Correlation is Not Causation, for Broadband, Internet or Mobility

Some problems are difficult to solve: wealth disparities, including Pareto distribuion patterns; population density and economic growth that benefits most geographies and regions instead of urban centers.   

Though it is widely believed that broadband access leads to economic growth, that cannot be proved, though many studies suggest a correlation. But correlation is not causation. 

“A  positive relationship between broadband expansion and employment growth could arise for other reasons,” says Jed Kolko of the Public Policy Institute of California. “For example, if

broadband providers expand in locations where they anticipate future growth, then the positive relationship would in part or entirely reflect this strategic decision of providers rather than a causal effect of broadband on growth.”

“Alternatively, population growth could cause both broadband expansion and employment

growth: Broadband providers could invest in areas where population (and therefore demand for broadband) is growing, while at the same time population growth could cause employment growth in industries (such as retail, restaurants, and personal services) that serve local populations<” Kolko says. 

Virtually everyone believes it is “a good thing” for people to have access to roads, clean drinking water, electricity and internet access. Yet even when these goods are nearly-universally supplied, disparities in economic growth; job creation; wealth and income persist. Those forms of infrastructure are perhaps necessary but not sufficient to cause the outcomes. 

Likewise, economists Chris Doucouliagos, Professor of Economics, Deakin University and 

Tom Stanley, Professor of Meta-Analysis, Deakin University, examined 59 studies of economic growth in developing and developed countries. 

Even some studies reporting correlation between digital technology use and economic development note the uneven outcomes, ignoring for the moment the issue of correlation or causation. 

As always, we must separate causation from correlation. They find “evidence that ICT has indeed contributed positively to economic growth, at least on average.” In other words, as we all might expect, information and communications technology are correlated with economic growth.

But “benefit” or “contributed” value is not necessarily the same as causation. It is correlation and presumed “advantage,” to be sure.

The researchers find a greater “benefit” from mobile phones than landlines, for example. They argue that mobile service has a growth effect “twice as strong as landlines.” 

source: Researchgate 

But we can note the correlation in the reverse: since mobile phones have a global penetration rate in excess of 100 percent, while landline telephones have adoption only in the 

12 percent range. So one would expect greater correlation between mobile use and fixed telephone impact. 

Perhaps economic growth leads to higher mobile phone use. Perhaps the cost of building mobile networks, compared to fixed networks, is high enough to cause much-higher mobile availability. Perhaps mobile costs are lower, and value are higher,  than for fixed service. 

In other words, perhaps mobile usage is so high because its availability is so high; its costs relatively low; its value considerable for all sorts of reasons not dependent on contribution to economic growth. 

“In contrast, we find little evidence that the Internet has had a positive impact on growth,” say the economists at Deakin University. 

As a matter of public policy, virtually everyone believes all citizens should have electricity, internet, mobile and fixed communications, clean drinking water and sanitation. Most likely believe income and wealth disparities are a problem to be fixed, if possible. 

Most likely believe that economic growth, education and other quality of life measures in rural areas should be close to that of urban areas. 

But disparities stubbornly persist. It is one thing to prefer ubiquitous access to infrastructure. But it is quite something else to believe that once provided, such ubiquitous infrastructure actually can overcome all the other background factors that create disparities of wealth, income, economic growth rates or other social amenities. 

Perhaps another way of stating the issue is that it is one thing to assure that necessary infrastructure is in place. It is quite something else to expect that what is “necessary” is therefore “sufficient” to cause different economic and social outcomes. 

Universal broadband access is a “good thing” to achieve. But it is no panacea for economic growth. In fact, we cannot actually prove that broadband “causes” growth. It might be easier to argue that broadband quality is itself an artifact of economic growth.

Wi-Fi Value Has Changed Since 3G

The perennial debate over Wi-Fi ability to substitute for mobile network access will not change in the 5G era. But user behavior could change as moble access speeds become a functional substitute for fixed (Wi-Fi) access and as unlimited-usage plans eliminate the financial incentive to switch to Wi-Fi access. 

Beyond a fairly low threshold (perhaps 25 Mbps to 50 Mbps), most apps do not benefit from higher access speeds. With a few exceptions, the primary benefits of higher-speed connections (500 Mbps to a gigabit per second) are enough bandwidth to support multiple devices and users simultaneously, plus any financial advantages of unlimited-usage plans, higher return bandwidth or other values bundled with the connection. 

