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Monday, May 20, 2019

5G as an enterprise LAN / Wi-Fi replacement is a myth


There are at least 10 reasons why 5G will not be a viable WLAN (wireless local area network) technology for mainstream enterprise. Despite recent claims to the contrary, it is not an alternative to Wi-Fi in offices, hospitals, apartment blocks or similar locations. 

Enterprises, investors, policymakers and vendors should be extremely skeptical of assertions 5G will displace mainstream Wi-Fi uses. Indeed, they should question the credibility and honesty of those uttering such claims.

There will certainly more deployments of indoor cellular (including private and neutral host networks) in future, but these will almost all be incremental and not substitutional to Wi-Fi. They may be used for IoT/OT uses, but typically these will be entirely new. 

4G / 5G technologies will not be integrated into most laptops or tablets, despite hype.

This post looks at why 5G cannot replace enterprise Wi-Fi - including numerous obvious reasons - and then examines why the cellular industry (which mostly understands the problems) is pretending otherwise. What's the story behind the unrealistic fantasy?

(It's quite long. Get a coffee first.)

What is wireless used for in enterprises?

Before drilling into the specifics of 5G, it is worth looking at how and why wireless gets used in enterprises at a local area. Local area here means a single office or site - whether that's an office block, a supermarket, a hospital or a factory. Some locations have multiple LANs across several buildings on a campus network, such as a university, corporate HQ site or major new property development.

(By contrast, WANs run over wide areas, such as between a retail chain's stores and warehouse sites in different cities, or linking a multinational bank's offices in several countries. Huge locations like smart cities and airports are somewhere in the middle).

A top-level list of local wireless uses, often with separate infrastructure, includes:
  • Local IT / Internet connectivity - this is the main LAN space, dominated by fixed ethernet and Wi-Fi. It connects PCs, laptops, deskphones, tablets, conferencing gear and various other computing products, either to the business's own servers or to the Internet and cloud. It is also good for private use of smartphones.
  • Coverage extension of public mobile operator (MNO) services onto private property, where outdoor-to-indoor signals don't reach. This uses various forms of distributed antenna system (DAS), repeaters, small-cells etc, typically installed today only in the largest buildings. Essentially, this enables local smartphone connectivity both to the telco's services (eg telephony) and to the public Internet. In some cases Wi-Fi is used to "offload" data that could normally have gone over the carrier network. Note: genuine offload is a tiny fraction of total smartphone data traffic - see this post for more (link)
  • Local IoT connectivity (connecting building automation systems, HVAC, entry control etc. This can be further divided into
    • Static IoT - things that don't move around, such as sensors, door controls, CCTV cameras & aircon units
    • Mobile IoT, for instance credit card terminals, robots, wearables, asset-tracking tags etc
  • Local OT connectivity - operational technology, often business/safety-critical with a need for realtime deterministic control, such as industrial machinery, process controls, medical equipment and so on.
  • Local voice connectivity - especially walkie-talkies and private two-way radio, which are now starting to be replaced with cellular alternatives.
  • Other local uses - numerous sectors have their own niche wireless requirements, maybe linking to public safety / first-responders, broadcast, audiovisual systems etc
While some of these categories overlap (for example, smartphone connections), others remain pretty well-defined in practice. Yet often, they get conflated, especially in discussions about the future roles of 4G/5G cellular networks, whether run by mobile carriers, or new/specialist indoor operators and the enterprises themselves.

This post is specifically about the IT/LAN/Internet access use-case. I think cellular has a lot to offer IoT (especially mobile IoT) for enterprise, as well as OT in industrial settings. We will also see more indoor / premises neutral-host networks (NHNs) both for coverage and private onsite voice/smartphone access. However, none of those generally gets classed as "LAN" connections.

(SAVE THE DATE: I will be running a private workshop in London on July 9th about NHNs, looking at both indoor and wide-area / metro / rural uses and deployment scenarios)

Why can't 4G/5G be used for wireless LANs instead of Wi-Fi?

At the heart of this debate is whether 3GPP cellular technologies can be used for local-area computing networks, especially for laptops, tablets and private smartphone use. Can it replace fixed ethernet and especially Wi-Fi connections? Will future PCs connect to the Internet via 5G? I'm being asked this by various of my clients, so it's worth going in to some detail here (and obviously, more detail & analysis for paying advisory customers)

This is not a new discussion - the 3GPP vs. IEEE standards war has waged for decades. I've addressed the topic multiple times, whether that's been about in-home usage (link), debunking the "5G will kill WiFi" myth (link) or discussing the important role for private cellular in industry and the need for local spectrum licensing (link). 

