Its more like this...
The main TV services are
- Freeview (via TV aerial)
- Freesat (via satellite dish)
- Sky (via satellite dish)
- Virgin (via underground cable connection)
These will all provide the full range of free-to-view* TV channels, and the extra subscription channels if you're a Sky or Virgin customer.
Internet-only TV services tend to focus on catch-up and subscription services rather than the everyday BBC1, BBC2, ITV, Ch4, Ch5 etc live TV channels. There are products such as Now TV (owned and operated by Sky) which provides access to selected catch-up and subscription channels (movies, sport, box sets, entertainment channels) for a monthly charge or on a Pay-per-View basis. These are accessed via a Now TV box which uses the house internet connection.
Sometime next year it is rumoured that Sky plans to launch a full TV service via the internet.
At this stage there's no other official internet version of Freeview or Freesat that's universally supported on web streaming TVs, PVRs and other set-top boxes. There are services that exist such as
www.watchtvnow.co.uk that make it possible to watch TV via a PC.
As far as wiring is concerned, Freeview is via a single TV aerial coax cable either direct from the TV aerial or via an aerial distribution amplifier. Freesat and Sky both require a direct feed from the LNB (low-noise block downconverter) which is the lump sitting on the end of the "stick" that you see wires coming from on a satellite dish.
LNBs for Sky/Freesat come in single-output, 4-output and 8-output versions. A single feed is generally used for a "watching live" box or TV connection. [Note: there are exceptions to this, but I'm talking about the typical garden-variety everyday Sky/Freesat installation here]. A Sky or Freesat recorders generally need two connections. This enables the "
watch-one-channel-while-recording-another feature". A 4-output LNB then can feed either two recorders, or one recorder and 2 watch-live devices, or 4 watch-live devices. The 8-output LNB does the same only more so.
If you have Virgin installed then the installer will run their own cable to either their modem or to a TV recorder. Virgin are very fussy about the cable. It has to be triple shielded, so it's difficult for a home owner to pre-wire for Virgin and guarantee that the installer will accept running their signal through your cable.
* UK TV licence required
