DAB stands for Digital Audio Broadcasting.It is a digital radio service which is broadcast from a UK-wide network of transmitters.
It usesdigital technology which enables broadcasters to package together several radio stations; this is called multiplexing. Multiplexed radio stations are then broadcast on single frequency networks. This is an efficient way to provide lots more radio stations using fewer radio frequencies.
The tv operatesits own multiplex which is used to distribute all of its national Network radio stations. It rents space on commercial multiplexes to distribute Nations and Local radio stations.
Additional radio services
DAB has allowed the tv to broadcast digital only radio services.These include 6 Music and Radio 4 Extra. It has also allowed us to broadcast World Service in the UK and given the whole of the UK access to services such as Asian Network.
DAB multiplexes
We bundle a number of radio services together, before we broadcast them, into what is known as a multiplex. Your DAB radio can then pull out each individual radio service from the multiplex.To understand the differences between the tv’s own DAB multiplex and the commercial multiplexes used for Nations and English regions services, see our DAB multiplex guide.
We keep an updated list of the tv radio services and the multiplexes they are carried on.
Single Frequency Network
We broadcast our DAB multiplex using the same frequency (12B) from a network of transmitters, which is why we describe it as a Single Frequency Network (SFN). This differs fromFM broadcasting for example, where aradio station is broadcast usingan individualfrequency from eachtransmitter.
An SFN is beneficial to listeners if they are able to receive signals from more than one transmitter. The DAB radio will combine all the signals and make the reception more robust.It is also a more efficient use of spectrum and uses less electricity compared withanalogue radio transmission.
Electronic Programme Guide (EPG)
In the DAB multiplexes we also add some additional service data. If your radio has the function,it allows you to see the schedule of services on each radio station, the same way you can on televisions.
