5G Cellular: Why Wi-Fi Not Just Survives, but Prospers

OK, what we know so far is two very important facts. First, 5G is absolutely going to happen in the early 2020s, and, second, 5G borrows quite liberally from what Wi-Fi already is today. 

So if the cellular carriers are dedicated to using 5G to expand their empires, then why wouldn’t they use 5G to replace Wi-Fi, initially in public spaces, but without too much additional effort in enterprises and other organizations, and perhaps even the residence? After all, they’re more than interested in growth, as well as already eyeing unlicensed spectrum for LTE deployments, where they even claim a few technical advantages over Wi-Fi for their unlicensed implementations.

One stop shopping and a superior offering? Sounds attractive, doesn’t it?

Well, not so fast there, carriers. Yes, 5G will be the best you’ve ever had. It will be successful in displacing, and perhaps as early as 2030, all previous cellular generations. It will offer throughput sufficient to meet the needs of essentially all voice, data, and video traffic. It will duplicate the function of consumer-level wire and continue the displacement of wireline services already underway with some leading-edge organizations and consumers. 

But as we’ve seen with the carrier’s interest in both the unlicensed bands and the rather tricky millimeter-wave bands, access to spectrum sufficient for wideband/broadband deployments on a very large scale is the key to 5G success. As we noted earlier, it’s all about capacity – something Wi-Fi already has, thanks to a lengthy base of experience and roughly a gigahertz of spectrum. Unlicensed, yes, but optimized via specialized protocols and reused quite efficiently via small cells – I mean, dense deployments.

So could 5G to translate well into the unlicensed spectrum used by Wi-Fi today? Not likely – the protocols used by licensed and unlicensed services are completely different from one another. This is by design and absolutely necessary. Reworking protocols for a new mission involves massive effort and investment, but usually with little return on investment – a bit like building a car that can also be an airplane. 

Hey, wasn’t that tried some time ago? And just how massive was that success? The bottom line: Why build another Wi-Fi if there are no advantages in so doing? 

All of this is reminiscent of efforts across the recent history (20 years or so) of wireless, with proponents of a given technology sometimes (often?) attempting a force-fit into a mission for which that technology is unsuited. Remember WiMAX? WiMAX was actually (as IEEE 802.16m) an official 4G technology, but it crashed and burned. Why? Because it offered no real advantages over LTE-Advanced, and marketing hype destroyed its credibility. Ditto for Bluetooth, which in the early days was promoted as a wireless LAN – a role for which it was obviously unsuited. 

Bottom line: Any proposed replacement technology must have a demonstrable and sustainable competitive advantage in at least one dimension (technology, financial, operations, etc.), or it will fail. And unlicensed 5G has none.

Flipping this around, I previously somewhat facetiously suggested that Wi-Fi be adapted for use in licensed bands. OK, that’s not going to happen either, and for the same reason that the reverse is so difficult.

So, instead, the future I see is 5G eventually becoming the wide-area technology. And Wi-Fi, with .11ac today (and eventually in the form of 802.11ax and maybe 802.11ay during the rise of 5G) interworking (sometimes called hard handoff) with 5G transparently. Thus applying, and transparently, I might add, the best tool for the job in terms of both technology and economics with appropriate venue, traffic, and policy.

This is the strategy of heterogeneous networks, or HetNets – cooperating WWANs and WLANs, and is ultimately the most cost-effective option – which is why it wins. 

Finally, and perhaps most importantly, Wi-Fi has one other attribute that will simply prove insurmountable to anyone attempting to replace Wi-Fi with 5G – a massive installed base.

Key here is the fact that a large installed base mitigates almost every potential threat for a long time, and often forever. Think about it: cellular vendors cannot clobber Wi-Fi services with competing signals or attempt a wholesale replacement of Wi-Fi with a new technology that has precisely the same functionality without incurring the fundamental wrath of their customers.

This will certainly be true for at least the next 15+ years, and probably forever. The upgrade/replacement costs would be enormous, and let’s agree: W-Fi has become cultural – an expectation, everywhere, with billions of users and devices happily working and playing globally today. IEEE 802.11 and the Wi-Fi Alliance are showing no signs that it’s time to close the Patent Office.

Replace Wi-Fi with 5G? Nice try. But it ain’t going to happen. And prosper may just be an understatement.

All Posts In This Series:

1) Setting The Record Straight On 5G Cellular: What It Is – And Isn’t

2) Learning About 5G Cellular: The Technologies

3) 5G Cellular: Why Wi-Fi Not Just Survives, but Prospers

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Craig J. Mathias is a Principal with Farpoint Group, an advisory firm specializing in wireless networking and mobile IT. Founded in 1991, Farpoint Group works with technology developers, manufacturers, carriers and operators, enterprises, and the financial community. Craig is an internationally-recognized industry and technology analyst, consultant, conference and event speaker, and author. He currently writes columns for Boundless, Connected Futures, CIO.com, and various sites at TechTarget. Craig holds an Sc.B. degree in Computer Science from Brown University, and is a member of the Society of Sigma Xi and the IEEE.

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