The EDCF Guide to ALTERNATIVE CONTENT in Digital Cinema

link budget calculation to be completed. Such a calculation
will ensure that the signal being received into the antennae is
within specification under all realistic operating conditions. As
with any technology, however, nothing is infallible and system
failures occasionally occur - which is why redundancy is
included in the first place.
Satellite reliability considerations
The myth that a satellite itself is not reliable needs to be dispelled
as it is a very robust and widely used delivery system.
Satellites are expensive systems and are designed to operate
for a number of years without maintenance.
Internet Protocol solutions
IP-based solutions for delivery of alternative content are
beginning to be used, but the problem with these solutions is
the available throughput that can be obtained from existing
broadband links. When using IP-based systems across shared
ADSL networks, video quality often suffers, (usually due to the
non-deterministic characteristics of packet-based terrestrial
networks giving variable path parameters and also to user
contention ratios) and services are usually provided on an
“available bandwidth” basis rather than guaranteed bandwidth.
This is not the case with dedicated media channels
such as satellite or point-to-point fibre. Of course, there is a
cost implication with securing 100% reliability through satellite
channels, but to elicit the benefits that showing alternative
content can provide, it is worth the investment to ensure that
customers are happy with the service they receive. This will
increase their loyalty and ensure that they keep coming back
for future programming.
Satellite delivery to cinemas - it is the way forward
Alternative content looks set to play an integral role in the
future of digital cinema as exhibitors look for ways to maximise
their profit through the programming they show. This
content will include live broadcast as well as pre-recorded
material, both of which can be distributed highly successfully
through satellite channels. Broadcasting live content means
that the quality of the service depends on the amount invested
in ensuring reliability. It is likely that the digital cinema industry
will embrace the delivery of content via satellite which is
why companies such as Datasat Communications and DTS
Digital Cinema are working together to ensure reliable distribution
becomes part of the norm.
Scott Mumford
Datasat Communications
www.datasat.com
Satellite Distribution
5. Satellite Distribution -
Achieving Cost-reduction through
consumer electronics.
Bob Hannent
Chief Technologist, Humax
Electronics Co. Ltd
Introduction
The usefulness of satellites in distributing content over a wide
geographic area and particularly into remote or non-metropolitan
areas has now been demonstrated to be indisputable.
The satellite signal is broadcast from an ‘earth station’ to the
satellite and the satellite with just some frequency transposing
and amplification rebroadcasts that signal back to earth. The
returned signal has a ‘footprint’ which is designed in to cover
a particular geographical market and can either broadcast
with a tight focus, with the associated focus of energy, or to a
much wider area with still good performance. Typically
broadcasters and network operators take advantage of this to
distribute content either for ‘one to many’ contributions of
events (such as sports and concerts) or for the core of their
business ‘direct to home’ (DTH) broadcasting.
Comparatively the cost multiples of delivery over fibre or
ADSL are not as advantageous as simply broadcasting when
making use of existing satellite broadcast systems (rather than
having a dedicated transmit infrastructure). The focus of this
Typical satellite uplink station, and
Footprint of the North beam of Astra 2A
Images courtesy SES-Astra.
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