Freeview retune in north Wales over 4G mobile broadband
Freeview TVs and boxes in north Wales will have to be retuned next month as local airwaves are cleared for the roll-out of faster mobile broadband.
Technical changes to the Moel-y-Parc and Llanddona transmitters will free up frequencies for future fourth generation (4G) mobile services.
The UK's first major 4G service went live in 11 cities, including Cardiff, on Tuesday.
Freeview boxes across north Wales will need retuning on 14 November.
Between now and the end of 2013 a number of transmitters across the UK will undergo similar upgrades to prepare for 4G.
4G offers increased speed and capacity and allows for high-quality streaming of audio, video and other content while on the move.
Channels including BBC One, ITV1, S4C, Channel 4, Channel 5, Film4 and Yesterday are moving to new frequencies as part of the retune.
Work at the Moel-y-Parc and Llanddona transmitters is expected to be completed by 06:00 GMT and viewers can retune at any point after this on 14 November.
Digital UK is launching an information campaign to make viewers aware of the need to retune, including local advertising and messages on screen.
David Scott, Digital UK chief executive, said: "It's a good idea to retune your Freeview TV or box regularly to make sure your channel list is up to date.
"It usually only takes a few minutes but if anyone is unsure what to do, there's plenty of information available on our website or from our advice line team."
The UK's conversion to digital TV began in 2007, with a region-by-region switch-off.