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CBRS Alliance and Small Cell Forum pool efforts to drive densification

The CBRS Alliance is keen to put on a big show of progress at Mobile World Congress later this month, after its schedules were set back for a while by the US government shutdown.

No date has yet been set to auction rights to the licensed portion of the USA’s three-tiered CBRS spectrum scheme, but the Alliance expects to see initial commercial deployments in the unlicensed tier during the second quarter of this year, and full commercial services in Q3.

The CBRS scheme applies to the 3.5 GHz band and relies on spectrum access systems (SAS) to assign channels to devices in order of priority. There is guaranteed access for the top tier – federal incumbents; next priority goes to holders of Priority Access Licences (PAL). General authorized access (GAA) usage is available when these other groups are not using a channel, and 80 MHz is available only for GAA (in the absence of incumbents).

The Alliance is planning a campaign to raise the profile of its brand for certified CBRS equipment, OnGo. This signifies that equipment will be interoperable. The shutdown had caused a hiatus in the FCC authorization process for CBRS infrastructure and devices. There was also a delay in certification of the SAS and Environmental Sensing Capability (ESC) systems, which will protect the priority signals from interference. The  Institute for Telecommunications Sciences (ITS) had been contracted by the FCC to conduct SAS and ESC testing.

Another shutdown would cause further delays, but the Alliance will come to Barcelona ready to highlight the OnGo program, and various milestones and partnerships. One of the latter is a new deal with the Small Cell Forum. The two groups have agreed to work

together on a range of initiatives to drive densification based on OnGo-certified small cell networks in the 3.5 GHz band.

Shared spectrum will be very important to accelerate adoption of small cells, especially in enterprise environments where the business model may be more robust for a specialized service provider than for a spectrum-owning MNO. The licensed portion of CBRS should – with its relatively short licence terms and small coverage areas – be affordable to a wide range of bidders, including enterprises, private network operators and neutral hosts, and that will extend the ecosystem for small cells and open up new use cases.

Rethink Technology Research is just about to publish a report forecasting the adoption, from 2019 to 2025, of small cells in shared spectrum, with a special focus on CBRS. It argues that only a larger availability of shared spectrum will make large-scale densification, especially for indoor and enterprise environments, economically viable.  Not only will spectrum schemes like CBRS drive small cells, but the reverse will be true too, since small cells are the most appropriate equipment to roll out in relatively high frequency, short range bands like 3.5 GHz, especially with indoor power constraints.

Areas of collaboration between the CBRS Alliance and SCF will include investigating multi-operator solutions in the 3.5 GHz band; defining architectures for indoor densification; and exploring the international opportunity for SAS-coordinated shared spectrum – which provides a halfway house between the protections of high cost exclusive licences, and the free-for-all of unlicensed bands like 2.4 GHz.

“As the industry shifts to focus on network densification, we expect that small cells will be a key driver for the adoption of 4G and 5G solutions in the 3.5 GHz band,” said Alan Ewing, executive director of the Alliance.

Meanwhile, a little further up the spectrum, in 3.7-4.2 GHz, there are plenty of disputes raging in the USA. The country is out of step with the rest of the world in 3.5 GHz – which is becoming a near-global band for early 5G elsewhere – because of the federal incumbents. And it is unclear whether it will adopt the same solutions as other regions to coexistence with incumbents higher up the C-Band, notably satellite operators.

The C-Band currently carries live TV and radio programming from content producers to local stations and cable systems nationwide in the USA.

The satellite industry C-Band Alliance (CBA) has proposed making 200 MHz of 3.7-4.2 GHz satellite spectrum available for sale for 5G, but critics have said the plan could violate the Communications Act and lead to litigation. Representatives from Google and Charter Communications have also suggested the CBA plan would take longer to get the spectrum to 5G deployers than a public FCC auction would because it involves private negotiations rather than a single process involving all interested parties.

The Open Technology Institute (OTI) at New America held a forum last week called ‘The Great Airwaves Robbery II’, arguing that the CBA was wrongly trying to get paid for  government-controlled spectrum – something which the 2002 Communications Act had guarded against.

The American Cable Association (ACA) and T-Mobile assert that the CBA’s approach would violate the Act because it would allow negotiations among “private parties” rather than a transparent process like an auction.

The CBA – made up of Intelsat, SES, Eutelsat Communications and Telesat—responded to these criticisms last week, claiming its “market-based approach” would be permissible under current law. It told the FCC: “These entities offer no support for their contention that the statutorily authorized ‘negotiations’ cannot take place among private parties. Nothing in the language of the statute limits this term.”

The satellite body also pointed out that all the satellite operators are prepared to support its plan, by contrast with the 600 MHz incentive auction, in which it was voluntary for broadcasters to surrender their airwaves – and not all of them did. In the C-band, each satellite operator has equal access to all 500 MHz at their disposal, so in a public auction, every carrier would have to agree to participate and be happy with the resulting price they would get – which the CBA says has zero chance of happening.

The C-Band issue was also prominent at the first full hearing in this Congress, of the US Senate Committee on Commerce, Science and Transportation. Meredith Attwell Baker, CEO of the CTIA, which represents the US mobile operators, said the USA was well positioned to deliver on the promises of 5G, but only if there were a more friendly regulatory environment. “The main building block required is spectrum and we need more of it—specifically midband spectrum—to maintain our global leadership role in wireless,” she testified.

“US wireless providers will invest some $275bn in 5G-related networks—creating 3m new jobs and adding $500bn to our economy, according to Accenture,” she wrote. “To fully realize the technical breakthroughs we are talking about, we need more spectrum, and we need it as soon as possible …  the best available option is the 3.7 GHz band of spectrum under current FCC review.”

For more information about the forthcoming forecast and report about small cells and shared spectrum, including CBRS, please email John Constant on [email protected].

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