is broadcast to viewers using a group of 6 television channels known
as 'Multiplexes'. Each Multiplex provides MPEG Transport Streams
of around 24.1 Mbit/s data capacity. These Transport Streams carry
the data of a 'bouquet' of TV, audio and data services. It is worthy
to note that a Multiplex occupies the same 8Mhz of radio frequency
spectrum as a single analogue television channel. Go
here For a more technical description.
a consortium of some ITV companies, won the bid and created a digital
network of free-to-view and subscription channels which started
in late-1998. Also included in the channel line-up were the five
main broadcasters. However the overwhelming competition of digital
satellite, poor advertising revenue, poor picture quality, small
customer base and easily 'hacked' subscription cards spelt financial
doom for the consortium. A last-ditch attempt to re-brand as ITV-Digital
couldn't prevent the closure of the service in May 2002.
was re-started by Freeview in late-2002 (a joint venture between
BBC, Sky Television and Crown-Castle Communications). Changes were
made in the technical specification and the line-up of TV channels.
Less compression is used (see
here) - the result is fewer channels but with much
improved picture quality.
re-launch did not include subscription channels, but in early 2004
'Top-Up TV' announced a bouquet of subscription channels.
Top-Up TV service began on March 31, 2004, with only those subscribers
with old the old type On-Digital (ITV Digital) receivers being able
to receive the programming. In late-2004 a few receivers with a
built-in access module and viewing card slot began appearing in
coverage in UK is poor. It is important to check that your area
is served by Freeview before buying a DVB-T receiver.
The Freeview site has a useful checker based on your Postcode. An
alternative website by Wolfbane
Cybernetic offers a more accurace analysis and a lot of
other interesting technical stuff).
up-to-date information visit the Freeview