The mobile network EE has been named the best in the UK in a study of the performance of phones as experienced by consumers.
The report by network analysts RootMetrics found that the major networks provided "hugely varying" levels of service across the UK, with EE winning or tying for first place in every category and Three taking second place.
The company claims to have driven more than 23,000 miles across the UK and collected more than 840,000 samples - or one sample for every 100 mobile phone contracts in the UK.
It used off-the-shelf phones to take samples outdoors, during driving and at more than 1,000 indoor locations to assess how each network performed across mobile internet, call and text testing, as well as a summary of which network was the fastest and which was the most reliable.
RootMetrics concluded that EE's early rollout of 4G "paid big dividends", leading to the network taking the highest score for mobile internet, calls and texts and also finishing first in the reliability and speed categories, with an overall score of 84.6 out of 100.
Three took second place with an overall score of 73.5, followed by O2 (66.5) and Vodafone (52.4).
RootMetrics chief executive and president Bill Moore said: "These results give UK consumers and businesses the most accurate view of mobile performance in the UK that has ever been made available.
"From nation to neighbourhood, people now have access to data showing them the best network in their area.
"No other study of this size and scale for mobile performance has ever been carried out before in the UK, and it has, for the first time, shown consumers the true services they are receiving from their network provider."
Vodafone UK, which the report claimed "trailed markedly" in the reliability results, dismissed the findings.
A Vodafone UK spokesman said: "We'd love to give a fully detailed response, but believe the way RootMetrics carried out its testing does not appear to follow standard industry practices or is fully impartial, while it also incorporates data some of which may well be over six months old.
"The evidence we have seen of how Root Metrics conducted some of its tests leads us to believe that they were carried out in an inconsistent manner.
"Those looking for more robust research should be approaching more established researchers, such as Ookla, who are completely independent and use hundreds of thousands of real, unbiased customers across the country for their results.
"We cannot take the results of this report seriously and neither should our customers."
EE chief executive Olaf Swantee said: " Today's results show that the EE network gives customers everywhere in the UK the best mobile experience. This is down to our ongoing investment in introducing 4G, increasing 3G capacity and upgrading 2G, while also spending hundreds of millions on phone call quality.
"We encourage the most rigorous independent testing of mobile networks in the UK, and strive to set new standards in performance and reliability."