Ofcom have warned that next-generation mobile broadband services using LTE (Long Term Evolution) could interfere with digital terrestrial TV (DTT), affecting around 3% of users in the UK (760,000 households). The problem exists as the DTT frequencies are so close to those which will be used by the mobile networks and some DTT receivers were designed to receive the whole of the frequency band including that which has been assigned for use for LTE.
Testing carried out by Ofcom found that households which use an amplifier are more prone to this problem as they get overloaded by the mobile signal more easily than a standard TV receiver. Ofcom have various proposals for ways to deal with this interference and that includes deploying satellite or cable services where restoring digital terrestrial TV is not possible. Other mitigation techniques include:
Ofcom believe filtering should form a large portion of preferred mitigation options and modelling proposes that the use of receiver filters could decrease the affected households by around 90% and when combined with transmitter filters, this would reduce the amount affected to only 30,000 (down by 95%). Funding for this will be through the mobile network licensees (with receiver filters costing in the region of £10 for homes, but more where a communal aerial system is employed). One could perhaps argue that this should be funded by the digital switchover process which had an underspend of around £250m, but this money has already been appropriated for use for by BDUK (Broadband Delivery UK) for next-generation broadband services (which could include LTE).
The consultation is open for responses until the 11th August and the full document can be found here.