ITU Releases Framework Document for 6G

The International Telecommunications Union has published some details of its framework for 6G  networks, and many of the objectives are what you’d expect. Compared to 5G, 6G will support higher speeds, lower latency, be more spectrally efficient, energy efficient, feature artificial intelligence and sensing. 

• Peak data rates of 50 Gbps, 100 Gbps or 200 Gbps

• User experienced data rates of 300 Mbps and 500 Mbps

• Spectrum efficiency 1.5 and 3 times greater than that of IMT-2020 (5G)

• Area traffic capacity of 30 Mbps/m2 and 50 Mbit/s/m2

• Connection Density could be 106 to 108 devices/km2

•  Mobility Maximum speed, at which a defined QoS and seamless transfer between radio nodes could be 500 – 1 000 km/h

• latency (over the air interface) could be 0.1 – 1 ms.

In addition to those quantitative metrics, there are the expected qualitative benefits. The framework document includes talk of ubiquitous computing, ubiquitous intelligence, immersive multimedia, digital twins, virtual worlds, smart industrial apps, digital health, ubiquitous connectivity and sensing integration.  

As with prior generations (3G, 4G, 5G), many of those qualitative outcomes might be delayed or available only in rudimentary form. 

There are good reasons why mobile operators are much more concerned about “application revenue” than home broadband providers. Mobile operators always are in the “applications” business, where home broadband providers are only in the “internet access” business. 

In other words, mobile operators derive significant revenue from their own voice and messaging applications. ISPs providing home broadband mostly make money from subscriptions providing the internet access function. Most of their other revenue is related to the access function, such as equipment rentals or install fees. 

Revenue Source	Home Broadband Network	Mobile Operator Revenue
Subscription Fees	70.00%	40.00%
Voice Services	0.00%	25.00%
Data Services	0.00%	20.00%
Equipment Rental Fees	10.00%	0.00%
Installation Fees	5.00%	0.00%
Roaming Fees	0.00%	5.00%
Other Revenue	15.00%	10.00%

Also, mobile operators are dependent on government regulators to authorize additional spectrum, so there is a political underpinning to arguing that additional spectrum will lead to public advantages beyond “faster speeds.”

Still, in large part, the success of  built-in “app capabilities” will likely be hard to predict. Since mobile network value includes a mix of “apps” (largely voice and messaging) and “internet access” (dumb pipe access), much--if not most--of the value comes from the “internet access” function. 

As for home broadband networks, faster speeds are a continual requirement, as are support for carrier voice and messaging. Beyond those essential functions, it always is difficult to say how much other value can be reaped directly by mobile operators in the “apps” space and beyond connectivity itself. 

6G might not be so different from earlier generations in that regard.

6G Should "Enable," Not "Create" New Apps and Use Cases

After our experiences with 3G, 4G and now 5G, perhaps we ought to be more circumspect about all the positively amazing new experiences that will actually develop when we get to 6G. 

Already, observers offer examples of new applications and services that could be enabled by 6G:

• Real-time holographic video conferencing

• Augmented reality experiences

• Self-driving cars

• Remote surgery

• Mobile broadband in rural areas

• IoT connectivity in dense urban environments

None of that will startle: those were raised as apps that could be supported by 5G, and might yet emerge. 

And more to the point, despite the expected improvements in latency performance and bandwidth, maybe we should be cautious about claiming too much for the ways artificial intelligence or virtual reality will be embedded into the core network. 

No doubt AI will be used to support the core network and its processes. But that’s different from possible efforts to embed AI or AR or VR as customer-facing features of the networks, as some might propose. 

Beyond making the network operate as efficiently as possible, offering the best latency performance and bandwidth support we can reasonably develop in the next generation of networks, we might remain skeptical of efforts to claim or support network features that go beyond making the network as liquid as possible; as dynamic as possible; as flexible as possible. 

An energy-efficient network, using an on-demand architecture featuring low latency capabilities and no restrictions on bandwidth, using virtual mechanisms, is a reasonable goal. 

Beyond that, what we probably still need is a permissionless development environment, where app software does not have to assume much other than the existence of the low-latency, high-bandwidth connectivity. 

In other words, perhaps all we want is a network that is as open as possible, as virtualized as possible, as flexible and dynamic as possible, capable of supporting any conceivable application but without embedding any of that inside the core network. 

But some will try to create capabilities that are embedded into the core network, no doubt. That’s one way of attempting to profit from apps using the network.

Why Fixed Wireless Will be a Bigger Use Case for 6G

Even if support for ever-faster mobile internet is the objective of each mobile next-generation network--including 5G and succeeding platforms--there is reason to believe that fixed wireless might be a growing use case. 

The reason has to do with radio frequency signal propagation in the millimeter regions that will become necessary. 

