The Myth of "Always Best Connected"

 (This was originally posted as a LinkedIn Newsletter article. See this link, read the comment thread, and please subscribe)

It Was the Best of Times, it Was the Worst of Times

One of the most ludicrous phrases in telecoms is "Always Best Connected", or ABC. It is typically used by an operator, network vendor or standards organisation attempting to glue together cellular and Wi-Fi connections. It's a term that pretends that some sort of core network function can automatically and optimally switch a user between wireless models, without them caring - or even knowing - that it's happening.

Often, it's used together with the equally-stupid term "seamless handover", and perhaps claims that applications are "network agnostic" or that it doesn't matter what technology or network is used, as long as the user can "get connected". Often, articles or papers will go on to describe all Wi-Fi usage on devices as "offload" from cellular (it isn't - perhaps 5% of Wi-Fi traffic from phones is genuine offload).

There's been a long succession of proposed technologies and architectures, mostly from the 3GPP and cellular industry, keen to embrace but downplay Wi-Fi as some sort of secondary access mechanism. Acronyms abound - UMA, GAN, IWLAN, ANDSF, ATSSS, HetNets and so on. There have been attempts to allow a core network to switch a device's Wi-Fi radio on/off, and even hide the Wi-Fi logo so the user doesn't realise that's being used. It's all been a transparent and cynical attempt to sideline Wi-Fi - and users' independent choice of connection options - in the name of so-called "convergence". Pretty much all of these have been useless (or worse) except in very narrow circumstances.

To be fair, accurate and genuine descriptions - let's say "Rarely Worst-Connected" or "Usually Good-Enough Connected" or "You'll Take What Connection We Give You & Shut Up" - probably don't have the same marketing appeal.

Who's Better, Who's Best?

The problem is that there is no singular definition of "best". There are numerous possible criteria, many of which are heavily context-dependent.

Which "best" is being determined?

• Highest connection speed (average, or instantaneous?)
• Lowest latency & jitter
• Lowest power consumption (including network, device and cloud)
• Highest security
• Highest visibility and control
• Lowest cost (however defined)
• Greatest privacy
• Best coverage / lowest risk of drops while moving around
• Highest redundancy (which might mean 2+ independent connections)
• Connection to the public Internet vs. an edge server

In most cases involving smartphones, the basic definition of "best" is "enough speed and reliability so I can use my Internet / cloud application with OK performance, without costing me any extra money or inconvenience". Yet people and applications are becoming more discerning, and the network is unaware of important contextual information.

For instance, someone with flatrate data may view "best" very differently to someone with a limited data quota. Someone in a vehicle at traffic lights may have a different connection preference to someone sitting on the sofa at home. Someone playing a fast-paced game has a different best to someone downloading a software update. A user on a network with non-neutral policies, or one which collects and sells data on usage patterns, may want to use alternatives where possible.

In an era of private cellular, IoT, multiple concurrent applications, encryption, cloud/edge computing and rising security and privacy concerns, all this gets even more complex.

In addition to a lack of a single objective "best", there are many stakeholders, each of which may have their own view of what is "best", according to their particular priorities.

• The user
• The application developer
• The network operator(s)
• The user's employer or parents
• The building / venue owner
• The device or OS vendor
• A third-party connection management provider (eg SD-WAN vendor)
• The government

On some occasions, all these different "bests" will align. But on others, there will be stark divergence, especially where the stakeholders have access to different options for connectivity. A mobile phone network won't know that the user has access to an airport lounge's premium Wi-Fi, because of their frequent flyer status. A video-streaming app can't work out whether 5G or Wi-Fi will route to a closer, lower-power edge server.

So who or what oversees these conflicts and makes a final decision on which connection (or, increasingly, connections plural) is chosen? Who's the ultimate arbiter - and what do the other stakeholders do about it?

