The Voice of the Listener and Viewer (VLV) has entered the debate on the effects of 4G interference on the Freeview signal, joining the BBC and other digital multiplex operators in voicing their concerns to Ofcom.
|The VLV is seriously alarmed at the threat of interference from 4G mobile broadband|
As part of the proposals to convert the upper part of the frequency band currently used for terrestrial television broadcasts, the government has committed to keep £180 million from the spectrum auction to fix viewer's reception problems. This would be in the form of one filter per householder, and payments to some householders to get cable, satellite or broadband television where the terrestrial signal would be knocked out by the interference.
However, there are worries that the proposed scheme announced by the Department for Culture, Media and Sport (DCMS) does not go far enough. For example, it offers only limited technical support and does not take into account viewers with indoor or communal aerial systems.
“These proposals to sell spectrum to mobile phone operators in order to raise millions for the Treasury could remove the option of free-to-air television from millions of viewers.“This runs completely against the UK’s system of public service broadcasting whereby there is universal access for all citizens to programmes made by the main terrestrial channels. It is an outrage.”
The organisation also critised that viewers were not being told about the potential problems starting as soon as next year, stating “despite the elaborate and costly plans for digital switchover, little if anything was done to alert home-owners and viewers to the possible adverse consequences of frequency sales to mobile providers”.
- You can read the VLV's submission to Ofcom at the following link (PDF reader required): http://www.vlv.org.uk/documents/1231.12VLVsResponsetoOfcoms2ndconsultationoncoexistenceofnewservicesinthe800Mhzbandwithdtt26.pdf
Background - to 4G or not to 4G:
UHF channels 61-68 are currently part of the frequency band used for TV services. Although in most areas most of that band is now free of services, some services remain in pre-switchover regions on the affected frequencies until this autumn. Numerous transmitters still broadcast on UHF channels 61 and 62, as these were not originally part of the frequency band to be cleared. Viewers receiving Freeview in areas where the local transmitter transmits on UHF channel 61 or 62 and some viewers in neighbouring areas will need to retune during late 2012 or during 2013 (see the 4G clearance retunes page above for a "living document" which is being updated when new information emerges).
Even once all services are off that part of the frequency band, the UK is left with devices and aerials designed to pick up services right up to UHF channel 68. In order to block 4G mobile broadband services, filters will be required to cancel out the interfering signals. However in some areas, the mobile phone mast transmitting the 4G services will be so close, and so powerful that it will have the ability to drown out TV signals on adjacant frequencies, especially those above UHF channel 50. If more frequencies are cleared to create a clearer buffer zone between 4G and TV, there is a risk that some TV services would have to be removed as there would not be enough frequencies. Alternatively, TV services would have to speedily migrate to DVB-T2, which enables more services to be broadcast on less frequencies. However, this would make any non Freeview HD receiver accessing the Freeview (standard definition) service obsolete.
In countries such as Denmark, safeguards are being put in place by reducing the power of 4G masts in areas where there are TV services on immediately adjacant frequencies.
Satellite television services, such as Sky and Freesat are unaffected by these proposals.