EE has now performed best in 11 consecutive rounds of testing, dating back to when RootMetrics first began UK-wide testing in the second half of 2013. EE's impressive rankings in the second half of 2018 were based on the testing of reliability, speed, data, call and text performance.

Vodafone's performance was generally strong across categories, giving consumers food for thought when selecting one of the UK's main four operators. Vodafone surpassed Three to take second place for overall performance, aided by strong results in network speed, data performance and text performance.

Three showed specific improvement in call performance testing and solidified its recognised position as a strong network for reliability, narrowly trailing EE in the reliability category for the third consecutive test period.

O2's performance kept the status quo, with the operator ranking last in four out of six test categories, remaining identical to the prior round of testing conducted earlier in 2018.

In its latest round of testing across the UK, RootMetrics performed 600,476 tests, drove 20,294 miles, tested 652 indoor locations and covered 100% of the population.

Kevin Hasley , head of product at RootMetrics and executive director of performance benchmarking at IHS Markit, said: "EE's strong performance in testing is testament to the consistent investment into improving its 4G network. Vodafone and Three are also making improvements as they vie for market position. Although O2 ranks fourth in our testing, it is well placed to improve, having secured key parts of the 5G spectrum in 2018."

How population , location and other variables can impact mobile performance
In addition to testing the UK's 16 most populated metro areas, RootMetrics conducted testing in highly congested areas of three select cities in the second half of 2018. The additional tests focused on where the most people spend their leisure time. Testing was performed in popular tourist areas, travel destinations, business districts and other high-traffic areas.

"The latest data suggests that download speeds are highly influenced by variables such as network capacity, demand, time of day and location. Our latest approach to testing in highly congested areas enables consumers and businesses to be better informed before making key buying decisions, such as where to visit, shop, eat and work," Hasley said. "This type of analysis will be key to providing accurate data on 5G experience when it rolls out in earnest."

Learn more

To learn more about operator performance across the UK, view the three-part report below:

• Mobile performance in the UK part 1: performance across the entire UK - 2H 2018
• Mobile performance in the UK part 2: performance in the four UK nations - 2H 2018
• Mobile performance in the UK part 3: performance in the UK's 16 most populated metros - 2H 2018

About RootMetrics
RootMetrics by IHS Markit is mobile analytics that measure mobile network performance and offer insights into the consumer mobile experience. RootMetrics provides data on mobile network performance to help the networks improve and give consumers an end-to-end look at mobile performance. To ensure that RootMetrics results reflect real-world mobile usage, testing is conducted based on where, when and how consumers use their smartphones most often.

IHS Markit and RootMetrics are registered trademarks of IHS Markit Ltd. and/or its affiliates. All other company and product names may be trademarks of their respective owners © 2019 IHS Markit Ltd. All rights reserved.