The UHF channels used to broadcast some DTT multiplexes at certain transmitters in the Border, Channel, Wales and Westcountry regions will be changing between February and March 2019. These changes are part of work being carried out for the 700MHz clearance programme. The full briefing from Digital UK can be download on the following link - https://tinyurl.com/y9qshpnr.
Following a decision by Ofcom, spectrum in the 700MHz UHF band currently used for digital terrestrial television (DTT) is being reallocated for the development of future mobile services. Some DTT multiplexes will be moving to new broadcast frequencies as a result of this change.