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2018: Freeview roadworks ahead

Technical briefing | The new year heralds a hectic period of change across the UK's digital terrestrial TV network.

Within the next two and half years, major work on the infrastructure supporting Freeview will need to be completed.

An intensive reconfiguration of the frequency band used for Freeview to create space for new 5G mobile services in the 700MHz band has to be finished by mid-2020: the deadline imposed by regulator Ofcom.

For viewers in all but the north of Scotland, this means at least one, but in some cases multiple retunes. For a small minority of viewers, a new aerial or an aerial realignment may be required. Retune dates for the next three months are listed here.

For the broadcast industry, this means a busy schedule of transmitter work, including temporary masts at sites such as West Yorkshire's Emley Moor to allow transmitting equipment to be reconfigured for broadcasts on new frequencies.

Meanwhile, aerial installers will be busy making any necessary adjustments to viewer's aerial set-ups as well as assisting with the inevitable retune enquiries from customers.

While services currently broadcasting in the 700MHz frequency range will be moving down the band to new frequencies on a staged region-by-region basis, two multiplexes will be moving the other way into the 700MHz band: COM7 and 8 -the home of channels such as BBC Four HD, 4seven HD, FreeSports and Forces TV - are temporary multiplexes and are moving to temporary holding frequencies while awaiting an Ofcom announcement as to when their licence will be ended in order to complete the total clearance of TV services from the 700MHz band.

Consultation responses posted on the Ofcom website recently indicate that some in the industry are still lobbying to keep COM7 and COM8 on air on the temporary frequencies until 2022. Whenever Ofcom decides to terminate the licences for COM7 and 8 will determine when we will see some of the existing multiplexes switch to the newer DVB-T2 standard in order to carry some of the displaced services. This is because DVB-T2 enables each multiplex to increase its payload - or number of channels it can carry. In this case the increase can be used to accommodate channels currently on COM7 and 8 on top of existing channels.

As a result, the COM7 and 8 switch-off date may well determine when users of basic / older Freeview receivers might start to lose access to some services, although at this point no-one has spoken of a complete switch-off of first genration DVB-T, although for it would bring about cost savings for broadcasters currently having to duplicate transmission in both SD and HD.

As part of the changes, and in order to ensure viewers can still receive Freeview, additional transmitters will be brought into service, while other transmitters will begin to carry a full set of Freeview channels for the first time to plug expected coverage holes caused by the frequency changes.

Such changes are most notable in a triangle between Gloucestershire, Birmingham and Swindon as well as in the south-east of England.

In Herefordshire, the Ridge Hill transmitter currently beams an additional regional version of ITV for viewers in the Gloucester area, so that they can receive the more relevant ITV West service instead of ITV Central. This arrangement was set-up following the demise of the old ITV Central South region, which previously plugged the gap between the Central West, [HTV] West and Meridian TV regions.

From the 1st March 2018, the special multiplex serving Gloucester with ITV West will be reduced in power from an effective radiated power (ERP) of 20kW down to 2kW. To ensure the signal is still robust to be received in the Gloucester area, it will be changed to QSPK modulation. Some receivers may need to be retuned if they can't handle the change automatically.

Meanwhile, for viewers in the centre of Worcester, a new six-multiplex Freeview relay will be taken into service; the exact launch date is to be confirmed. Worcester has previously been on the edge of the Sutton Coldfield coverage area; but the new relay will operate as a single frequency network (SFN) will Ridge Hill. There will be no changes to regional news.

In Swindon, a new SFN carrying a six-multiplex Freeview service is being set-up with the existing reduced service relay at Seagry Court linking up with a new site at Wroughton. This area is currently divided between signals from the West and Oxfordshire TV regions, with many households using two aerials. The new SFN will provide access to the West TV region variants and plug a coverage gap between the Oxford and Mendip transmitters following the frequency changes.

In the south-east, two relay transmitters will be upgraded to carry a six-multiplex service to fill coverage gaps.

The Rouncefall relay near Hockley, is to be upgraded first. The site, north of Southend, first went live at digital switchover in 2011. The relay was put into service to plug a post-switchover coverage hole in South Essex, allowing viewers to access BBC East and ITV Anglia via a SFN with parent transmitter Sudbury in Suffolk. Many households in the area found that otherwise, they had to rely on signals from either North Kent or London, with the wrong regional news. With changes to frequencies and radiation patterns (affecting how much of a signal is beamed in various directions from the transmitters) as part of an international co-ordination of frequencies with neighbouring Belgium, France and The Netherlands to avoid interference, the Rouncefall relay will commence broadcasting the COM6/ArqB multiplex (home of 5Spike, Yesterday, Talking Pictures etc) on 7th February 2018. The remaining two of the main six multiplexes will follow at a later date meaning households in the area will be able to use the local Rouncefall relay for all national Freeview services in the future.

On the 21st March, the low-power Haslemere relay in South Surrey will be upgraded to carry a six-multiplex Freeview service. In addition to boosting the reduced Freeview service for the few current users of the relay, the upgrade will provide viewers in the area who currently can get a signal from the main Midhurst transmitter a more reliable signal following the various frequency changes. Eventually, it will operate as a full SFN will Midhurst.

The changes are being co-ordinated by Digital UK, the organisation that was behind the original digital switchover programme. Housing associations and other communal landlords are receiving direct communication from Digital UK as are aerial installers. Channelised aerial systems installed in tower blocks, for example, will need to be changed in line with the adjustments.

Viewers themselves will receive further information about the changes as they reach their area via Freeview.