the auctioned licenses make sure equipment gets developed quickly, the GAA helps get more users involved and brings more vendors to the table, driving equipment prices down, McCarthy noted.

RELATED: Federated Wireless gets ready to enable sharing in 6 GHz band

Federated would have liked for the CBRS model to be extended to the 3.45-3.55 GHz band, which is teed up for auction in October, but that didn’t happen. Currently, there’s a lot of debate now about how the coordination will happen with future licensees and the DoD in that band.

Other places where sharing could be implemented to one extent or another include the 3.1-3.45 GHz, 4.9 GHz, 12 GHz and 7 GHz bands. For the 6 GHz band, Federated developed an automated frequency controller (AFC), a simplified version of the SAS, to protect incumbents while allowing for new users in the spectrum, which is a model that could be adapted for other bands.