Digital Switch Over
Digital Switch Over (DSO) is the largest broadcast engineering project ever undertaken in the UK. It involves the complete replacement of the old analogue and low-power digital TV networks with a completely new high-power digital network.
Arqiva is investing £630 million and 1200 man-years of work in order to implement the task over a five-year period. It will bring multi-channel digital terrestrial TV (Freeview) to 98.5% of UK homes, including those served by over 1000 relay stations which will no longer be restricted to four analogue channels. Other benefits include widescreen and high-definition services, and far more efficient use of valuable frequency spectrum.
Digital TV switchover comprises 66 transmitter groups across 15 TV regions. Each transmitter group comprises of a main switchover transmitter and its relays, with switchover being a two-stage process for each group.
Arqiva’s role
As the transmission contractor for all UK terrestrial television services, Arqiva has the responsibility for implementing the switchover at all 1154 transmitter sites. Every single site has had to be re-engineered, each one an operational site requiring existing services to be maintained right up to switchover. Transmitter output power ranges from 2 watts for the smallest relays to 200 kilowatts for the largest main stations (effective radiated power per multiplex).
Apart from replacing all the electronics and electrical plant, most sites have required new, larger antenna systems. This means we’ve had to strengthen many masts and towers, and construct five major new ones at Caldbeck (Borders), Black Hill (Central Scotland), Rowridge (south coast), Tacolneston (East Anglia) and Divis (Northern Ireland).
'Arqiva is managing this complex and extensive engineering task in an exemplary manner.' Digital UK 2011 Annual Report
DSO facts and figures
- £630m investment by Arqiva
- 1200 man-years of work
- 1154 transmission sites re-engineered
- 5000 analogue transmitters removed
- 500 low-power digital transmitters removed
- 3700 new high-power transmitters installed
- Output power from 2 watts to 200 kW (ERP) per multiplex
- Five new tall masts
We’ve had to overcome many challenges in hazardous environments and deal with inclement weather over successive poor summers. We’ve pioneered the use of special load-carrying helicopters to install new antennas at great heights. Unforeseen events like the Icelandic ash cloud and the Japanese earthquake have threatened travel and equipment supply. Many of Arqiva’s transmission sites are in remote rural locations where rare flora and fauna have had to be protected or worked around during times of major activity.
Any project on this scale will have unexpected challenges, but so far every site has been completed successfully on time. In doing so Arqiva has built a new transmission network fit for the 21st century and demonstrated its capabilities in delivering critical national infrastructure.
‘The project is on-time and has run brilliantly smoothly. Switching to digital TV provides people with more channels while freeing up valuable spectrum.’ Ed Vaizey - (Communications Minister)
Find out about Digital Switch Over in the London region.
