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| Digital Terrestrial Television (DTTV) Since August 2006, the Department of Communications have been running Digital Terrestrial tests at both the Three Rock and Clermont Carn TV transmitter sites. The tests will shortly become a pilot service aimed at a closed group of 1000 test users. What impact does this have on the rest of us? The first and most important point to make about the current state of Digital Terrestrial TV in the Republic is that this is NOT a service aimed at the general public - it is intended purely for the closed group of 1000 users - so if anyone can receive sound and pictures from the pilot then that is purely by chance than by design. In short, don't go out and buy any digital receivers or TVs on the basis that anything is available because the Department of Communications could encrypt the broadcasts at any time!! The pilot is being broadcast by BT Ireland. The signal is noticeably more robust than its UK equivalent - it is believed that the Department of Communications want the signal to be receivable via a simple set top antenna rather than a rooftop antenna - certainly at my receive site in Celbridge, Co. Kildare it is possible to get all channels at full signal strength using a set top UHF antenna. It is planned that main DTTV transmitter sites will broadcast at a typical ERP of 50kW. Compare and contrast this with the UK DTTV transmissions operating on a range of 2.5 kW to 10kW. At the time of writing - February 4th 2007 - the following multiplexes were available from Three Rock in Celbridge using a both standard UK Freeview receiver (Philips DTR1500) and a standard French TNT receiver (Bluesky):
Offscreen photos The following offscreen photos were taken in the summer of 2006 shortly after the initial tests commenced from Three Rock. The receiver was a Philips DTR1500 Freeview box connected to a "Colour King" rooftop aerial pointed directly at Three Rock. There is line of sight to the mast from the receive location. Note the EPG data!
Some historical background A full digital terrestrial service was expected to be up and running in 2002. However, the collapse of the ITV Digital service meant more delay. RTÉ DTTV tests were ongoing from Three Rock with a six channel multiplex on channel 26, but these ceased along with the Digital Audio Broadcasting (DAB) pilot service that was being transmitted from Three Rock. Only one applicant for the DTTV licence was announced by ComReg's predecessor body the ODTR - a company called It's TV applied to run the service, however banks were unwilling to lend them money so the service never started. RTÉ did broadcast RTÉ One, Network 2, TV3, and TG4 with occasional use of the other two channels. RTÉ carried Tara TV on one of the spare channels. No EPG information was carried. RTÉ tested the wireless return path (which means that there would be no need to plug the digibox into a phone line). RTÉ also ran a Band III transmitter set up at Three Rock on Channel D for VHF tests. RTÉ intended to put into place a two way channel allowing the viewer's home aerial to send a signal back to the DTTV transmitter rather than having to keep the set top box plugged into a telephone line. Here are the original proposed Irish digital terrestrial TV
channel allocations: As we can see from the current configuration of Three Rock
this plan may well be replaced as and when the national roll out of DTTV:
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