Digital Satellite Radio

In the days of analogue satellite television, all television channels came with around nine mono audio channels, primarily meant for transmitting different language versions of the same television programme. While some channels used this, notably Eurosport, many channels sublet their audio carriers to radio stations. Tuning in to radio in this way was difficult, and confusing - since the picture of the hosting channel remained on the screen - and consequently few people knew of the facility, let alone tried it.

With the advent of digital satellite transmissions in late 1999, radio stations were given their own channel numbers and displays, so publicly-accessible digital satellite radio became a reality.

Sky and Freesat are the only satellite system aimed specifically at the UK, and there are currently over sixty radio stations available on the system, starting at channel 0100.

Radio stations are accompanied by a 'soft' dark-blue display, including information related to the current programme. On Freesat, some BBC stations are accompanied by a logo and limited information.

Benefits: Satellite can deliver high quality audio over a large coverage area. Large choice.
Drawbacks: Few local radio stations use the system. No dynamic 'now playing' information on Sky. Limited information on Freesat. Fixed antennas only, so no mobile coverage.
Potential listeners: 1,000,000 FreeSat boxes sold (FreeSat, Q1 2010); 9,300,000 Sky households (Ofcom, Q1 2010)
Current listeners: Unrecorded (separately) by RAJAR. 4% of all radio listening is via the television (RAJAR Q1 2010).
Sound quality: Digital, between 128 and 192k, MP2 encoded.
Transmission cost: Around £20,000 for transponder space, and £20,000 for appearance in Sky's Electronic Programme Guide (and therefore allocation of a channel). Freesat also charges for appearance in their EPG.
Reception cost: A digibox is free with commencement of a SkyDigital subscription (the cheapest is around £228 a year), or you can buy without any subscription for a one-off £175. No subscription is required to receive the majority of stations. A FreeSat box is normally a one-off charge from £105.
Coverage: UK-wide (in practice, most of mainland Europe), to fixed antenna
Pay-radio capable: Yes (Sky only)
Now playing capability: None on Sky; limited on Freesat
Schedule capability: Now/Next only on Sky; a full schedule on Freesat
Display: limited to text in a standard format
Best for: people who don't want local information, but a wide choice of music, including the ethnic and the unusual. High amount of speech-based programming.