Critical and complementary – setting the record straight on 5G and Wi-Fi
Time to set the record straight on cellular 5G and Wi-Fi 6/7, a panel of Industry 4.0 luminaries suggested at Private Networks Forum (PNF) a couple of weeks back; these technologies are not, and never will be, mutually exclusive, it implied. They will not be competitor-technologies, ever, and should not be pitched as such. Their futures are separate and together, they said; geared for different ends, even if they are in close company in the same venues.
And yet this idea that private 5G will replace Wi-Fi, or that Wi-Fi 7 will replace 5G, will not go away. Which is why Arden Media put on the session at PNF in the first place, and why the commentary from it is worth hearing again. “None of that will happen; neither will replace the other. They are complementary; they will coexist,” responded Rahul Patel, senior vice president and general manager for connectivity, cloud and networking at Qualcomm Technologies.
The question was about their overlap in Industry 4.0. Patel explained: “5G is an upgrade on cellular that brings robustness in a different way, and brings bandwidth and latency to new heights. And Wi-Fi 7 does the same in unlicensed spectrum, by bringing in tremendous robustness and latency, as well as enhancing bandwidth. They are very complementary. One is a [local-area] LAN technology, and one is largely a [wide-area] WAN technology.”
But why the confusion? The simple answer is that these generational upgrades both bring giant leaps in performance, which precipitate new Industry 4.0 dynamics. We know the 3GPP-developed 5G NR standard quite well, especially as it is introduced (often via LTE) by private enterprises in private and shared spectrum. Wi-Fi is written about less (here), just because it is familiar already, and its Industry 4.0 credentials are less spectacular.
This is a fair assessment, borne out in the PNF session; the task to animate business/mission-critical operations, at the higher-end of the Industry 4.0 chain, will be a mostly-5G affair, the panel concluded. But Wi-Fi, ever-more capable, will provide crucial support besides. “[You find] use cases where 5G, for mission critical needs, is going extremely well, and Wi-Fi, [for] less mission critical [needs], is complementary,” said Patel.
Airbus is putting this into practice. The company set up as a private MVNO in France seven years ago in order to run post-flight data offloads and predictive aircraft maintenance over LTE (4G); its adventures in cellular expanded into its manufacturing business five years ago – and into private LTE, initially, on the grounds it could not find a single operator to replicate service across its multiple production sites. in France, Spain, Germany, and the UK.
In the end, with liberalisation of radio spectrum and optimisation/miniaturisation of network systems, Airbus was able to engage with cellular on its own terms, with a roadmap eventually to private-industrial 5G; it is the same story that is being multiplied across Industry 4.0 sectors. But Patrick Castagnino, in charge of connectivity and strategy innovation for digital aviation for the company, makes clear its interest in cellular is not at the expense of Wi-Fi.
He explained: “Why cellular? Because the performance of Wi-Fi is not enough to perform certain manufacturing tasks. Because we cannot [even] receive Wi-Fi properly within an aircraft during the manufacturing process – only 4G/5G delivers coverage for workers inside an aircraft. So that was the demand: full roaming and connectivity everywhere, for every worker on the campus.”
But the previous assessment, about 5G for mission-critical comms and Wi-Fi for general-purpose support, is unfair as well, at the same time. Castagnino, it might be noted, is comparing past and present cellular and Wi-Fi versions, even if his point stands about wireless WAN-versus-LAN inside complex manufacturing plants. At the same time, Wi-Fi 7, coming some time after 2024, builds significantly on Wi-Fi 6 and 6E, only just starting to be available.
Wi-Fi 7 will offer a number of gains; mostly significantly, higher throughput. Also referred to as Wi-Fi Extremely High Throughput, the key metric, on paper, is it will deliver 30 Gbps speeds; about three times faster than Wi-Fi 6. It also proposes wider transmission (at 320 MHz; double of Wi-Fi 6), higher modulation (to 4096-QAM, optionally; four-times Wi-Fi 6 levels), plus broader band/channel aggregation, greater spectrum efficiency, and less signal interference.
It should also support applications that need absolute determinism, higher reliability, and dynamic service (QoS). Which pitches it against incoming 5G versions, from Release 16 onwards, featuring the same industrial magic that is supposed to deliver total control of high-end Industry 4.0. The real comparison, then, should be between Wi-Fi 7 and Release 18-level 5G, similarly scheduled for the medium-near term (after 2024), rather than the short-near term.