I can see at least 10 reasons why cellular (whether provided by MNOs as a service, or owned by the business or an NHN provider) is not a suitable IT LAN technology for enterprise:
  • 13bn installed base of actively-used Wi-Fi devices today, of which only smartphones typically have cellular radios. Some have shortish replacement cycles (eg tablets) but others will last for 10+ years. They will need to be supported in-building.
  • A tiny fraction of laptops & tablets have in-built 4G radios today. Despite the hype, this will not change significantly with 5G. Customers won't pay more for them, and manufacturers don't want the margin hit. We might see 10-20% penetration, but I'm doubtful (This is a whole other "10 reasons" post in its own right...) Wi-Fi remains primary.
  • Plenty of other devices will never have cellular connections (5G printers? Servers?!). The number of Wi-Fi devices is exploding in IoT as well - from smart-speakers to lighting to interactive screens and terminals. Add in new low-power Wi-Fi for things like headsets (and a separate battle between Wi-Fi / BLE / ZigBee which cellular doesn't even have a toe in). Again, Wi-Fi remains primary. High-end/critical IoT devices may actually adopt passive optical LAN connections, rather than any wireless technology.
  • Private 4G/5G networks are not just radios. They need core networks, control software, and maybe SIMs/eSIMs. The average IT department does not want to, or have the skills, to deal with all this, compared with installing some ethernet wiring and some Wi-Fi APs.
  • Almost no businesses want to deal with the complexities of private / public cellular interconnection, roaming, regulation (lawful intercept?!) and so forth
  • Even if some IT departments want to go towards 4G/5G connectivity, they still have BYOD policies, and guests, contractors and tenants who will keep desiring (& often expecting) Wi-Fi
  • In-building 5G is going to be hideously complex anyway, especially for mmWave frequencies. Installing small cells also needs fibre backhaul, power etc. in the right places, whch may be different locations to Wi-Fi APs.
  • Ironically, in-building 4G small cells usually need wired LAN connections to connect them. In future, it might even be possible to use Wi-Fi6 as backhaul, as it should have good-enough deterministic QoS for the time-sync requirements.
  • The world would need, I estimate, 100-300,000 more enterprise cellular specialists for designing, installing, maintaining & operating 5G LANs. And AFAIK there aren't even proper training programmes, or certification schemes. That's a decade or more on its own (and probably a big opportunity for some) 
  • Indoor wireless coverage is difficult and variable. Radio is absorbed by interior walls, partitions, furniture, insulation, pipework etc. Giving QoS guarantees is almost impossible. Few design, planning and testing tools are available.
  • Device-to-device use cases for Wi-Fi are not easily replicable with cellular. Maybe in the future.
  • User perceptions of Wi-Fi and cellular, and behaviour around it, are entrenched and will take years to change, if ever.
  • Patent & royalty costs for cellular are higher, as well as the extra chipset costs.
  • Unknowable new security / threat surfaces (and the fact that Wi-Fi security is often integrated with the enterprise's identity & threat-management systems today)
I could go on. Some of these will change, some will have rare exceptions, and some industries will have particular local requirements for whatever reasons. But the underlying story is clear: 5G is not a Wi-Fi replacement for the enterprise. 
This should not really be a surprise to anyone. I honestly find it hard to believe that most people involved in networks/telecoms don't realise at least 4 or 5 of these points off the top of their heads.

Historical note: I've been skeptical of cellular-enabled laptops since 2006 (link). I wrote a full report in 2008 (link), which was actually far too optimistic (I predicted 30% attach-rate by 2011) despite being criticised as too-negative by the cellular industry. Most of the arguments remain valid for 5G.

So why the hype?

What's a bit baffling is why the 5G/WiFi replacement fantasy is becoming more common. Even AT&T's CEO was quoted at the company's financial results event (link) as saying "It’s serving as a LAN replacement product". Other 5G-centric commentators have said similar things.

To be fair, in some cases it will be genuine ignorance, although frankly anyone that clueless about enterprise networks shouldn't be making pronouncements anyway. Another more important issue is the conflation of all the different use-cases for connectivity (as above), and people conflating the LAN, offload and IoT domains in particular. Through that lens, the AT&T statement could (very generously) be considered applicable to some IoT scenarios.

Yes, 5G has a long-term role in some industrial verticals, especially with time-sensitive networking and private control of core and/or radio & spectrum. Neutral-host cellular will be important indoors too. But controlling robots & process machinery, or doing asset-tracking in a hospital, is not the same as accessing SaaS applications from a laptop or tablet, or local IoT applications from billions of devices with local gateways. Neither is using a new 4G/5G CBRS or local-spectrum network for "reverse roaming" or "MVNO onload" really a LAN business either.