As has been the case in the 4G era, Wi-Fi access might have more value for multi-user households; less value for single-user households and households where every inhabitant pays for their own mobile access. 

Mobile-only access wil have higher value for lower-income households and users, phone-centric users and younger adults. 

Unlimited-usage data plans will eliminate the financial incentive to switch to Wi-Fi, at least when mid-band spectrum is available to support 5G access, as there will not generally be a speed incentive to switch to Wi-Fi access. 

On the other hand, signal strength could be a more-inportant driver of behavior. Indoor signal coverage has been an issue since mobile operators began using frequencies around 2 GHz. Should that become a worse problem when other mid-band frequencies in the 3.5 GHz to 6 GHz range are used, then Wi-Fi offload will still make sense. 

In the 3G era, the advantage of switching to Wi-Fi was speed. In the 4G era the advantage was cost. In the 5G era, the advantage could often be signal strength. 

 

But T-Mobile believes customers of its unlimited usage  5G service are starting to rely on the 5G network and not shifting access to Wi-Fi. 

In mid-December 2021, T-Mobile said “13 percent fewer MAX users are connecting to Wi-Fi, 80 percent more are hosting a Wi-Fi hotspot and their hotspot usage is up 20 percent on average during the weekends.”

That is not unexpected, as the leading mobile service providers shift users to higher-priced unlimited usage plans that eliminate the financial incentive to switch to Wi-Fi. 

In 2021, Wi-Fi represented as much as 46 percent of total global end user IP traffic, according to Cisco. Mobile networks supported about 17 percent of total end user IPtraffic in 2021. Fixed networks delivered nearly 53 percent of internet traffic in 2021, compared to the share delivered by mobile networks, at about 21 percent, Cisco says. 

Usage varies by market. In India, about 98 percent of total internet access uses a mobile device. Globally, mobile users consume as much as 60 percent of total data on fixed networks (Wi-Fi).

In recent years, U.S. mobile customers have spent about half their connected time on Wi-Fi (fixed network), not the mobile network . 

By 2023, U.S. mobile users might offload as much as 75 percent of data consumption to fixed networks, some in the Wi-Fi community believe. But much hinges on how consumers behave when they have unlimited usage plans, which might reduce Wi-Fi consumption. 

source: Cisco, WiFiForward 

It might also matter how mobile tariffs are shaped. Home broadband allows multiple users and devices to share a single account. As mobile plans move towards unlimited usage, and if multi-user plans create incentives for smartphones to remain on the mobile network all the time, and if indoor reception is not an issue, then more users might remain connected to the mobile network all the time. 

An Ericsson study found that 5G customers on unlimited-usage plans reduced their reliance on Wi-Fi. In markets such as the United States, Taiwan, Switzerland, Finland and South Korea, where a higher proportion of 5G users are on unlimited plans, 22 percent have decreased their home Wi-Fi usage, while 14 percent have stopped using Wi-Fi after upgrading to 5G, Ericsson found.

Older data (from 2016) shows the same pattern. A 2018 analysis suggested that unlimited-usage mobile data plans decreased use of Wi-Fi by about eight percent. 

source: Nielsen 

Motivations can change over time. In the 3G era, users switched to Wi-Fi because Wi-Fi was faster than 3G. In the 4G era, when 4G was generally faster than Wi-Fi, the switch to Wi-Fi made sense because it reduced mobile data plan usage. 

The 5G pattern is not so clear, at least not yet. Assuming the financial benefit of switching to Wi-Fi is not present, then speed, signal stability or other advantages could be decisive. 

5G Uptake Will be an S Curve

Even if the 5G networks could magically spring up fully-deployed, with no construction obstacles, there would still be a lag between availability and customer acceptance. The reason is that not all customers are early adopters 

Early on, innovators and early adopters drive take rates. For them, the value of better performance is enough to create demand, even in the absence of compelling new use cases or applications. 

source: Researchgate 

Novelty does not create demand for mainstream customers, who need a value proposition oriented around some practical value beyond bragging rights. Mainstream customers must see a solution to some existing problem.

