Hybrid Networks, the New Land Grab

I'm helping produce a webinar on Tuesday, June 16, at 10am PDT about Hybrid Networks and the Convergence of Wi-Fi 6 and 5G. The registration link is here.

Two highly impactful technological changes have just happened in America which has the potential to change the way we do business in many different industries. One is new spectrum in the CBRS band, and the other is new spectrum in the 6GHz band. Spectrum is like land, and these two new additions are causing a rush to stake a claim on the new land.

First, new spectrum for cellular in the 3.5GHz CBRS band has opened up and there is a process in place to arbitrate users in this band. Anybody can use this spectrum "with permission". There are incumbents already using this band who will retain priority over new users, such as the US Navy. Five companies are designated as operators of Spectrum Access Systems that will detect and handle interference issues, kind of like Air Traffic Controllers guiding aircraft safely to avoid collisions. The five authorized SAS companies are Amdocs, CommScope, Federated Wireless, Google, and Sony. Although "anybody" can use this spectrum, there is a registration process required to become a General Authorized Access user, and there is a Federal auction in July to sell Priority Access Licenses on a county by county geography basis.

So basically there will be three tiers of users: Incumbents like the Navy who will retain highest priority for their communications, followed by PAL users who will buy their licenses but never fully own exclusive rights to their spectrum (and may have to share spectrum and be shifted around to different frequency channels if interference becomes an issue), followed by GAA users.

Example use cases are sports stadiums, airports, event venues, campuses, factories, rural or urban areas that need better cellular coverage, and many others. Existing cellular service providers like Verizon and AT&T might bid on PAL licenses because they might want to augment their coverage in dense areas or undercovered areas. Independent companies might bid on PAL licenses and deploy 4G or 5G base stations and then sell extra capacity as "neutral hosts" to CSPs like Verizon, AT&T, T-Mobile, or Dish, perhaps for some event like the Superbowl where user density will spike and carriers want their customers to be happy. But there are likely to be enterprise and industrial companies, municipalities and utilities who want to deploy their own private network, for industry 4.0, Smart Cities, manufacturing automation, telemetry, meter reading, or anything using cellular communications.

What's the point? So what? Well if you manage to peacefully coexist as a GAA user, then you can use cellular technology without paying a monthly subscription fee to a traditional cellular company. Even a PAL might find the up-front investment cheaper than paying Verizon or AT&T monthly subscription charges. And there might simply be use cases that are impossible to achieve using public cellular networks that only work when a more "private" network is deployed. Of course, Verizon and AT&T will gladly work with you to set up a private network that is tied to their network backbone and deploy base stations on your campus that are dedicated to you -- for a fee. So in some cases there might be a technical reason that this particular CBRS spectrum with a private network enables your use case, or there might only be a business cases analysis needed to compare buying access from Verizon, AT&T, etc. versus "rolling your own".

The second major new spectrum grant is massive. The FCC opened unlicensed spectrum usage of 1200MHz in the 6GHz band. That's huge! By comparison, CBRS is only 150MHz wide. So this new 6GHz band is 8 times more.

Traditionally, unlicensed spectrum has meant Wi-Fi, and there certainly are a lot of companies eager to push the newest upgrade of Wi-Fi 6 into this spectrum. However, since it is unlicensed spectrum, there could be 4G or 5G cellular communications deployed in this spectrum to coexist. There is currently a lot of debate as to which technology will be better for various private network use cases: cellular or wi-fi? And the answer is: Yes.

There are rules for this new 6GHz spectrum which open new possibilities for Wi-Fi to boost its transmit power outdoors and start to cover wider areas like cellular. Similar to CBRS, there will be an arbitration system to avoid interference, especially for incumbents like public safety, microwave relay for cellular backhaul, and satellite users. These incumbents requested protection from the FCC in the form of protected frequency bands, but the FCC designated Automated Frequency Coordination as the answer to keep everybody peacefully coexisting in the same frequency bands. Federated Wireless is a CBRS SAS who will also be a 6GHz AFC.

So there will be some use cases that will be easier and cheaper to deploy using Wi-Fi 6 and others using 4G/5G, but there is no way to make a blanket statement that one or the other is always better. Everything will be a case by case analysis, involving both a technical site-survey and usage analysis as well as a cost versus benefit analysis. Nokia claims to have a calculator where technical inputs like environment (reflective surfaces, fading, interference, density of receivers, etc.) and like cost of equipment get fed in and then out drops your answer. In some cases, six 5G base stations will do a better job and be cheaper than 300 Wi-Fi access points. In other cases, the clear choice will be Wi-Fi 6. While in other cases, there might be a hybrid combination of Wi-Fi 6 and 5G to tie everything together and keep the wheels turning.

Needless to say, all of the Network Equipment Providers are scrambling to develop new Wi-Fi 6 and also 5G equipment. Even my home office will need an upgrade when Wi-Fi 6 becomes widely available.

We will discuss these topics and "how to" and others in more detail in our webinar on Hybrid Networks.