3.5GHz CBRS Band Deployments Face Yet Another Delay

The NTIA is still testing spectrum sharing in the 3.5GHz CBRS band. Such testing has delayed commercial operations in the band for almost a year.

Mike Dano, Editorial Director, 5G & Mobile Strategies

July 18, 2019

4 Min Read
3.5GHz CBRS Band Deployments Face Yet Another Delay

Initial deployments in the 3.5GHz CBRS band are facing yet another delay due to ongoing testing of operations in the spectrum by NTIA.

NTIA acknowledged the delay in a statement to Light Reading, explaining that the agency's testing needed to include "more comprehensive analysis and interpretation, which SAS vendors appreciated." The NTIA added that "work is on track to enable initial commercial deployments," but the agency didn't provide any further details on timing.

It's debatable whether CBRS SAS vendors actually "appreciated" the ongoing delays, as their businesses are directly contingent on receiving NTIA approval for commercial operations in the CBRS band.

Nonetheless, one major SAS vendor -- Federated Wireless -- acknowledged the NTIA's ongoing testing and offered a mostly positive spin.

"The anticipated delays are simply due to organizational changes in the ITS engineering group [which is the CBRS testing organization within the NTIA] that have resulted in some decisions being slowed," Federated Wireless CEO Iyad Tarazi said in a statement to Light Reading. "The FCC and all parties are extremely supportive, and we still anticipate ICD [Initial Commercial Deployment] approval in the August/September timeframe."

Backroom conversations on the topic among all parties are probably much less convivial. Initial commercial deployments in the CBRS band could ultimately be delayed by almost a full year.

Hanging over the issue is the recent, unexpected resignation of NTIA chief David Redly, and complaints by FCC commissioners of foot-dragging at the NTIA. Indeed, according to a report from Axios, President Trump's acting chief of staff, Mick Mulvaney, recently held a high-level White House meeting to address spectrum policy disputes among government agencies including the FCC, NTIA and departments of Defense, States and Education. There was probably plenty to talk about given the president's 5G spectrum directive and problems such as how the 24GHz auction might impact weather forecasting.

A novel approach to spectrum management
The US Navy currently uses the 3.5GHz CBRS spectrum band, thus preventing a standard auction of the spectrum. However, the US wireless industry developed an innovative solution to the problem: spectrum sharing. If the sharing system is approved by the NTIA and the FCC, commercial operations will be allowed in the band when the Navy doesn't need it. Those commercial operations can be kicked out of the band when the Navy does need the band.

And that's where SAS comes in. SAS database operators like Federated can track CBRS users and move them around in the band to prevent them from interfering with Navy operations. NTIA is the agency in charge of managing the US government's usage of spectrum, and as a result its ITS lab has been charged with testing the CBRS sharing system to make sure it works. After the NTIA signs off on the system, it will turn its test results over to the FCC. If the FCC signs off on the NTIA's test results, the FCC will then allow "Initial Commercial Deployments" (ICDs) in the band. Companies have to apply for FCC approval to conduct ICDs, and agency staff essentially will look over vendors' shoulders while they run these initial commercial deployments to make sure that everything is working right. Federated is one of the SAS administrators that has submitted ICD proposals to the FCC. If the FCC is OK with the ICDs, regular commercial operations can then begin in the band.

FCC Commissioner Michael O’Rielly suggested that ICDs in the 3.5GHz CBRS band would begin sometime in May. However, during this week’s House hearing on spectrum policy, FCC and NTIA officials suggested that ICDs won’t start for another few months.

That's a far cry from some hopes that CBRS testing would have been finished in the third quarter of last year.

Nonetheless, the issue is important because the wireless industry would like to expand the concept of spectrum sharing into additional bands. For example, Federated has been testing a spectrum sharing system in the 6GHz band.

Facebook, Charter and 5G in CBRS
Regardless, there certainly appears to be pent-up demand for commercial access to the CBRS band. Companies ranging from Facebook to Verizon to Charter to Microsoft have expressed interest in operations in the band. And that interest could grow next year when the FCC begins its promised auction of licensed CBRS spectrum -- initial CBRS deployments will make use of unlicensed spectrum in the band.

Further, the CBRS community recently announced that the band could well play a role in 5G -- which is noteworthy considering most initial CBRS deployments are expected to use existing wireless technologies like LTE. Specifically, the CBRS Alliance just today announced that the Wireless Innovation Forum (WInnForum) approved the 5G NR air interface in the band. "This approval is a key step in providing a solid foundation for 5G NR in the 3.5 GHz band and sets the stage for the first mid-band 5G deployments in the US," the CBRS Alliance wrote in a press release.

Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano

About the Author(s)

Mike Dano

Editorial Director, 5G & Mobile Strategies, Light Reading

Mike Dano is Light Reading's Editorial Director, 5G & Mobile Strategies. Mike can be reached at [email protected], @mikeddano or on LinkedIn.

Based in Denver, Mike has covered the wireless industry as a journalist for almost two decades, first at RCR Wireless News and then at FierceWireless and recalls once writing a story about the transition from black and white to color screens on cell phones.

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