“Wireless channels in this frequency range experience large propagation and reflection loss, sporadic availability of line-of-sight links due to blockage, and molecular absorption,” notes MediaTek. “These phenomena result in a link performance with shorter range and an intermittent on/off behavior.”

Millimeter wave radio signals will use beamforming to overcome signal loss. But that also means near line-of-sight performance. 

For that reason, sub-THz spectrum will be suited for fixed backhaul or nomadic devices communicating with a hub or as part of a network mesh, says MediaTek. The mesh capability is important as mobile users might move often among radio sites, requiring ability to shift between different radio sites on a dynamic basis. 

In principle, this mesh approach means a mobile user might be serially (or simultaneously) connecting to different mostly line-of-sight radios. Though the physical paths might be fixed, the mobile user will take advantage of any number of fixed paths to sustain a mobile connection to the “capacity” millimeter wave spectrum, while defaulting to coverage spectrum when necessary. 

Faster speeds are coming. The issue is how the radio access network is re-architected to take advantage of frequencies that largely are line of sight. 

MediaTek believes 6G will bring speeds 10 times to 100 times faster than 5G. That is not an unusual prediction. Indeed, every mobile digital generation has increased bandwidth by 10 times to 100 times, and reduced latency about 10 times, each generation.

source: MediaTek

Devices might also have the ability to sidelink, much as current devices can use Bluetooth for short-range device-to-device communications. 

 source: MediaTek

Other changes are possible. “A distributed MIMO deployment, where Tx-Rx signal pairs are not just bound to one node/site but distributed across multiple sites and nodes, has the ability to improve spectral efficiency and user experience across an area,” MediaTek says. That would not eliminate the use of transmitting “cells,” as the architecture is described as “cell free,” but rather mean user devices could communicate with more than one radio site at a time. 

There would still be transmission cells, but user devices would be free to connect with any adjacent cells and not be restricted to a single tower or radio. The practical advantage for end users is that the edges of a cell would no longer be a transmission quality issue. 

With a traditional one-cell connection design, lower signal strength at cell extremities has always meant reduced signal quality. In the cell-free design, signal quality close to the radio would be the same as quality at the edge of any single  radio’s coverage. That includes the degree of packet loss. 

The ability to incorporate non-terrestrial (satellite) connections with mobile connections also is envisioned. Artificial intelligence should be a native capability. 

In the spectrum area, frequencies in the 7 GHz to 24 GHz bands will probably be parts of the 6G standard, as will spectrum sharing, MediaTek says.

Why 5G Could be a Wild Success....When 6G Arrives

The “5G-NORMA” initiative by the 5G Infrastructure Association Public Private Partnership (5G PPP), an international non-profit association for collaboration on 5G, is one of a number of groups working to define the features and attributes of the fifth generation mobile network.

The 5G NOvel Radio Multiservice adaptive network Architecture does face some potential issues, though. The effort has goals other than the purely technical.

It is intended that 5G-NORMA will help 5G “create a single digital economy and put Europe back in the driving seat with a ubiquitous network,” 5G-PPP says.

Granted, all standards involve commercial interests and pressures. But the 5G-PPP effort also has serious political constituencies and objectives as well. Whether that is helpful or harmful cannot yet be determined.

But it is probably worth noting that most “next generation network architectures” proposed by the telecom industry have had mixed fortunes.

In terms of commercial success, a wide variety of protocols and platforms have missed the market. ISDN, broadband ISDN (ATM), OSI, IMS and RCS are examples of next generation platforms that have had modest success, compared to Internet Protocol, for example.

Mobile next generation platforms have had adoption issues as well, but might generally be seen as more broadly accepted than the core network protocols and platforms. It would be hard to fault 2G or 3G as platforms or protocols that “failed” in the market, or had only a modest financial impact.

Long Term Evolution 4G seems destined for clear success. Eventual success for 5G likely is somewhat inevitable. But the impact could well be shaped by any number of matters.

The more-complicated and sweeping the standard is, the more complicated its political context, the less likely 5G is to succeed in the near term. As arguably was the case for 3G, success might be delayed. And most of the developments foreseen for 3G arguably happened only with 4G.

So the possibility exists that much of the hoped-for 5G success could be delayed until 6G. It would not be an unprecedented development.

How Much Does Fixed Wireless Matter?

You can get a robust debate pretty quickly when asking “how important will 5G fixed wireless be?” in the consumer home broadband market. Will it matter? 

Probably. But it also matters more to some than to others, and will matter even if the net result is installed base market share shifts of just a few percentage points. So there is no actual contraction between cable operators saying “fixed wireless is not a threat” and a few firms arguing it will be highly significant as a driver of revenues. 

