Recently, the US mobile operators’ trade association CTIA released data from its annual survey of members. Its headline focused on a very large number – 100 trillion megabytes – which CTIA claims was the total amount of mobile data traffic in the US in 2023. Unsurprisingly, CTIA then pivots to talking about obtaining more mid-band spectrum and the need for exclusive national licenses.
But problematically, CTIA’s announcement leaves multiple questions unanswered – and relies on multiple non-sequiturs in arriving at its policy demands.
The US is unusual in how data such as this are published. In most countries, the national regulatory agency or telecoms ministry publishes data on the numbers of subscribers, volumes of voice and data traffic, network coverage and much more. Agencies such as UK’s Ofcom, France’s ARCEP, Japan’s MIC, China’s MIIT and many others collect information from licensed operators, aggregate it and publish a variety of statistical outputs for use by policymakers, investors, analysts and others.
But in the US, the FCC and other agencies put out very little statistical data of this type. Instead, this is left to bodies like the CTIA, which release data primarily to support their own lobbying positions, rather than as an unbiased snapshot of the marketplace. They can and do frame data in a way that supports their position on topics such as spectrum policy.
At a trivial level, this can easily be seen in the recent release. Nobody counts mobile data in megabytes (MB) anymore – most plans and analysis have used gigabytes, or even terabytes, for ten years or more. The only reason that CTIA chose that metric is to create a large number for the press release. I guess we should feel relieved they didn’t spell out ONE HUNDRED TRILLION in all-caps, too.
But the data points themselves need closer scrutiny. CTIA claims the traffic figures jumped 36% in 2023, up by 26 trillion MB, from 74T to 100T. (On stage at a recent spectrum conference, they even rounded up the 36% to about “40%”).
But what does that number actually represent? Where is that extra data from, and what is it used for? There are no more specifics, at least for public consumption.
Helpfully however, CTIA’s own report inadvertently gives some hints. From late 2021 onwards, fixed wireless access using 4G/5G networks has grown significantly, adding around 4 million new subscribers during 2023 alone. A quick estimation shows that the vast bulk of the claimed traffic derives from FWA, not normal mobile broadband (MBB) for smartphones, vehicles and similar devices.
This is important for a number of reasons:
- FWA does not need exclusive, high-power spectrum to be deployed everywhere, unlike MBB. Its users are fixed – homes or business sites. This means it can rely on shared or locally-available spectrum, rather than needing nationwide licenses. There are many examples of FWA working perfectly well in unlicensed spectrum bands, as well as using CBRS GAA shared spectrum.
- In addition, various vendors are working on repurposing existing 5G mmWave bands (which remain almost unused by US MNOs) for FWA usage. Nokia now claims a range of up to 12km for line-of-sight usage. In other words, carriers have various spectrum options at their disposal, if they want to expand their FWA footprint. It doesn’t need yet more exclusive spectrum.
- FWA subscribers generate around 20-30x the traffic of average MBB users, but roughly the same revenue. That suggests that any complaints about traffic growth impacting the carriers’ economics and investment are either overstated, or self-created. Why are carriers willingly creating so much extra low revenue-per-bit traffic on their high-cost licensed spectrum – when lower-cost shared and unlicensed bands are available?
- FWA tends to be deployed and marketed by MNOs primarily in areas where they have excess capacity, and “spare” spectrum, such as rural districts or sparse suburban markets with limited fixed network availability, speed or competition. This may be why they can afford the 20x per-user traffic growth, as it is soaking up spectrum and RAN capacity they have already paid for.
In addition, CTIA does not make a distinction in its “mobile” traffic statistics between data consumed indoors vs. outdoors. Industry estimates usually put indoor usage at 70-80% of cellular data – primarily delivered “outside-in” in homes or businesses through the wall from the main “macro” network towers.
Critically, much of this indoor data could be shifted to Wi-Fi – which would also likely reduce the energy required and carbon footprint as well. This is an important area that policymakers should be tracking and collecting data about.
Irrespective of the potential for “offloading” traffic to Wi-Fi or dedicated indoor cellular systems (which can also use CBRS or mmWave bands), there is another issue here: Higher midband frequencies, especially above 3GHz, are poor at outdoor-to-indoor penetration, especially into well-insulated buildings. This means that even if new full-power spectrum in the 5-8GHz band is made available for 5G, it will be almost useless for most of the actual data consumption by end users, or at least very wasteful. Blasting through walls with advanced antennas would just mean wasting most of the capacity on warming up the concrete or bricks. And the end-user device radios and batteries would struggle even more.
In other words, CTIA’s claims about 100T megabytes of mobile data and continued growth need much closer scrutiny. That growth is mostly – perhaps 90% – the outcome of a deliberate choice by the MNOs, selling high-traffic / low-revenue FWA services where there is spare capacity. It’s padding out the numbers, mostly because other 5G services have been disappointing. Indeed, much of the rest of the data usage is consumed indoors, where midband spectrum is of limited use – and where Wi-Fi is usually available as a superior alternative.
Ideally, policymakers would collect their own statistics about mobile data traffic from the MNOs – and ask for much more granular detail about what it is used for, where, and in which bands.
If the carriers want to make arguments for more spectrum, it’s incumbent on them to give much more information about the usage of their current frequency allocations, and how that is changing over time. Given the claims about the volumes of data flying around, it seems ironic how little of it relates to the networks’ own operation and usage.
Appendix – FWA traffic estimation methodology
The average US household uses about 650GB of data per month via fixed broadband, with “power users” generating as much as 2TB of traffic or even more. A comment from T-Mobile to an industry website in January 2024 about its 5G Home Broadband service says that 1.2TB/month, the point at which throttling kicks in, is “over 2X the average user”, which implies that the average is 400-600TB. (If it was less than 400GB/mo, then it would have said 1.2GB was over 3X the average).
So broadly speaking, we can estimate that during 2023 about 4 million FWA customers were added. If we take a midpoint of 500GB per month, that translates to 500,000MB / month, or 6 million MB / year. That would imply that, roughly speaking, an extra 24 trillion MB in the year derives from FWA. Obviously those joining late in the year would not have 12 months of traffic, but that’s statistically balanced out by those joining late in 2022 whose data would not have applied earlier that year.
That 24T MB would imply that about 90% of the claimed extra traffic in 2023 came from FWA, even without adding in any extra usage by existing FWA subscribers. Even if we’re generous and suggest some of those new users are relatively “light” customers, it seems probable that at least 70% of the traffic growth (18T MB) is from fixed wireless. There’s even a small chance that existing mobile broadband traffic fell, and that FWA made up more than 100% of the net increase. If CTIA releases more accurate data about FWA traffic – or if the FCC collected and published it – we could be more certain.
Editor’s note: Dean Bubley (@disruptivedean) is the Founder of Disruptive Analysis. He is one of the leading analysts covering 5G, 6G, Wi-Fi, telco business models & regulation, and the emergence of technologies such as quantum networking and AI.