Ofcom consultation on interference to DTT from 800MHz band


Last year Ofcom commissioned a report into the possibility of interference from LTE (4G) handsets and base stations on DVB-T reception. This concluded that the installation of high quality filters in the input to receivers could resolve most of the issues for standard installations. These are defined as those installations using rooftop antennas. No consideration of the effect on receivers using set top antennas was given and any effects on these receivers are likely to be much greater.
Ofcom has now released a new consultation document detailing the effect of LTE services on DVB-T reception and vice-versa. The consultation details the possible effects and the effectiveness on the problem of different measures. These measures include the use of filters and an information scheme for viewers. Ofcom proposes that the majority of the cost should be borne by the future 800 MHz licence holders.
Ofcom also notes that for less than 0.1% of DTT viewers, filters may not solve the interference problems and it may be necessary for them to switch television delivery platforms.
The consultation asks five questions on the ways that the problem can be lived with.
The problem occurs because the “Digital Dividend” frequencies to be used for LTE are those previously occupied by analogue TV transmissions and are in some cases only separated by 1MHz from channels used for current DTT reception.
The report says that up to 3% of DTT users could potentially loose DTT reception because of these services if the problem is ignored.
The current consultation closes on the 11th August but depending on the response more consultations may be issued before a final decision on the way forward is taken.
Source: Ofcom website
Item added: 6th June 2011