Keep in mind that the home broadband market generates $195 billion worth of annual revenue. Comcast and Charter Communications alone book $150 billion annually from internet access services that largely are generated by home broadband customers. 

T-Mobile has zero market share in that market. Taking just two percent means new revenues of perhaps $4 billion annually. That really matters, even if cable operators minimize the threat. 

“Addressable market” is a key phrase. Right now, Comcast has (can actually sell service to) about 57 million homes passed.

The Charter Communications network passes about 50 million homes, the number of potential customer locations it can sell to.

Verizon homes passed might number 18.6 to 20 million. To be generous, use the 20 million figure. 

AT&T’s fixed network represents perhaps 62 million U.S. homes passed. CenturyLink never reports its homes passed figures, but likely has 20-million or so consumer locations it can market services to. 

The point is that, up to this point, T-Mobile has had zero addressable home broadband market to chase. Verizon has had 20 million homes to market for that purpose. AT&T has been able to market to perhaps 62 million homes; Comcast 57 million homes and Charter about 50 million homes. 

So T-Mobile and Verizon have the most market share to gain by deploying fixed wireless. And the value will not necessarily be that fixed wireless allows those two providers to “take half the market.” The revenue upside from share shifts in low single digits will be meaningful. 

Some might counter that early fixed wireless will not match the top cabled network speeds. That is true. But it also is true that half of U.S. households buy broadband services running between 100 Mbps and 200 Mbps, with perhaps 20 percent of demand requiring lower speeds than that. 

So even if fixed wireless offers lower speeds than cable hybrid fiber coax or telco FTTH, it might arguably still address 70 percent of the U.S. market.

It is conceptually possible that untethered access could eventually displace a substantial portion of the fixed networks business, longer term. 

Up to this point, mobile networks have not been able to match fixed network speeds or costs per gigabit of usage. But that should change. 

Mobile network speeds will increase at high rates, with a rule of thumb being that speeds grow by an order of magnitude every 10 years. One might argue that is less capacity growth than typically happens with fixed networks. +

 

source: Voyager8 

But that might not be the relevant context. What will matter is how much speed, at what price points, mobile or fixed wireless solutions must offer before becoming a reasonable choice, compared to fixed access. 

Assume that in its last release, 5G offers a top speed of 20 Gbps. The last iteration of 6G should support 200 Gbps. The last upgrade of 7G should support 2 Tbps. The last version of 8G should run at a top speed of 20 Tbps.

At that point, the whole rationale of fixed network access will have been challenged, in many use cases, by mobility, as early as 6G. By about that point, average mobile speeds might be so high that most users can easily substitute mobile for fixed access.

To be sure, cost per GB also has to be roughly comparable. But, at some point, useful bandwidth at a reasonable enough price could allow wireless solutions to take lots of market share from cabled network providers. 

 

We never get away from debates about “which is the better choice?” in the connectivity or computing industries. Nor do we generally remember that “one size fits all” rarely is the case. Additionally, all choices are conditioned by “when, where, by whom and why” technology must be deployed. 

The global choice of internet protocol rather than asynchronous transfer mode as the foundation for all next-generation networking is among the exceptions. That really did result in an “all or nothing” outcome. 

But few other choices are so stark. Consider access network platforms. Decades ago there were serious--if brief--debates about whether “fiber or satellite” technologies were “better” for wide area networks. There was speculation about whether “Wi-Fi or mobile” was the better platform for phone connectivity.

There were debates about whether fiber to the home or hybrid fiber coax was “better” for consumer broadband access. 

Now there are arguments about whether local connections, unlicensed wide area low power networks or mobile networks are “better” for internet of things sensors. 

Such questions, while valid, always have to be qualified by the issue of “better for whom?” It might not make sense for a public network provider to consider HFC as a foundation access technology. It virtually always is a logical choice for a cable operator, for the moment.

 “At some point,” optical fiber is universally seen as the technology of choice for telcos and other “cabled media” providers. But wireless remains the key approach for satellite, wireless ISPs and mobile operators. 

What is “better” cannot be determined without knowing the “for whom” part of the business context; the “when?” part of the discussion or the “under what other circumstances?” detail. Fiber to the home might be the “ultimate” choice, but “when to deploy” or “where to deploy” also matter. 

U.S. cable operators in 2020 had at least 69 percent share of the installed base of accounts, according to Leichtman Research Group. Telcos likely had something less than 28 percent of the installed base, accounting for share held by independent internet service providers (wireless, fixed and satellite). 

source: FCC, Bloomberg 

Without government support, FTTH might never make business sense, in some locations. In other cases the business case is so marginal and risky that an alternative, such as fixed or mobile wireless, might well be the alternate choice. For a telco, a “fiber” upgrade might make sense when existing copper facilities must be retired in any case, and where need is not driven by revenue upside, merely facilities replacement. 

