It used to be the case that around 80% of smartphone data was delivered over Wi-Fi and 20% by cellular. Fast, high capacity LTE together with competitive pricing is shifting that mix – in some cases quite dramatically. Recent statistics support this trend, both in developed and developing markets.
Reliance Jio provides a view to the future
Launched as a greenfield LTE only network throughout India, their extremely low pricing is predicated on quickly building up a large customer base. Since September, they’ve signed up 50 million customers – initially offering free data that is only now capped at 1GB PER DAY.
OpenSignal, which uses crowdsourcing data from their App installed on many hundreds of thousands of smartphones, reports that the average Jio user spends just 8.2% of the time connected to Wi-Fi, well below the 29.8% for India overall. Now you might say the figures are skewed because those users downloading the OpenSignal App may not be quite as typical as others, but the large user base does inspire confidence.
There are two likely reasons for this trend – users generally search out Wi-Fi either to save cost or to connect at higher speeds. When data is plentiful, fast and free, neither of these apply.
Figures just published by Strategy Analytics for the US also show a downward trend, although with substantially higher Wi-FI usage than India. This study is based on a much smaller sample size of 2,300 users nationwide. There is quite a difference between time spent on Wi-Fi and the volume of data transferred, almost certainly because so many Apps are designed to wait until connected by Wi-Fi before synchronising their background data.
Time spent on Wi-Fi: AT&T 48%, Sprint 49%, T-Mobile 50%, Verizon 55%
Data transferred on Wi-Fi vs Cellular: AT&T 72%, Sprint 61%, T-Mobile 67%, Verizon 69%
Sprint's substantially lower volume of Wi-Fi data transferred may be down to offering unlimited data bundles.
Data synchronisation remains a major factor
A third reason I find myself connecting to Wi-Fi these days is to synchronise and upload photos, podcasts and Apps which are normally blocked from what used to be considered expensive cellular data. I’d be most concerned about the size of HD video recordings than anything else, but even simple App updates can be 100Mbytes or more. But with a larger data bundle and faster connection speeds (actually faster upload than available on my residential broadband), it’s becoming much less of an issue.
This is quite relevant elsewhere too. When asked to list what the most common traffic destinations are at some large stadium and festival events, I’ve often heard that Apple iCloud (for photo uploads) and App Stores (for App updates) regularly feature in the top three. While this was very much the case for public Wi-Fi in the past, it’s also becoming true for cellular today also because users are prepared to enable data synchronisation over cellular.
Another factor is that we spend a lot of time using our smartphones for recreational purposes when at home and in the office, watching video and often connected by Wi-Fi. This together with data sychronisation explains why the data transferred on Wi-Fi is typically much higher for the same time spent.
Wi-Fi Speeds haven’t kept pace
The chart below compares the progress of 3G, 4G and Wi-Fi in recent years, giving average speeds for each on a worldwide basis. While theoretical peak rates are possible for all technologies, I suspect that a major limiting factor for Wi-Fi is the backhaul – many access points are connected through wireline DSL broadband that may be shared for many other uses.
Public Wi-Fi remains a thorny problem to crack. I find today that I generally stick with cellular if available, even in hotels and transport hubs. I can easily use my smartphone as a Wi-Fi hotspot for my laptop. It’s only when travelling abroad that I’d seek out Wi-Fi for more demanding tasks.
Free Wi-Fi remains a misnomer
Last year, I proposed the four levels to classify Free Wi-Fi based on security, privacy and performance. I argued that many are deterred from signing on to public Wi-Fi because of these concerns. It's much easier to remain on cellular unless you have good reason not to.
Variable performance of Wi-Fi remains an important issue. It takes good engineering and higher quality products to provide a good service. Some organisations do make the investment to do this properly, especially throughout the Enterprise sector.
On the other hand, the Wi-Fi performance of mainstream smartphones has also significantly improved in recent years, not just because of the latest 802.11 standards but because of increasing scrutiny of the RF chain, looking at everything from the antenna to the software stack.
LTE in unlicensed bands promise substantial additional capacity to satisfy demand
We can expect to see both LAA and MulteFire appear on the market in the near future. This has the potential to greatly expand available capacity, more usefully through in-building small cells. Neither is conducive to DAS or wider area cells.
This potential to augment data capacity with ad-hoc additional traffic channels on demand will greatly help handling those large photo, video and application updates. It can operate in a seamless, hassle-free manner with the same privacy and security that we expect from regular cellular service.
The initial target market for LAA will be those busier Enterprise locations. Whether these technologies will find their way into the residential side alongside Wi-Fi remains to be seen.
It will be interesting to see what this mix of cellular vs Wi-Fi looks like 12 months from now, but I think the general direction of the trend will see a further increase in cellular over the next few years.
The majority of Wi-Fi deployments are not "Carrier-grade" !