Better Tech Needed to Replicate CBRS-Like Sharing in Other Bands: SCTE Event Panel

Spectrum experts repeatedly talked up the CBRS sharing model.

Flynn Rico-Johnson, wireless aide to FCC Commissioner Geoffrey Starks, said the model shows the U.S. can allow more intensive use of federal spectrum. Starks, he said, is interested in ensuring data is gathered that will allow further CBRS operational changes atop the expanded reach of the band announced in June (see 2406120027). John Chapin, National Science Foundation spectrum special adviser, said the CBRS model shows more-complex spectrum sharing than previously thought feasible. There have been no reported incidents of incumbents receiving harmful interference, he said.

Charles Cooper, associate administrator, NTIA Office of Spectrum Management, said that while the tide is moving toward increased sharing, there are hurdles, such as having to accommodate dissimilar services in a swath of spectrum. Another challenge is ensuring that federal agencies like DOD and FAA have spectrum available that they need for their missions, he said.

When it comes to allowing more non-federal access to a band that federal agencies use, Cooper said, a “sensing” methodology shows more promise than a “scheduling” one. But wide use of sensing will require R&D on technologies that would enable that, he said. "The technology still has to catch up." A sensing methodology would have nonfederal devices quit using a particular band when they sense a federal user is suddenly using it; a scheduling methodology has federal and nonfederal users time-sharing a band. Monisha Ghosh, University of Notre Dame electrical engineering professor and the NSF Center for Spectrum Innovation's policy outreach director, said intelligent sensing will need to be a part of a new entrant’s capabilities when applying the CBRS sharing model to other bands.

NSF's Chapin said the approach of the U.S. to spectrum management is based on underlying assumptions rooted in technology 70 to 90 years old. Ghosh said the U.S. remains rooted in a paradigm of licensed vs. unlicensed spectrum when the focus should be on connectivity as a whole.

Federal agencies touted the multistakeholder forums that are part of the national spectrum strategy and urged industry participation. The first, regarding studies of the lower 3 and 7/8 GHz bands, was held in August, and a report on those bands and a potential path forward will be issued later this year, said Shiva Goel, NTIA senior adviser-spectrum policy. Goel said the aim is bimonthly meetings, with the next likely in late October. He said future meetings will likely have a virtual option, though the hope is presenters will be in person.

Lynna McGrath, NASA director-spectrum policy and planning, said NASA isn’t significantly worried about its uplinks receiving interference from greater spectrum sharing with nonfederal users, considering how high-powered those uplinks are. A bigger concern for the agency, she said, is its ability to increase use of some bands, such as the 7190-7235 MHz band, which will be deployed for lunar mission communications. NASA also heavily uses the 7145-7190 MHz and 8125-8400 MHz bands, she said. The agency will be heavily involved in NTIA's national spectrum strategy multistakeholder process, she said. The more information it provides about NASA operations, the easier it is for industry to find routes to protect those operations, she said. “We love to talk with you guys.” But, she added, DOD often can't have the same open conversations.