For a cable operator, an FTTH overlay could make near-term sense to support business customers, but not yet consumers. But fixed wireless might also make sense for cable operator “edge out” operations, and for the same financial reasons that telcos used wholesale as a way to enter geographically-adjacent markets. 

The questions are even broader when looking at total demand for broadband access. In terms of total connections, in the U.S. market 75 percent of all internet access connections use mobile networks. Just 16 percent use cable HFC, while perhaps 8.6 percent of connections use either fiber or copper telco connections, while everything else--including satellite and fixed wireless--represents less than one percent. 

source: FCC

The point is, how much faster do untethered services need to be--assuming roughly equivalent terms and conditions of usage and price--before a significant percentage of home broadband users consider an untethered solution a functional substitute for fixed network access?

Matching headline speeds might not matter, as most consumers do not buy those services. Untethered options simply have to be “fast enough, priced well enough” to contend for significant share of the home broadband market.

How fast Will Fixed Networks Be, by 2050?

How fast will the headline speed be in most countries by 2050? Terabits per second is the logical conclusion, even if the present pace of speed increases is not sustained. Though the average or typical consumer does not buy the “fastest possible” tier of service, the steady growth of headline tier speed since the time of dial-up access is quite linear. 

And the growth trend--50 percent per year speed increases--known as Nielsen’s Law--has operated since the days of dial-up internet access. Even if the “typical” consumer buys speeds an order of magnitude less than the headline speed, that still suggests the typical consumer--at a time when the fastest-possible speed is 100 Gbps to 1,000 Gbps--still will be buying service operating at speeds not less than 1 Gbps to 10 Gbps. 

Though typical internet access speeds in Europe and other regions at the moment are not yet routinely in the 300-Mbps range, gigabit per second speeds eventually will be the norm, globally, as crazy as that might seem, by perhaps 2050. 

The reason is simply that the historical growth of retail internet bandwidth suggests that will happen. Over any decade period, internet speeds have grown 57 times. Since 2050 is three decades off, headline speeds of tens to hundreds of terabits per second are easy to predict. 

source: FuturistSpeaker 

Some will argue that Nielsen’s Law cannot continue indefinitely, as most would agree Moore’s Law cannot continue unchanged, either. Even with some significant tapering of the rate of progress, the point is that headline speeds in the hundreds of gigabits per second still are feasible by 2050. And if the typical buyer still prefers services an order of magnitude less fast, that still indicates typical speeds of 10 Gbps 30 Gbps or so. 

Speeds of a gigabit per second might be the “economy” tier as early as 2030, when headline speed might be 100 Gbps and the typical consumer buys a 10-Gbps service. 

source: Nielsen Norman Group 

If consumers on every continent purchased service at equivalent rates, in 2050 one would expect Asia to represent nearly 60 percent of demand, Africa nearly 20 percent. Europe would represent seven percent of demand, South America nine percent, North America four percent. 

source: Chegg 

Most observers would guess Asia will do about that well, while Africa lags. Europe and North America likely will over index, while South America might do about what the population alone would predict. 

Though the correlation might be less than one might expect, fiber to home deployment should correlate with terabit take rates in 2050. The wild card is 8G mobile access. As mobile speeds likewise continue to increase, most consumers might prefer wireless access to any fixed connection. 

In mobility as in the fixed network, the theoretical headline speed is not matched by mass market commercial experience. Still, the pattern has been that each next-generation mobile network features data speeds an order of magnitude higher than the prior generation. 

source: Voyager8 

Assume that in its last release, 5G offers a top speed of 20 Gbps. The last iteration of 6G should support 200 Gbps. The last upgrade of 7G should support 2 Tbps. The last version of 8G should run at a top speed of 20 Tbps.

At that point, the whole rationale of fixed network access will have been challenged, in many use cases, by mobility, as early as 6G. By about that point, average mobile speeds might be so high that most users can easily substitute mobile for fixed access.

6G Poses Challenges for Fixed Networks

Since most observers expect 6G to feature access speeds at least 10 times greater than 5G, that implies top speeds in the range of 100 Gbps, with a lower range in the 10 Gbps region. 

 

source: Navixky

In fact, some believe top speeds could reach a terabit per second. 

 

source: Navixky

All that has to be a driver of thinking about upgrades of cabled internet access networks. If, within the next decade, mobile networks can reasonably deliver gigabit to 10 Gbps speeds, that makes them substitutes for the fixed network. And if, in a decade, 10 Gbps to terabit-per-second speeds are feasible, then cabled networks might in some cases be the second-fastest networks available to consumers. 

All of that could have big implications for internet service provider market share. The issue in some markets will not be “cable or telco” but rather “mobile versus fixed.”