In some cases, that problem might be “predictability of service charges” more than “speed” as such. “No overage charges” is a value people understand. In other cases the lure might be “no additional cost video streaming subscriptions.” In yet other cases the value might be the ability to “use all the features of my new phone.”

The point is that mainstream consumers need tangible benefits, and those benefits might not flow directly from “faster speed” claims. 

The concept of the S curve describes consumer adoption behavior,  product life cycles, suggests how business strategy changes depending on where on any single S curve a product happens to be, and has implications for innovation and start-up strategy as well. 

source: Semantic Scholar 

Some say S curves explain overall market development, customer adoption, product usage by individual customers, sales productivity, developer productivity and sometimes investor interest. 

It often is used to describe adoption rates of new services and technologies, including the notion of non-linear change rates and inflection points in the adoption of consumer products and technologies.

In mathematics, the S curve is a sigmoid function. It is the basis for the Gompertz function which can be used to predict new technology adoption and is related to the Bass Model.

I’ve seen Gompertz used to describe the adoption of internet access, fiber to the home or mobile phone usage. It is often used in economic modeling and management consulting as well. 

The S curve also fits and explains consumer adoption of new technologies.

Why Some Users Find 5G Unsatisfying

5G value is an issue for some users who have bought it, especially in some markets where low-band spectrum has been the way 5G is mostly experienced. But there arguably are reasons why user experience could be challenged even in markets where mid-band spectrum underpins 5G experience.

One reason is the difference between what users do--and what the networks must support--on fixed and mobile networks. Fixed networks are multi-use networks. So the obvious value in a fixed network setting is "speed" or "bandwidth" to support multiple simultaneous users.

That is not the case on mobile networks, where accounts are set up on a one device, one user basis. Even when there are multiple users on a single account, those users do not "share" a local access connection. So the advantage of "speed" is different on a mobile network.

There is no "sharing" of a single connection. Also, fixed networks support screens of many sizes. Mobile networks mostly support very-small screen devices. That shapes bandwidth demand.

Apps typically used on large screen or medium-screen devices further shape bandwidth demand. Entertainment devices such as 4K TVs will consume more bandwidth than standard-definition or high-definition viewing on very-small screens.

Mobile-connected devices supporting artificial reality are the exception, at the moment, but also are relatively rare. And even many of those use cases rely on a local Wi-Fi connection, not the mobile network.

Up to a point, bandwidth affects user experience. Just as surely, additional bandwidth does not improve experience, once a threshold is reached. Latency and jitter also matter, but users might not be able to discern such changes, or wrongly attribute the lack of perceived improvement to "bandwidth" issues.

But if 4G provides any evidence, 5G value is going to change over the lifespan of the network. 

The initial value will be “speed,” even if user experience is less changed than some will expect, even if the perceived value is the marketing value of 5G delivering data faster, irrespective of user experience value.

The value after a decade will be “new use cases” and apps, for consumers and business use cases. But that will take time. And consumers might well find there is "not much difference" between 4G use cases and new 5G apps. They have not been created yet.

The betting early on is that many--perhaps most--of the new use cases will come from enterprise, not consumer uses. 

After a decade or so, we are likely to have discovered new consumer apps as well. It just is hard to say what those mass deployed use cases will be. Perhaps nobody predicted the emergence of ride sharing as an important 4G use case. 

Few predicted turn-by-turn navigation would be important. And though streaming video and audio were foreseen, even those apps do not rely so much on “speed” as the creation of easy-to-use and popular streaming apps.

In fact, the rise of “mobile-first” apps does not depend, strictly speaking, on bandwidth improvements brought by 4G, though faster speeds are an enabler. 

That would not be unusual for a next-generation mobile network, up to a point. If nothing else, coverage is an issue, early on. Even a better network does not help if it is not “generally available.”

Complicating matters is the rollout of 5G during the Covid pandemic and many restrictions on “out of home” and “on the go” usage. Working or learning remotely, many users likely spend most of their time connected to home Wi-Fi. So even if 5G is faster, the amount of time any single user might use it is far more limited than under normal circumstances. 

Still, faster speeds should help, up to a point, with existing applications, as page loading on a 600-Mbps fixed network connection should provide some noticeable advantages compared to a 300-Mbps connection (especially in multi-user and simultaneous multi-device usage cases. 

