Massive MIMO, adaptive beamforming spiff up to 12 GHz band


Advances in wireless technology are sparking interest in the fight over whether the 12 GHz band should be used for 5G.

In his final arguments before the FCC, the long-time supporter of 5G 12 GHz RS Access points (PDF) to a report that identifies recent technological advancements to make the 12 GHz band so desirable for 5G, including Massive MIMO, beamforming, and 5G carrier aggregation.

In support of the 12 GHz band offering a “huge technical advantage”, RS Access highlights the conclusions of engineering firm Roberson and Associates that the 12 GHz band is an excellent “Goldilocks” band combining the best of the band. C and millimeter waves (mmWave) characteristic in the areas of capacitance, coverage, path loss and equipment development.

RS Access is putting a renewed emphasis on its quest to achieve the 12 GHz band for 5G. The company, which has ties to Dell Technologies founder Michael Dell, has in-band MVDDS licenses, which could be used for 5G, a more lucrative use than the spectrum originally intended. Dish Network is another big player in the RS Access corner – one that is at odds with big guys like Elon Musk’s Starlink, who also wants to use the 12 GHz band, but for other purposes. RS Access believes they can all coexist.

RELATED: RC Access: Studies Show 12 GHz Band is ‘Win-Win’

In a September 17 meeting with FCC staff, RS Access representatives reviewed the history of the proceedings and claimed to be the only party to have submitted detailed technical and economic studies demonstrating that the services Satellite and terrestrial 5G can coexist “while unlocking enormous social value”.

Its opponents, led by SpaceX, have provided “no science-based analysis or rebuttal; instead, they offered rhetoric and misrepresentation that distracted attention from the serious policy-making issues before the Commission, ”RS Access CEO V. Noah Campbell wrote to the FCC.

Indeed, SpaceX came out with blazing guns recent FCC filings (PDF) on his own, saying RS Access’s arguments are “fatally flawed” and demonstrate a “worrying lack of understanding of how customers are actually served using the 12 GHz band”. Even more troubling, according to SpaceX, is that RS Access “ruthlessly concludes that the Commission should grant DISH and RS Access new rights free of charge, even if such a donation would deprive tens of thousands of otherwise unserved Americans of the service.” next-generation satellite broadband. the country.”

RELATED: T-Mobile Refines Argument for 12 GHz Auction

12 GHz: what is its value?

In a recent interview with Fierce, Roberson and Associates Founder and CEO Dennis Roberson said some of the things he had heard on the 12 GHz band reminded him of the types of comments people made on other bands. spectrum many years ago. (Roberson has been chairman of the FCC’s Technology Advisory Board for eight years.)

However, in his opinion, the 12 GHz is much closer to the 3.7 GHz C-band than the 28 GHz band, which is considered mmWave, and he’s not just talking about where the numbers land in. order.

The 12 GHz specifications are much closer to what is currently considered a high mid-band 5G spectrum. Advances in technology over the past five years have made it more efficient, including compared to mmWave, where the road has been “bumpy,” but technical improvements are underway, he said.

In the last five years, Massive MIMO antennas have appeared, and the ability to beamform is much more convenient. Massive MIMO is something that T-Mobile benefits from, and it’s a safe bet that AT&T and Verizon will take full advantage of it in C-band. But these techniques are also applicable in the 12 GHz band, he added.

Unfortunately, some tools get much bulkier when you access mmWave, Roberson added. As the antenna narrows to the higher spectrum in dense configurations, the energy is also concentrated in a smaller area and this generates a lot of heat. But that’s not a problem in the lower 12 GHz band, he said.

If you look at the 280 megahertz of spectrum in the C band versus the 500 megahertz available in the 12 GHz band and the 800 megahertz at mmWave, “the surprising fact is that you get a lot more throughput on the 12 GHz band than you get. would do in millimeter waves, ”even though there is a lot more spectrum available at mmWave frequencies, he said.

For example, his company discovered that 1 MHz of 12 GHz spectrum can carry 3.76 times more data than 1 MHz of 28 GHz spectrum (under peak throughput conditions). In addition, they estimate that 500 MHz in the 12 GHz band could support a cumulative downlink throughput of 20 Gbps, which is significantly higher than the 15.1 Gbps estimated to be achievable using the 280 MHz of spectrum. in the 3.7 GHz band or the 9 Gbit / s estimated using the 800 MHz spectrum in the 28 GHz band.

These are not the only differences. 5G deployments will require significantly more base stations at mmWave frequencies than in the 12 GHz band, and semiconductors and other network elements can be produced more cheaply in the 12 GHz band than at mmWave frequencies, according to Roberson.

Carr: It all comes down to engineering

Ultimately, it will be up to the FCC, which is still acting without permanent chair and awaiting a fifth appointed commissioner.

At an American Enterprise Institute Event last week Commissioner Brendan Carr was asked about the matter. He said the 12 GHz band “really comes down to engineering” for him. In short, “we have incumbent terrestrial vendors that have 12 GHz licenses who want to do more with those licenses, who want to get into the 5G game with that 12 GHz spectrum,” he said.

On the other side of the equation, “we have this spectrum that is currently being used for a lot of these low earth orbit satellite operations,” including the type of SpaceX. “There’s going to be an expert engineering battle over: Can we do it all? Which is obviously the preferred political outcome, ”he said.

“If we can get greater terrestrial use of 12 GHz without causing harmful interference or interfering with those low Earth orbit satellite connections, that’s great. We’ll just have the procedure and see where the engineering takes place,” did he declare.


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