The data analysis was carried out by a mobile phone retailer.
County Derry's three council areas are among the bottom four for mobile phone signal in Northern Ireland, with one ranking as the worst in the UK, according to recent research.
Data analysis carried out by mobile phone retailer Fonehouse has revealed that Derry City and Strabane has the worst mobile coverage in the UK.
The council area is ranked lower than the remote Shetland Islands, the western Scottish area of North Ayrshire and Isles of Scilly off the south western coast of England.
The study used data from Ofcom's Connected Nations 2021 report and coverage checker tools on Three, Vodafone, EE and O2’s websites to create a total coverage score using five factors.
3G services, 4G services, 5G services, voice services and data services were all taken into account before the areas were ranked to reveal the best and worst areas.
The final rankings were calculated using an average from all local authority areas within the region.
Out of a possible score of 2,500, Derry City and Strabane scored 1,869, a full 14.08% below the average UK score.
Mid Ulster was ranked second worst in NI with a score of 1,920 – 11.72% below the average, a result that saw it ranked in the bottom ten areas for mobile phone coverage across the UK.
Causeway Coast and Glens faired slightly better, ranking 20th from bottom with a score of 1,952 – 10.23% below the UK average, and fourth worst in NI behind Newry, Mourne and Down in third.
Neither Mid Ulster or Causeway Coast and Glens was found to have any 5G coverage according to the data analysis.
Ben Branson, CEO of Fonehouse, said the roll-out of mobile coverage in some areas had been hampered by technology not keeping up with demand.
“Mobile networks are constantly evolving and improving as years go by, as more networks put up masts around the country, improving the scope and quality of mobile coverage.,” he said.
“Even so, there are still areas where coverage is weaker than others as the roll-out has been hampered by technology availability.
“5G has come a huge way since it was first released, with a much wider range of compatible handsets, available areas and networks offering it.
“The latest devices that feature newer 5G chipsets, such as the iPhone 13 and Samsung Galaxy S22 will benefit from the fast network roll-out for 5G across the UK.”
Belfast City was the highest ranked area in Northern Ireland for mobile coverage, (57th in the UK), followed by Lisburn and Castlereagh (104th) and Antrim and Newtownabbey (121st).
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