Since 3G, the key user experience gain has been “faster mobile data access.” Sometimes that is tangible; but sometimes not so much.

An argument can be made that latency has even greater user experience impact on a mobile network. Beyond some relatively low point, additional speed might not improve user experience. We can debate what that threshold is, as it changes over time. 

If a consumer’s primary reason for buying 4G was a tethering experience closer to fixed network experience, the 4G advantage was immediately tangible. If the primary advantage sought was mobile web browsing experience similar to fixed network experience, then the advantage might well have been tangible. 

5G poses a bit of a tougher problem. When downstream 4G speeds are routinely in the 20 Mbps to 30 Mbps to 35 Mbps range, how much does experience change when 5G offers 165 Mbps? It should help, but how much?

It depends on what a user does on a phone. Web page loading will be faster, but how much faster? Ignore for the moment the authoring of a web page (optimized for mobile access or not; how well optimized). 

For fixed network access, faster access speeds have not necessarily meant that web pages are loading faster, for example. 

On mobile networks, connection speeds have improved, but mobile page load times tracked by have increased, according to the Nielsen Norman Group.

source: Nieslen Norman Group 

Of course, page and landing page loading times are not a direct function of access speed but perhaps largely an artifact of remote server performance. So access speed is not the only, or perhaps not even primary determinant of user experience. 

The build-out phase of a national next-generation network takes years, so coverage outside of urban cores will typically be an issue. In some markets, where low-band and millimeter wave frequencies have been the mainstay, users might not often find there is much mobile data performance difference.

Fixed Network Broadband Grows, Mostly in China

Even if mobile internet access remains the main way most humans use the internet, fixed broadband accounts continue to grow at a two-percent rate, according to Point Topic. 

source: Point Topic 

Where global fixed network broadband accounts number a bit over one billion, mobile broadband accounts are nearly seven billion, according to Ericsson. 

source: Ericsoon 

And much of the increase in fixed broadband is happening in China. 

source: Point Topic 

"Middle Mile" Sometimes is "Muddled Mile"

Some seemingly define middle mile too loosely. In fact, some projects talked about as middle mile might not have anything to do with middle mile infrastructure. In fact, local access often is what is meant, not middle mile infrastructure.  

Terminology changes in the connectivity business, over time. The term refers to the part of the network segment between the core network backbone (the wide area network) and the local access network.

Think of this as what we used to refer to as the trunking network, or perhaps the distribution network. If the core network terminates at a class 4 switch or a colocation facility, then the “middle mile” is the transport network connecting the colo to the local access network (a central office or headent, for example).

 

Some illustrations tend to distort the network architecture, even when subject matter experts correctly understand the concept. In this illustration, which shows the way an enterprise user might see matters, the entire WAN is considered “middle mile,” not simply the connections between a colo site and the WAN. 

source: Telegeography

That is understandable if we conceive of the network the way an enterprise might: that “everything not part of my own network” (“my local area network”) is “in the cloud,” an abstraction. 

Even viewed that way, the middle mile is an abstraction. It is part of the network “cloud,” in the sense network architects have depicted it: all the network that is not owned by the enterprise. 

The point is that there is a difference between network terms such as “middle mile” as a description of network facilities and the use of the term (perhaps even incorrectly) as a matter of networking architecture. 

“WAN transport” is not “middle mile,” in terms of network function. But everything other than the enterprise LAN is “cloud” or “not owned by me” in terms of data architecture. But in that sense the term middle mile is unnecessary.

Of course, such terms are more important for service providers than end users and customers. Even if WAN and “network core” refer to specific parts of a network; access to a different part;  and middle mile, distribution, backhaul or trunking network being a third part, none of that matters to most enterprises or consumers buying connectivity. 

The term arguably matters most to retail internet service providers needing to reach internet points of presence. It matters most when ISPs need to buy capacity on such networks to reach an internet PoP. 

Still, usage does change, over time. 

We used to define “broadband” as any data rate at 1.544 Mbps or faster. Now the definition is more flexible, and deliberately changes over time. The U.S. Federal Communications Commission defines “broadband” as a minimum downstream speed of 25 Mbps, with 3 Mbps upstream. 

