Digital TV
Ways to receive Digital TV
TV in the UK is going digital. After 2012 everyone (who wants to watch TV!) will need to have moved to one fo the various digital TV platforms available, existing analogue terrestrial TV service will cease. This article outlines some of the ways you can receive digital TV
Integrated Digital TV
Many new TVs now incorporate a digital Freeview tuner (a so called Integrated Digital TVs or IDTV). These receive digital from an existing house TV aerial, if the quality of the signal's good enough.
(If your analogue reception is good, you'll usually be ok with digital, but if its less than great, then probably not. (There are exceptions to this.)
Set top box
A set top box (STB) is a generic term for any external box that decodes a digital TV service (from a conventional TV aerial, a satellite dish, or a digital cable service) and allows it to be displayed on your TV. The box is typically connected to the TV by either a SCART lead or a HDMI lead (and on rare occasions by a co-ax). Most of the standard definition converter boxes have a SCART output, and HDTV ones will typically have HDMI also.
Personal Video Recorder
Personally Video Recorders or PVRs are more sophisticated set top boxes that are also able to record programmes. Programmes are usually recorded onto an internal hard drive these days - with a typical entry level recorder containing 160GB of hard drive space (or about 80 hours of recording capacity). Unlike video tapes or DVDs, a PVR can usually perform a number of playback tricks that were not previously possible, such as watching a recording from the start before it has actually finished recording - so called "chase play", pausing and rewinding a live broadcast etc.
The better boxes have twin tuners to allow recording of a different program to the one being watched or recording two different programs at once. The most sophisticated boxes offer advanced features like USB or Ethernet interfaces to allow connection to a computer or network.
The Internet
Another digital TV source is the internet. This can be accessed by computer and a growing number of games consoles and other media devices.
What's available:
- BBC iPlayer: plays a selection of the most popular programs on demand, up to 7 days after airing. Plus it allows you to catch up on previous episodes of a series during the duration of the series being shown.
- ITV, Channel 4, and 5 also have a similar service.
- Various video viewing sites, eg youtube, google, allow viewing of user created video footage (and large swathes of unlicensed commercial content that has been illegally uploaded!)
- P2P file sharing sites allow the (typically illegal) download of TV and movie content from around the world.
- Masses of instructional videos on numerous sites, covering pretty much any subject you can think of.
Some of the main channel sites also allow "live" viewing of at least some of the content. (note that UK residents will require a TV license if using computer equipment to view or record live TV in this way)
To watch much TV over the internet on your computer will takes a lot of data, so a low download limit ISP account won't do.
Digital TV Performance
Performance of broadcast digital TVs in poor signal conditions is different to that of analogue. Where an analogue TV will suffer a progressively degrading picture (becoming ever more "snowy"), a digital picture will remain "perfect" until close to the minimum signal level, and then will begin to experience serious errors and glitches followed by complete loss of picture shortly afterwards. This is known as the digital "cliff effect".
This is most noticeable with the freeview DTV service, where an existing aerial installation is reused. A signal that may have resulted in a slightly grainy (but watchable if you are not too fussy) analogue picture, may not provide an acceptable DTV service.
Performance of Internet based services can vary greatly - from very poor to "ok" for real time streamed services, and poor to excellent for downlaoded services. Most online TV is only viable with a broadband connection offering at least 256kbps or better download speeds.
Content providers
Freeview
With freeview STBs or IDTVs, you buy the box/tv, but there are no ongoing costs, no contract, no subscription. You just plug it in to an aerial and watch.
Freeview and other DTV details
Freesat
A free satellite service offering a range of channels including some High Definition (HD) ones (assuming you have the right equipment). You will need to purchase the relevant Freesat STB or Freesat PVR, and possibly pay for a dish to be installed, however there is no ongoing charge.
Sky
Offer various pay per month and pay per view channels and programs. They also offer HD content on some channels (at extra cost)
You may also use a sky box without any subscription. There are two ways to do this; one is by paying the one off setup fee for a "Freesat from Sky" decoder card for the SKY STB. The other is simply using any sky STB without a decoder card at all. The Freesat From Sky card adds a few extra channels that are technically free to view, but are protected by SKY's encryption, and hence can't be watched without a decoder card in the STB)
Sky Details Freesat from Sky Details
Virgin
Pay per month and pay per view cable service, choice packages with different channels included, with differing prices. Pay per view content also available on all packages. Some customers can get cable TV at no extra cost if they also have other services from Virgin.