RootMetrics tested mobile operator performance in the most densely populated parts of the city, reflecting how speeds can vary depending on congestion, location and other factors that can affect the consumer mobile experience.

Speeds throughout the day

Download speeds in London were generally at their fastest early in the morning, when demand for connectivity is lower. But as commuters began their journey to work along key train lines, such as from Birmingham to London , data reliability was generally poor compared to what was recorded both in London and across the UK's largest towns and cities. However, when workday testing was carried out, although speeds slowed down, Vodafone was an anomaly, recording increased download speeds. Additionally, data shows EE customers will experience fast speeds throughout the entire day. The speeds of O2 and Three in London's busiest areas, however, were at least seven times slower than those of EE and Vodafone.

Kevin Hasley , head of product at RootMetrics and executive director of performance benchmarking at IHS Markit, said: "While London's infrastructure can impact mobile network performance, the increased demand for connectivity from users can also slow download speeds during the day. This is in contrast to the strong performance experienced throughout the evening and outside the city centre."

Speeds in the city and towns

Canary Wharf, a global financial hub, saw varied download speeds among the UK's big four carriers, particularly between EE and Vodafone. While EE's speeds were generally outstanding across London and in the towns that surround it, the operator's median download speed in Canary Wharf was similar to those of O2 and Three and much slower than that of Vodafone.

Variations by neighbourhood

EE and Vodafone both delivered strong median download speeds in Westminster, with EE at 62.3 Mbps and Vodafone at 45.2 Mbps. A similar trend was observed in Shoreditch and Knightsbridge. However, Three's speeds were notably better in the suburbs, as its HSPA+ network is a robust 3G option that maintains speeds when 4G isn't available.

5G coming soon

5G is on the fringes and two factors critical to the readiness are current 4G coverage and maximum download speeds. Tests reveal that both EE and Vodafone are well placed, delivering comparably higher median download speeds than O2 and Three.

Hasley said: "5G will transform our mobile experience and dramatically change what we can do at home and on the move. The current 4G technology provides users with fast and reliable experiences, but 5G will open up possibilities for the Internet of Things and provide capabilities to enable zero-latency gaming and driverless cars.

"The evolution to 5G will result in a quantum leap, with median download speeds expected to be in the range of 150 Mbps to 450 Mbps. With these speeds, everyday mobile functions that currently take a few seconds to buffer will happen instantaneously. Current and planned 4G technology and coverage in London suggests that we can expect to see a 5G rollout for customers in 2020."

Cities such as London will be the first areas to see a full rollout of 5G, but over time the wider population will benefit from the added capability that the technology provides.

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.