Digital dividend: Clearing the 800 MHz band

On Tuesday the UK regulator Ofcom published its statement confirming its decision to clear the 800 MHz band and align the upper band of the UK’s digital dividend with the spectrum being identified for release by an increasing number of other European countries.

This will allow new wireless services, particularly the next generation of mobile broadband, to be launched in the UK.

The statement also sets out how they intend to clear digital terrestrial television (DTT) and programme-making and special events (PMSE) from channels 61, 62 and 69 in UHF Bands IV and V.

The full statement can be found here:
http://www.ofcom.org.uk/consult/condocs/
800mhz/statement/

The statement mentions the interference problems that could be caused to Set Top Boxes when new services start using these frequencies, it says:

3.40 Virgin Media advised us of a potential interference problem that new two way mobile services in the 800 MHz band may cause to its cable network and set top boxes.
It also suggested that DTT receivers may be similarly vulnerable. Virgin Media claimed that this could be raise significant costs to it and its customers and should be included in the CBA.

3.41 Our understanding is that this is an issue of electromagnetic compatibility between cable systems and any new services using the 800 MHz band. In particular, imperfect screening in cabling or other parts of the receive system may allow energy radiated from mobile transmitters in close proximity to cause interference to TV reception.

This would still occur regardless of any decision to clear the 800 MHz band and therefore it is not appropriate for it to be included in this CBA. However, we recognise that interference into either cable TV set top boxes or DTT receivers could adversely disrupt reception for viewers of either service.

Virgin Media is currently investigating the extent of this problem in the UK, where we understand the main distribution elements of its cable network to be less susceptible to interference than cable networks in other European countries because the majority of it is underground.

At the same time we are conducting our own studies to evaluate the potential for interference problems and exploring what mitigating measures, if they prove to be required, are likely to be suitable and available.