DMSL runs and manages the TV interference mitigation programme, at800. The programme was set up under Government direction to ensure that viewers who rely on Freeview for TV can continue to receive it, or are offered a suitable alternative, when 4G mobile services at 800 MHz are activated in their area.

The at800 programme is funded by the UK mobile operators who are rolling out 4G mobile services at 800 MHz: EE, Telefónica UK (O2), Three and Vodafone. Each operator contributes to our funding to enable us to provide corrective support for households whose Freeview services could be affected by the rollout of 4G at 800 MHz.

We identify properties at risk of experiencing interference to their Freeview service from 4G at 800 MHz. We send those properties a postcard explaining the issue and ask viewers to look out for new interference to their Freeview service. If we believe the interference is due to 4G we provide a filter for viewers to fit themselves and, if eligible, we may arrange for an at800 engineer to visit the property.


For more information, visit the at800 website