Average download speeds declined from 19 Mbps in September 2013, to 10.16Mbps this August.
Speeds of 4G mobile services in the UK have dramatically slowed to nearly half over the past year due to network congestion, a new report has revealed.
The latest OpenSignal UK research, carried out in association with consumer watchdog Which?, revealed that network congestion was mainly due to a rise in users signing up for new services offered at a premium price.
During the launch of the service in 2012, mobile phone firms assured users that 4G would be five to 10 times faster than the already existing 3G networks.
Average speeds at which users can download on 4G networks have drastically declined from 19 Mbps in September 2013, to 10.16Mbps this August.
The report adds: "As more people sign up to 4G LTE and use the network, the average speed inevitably comes down.
"There are several competing forces at play here – an increase in users slows the network down but the networks are constantly rolling out improvements and adding LTE-enabled cell towers, which goes some way towards explaining the deviations in the downwards line."
According to the research, London offered the fastest and most reliable network coverage, while consumers in Wales, parts of the South West, the East Midlands and North East get a worse service at the same price.
EE topped the list of major networks for 4G in terms of geographical coverage, surpassing services offered by O2, Vodafone and Three.
Which? executive director Richard Lloyd said: "We’ve looked at consumers’ real-life experiences and found big differences in service between mobile phone providers, depending on where you live or work.
"We’re calling on providers to publish the reliability and speeds their networks actually achieve so people can make an informed choice before signing on the dotted line."