This problem isn't unique to network connectivity - it's true for transport as well. I live in London, and if I want to get from my home to somewhere else, I have lots of "best" options. Tube, bus, drive, taxi, walk, cycle and so on. Do I want to get there via the fastest route? Cheapest? Least polluting? Easiest for social-distancing? Have a chance to listen to a podcast on the way? If I want to put the best smile on the most people's faces, maybe I should go by camel or unicycle? And what's best for the city's air, Transport for London's finances, other travellers' convenience, or whoever I'm meeting (probably not the unicycle)?

 

There are multiple apps that give me all the options, and define preferences and constraints. The same is true for device operating systems, or connection-management software tools.

Hit Me With Your Best Shot

There are also all sorts of weird possible effects where "application-aware networks" end up in battle with "network-aware applications". Many applications are designed to work differently on different networks - perhaps "only auto-download video on Wi-Fi" or "ask the user before software updates download over metered connections". Some might try to work out the user's preferences intelligently, and compress / cache / adjust the flow when they appear to be on cellular, or uprate video when the user is home - or perhaps casting content to a larger screen. The network has little grasp of true context or user/developer desire and preferences.

Networks might attempt to treat a given application, user or traffic flow differently - perhaps giving it priority, or slowing or blocking it, or assigning it to a particular "slice". The application on the other hand might try to second-guess or game the network - either by spoofing another application's signature, or just using heuristics to reverse-engineer any "policy" or "optimisation" that might get applied.

You're My Best Friend

So what's the answer? How can the connectivity for a device or application be optimised?

There's no simple answer here, given the number of parameters discussed. But some general outlines can be created.

• Firstly, there needs to be multiple connections available, and ways to choose, switch, arbitrage between them - or bond them together.
• The operating system and radios / wired connections of the device should allow the user (or apps) to know what's available, with which characteristics - and any heuristics that can be deduced from current and previous behaviour.
• The user or device-owner needs to know "who or what is in charge of connections" and be able to delegate and switch that decision function when desired. It might be outsourced to their MNO, or their device supplier, or a third party. Or it could be that each application gets to choose its own connection.
• As a default, the user should always be aware of any automated changes - and be given the option to disable them. These should not be "seamless" but "frictionless" or low-friction. (Seams are important. They're there for a reason. Anyone disagreeing with this statement must post a picture of themselves wearing a seamless Lycra all-in-one along with their comment).
• Connectivity providers (whether SPs or privately-owned) should provide rich status information about their services - expected/guaranteed speed & latency, ownership, pricing, congestion, the nature of any data-collection or traffic inspection practices, and so on. This will be useful as input to the decision engines. Over time, it will be good to standardise this information. (Governments and policymakers - take note as well)
• We can expect connectivity decisions to be partly driven by external context - location, movement, awareness of indoor/outdoor situation, environment (eg home, work, travelling, roaming), use of accessories like headphones or displays, and so on.

Going forward, we can expect wireless devices to have some form of SD-WAN type control function. Using technologies such as multipath TCP, it will become easier to use multiple simultaneous connections - perhaps dedicated some to specific applications, or bonding them together. For security and privacy, the software may send packets via diverse routes, stopping any individual network monitoring function from seeing the entire flow.

Growing numbers of devices will have eSIM capability, allowing new network identities / owners to be added. Some may have 2+ cellular radios, as well as Wi-Fi (again, perhaps 2+ independent connections), USB and maybe in future satellite or other options as well.

Add in the potential for Free 5G (link), beamforming, private 5G, local-licensed spectrum WiFi, relaying & assorted other upcoming innovations to add even more layers here.

The bottom line is that "best connected" will become even more mythical in future than it already is. But there will be more options - and more tools - to try to optimise it, based on a dynamic and complex set of variables - especially when going beyond connectivity towards overall "quality of experience" metrics spanning eyeball-to-cloud. There's likely be plenty of opportunities for AI, user-experience designers, standards bodies and numerous others.

But (with apologies to the Tina Turner), users should always be wary of any software or service provider that claims to be "Simply the Best".

If you've enjoyed this article, please sign up for my LinkedIn Newsletter (link). Please also reach out to me for advisory workshops, consulting projects, speaking slots etc.

#5G #WiFi #cellular #mobile #telecoms #satellite #wireless #smartphones #connectionmanagement

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

Introduction

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).

