Steps taken prior to 2012 towards the Digital Dividend
The ITU World Radiocommunications Conference 2007 (WRC07) made part of the UHF TV band available to mobile telephony.
In 2008 the
Commission for Communications Regulation (ComReg) began discussions with their counterpart Ofcom in the UK. They jointly prepared a revised digital television plan. That plan fitted within the reduced spectrum available for TV in the UHF band.
ComReg are responsible for international negotiations with neighbouring countries regarding the detail of spectrum use in Ireland. They also issue Wireless Telegraphy licences. ComReg undertook a number of consultations (ComReg 10/59) regarding this work.
The Broadcasting Act of 2009 requires ComReg to make spectrum available for Digital Television multiplex transmissions. Digital Television services started in May 2010. RTE kept the Department informed on the Saorview network roll out process.
Terrestrial television broadcasting completed migration from the traditional analogue transmission to digital transmission in October 2012. TV services stopped using the frequencies 790-862MHz (800MHz band), in November 2012. The first Digital Dividend happened when that spectrum was allocated to mobile telephony,
ComReg manage Ireland's spectrum resource. In 2012 ComReg auctioned the digital dividend 800MHz band spectrum with the existing 900MHz and 1800MHz band cellular telephony spectrum . The first digital dividend enabled cellular telephony systems to be use 60MHz of the 800MHz band.
Filters may need to be fitted in some households.
Since 2013 "Long Term Evolution (LTE)" 4G systems operate on the frequencies previously used by TV. Some viewers may have to have a filter installed at their TV or Set Top Box. This is in order to reduce the strength of the cellular signal. Such filters improve the compatibility (see EBU article) between TV and 4G mobile telephony systems.
Viewers will most likely need to use filters where DTT uses channel 58 (770MHz) or 59 (778MHz). Some viewers may need to fit filters where their TV or set-top-box receives DTT operating above channel 51. This is due to the so called image channel "N+9" sensitivity of some receivers. Thus installations using the "group C/D" type aerial may need a filter. Experts expect more difficulties could arise at locations close to LTE base stations. A number of suppliers offer such filters. Both indoor filters and outdoor filters are available. For reception of channel 59 the filter will need to provide signal reductions above 790MHz whilst having a low loss in ch 59 (778MHz). The Broadcasting Act of 2009 requires ComReg to make spectrum available for two PSB mulitplexes and four other multiplexes. ComReg has planned that these DTT services will not use ch 60 (786MHz). ComReg have addressed this matter in Annex 9 of their document Multi-band Spectrum Release - Annexes to 12/25 (Response to Consultation and Decision on Multi-band Spectrum Release [D04/12]) (ComReg 12/25a).
Viewers should use the Saorview coverage checker to determine which channels DTT uses in their area.
Consumers should fit filters when they have also installed a mast head amplifiers.
All Installations which use a mast head amplifier for TV reception will most likely need a filter. This is because mast head amplifiers are prone to overloading. An "overload" condition can occur if the signal level from either DTT or other sources is very strong.. In these overload conditions unintended signals called "intermodulation products" can be radiated causing interference to other users of the spectrum.
Viewers should only use mast head amplifiers for reception of DTT where there is a clear need to do so. Excessive amplification of a DTT signal can cause set top boxes not to work properly. The set top box appears not to be able to decode the DTT service even though there a stong signal.
There will be a second digital dividend in 2020.
The ITU World Radiocommunications Conference 2012 (WRC12) made more UHF spectrum (694-790 MHz) available to mobile telephony. This is a second digital dividend.
ITU groups and
CEPT groups decided to adopt the mobile telephony band plan used in Asia for Europe. This band plan allows cellular telephony to use 60MHz. Experts think that security and emergency service radio systems could also use part of the second digital dividend spectrum.
ComReg has already completed discussions with neighbouring countries. ComReg agreed a new TV channel plan with Ofcom UK. The replanning process included
2rn (formerly RTE Networks Ltd) and Arquiva, the transmission network operator in the UK.
TV manufacturers might install adequate filters in TV receivers. Otherwise households may need to fit new filters after the second digital dividend.