State of Mobile Networks: UK (October 2016)

For the third time OpenSignal is teaming up with consumer rights advocate Which? to put U.K. mobile networks to the test. Looking at 3, EE, O2 and Vodafone under the microscope, we found that U.K. operators are delivering consistently fast data connections to their customers, but LTE availability still leaves a lot to be desired outside of London.

In our latest State of Mobile Networks report for the U.K., OpenSignal and Which? drew on 500 million tests conducted by more than 28,000 smartphone users between June and August. After we published our last U.K. report in April, OpenSignal made some adjustments to both the way we collect data from our smartphone apps and the methodology we use to parse that data. The update allows us to make more measurements, examine new types of network metrics and hone the precision of the measurements we've always collected, helping us isolate the typical consumer mobile experience more effectively (for more details, see our recent blog post). The changes haven't affected our overall rankings of networks in the U.K. or around the world, but for sake of analytical rigor we aren't making any direct comparisons between results collected from the two different methodologies.

For this report, we not only delved into the national scores for all four operators, but we also examined how accessible all four operators' 4G services were in 12 U.K. regions. In addition, OpenSignal and Which? looked at different regional 3G and 4G trends across the country in a separate analysis published in our blog. To kick things off, though, let's take a look at how the U.K.'s big four performed nationally.

Speed vs. Access

EE's LTE-Advanced network is really starting to rear its head. Over the summer, we saw EE pull ahead of its competitors in 4G speed, averaging 28 Mbps in our download tests. 3, which was tied with EE for fastest speed in our April report, came in second in our tests, with an average LTE speed of 24.5 Mbps, but the average speeds we measured for O2 and Vodafone both fell below the 20 Mbps bar.

Our prize for fastest 3G speed went to 3. We measured average download speeds of 6.1 Mbps on 3's HSPA networks. EE, however, took our overall speed award, which tracks the fastest aggregate speed over operators' 3G and 4G networks. Not only did EE have the fastest LTE connections in our tests, but OpenSignal users were able to access its fast speeds more often. The result was EE dominating the overall speed category with an average download of 18.6 Mbps, nearly 6 Mbps ahead of its nearest competitor.

In fact, LTE availability had a lot more impact than raw LTE speed in determining the typical download connection our testers experienced. Rather than measure geographic coverage, OpenSignal's availability metric tracks the proportion of time users can connect to a particular network. In the case of the U.K., availability scores were low, at least compared to North America, Northern Europe and East Asia. EE ranked highest in our results with a 64% availability metric. Meanwhile 3 ranked the lowest with an LTE availability 44% as our testers were able to connect to its 4G service less than half the time.

O2 and Vodafone were tied for second place in our availability rankings, each providing an LTE signal 60% of the time, according to our data. Greater 4G accessibility allowed both operators to make up ground in our overall speed metric. Though we measured faster 4G and 3G speeds for 3 than we did for Vodafone, we found Vodafone's overall speed of 12.3 Mbps was almost even with 3's. By providing our testers with an LTE connection more often than a 3G connection, Vodafone was able to close the performance gap.

The final national metric covered in this report was latency, which measures the time it takes data to make a round trip through the network. Low latency means more responsive connections: web pages begin to load faster and real-time services like chat and VoIP experience less delay. EE won our 4G latency award, averaging 41 milliseconds in our tests, while we recorded a three-way tie between 3, EE and Vodafone in 3G latency.

Capital vs. Country

Which? and OpenSignal didn't just examine 4G availability on a national level for this report. We looked at operator performance in each of England's nine official regions as well as in Northern Ireland, Scotland and Wales. Just as EE won our national LTE availability category, it performed quite well on the regional level. We measured the highest level of 4G availability for EE in seven of the 12 regions, but in the remaining five regions it faced some stiff competition. In South West England EE tied with Vodafone for the prize, while in North East and South East England, Scotland, and Yorkshire and the Humber, we recorded three-way ties for best availability between EE, O2 and Vodafone. As was the case in our national 4G availability metric, 3 wasn't even a contender on the regional level. We measured the lowest LTE availability on 3's network in almost every single area, and in one region — Wales — our testers could only connect to 3's 4G network in one of every four attempts.

In general the four operators performed worse in our tests than they did nationally in the East and West Midlands, East of England, South West, Scotland and particularly in Wales, where we measured the lowest levels of 4G availability in the country from all four providers. Conversely, U.K. operators generally outperformed their respective national benchmarks in North East England and Yorkshire and the Humber, but the biggest improvement for all four was in London. We measured LTE availability from each of the four operators 10% to 15% higher in the capital. That increase is to be expected to a certain degree. The region of London is a single densely populated metropolitan area, not a mixture of urban and rural areas as is the case with the other regions, making it easier for operators to build networks that cover a large number of users.

In a separate analysis published in OpenSignal's blog, we also looked at overall 3G and 4G performance trends across U.K. regions, and what we found surprised us. While London may be the most 4G accessible region of the country, it had the lowest average 4G speed in our measurements. The typical LTE connection in London clocked in at 18.8 Mbps, while everywhere else in the U.K. the average was over 20 Mbps. The fastest LTE connections we found were in Northern Ireland, averaging 23.3 Mbps. That may seem surprising given the enormous level of LTE investment operators have made in London, but what we're seeing is the downside of highly accessible networks. The capital's huge population and big demand for mobile data combined with its high level of LTE availability mean more people are connecting to 4G there than anywhere else in the country. That in turn creates congestion on the network, dragging down speeds for everyone.

A changing landscape

We see some interesting contrasts when it comes to mobile data in the U.K. On the one hand, the breadth of the kingdom benefits from fast 4G speeds, more so outside of London than within. On the other hand, the availability of those LTE connections is poor compared to many other developed countries, a limitation only exacerbated when you venture outside of London.

But U.K. operators aren't idly accepting the status quo either. Spectrum-rich EE has just begun a capacity upgrade to its LTE-Advanced network that could boost its speeds by 50%. As is typically the case, the first city to see the benefits of that enhancement will be London, starting with Wembley Stadium. Meanwhile Vodafone and 3 are repurposing old 2G and 3G spectrum for LTE use, with the aims of plowing more capacity into and boosting coverage on their 4G networks. We're highly likely to see LTE speeds increase even further in the coming year. What the U.K. really needs, though, is a big boost in 4G availability so consumers can take advantage of those speedy connections.