Ofcom acts on 4G digital TV interference

Ofcom has today put forward proposals to ensure digital TV signals received through a roof top aerial are not affected by interference from new 4G mobile services.

The media regulator will next year run an auction of the 800 MHz spectrum towards the aim of enabling the UK's mobile operators to launch next-generation mobile networks.

Ofcom says that the 800 MHz spectrum is essential to meet the massive increase in mobile traffic, fuelled by the growth of smartphones and mobile broadband.

It is hoped that the first 4G services will reach rollout phase by 2013, including superfast mobile broadband supporting download speeds of up to 100Mbps.

However, the 800 MHz spectrum is adjacent to the frequencies used for digital terrestrial television (DTT) broadcasting, meaning that in a "small number of cases" 4G mobile signals could interfere with set top boxes and digital televisions.

After the digital switchover reaches completion next year, the majority of the UK will be able to receive DTT signals. More than 10m homes already receive the Freeview DTT service.

Ofcom estimates that the 4G interference could potentially affect up to 3% of DTT viewers if no measures were put in place to address the problem.

The regulator has today proposed offering affected households a filter that would equip to their TV aerials and block the mobile signals that interfere with TV reception.

Under the scheme, the government would provide information and assistance to consumers requiring the aerial, with the costs covered by proceeds from the auction of 800 MHz licensees.

Ofcom said that in a "very small number of cases" - believed to be less than 0.1% of DTT viewers - filters would not solve the problem of interference.

A number of proposals are being considered to help these viewers, but Ofcom believes that they may ultimately have to switch to other digital TV platforms, such as Sky's satellite service or Virgin Media's cable television platform. However, it is not as yet clear how the consumer cost of the platform-switching proposal would be covered.

Ofcom is currently running a consultation on the proposals, which is due to close on August 11.