5G and Wi-Fi 6: Unlikely allies

July 01, 2020

You probably won’t find a 5G Wireless small cell or small base station within sight of where you’re seated right now. Maybe in the distance, you’re able to spot a 4G base station, perhaps one that’s already been upgraded with 5G transmitters. The move to incorporate 5G spectrum into existing mobile wireless is well under way, and in some regions is already done.

But chances are, it’s not on a lamppost or a stoplight, and almost certainly not sitting in a picocell station in your office. Small cells, once they’re operational and being fed with a good supply of backhaul data, should be much less expensive for telecommunications providers to operate and maintain, and even healthier for the ecological environment as a whole. They’re the end goals, and the actual reasons why the whole 5G transition was pushed forward in the first place, stepping on the back end of 4G’s service life.

The perfect storm of events — a plurality of near-simultaneous catastrophes, tossed about by a sea of unfortunate circumstances — has obstructed 5G’s progress towards this final goal. Without it, the technology portfolio’s ultimate promise — to be the foundation for a sustainable and profitable global communications system even beyond its service lifetime — may not be feasible.

“We have a huge cultural cliff that we need to climb, for us to get to the next-generation network,” declared Aeneas Dodd-Noble, principal 5G architect with Cisco, speaking at his company’s recent Cisco Live virtual event. “5G is way more than upgrading the protocols and upgrading the radio. It’s upgrading the culture of the service provider. And going forward, we’re going to see that the service provider looks nothing like we have today.”

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The future will be unlicensed

Last year, it appeared that 5G Fixed Wireless — connecting telco base stations directly with homes and offices — would face an uphill battle against Wi-Fi, which itself is due for an upgrade. In March 2019, a Cisco CTO told ZDNet’s Corinne Reichert, cellular wireless customers should wait until more near-Earth-orbit satellites are launched, before expecting to see speed increases indoors that would make 5G competitive, or quite frankly, even desirable.

Since the pandemic, the market demand for fixed bandwidth has risen sharply. There’s reason to believe that demand may not taper off — maybe not significantly, maybe never. If 5G is to succeed in its first mission of blanketing the world with low-power radios, it needs a new value proposition.

Here, at last, may be that proposition: A system of 5G Wireless hubs distributed through small cell towers, complemented with bandwidth supplied by customers through Wi-Fi 6, could jointly provide the speed and throughput that home offices require to conduct multiple, live meetings simultaneously, in high resolution at 60 frames per second. What’s more, the pairing with 5G could enable such a system to extend the appearance of Wi-Fi connectivity to customers who suddenly rise from their chairs and become mobile, or take a jog around the block.

Making such a patchwork functional without its seams showing, has been the mission of one element of the 5G portfolio that has escaped folks’ notice until now. It’s being ratified by the 3GPP engineering group as an official 5G component on Friday, July 3: 5G New Radio Unlicensed (5G NR-U). Like Wi-Fi, NR-U’s mandate is to be able to claim unused portions of publicly available spectrum for limited intervals.

From Qualcomm’s June press presentation.

“NR-U brings unlicensed spectrum to 5G,” explained Pratik Das, staff manager for technical marketing at Qualcomm. “That not only unlocks more spectrum, and globally, but it enables new markets and verticals, and new deployment scenarios, because of some finer differences. . . compared to [4G] LTE-LAA [license-assisted access], for example.”

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We’ve talked here in ZDNet about the emerging concept of private 5G, which has since taken on the abbreviation NPN (non-public network). It’s the ability for an enterprise to act as its own wireless carrier, in a limited area such as its own offices or manufacturing floor. The term “non-public” is a bit deceptive here, as the system does use public airwaves — just to establish private channels.

The private, or non-public, concept runs much deeper than securing a phone network for employees. For businesses such as Ford Motor Company, it enables private, manageable connectivity between all of its devices involved in manufacturing electric vehicles. On June 25, Ford received a public grant from the UK Government to establish its own 5G mobile private network (MPN) for its electric car production facility in Dunton, Essex, just east of London. For that particular deal, Ford partnered with European and British wireless provider Vodafone, from which it will lease 5G spectrum.

