Mobile users in Cardiff get a better 4G experience than in two other UK cities despite paying the same price, research revealed.
EE became the first and currently only mobile operator to launch a 4G network last October, promising those willing to pay a premium on their tariffs speeds of up to five times 3G.
New data from nearly 10,000 readings taken late last year from city centre sites around Cardiff, Sheffield and Liverpool have highlighted varying levels of service on the UK's first 4G network.
In Cardiff city centre, mobile network testing company RootMetrics said users were able to connect to 4G just over 70 per cent of the time, compared with 58.7 per cent for Liverpool city centre tests and 48.5 per cent for Sheffield.
Once on the 4G network, Cardiff-based tests achieved average download speeds of 16.9Mbs. This is compared with 12.9Mbs for Sheffield and 12.7Mbs for Liverpool.
RootMetrics said that despite varying geographical coverage, EE's 4G service across the UK is broadly in line with its pledge to provide faster mobile internet.
An EE spokesman said the discrepancies in 4G coverage were partly the result of the survey being taken just a few weeks after its launch.
He added: "It is due to the different stages of network rollout in each city. We can't deploy 4G across the UK simultaneously, so there will be some cities that are ahead. But in each city we are delivering our stated goal of speeds of 8-12Mbs."
The network originally rolled out in just 11 major cities but this has now been extended to around 28 locations.
RootMetrics said 4G customers could achieve speeds of more than four times faster than those using 3G, and the service was in keeping with similar services that have already launched in other countries.
Chief executive Bill Moore said: "When it comes to availability of EE 4G in city centres, the picture is positive if not universally excellent.
"We see the percentage of 4G improving in line with other launches, but there are some notable variations like people in Cardiff getting a better service than those in Sheffield, despite paying the same."