Conclusion

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.

No, 5G won't kill WiFi (or absorb it)

I've seen two things today that are trying to suggest that 5G (or even 4G) are going to cause problems for WiFi, or even "kill it".

Ignore them.

Firstly, this piece by Bloomberg (link) suggests that a combination of mobile operators' renewed flat-rate data plans, along with LTE-U, could render WiFi obsolete. It's one of the worst pieces of technology "journalism" I've read in ages.

Secondly a discussion on Twitter led to a 3GPP document about "New Services and Markets" from a year ago, which talks about "Mobile Broadband for Indoor Scenario" in section 5.5  (link). That seems to suggest that 4G/5G could replace office WiFi or even wired LANs.

Needless to say, both are total nonsense. There is a longstanding strain of thought among some "cellular fundamentalists" that WiFi is just a step away from being replaced by mobile operators' services. It is wishful thinking, verging on delusion. (It won't be subsumed as a mere secondary part of 5G, either - although that's a separate post).

While there are some corner-cases that might swing one way or the other, based on pricing and perhaps neutral-host cellular using LTE in unlicensed bands (perhaps in MuLTEfire guise rather than the anti-competitive LTE-U and LAA variants), those are rare exceptions.

In home, offices, and public spaces, there is essentially zero chance that owned WiFi or fixed ethernet are going to be replaced in large quantity, by 5G operators acting as LANaaS providers.

There are many reasons for this, but some of them are:

• Billions of WiFi-only devices, from PCs and tablets, to TVs, printers and a broad array of consumer and industrial products.
• Billions more WiFi-only devices in future (no, not everything will have a cellular module & eSIM - it's way more expensive and limiting - see my report link)
• The ability for WiFi to operate easily in "service", "subscription", "amenity", "owned", "free", "local", "sponsored", "venue-provided", "ad-supported" and many other business models. Cellular connectivity - reliant on SIM or eSIM - generally enshrines "subscription" and a service model as the only option.
• Ability of venue-owners to control and police WiFi network access (eg a cafe-owner or conference organiser can give the codes to their choice of user, under their conditions)
• Use of WiFi Direct for P2P connectivity
• Integration of WiFi in businesses with LAN and security systems
• Preferential use of WiFi in-built to smartphone OS's and connection-management tools
• Large % of people who are not using flat-rate mobile data plans, especially prepay users in most of the world
• A broad view that WiFi is not only "free" but also *different* as it isn't owned / metered / tracked by a service providers. (We all recognise that amended Maslow Hierarchy of Needs picture, with WiFi scrawled as a tier beneath food & shelter)
• Anonymity of most WiFi hotspots
• Huge push of WiFi by cable, fixed-broadband and some WiFi-first MVNO providers, including to outdoor / metropolitan zones and being built-into 500 million or more home gateways around the world
• Use of WiFi in public transport (buses, trains, planes) - even if backhauled by 4G and/or satellite, plus increasing use of WiFi hotspots in cars (again, linked via LTE to the network)
• Poor penetration of cellular for deep-inbuilding use without DAS or small cell coverage, which is often impractical
• Lower costs of infrastructure, especially given the heavy IPR load associated with 4G modems and base stations. 
• Enterprise desire to use multiple connections for cloud/WAN access, eg via SD-WAN

I think the most risible line in the Bloomberg piece is this "Wi-Fi also helps fill in gaps in some office buildings and homes that have spotty cellphone coverage" - in many ways, it's the complete opposite of the way many users view the two technologies.

Every analysis I've seen has suggested that WiFi use is generally growing faster than cellular data consumption, and there is very little reason to expect it to change. In many ways, I'd expect WiFi - and also other unlicensed band technologies for LPWAN and IoT - to outstrip coming cellular use-cases, especially indoors but also for the wide area.

