Hardware: set-top box and dish.

What you get: around 150 channels, a mix of free-to-air services (like the BBC and Channel 4) and subscription channels (prices from around Pounds 7 per month). Subscription is not necessary for buying a set-top box.

Cost: around Pounds 200.

Launch: On air now.

Terrestrial. (ONDigitai)

Hardware: set-top box and roof-top aerial.

What you get: around 30 TV channels.

Cost: Pounds 200 for box plus monthly subscription of around Pounds 10. Box can be bought without subscription for around Pounds 400.

Launch: November 1.

Cable. The three leading cable companies, CWC, Telewest and NTL, will offer digital services next year, which could include dozens of channels. Boxes will be free or rented.

No price details are yet available.

Note: Only digital satellite offers national coverage. Digital terrestrial TV and cable may not be available in your school’s area.