For now, both technologies exist effectively as half-baked technologies so far as Industry 4.0 goes. Which is not to say they are not useful, even crucial, for progressive enterprises looking to catch a sail on the rising swell and wild wind of industrial change and digital revolution. But they are different, the panel maintained, despite parallel development paths. And the reasons are plain, however far along they go. Because of coverage, mainly.
Back to Castagnino, responding to a question during the PNF panel session about whether the limitations of Wi-Fi will be addressed by future versions, or whether certain Industry 4.0 use cases will be forever out of reach of it, only serveable in the end by 5G. “Continuity of service will be addressed by cellular, not by Wi-Fi – by which I mean the roaming capacity of the technology. For Airbus, Wi-Fi is a coexistent technology; it is not one against the other.”
He continued: “But [you need cellular] to provide maximum coverage… We can cover a small area with Wi-Fi with specific performance. But we cannot cover a hangar with one Wi-Fi access point; we cannot cover all the sites and all the campus with it. So it is extremely [valuable] for us to be able to install one 5G mast for full indoor and outdoor coverage, versus multiple WI-Fi access points. That is the main reason: coverage and performance.”
Indeed, the idea that Industry 4.0 will wait on 5G-proper (Releases 17-plus), or Wi-Fi 7 potentially, is not right, said Guillermo Quintana, in charge of business development for private networks and multinationals at Telefonica’s global solutions business. He rejects the idea that private 5G is a two-speed market, between lightweight ‘carpeted’ verticals making use of consumer-style eMBB functions and hard-floored industry holding out for URLLC.
“We have seen demand for private networks in manufacturing, of course, and in logistics, utilities, ports, mining – with use cases that are way ahead of what we would expect from a simple step-by-step approach. In mining, for example, these autonomous haulage systems, these big self-driving trucks, pulling on average 400 tons in each load, provide lots of data to control centres by sending daily updates related to predictive maintenance and self driving.”
He continued: “The data needs to be very precise; these are business-critical, close to mission-critical, use cases we are supporting. So we have simple network setups with very simple use cases, and also very demanding use cases.” But back to the differences; it might be suggested, as well, that their network operation, alternatively, in licensed (and, importantly, privately-licensed) and unlicensed spectrum is another major point of difference.
Even if there is technical development to make 4G/5G function in unlicensed bands, pristine new 6 GHz spectrum coming available for Wi-Fi 6E, and new technical and regulatory work to make Wi-Fi spectrum management more prescriptive in unlicensed bands, these differences matter, for now – as the foundational Industry 4.0 networking layer goes in.
Back again, as well, to the idea that 5G is better for mission-critical comms; this is unfair, also, perhaps, because it does not consider the criticality of Wi-Fi as a support act. This seemed to be implicit in the PNF commentary. Patel’s run-down of dual-mode cases referenced a couple of key crossovers: Wi-Fi for offloading data from 5G infrastructure, and, more prosaically, for fixed wireless access (FWA) for SMEs in remote climes, where fibre will never reach.
“Both will exist in industrial applications. The [privatisation] and industrialisation of networks, [means] 5G will coexist with Wi-Fi in many situations. They will exist, and be very complementary,” he restated. But there are obstacles, most clearly for the cellular market, which – unlike the straighter path for the enterprise Wi-Fi ecosystem – is negotiating a complete about-turn in terms of network systems, user requirements, and sales channels.
Caroline Chan, vice president and general manager for Intel’s 5G infrastructure division and network platform group, said the conundrum for telcos goes way beyond spectrum (fragmented), devices (scarce), or service (undefined). She said: “This is a business problem to solve. I grew up in the telco business, and the telco business always chases the problem as a tech issue – solving radio coverage, and squeezing spectrum. Those things will be addressed.”
She explained: “But we are going into manufacturing and agriculture to solve business problems. It is about the end result. So the ecosystem is more complex. It is not just [about solving a] telco issue – it is telco, plus operations, plus IT, plus OT… Spectrum and devices are problems that need to be solved, but the number one thing is to enlarge the ecosystem to cover the needs of our verticals for 5G to thrive.”