‘Useful’ results from 4G interference test
April 4, 2013
at800 – the organisation responsible for ensuring people continue to receive free-to-air television when 4G mobile services operating at 800 MHz are launched in the UK – has completed its first live test to help assess the extent to which digital terrestrial television platform Freeview could be impacted when the services are launched later this year. Fifteen households in the test area reported problems with TV reception caused by 4G. Before the test, at800’s forecasting model predicted 120 households would be affected.
Approximately 22,000 homes surrounding the 4G at 800 MHz masts were sent information in advance of the testing asking them to contact at800 directly if they experienced problems with Freeview. Over 100 calls were logged by at800 from these households. Professional aerial installers, as well as TV signal experts from at800, the BBC, and Ofcom, visited locations that reported problems to verify their cause.
All issues that could be attributed to 4G at 800 MHz were in television systems with signal amplifiers, either in communal blocks or domestic installations where the amplifier was attached to the aerial. A filter that blocks 4G signals at 800 MHz from reaching TV tuners resolved problems seen by viewers when installed between aerial and amplifier. The filter does not affect the use of mobile phones.
Simon Beresford-Wylie, chief executive of at800, described the pilot as “a useful, small-scale test” adding that at800 would now improve its forecast model and look at the approach it uses to tackle the issues it had seen. Further extensive evaluation will occur during April and May as masts are switched on for tests across larger urban areas.
at800’s preparations for the commercial rollout of 4G at 800 MHz continue with a second phase of testing. These tests will focus on urban areas covering a larger number of addresses. at800 expects to be able to announce plans for a second test soon.