In a mobile network, “backhaul” used to mean the trunk connection between a cell tower and a mobile switching center. These days, as networks are virtualized, we talk about fronthaul, mid-haul and backhaul. All those deployments occur within a local network, but “fronthaul” applies to the connection between a baseband site and a radio site, for example.

Mid-haul can refer to the connection between a baseband processing site and a controller. Backhaul then refers to the connection with a wide area network access point. 

So it is with “middle mile.” Classic fixed telco networks featured wide area networks for long-haul traffic, connecting tandem offices, for example. Connections from central offices to end users or remote hubs were part of the local trunking network. 

The local access network then ran from central offices or remote hubs to end user locations. We did not use the term “middle mile.”

In the context of  internet traffic, “middle mile” often refers to that portion of the network connecting internet traffic from an ISP’s servers to an internet traffic exchange point or peering location. 

Partly a physical concept and partly a business concept, the middle mile is the segment of a network between an internet peering point or collocation center and central offices, headends, or ISP data centers. 

Still, it is a somewhat-murky concept. Facebook, for example, sometimes refers to the middle mile as facilities linking its own data centers at distances of hundreds of miles. That is hard to reconcile with a definition focused on connections between internet peering locations and headends or ISP data centers or telco central offices. 

Others appear to use the term “middle mile” to refer to private networks of almost any distance that move traffic between a wide area network colo location and an ISP’s headend or data center. 

Traditional telco voice networks connecting central offices within a city or region might also be called “middle mile” instead of trunking networks. 

It might be easier to look at “middle mile” as a business concept, representing capacity costs or investments that are made to move traffic between an ISP headend and an internet traffic exchange point.

"Evergreen Stories" Mean Nil Chances of Change

Some storylines are “evergreen:” they always are independent of current events and are not time sensitive. The good or bad news--depending on how one is affected by the evergreen stories--is that the unchanging nature means precisely that: the story does not change.

And that is likely the bad news for European mobile operators anxious to see more Europe-based supply of Open RAN infrastructure.

n a white paper, Deutsche Telekom, Orange, Telecom Italia (TIM), Telefónica and Vodafone want policymakers to make Open Radio Access Networks a strategic priority, arguing that (as has been argued for decades about other areas of innovation) Europe is “falling behind” the United States and Japan in developing O-RAN.

The problem is that this is an “evergreen” story. Europe has been seen as “falling behind” or lagging” in many areas of technology innovation and sales leadership for some decades. Whether it is “only” two decades or as much as four decades is the issue.

Indeed, most observers might well be forced to agree that technology leadership in computing, digital apps and communications seems to be coming from China or the United States. Open RAN is simply another example of that trend.

At stake, the telcos say, are global vendor revenues in the Open RAN value chain, with 38 percent of total revenue, followed by RAN hardware (24 percent), Cloud (18 percent), Semiconductors (11 percent) and RAN software (nine percent)

For infrastructure supplies, the global market is said to be worth EUR36.1 billion by about 2026. That includes Open RAN hardware and software (EUR13.2 billion) and revenue from the broader RAN platform as well.

And that might be a large part of the problem. The ecosystem spans so many other areas where European suppliers are not leaders that “catching up” in a short time seems highly unlikely.

And though legitimate questions can be asked about how soon Open RAN becomes a substantial commercial reality, it is hard to argue with the argument that--eventually--it will do so, as part of the broader move to cloud-native and virtualized telecom networks.

“Open RAN is coming regardless of what Europe decides,” says the white paper.

The study identified 13 major Open RAN players in Europe compared to 57 major Non-European players. However, many European players are at an early stage of development and have not yet secured commercial Open RAN contracts, while vendors from other regions are moving ahead in actual sales.

“European vendors are not even present in all Open RAN sub-categories (e.g. Cloud Hardware), and are outnumbered in almost all categories by Non-European players (e.g. 2 major European vs 9 major Non-European players in the semiconductor category),” the paper says.

That “Europe is falling behind” argument has been made for a couple to four decades, whether it is levels of research and development spending, digital technology, economic growth or innovation in general.

Probably few--if any--observers would be optimistic about changing Open RAN supplier capabilities in a short period of time, if it could be done at all.

It’s simply an evergreen story.