But I think there are a few other more cynical reasons in play too:
  • Embarassment over mmWave's poor indoor penetration (despite the rhetoric), meaning Wi-Fi is an essential in-building complement for any 5G FWA deployment. This applies in residential use, but also for businesses too. Pretending that some sort of 5G outdoor - 5G indoor hybrid could fix this might spare a few blushes.
  • Cost & complexity of future indoor 5G deployments: Reality is biting. Existing indoor systems are going to be hard to upgrade to even 3-4GHz bands, let alone adding mmWave and massive-MIMO support too. It's not just the radio elements, either - how exactly are carriers going to offer QoS / network-slicing over someone else's indoor wiring and antenna infrastructure? See this eBook I recently wrote for iBwave (link) for more details. Basically, if the telcos are going to help pay for 5G indoor connectivity, then new use-cases/revenues are desperately sought, beyond just MBB coverage. A "managed 5G LAN" line on a spreadsheet likely looks appealing, even if it's an exercise in wishful thinking.
  • Bluster & hype aimed at regulators considering the 6GHz or other bands for unlicensed use (& thus mostly more Wi-Fi). The US FCC and various European regulators seem minded to add another large band (500-1200MHz) to the unlicensed systems arsenal. Taking a public stance of saying "Oh, 5G could do all those use-cases as well - how about normal exclusive licenses for that band instead?" fits the political narrative, even if it doesn't fit reality. 
  • Some 3GPP fundamentalists' dislike of Wi-Fi and unlicensed spectrum generally, or non-telco controlled networks, explains some of the comments. I've seen posts on LinkedIn saying "I wish Wi-Fi would go away", and similar. They have long fantasised about MNO-managed cellular LANs , in the same way that some Wi-Fi (and satellite) fundamentalists think they can replace mobile networks. They're all wrong. (And so are the 5G FWA folk claiming it's a mainstream alternative that could replace fibre or cable).


So to sum up:
  • There's lots of different uses for wireless networks in enterprise, whether in individual buildings or across larger campuses. Ignore anyone who groups them all together.
  • IT-centric LAN connections, for normal computing devices connecting to the Internet, cloud or local servers, are dominated by ethernet - either using fixed cabling, Wi-Fi or occasionally optical LAN. Smartphones connect both by Wi-Fi and cellular, where indoor connection is good enough.
  • A handful of laptops and tablets can use 4G connections today, although few owners even bother to sign up for data plans. A slightly larger handful will have integral 5G in 5 years time, but most will just stick to Wi-Fi only. They will need to be supported in all the same locations as today, plus many new ones (eg public transport & retail).
  • Private 4G and 5G networks come in many varieties, with a huge range of shared/local spectrum options being considered by regulators (link). Most, however, are not aimed at LAN use-cases, but more oriented to IoT/OT/indoor cellular coverage requirements. In those instances, Wi-Fi has limitations, for instance in applicability to robots moving around a large factor or warehouse.
  • Some industrial/critical use-cases are not ideally suited to unlicenced spectrum, even with the better performance of new WiFi6 deployments. Given that the WiFi industry doesn't (yet) have a licensed-band version, then cellular is a likely option instead. 
  • Neutral host cellular networks are very exciting future developments, both indoors and out. But they're not going to be LAN replacements either.
  • Operator 4G and 5G networks are very important to extend in-building, especially if telcos want to offer new network-slicing or QoS products that don't just work outdoors. However, upgrading existing in-building coverage solutions to 5G is hard, expensive and has many unknowns. Many small buildings don't have indoor coverage solutions at all today. The mobile industry is casting around for new revenues, as well as costs. One takeout: end-to-end network slicing is largely mythical, and will need to work over 3rd-party Wi-Fi indoors.
  • We will also see various forms of Wi-Fi + cellular bonding, with devices connecting to both networks simultaneously. That's for another post.
  • As with all areas of 5G hype, there's an "it'll solve world hunger", "one-size fits all" pitch to politicians, regulators, investors and media. It needs to be called out for its disengenuousness.
Overall, the key takeout: 
Private/enterprise 4G and 5G networks have lots of potential future use-cases & market opportunities. Replacing Wi-Fi for IT/Internet access LANs is not one of them.

Note: if you're interested in deeper analysis, or a private workshop / advisory engagement on this topic, please drop me an email at information at disruptive-analysis DOT com, or contact me via LinkedIn or Twitter.

Also - on July 9th, I'm running a London private workshop on Neutral Host Networks, together with Peter Curnow-Ford of Viatec Associates. Drop me a message if you're interested, and look out for full details & registration coming very soon.