Now, that’s an MPN, where the telco carrier is involved. For an NPN, no carrier would be necessary. In countries that reserve segments of the radio spectrum for public use, an NPN can arbitrate channels of unowned airwaves for use by mobile or fixed devices, in a similar way to how Wi-Fi negotiates an open channel for over-the-air networking. Here, however, the coverage zone is as wide as it needs to be — not just the radius of a Wi-Fi router, but the combined footprints of all the cellular transmitters in the private network.

Last April, the US Federal Communications Commission voted unanimously to open up the entire 6 GHz band (5.925 – 7.125 GHz) for use in unlicensed communications throughout the country. Ostensibly, as the FCC said at the time, that order pertained to Wi-Fi 6E, with the “E” standing for the “extended” frequencies being opened up to Wi-Fi for the first time. Still on the table for the FCC is a proposed order that would make some 7 GHz of spectrum in the 64-71 GHz band available for unlicensed use for 5G, along with an additional 600 MHz of bandwidth in the 37-37.6 GHz band for shared use with commercial users.

In the meantime, though, there’s a full 1.2 gigahertz of new, unowned bandwidth up for exploration, to be subdivided into 400 MHz downlink and 100 MHz uplink channels. Theoretically, it could stand alone as all the bandwidth an enterprise may ever need — indeed, 3GPP calls this option stand-alone NR-U. If no one owns the 6 GHz band, the Wi-Fi 6E engineers can’t exactly claim it as exclusively their own. It’s prime real estate — what wireless operators call the mid-band.

200630-5g-re-jiggered-01-qualcomm-6-ghz-spectrum-map.jpg — This chart from Qualcomm’s presentation to the press depicts Wi-Fi and 5G as joint tenants of unlicensed spectrum.

“That’s 1200 MHz of spectrum that can be used by any technology,” Qualcomm’s Das remarked during a company press conference, “that plays fair, follows FCC regulations — like Wi-Fi 6E and 5G NR-U. It can be used indoors across the band, and in specific sections like UNI-5 and UNI-7 [shown above], with the support of an Automated Frequency Control (AFC) system, the spectrum can be used outdoors as well, and with higher power. That’s a significant addition of capability in the unlicensed domain, compared to what 2.4 GHz and 5 GHz used to offer.”

Das is referring here to the traditional frequency bands occupied by Wi-Fi, ever since the publication of the 802.11b and 802.11a standards, respectively. Since 2018, the wireless industry has taken to referring to new standards by their generation number rather than their more confusing international standard document number — thus, “Wi-Fi 6.”

Although there may be some sources of contention from incumbent users in the 6 GHz band — for example, noted Das, electronic news gathering (ENG) crews that transmit their signals back to television stations via microwave — he argues that such contention is intermittent, and limited mostly to outdoor situations. “As far as indoor environments are concerned, this is a brand-new field of spectrum, and there’s so much potential.”

“The enterprise has a set of requirements that really do fit the portfolio of 5G capabilities,” said Dodd-Noble. “We can see that Wi-Fi 6 is a great technology that provides connectivity, short-range. But we need to extend it, we need to augment it, with a 5G capability as well.”

A leg up

The use of unlicensed spectrum to boost cellular bandwidth is a young concept, though not entirely new. License-assisted access, where licensed (owned) and unlicensed channels are combined, is one methodology already in use today. If you have a 4G phone and your carrier is ATT, you may have seen LTE-LAA before, as the platform that carrier first used in late 2018 to boost its bandwidth for what it controversially called “5G E.” In July 2019, engineers with the US Food and Drug Administration (no, that’s not a typo) experimented with a system that utilized LTE-LAA frequencies, along with channels for 802.11ac (now called Wi-Fi 5) and Bluetooth near-field communication (NFC). Their aim was to determine whether signals in all spectra within a hospital setting would degrade one another, in order to better estimate whether a new class of device pairing both bands together would be efficient, or even functional.

In their report [PDF], the FDA team concluded that harmony was not an automatic thing. They asserted there was significant risk, at least at first, as signal users initially tended to choose channels that clashed with one another. A vigorous testing regimen based on the team’s own methods in finding suitable channels, they concluded, could enable a wireless device to use both spectra by choosing channels with low likelihood of signal collision.

