From Wikipedia: The Common Interface (CI) is the slot on a digital television receiver into which a conditional access module (CAM) may be inserted for satellite television. Receivers normally have two common interfaces. A receiver with a common interface allows the user to access encrypted television broadcasts as opposed to free-to-air (FTA) channels. You can use your Common Interface (CI) in combination with Conditional Access Module (CAM) and get some extra channels on top of the existing fr

free-to-view Freeview channels: http://www.radioandtelly.co.uk/ topuptv.html