A less-virulent strain of the same bad idea is that 5G will absorb or subsume WiFi, as part of its amazing network-slicing / HetNet / integrated architecture. That's wrong too - although some cellular networks are fairly-well integrated with some WiFi, there is a very large universe that isn't, and for many of the same reasons won't be in the future either. The notion that 5G is some sort of magical wireless umbrella (or Borg) that will assimilate all others is just a "mobile industry establishment" fantasy and lobbying hook. 

One last thing I'd add - I'm seeing an increased amount of interest in the opposite to LTE-U and LAA - the idea of running WiFi in licensed bands, either with new forms of spectrum-sharing, or perhaps even with adventurous regulators looking at getting more usage out of existing spectrum. After all, if the technical work suggests that LTE-U doesn't compromise or interfere with WiFi, then the converse is true as well, especially at lower power in regions with no cellular coverage, or indoors.

Overall: Ignore any reports of WiFi's demise, or the ability of 4G/5G to replace it in the future. It's simply not going to happen, except in a couple of tiny overlaps on the big wireless Venn diagram. WiFi puts downward pricing pressure on cellular data - it's probably part of the reason for the return of flatrate data in the first place. It's also a prime example of "network diversity" which would be worthy of protection against creeping "network monoculture" even if it wasn't already guaranteed a healthy future.


If you're interested in the dynamics of 4G, 5G, WiFi, network diversity & spectrum policy, please get in touch with me. I advise operators, vendors, regulators & investors. I'll also be speaking at the WiFi Now conference in Washington DC in April 2017 (link).

WiFi Offload.... or Onload?

One of the things I get annoyed by regularly is the mis-characterisation of a lot of WiFi use on smartphones / tablets as "offload".

In my view, true "offload" is a term only applicable to data which would otherwise have transited a cellular network, and which has been deliberately pushed to WiFi at a public hotspot, with the intervention of a service provider.

It is very different to "private WiFi" use, where the user has unilaterally decided to connected to a network (for example at home or office) of their own volition, or because a venue or other sponsor has made WiFi access available.

Care also needs to be taken about elasticity - user behaviour may change when on WiFi, even with "proper offload" - if the connection is cheaper or (more often) free/unmetered. At that point, a notional volume of traffic X that might be used on mobile might become 2X or 10X when on WiFi. This could be because of a shift in user perception ("Hmm, yes I will watch Game of Thrones streamed on my phone"), or it could be because an app-developer has created a different experience when connected to WiFi (eg auto-playing video, or enabling downloads of updates).  

[Sidenote: connectivity is not "all the same" - both users and developers make very different decisions when a device is on WiFi vs. 3G/4G. People & apps/OSs are aware of, and care about, the type of network which they're connected to. The notion that it doesn't matter is a core fallacy behind the notion of so-called "seamless" HetNets and integrated infrastructure] 

In other words, only a tiny fraction of smartphone WiFi use can be called "offload" with any reasonable definition. I'd estimate that it's well under 5% globally, and probably under 10% of phones' WiFi usage even on those networks which have extensive operator-driven offload implemented. For tablets, the numbers will be lower still, as the majority are non-cellular and therefore can never "offload", while even mobile-enabled ones are mostly non-activated or primarily used in static locations with private WiFi.

But there is another trend emerging in parallel to "real offload" that will make the numbers even more confusing.

In some cases, people or applications might deliberately switch to cellular from WiFi, for example if the WiFi network is congested, coverage is poor, or there are localised authentication problems. In other words, we will see "offload" from both cellular-to-WiFi AND WiFi-to-cellular. It may be that one direction of this gets referred to as "onload". It may also be that the WiFi-to-cellular onload is larger in volume. This would mostly driven by users' deliberate switching, but perhaps also by WiFi-primary policy clients on devices, for example from services provided by cable operators.

Takeouts from this:

• Be skeptical of most alleged "WiFi offload" figures - they're usually nonsense
• Most smartphone WiFi usage is private - traffic that would never have used cellular anwhere
• Be aware that WiFi/cellular onload happens, as well as cellular/WiFi offload
• Claims that "nobody cares which network they are on" are either ignorant or duplicitous
• View all discussions of cellular/WiFi combinations through the lens of WiFi-primary users as well as cellular-primary viewpoints