Frequently Asked Questions
What frequency is the DAB trial broadcast on?
The trial is broadcast on 223.936Mhz the second frequency assigned to Ireland for a national Single Frequency Network (SFN). This is also known as Block 12A of Band III spectrum.
RTÉ broadcast on the other national frequency assigned to Ireland 227.360Mhz (Block 12C).
Another DAB trial in Waterford City is broadcast on a regional frequency 204.640Mhz (Block 9B) and is operated by Total Broadcast Ltd.
What stations are broadcast on the trial?
We have launched with four stations; All 80s, Raidió Rí-Rá, Sunshine and UCB. Three more stations will join us in during Q4 2012.
Why can’t I hear stations with a “+” symbol after their name?
These stations are broadcast using the modern DAB+ system and you need a DAB+ compatible radio to hear them. When you do these stations improve your listening experience with pictures broadcast as well as the audio.
Will DAB be taken over by internet radio ?
We love the internet BUT it is not the sole future platform for radio. Read some of the reasons why and find out which platform listeners perfer here.
Is DAB expensive?
Yes and no!
It does cost more to operate a single DAB transmitter. However one DAB transmitter can broadcast ten or fifteen radio stations at the same time. On the other hand one FM transmitter can only ever broadcast one radio station. With many stations sharing the overall expense of DAB, the per station cost is much much lower than FM.
What is the difference between DAB and the new DAB+?
DAB uses an encoding algorithm called MPEG1 Layer II. While this was cutting edge when DAB was first introduced other more efficient algorithms have developed over the years such as the familiar mp3.
Possibly the best of the new algorithms is HE-AAC. This has become the standard known as DAB+. It allows a radio station to deliver very high quality audio while using less space on the transmitter hence lowering the broadcasting cost for each station.
What is a “bit-rate”?
This is the rate audio is encoded at for transmission and displayed as “kbps”. DAB typically needs 128kbps or higher for sound to be a good representation of the original audio. The newer HE-AAC used by DAB+ typically needs 64kbps or higher for sound to be a good representation of the original audio.
What are these “Extra” channels I hear about?
DAB allows for reconfiguration of bitrates and services on-the-fly with minimal effect on the listener.
For example, a station may broadcast most of the week using a bit rate of 128k. At the weekend it can split this 128kbps into two channels using 64kbps each. The first continues broadcasting the main station while the new secondary channel carries commentary on a football match. After the game is finished the DAB transmitter reconfigures back to the original 128kbps.
The listener does not have to retune their radio as reconfigurations are signalled in advance and the radio receiver knows what to do.
What are DAB Data Services ?
Because DAB is digital it can broadcast text, pictures, podcasts and other programme associated data in tandem with radio station audio. There are different types of data services on DAB which you can see in our Glossary.