That was with the traditional Wi-Fi 5 and 4G spectra, however. The approach Qualcomm advocates could solve the contention problem, perhaps entirely. Stand-alone NR-U would utilize a single broad patch of mid-band spectrum — which travels through thick walls and floors more easily — for devices driven by both towers and routers. Alternately, anchored NR-U would pair some unlicensed bandwidth with telco-licensed 5G bandwidth. Here, licensed channels would serve as “anchors” that would be perpetually available, with unlicensed space called into service when necessary.

“Anchored NR-U is going to boost mobile network performance,” remarked Das. “And because it can be paired with licensed spectrum or shared spectrum, it can solve different kinds of problems for the operator in question. When paired with licensed spectrum, using either dual connectivity with the 4G network or carrier aggregation with the 5G network, we alleviate spectrum constraints for 5G — which is a problem many are experiencing, some only because their regulatory authorities have not come around to auctioning new spectrum, for example.”

So why involve Wi-Fi at all? Shouldn’t enterprises instead be choosing one wireless platform over the other, not both?

“Mobility does exist with Wi-Fi,” noted Cisco’s Dodd-Noble. “But what is enhanced with a 5G cellular network is that the mobility is managed by the network. In Wi-Fi, the device manages the mobility events, whereas in a licensed spectrum, the network controls the mobility. And therefore, you can make the mobility far more predictable.”

In 2017, the healthcare technology publication HIT Infrastructure quoted an Aruba Networks representative as saying that the average hospital, running as many as 30,000 computers simultaneously, at the same time may be juggling some 85,000 connected medical devices (not counting all the healthcare personnel’s smartphones). Wi-Fi as we know it in our homes and branch offices, is impossible in a hospital setting. Designing and implementing a wireless LAN (WLAN) and industrial IoT (IIoT) environment for hospitals is a task that, at times, resembles reconstructing a working brain.

What may be inferred from Qualcomm’s projections is a future where a hospital, or any organization with a very large number of devices, can entrust the management of those devices to a single service provider that manages 5G. WLANs may be replaced with managed services, offloading the responsibility for managing them to off-site IT personnel. But because unlicensed spectrum is a key part of this picture, enterprises’ options for their wireless service provider would not have to be limited to telcos and established brands. There may also be startups, local ISPs, cloud service providers such as Amazon and Microsoft, and even MVNOs such as Comcast and Cox Communications.

Once it’s all established, though, what exactly would we have? What would an economy, instilled with unlicensed spectrum all over the 5G Wireless network, actually provide enterprises and customers that would be of business value or cultural value? Consider the following possibilities:

A hotel (which, as you may recall from back in the “before-times,” was a place one sought shelter when traveling abroad) typically provides guests with Internet access by way of a haphazard pick-up-sticks jumble of Wi-Fi routers and makeshift WLANs. In an optimized 5G world, a hospitality provider may host all its communications from a centralized location — perhaps its own data center, or maybe infrastructure leased from a public cloud provider. In either case, 5G could enable both voice and data services to be deployed from that central location, directly to the remote site. A group of guests representing a single enterprise employer could effectively be leased their own data center, complete with management portal, so they can coordinate and conduct their business while on-site, all using local communications. NR-U could provide these guests with the bandwidth they need to conduct live conferences from hotel ballrooms, record their sessions, and stream them live — again, using compute and storage infrastructure deployed locally.

An academic institution or network of research facilities could accomplish the same objective. They could communicate locally using voice and data services that are all centrally secured through a service portal that is operated by the customer institution. NR-U could enable researchers and educators to share their work through voice and data channels simultaneously, without any of their communications transgressing the public Internet.

An insurance firm responding to a natural disaster could use portable cellular communications equipment to quickly deploy emergency voice and data networks, linking field agents, central offices, and emergency service providers. NR-U could enable these field agents to deploy temporary shelters, in tents if necessary, that would keep all personnel connected with one another, and available in real-time. In addition, the bandwidth would be available for agents to deploy unmanned drones with cameras, to scan wide devastated areas and help agents map locations with more urgent needs. First responders could use infrared cameras to scan for as-yet-undetected signs of life.

One part of the 5G portfolio that we haven’t discussed here, which would also be necessary for these dream scenarios to be feasible, is the system that deploys the core services of data networks to remote locations. It’s now called Multi-access Edge Computing (MEC, though the “M” has stood previously for “Mobile” and maybe other things), and it aims to be the part of 5G Release 16 that transports “the edge” to wherever it needs to be. MEC will be the subject of our next installment. Until then, hold fast.