IPTV uses multicast to reduce network bandwidth. Multicast protocols
ensure that channels are only streamed to users that are actually viewing them.
Multicast is the technology that makes IPTV network friendly.
IPTV combines TV compression technology and IT data technology
to stream TV and video as a continuous flow of data packets
on an IT network.
Digital TV channels direct from a terrestrial aerial
and satellite dish are given IP "wrappers"
for transport across the
IT data network as IPTV packet streams. They remain in digital format throughout
Other sources such as DVD and SKY satellite receivers
are MPEG encoded, and they too get IP "wrapped"
output as IPTV streams on the IT network.
The IPTV channel streams are distributed ONLY
to the destinations that request a channel, by
IPTV Receivers or Digital Signage players convert the
IPTV streams back to video and audio for display on
TV screens or via projectors.
IPTV Player software shows IPTV channels on computer
desktops and can offer PVR functionality.
A Video On Demand (VOD) server can be added for recording, storage, and on-demand playback of IPTV channels and programmes.