veex_veex 06/03/2014 20:51 Page 2
network. The video,
audio, subtitle tracks and
program tables are all
encapsulated into an
MPEG Transport Stream
(MPEG TS). Each MPEG
TS is 188 bytes long.
Multiple MPEG TS are
combined into UDP or
TCP and encapsulated
into IP for transmission on
the network. This
multiplexing of MPEG TS into IP
packets means that a single MPEG
frame may be transmitted over multiple IP
packets, while an IP packet may contain audio
information or program table information as
well as video. It further proves that
monitoring IP impairments does not map to
video quality, since there is no one-to-one
mapping between them.
IPTV Impairments
IPTV delivery involves a chain of specialised
devices and links that all play a role in the
final quality of the service. The process starts
at the Head-end where th R6