User guide

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Examples:
Inthissectionsometypicalvaluesofzaptimeareshown.Actually,inIPTVtelevisionthese
delaysaregreaterthaninothertechnologies:
 Analog(Cable
)~1s
 Analog(off‐air
)~1–3s
 MPEG2overQAM
~1.2–3s
 MPEG2overQPSK
~2–4s
 MPEG2overIPTVMulticast~1.5–3.5s
 H.264overIPTVMulticast~1.7–4s
IGMPisthesignalingprotocolusedtoaccessbroadcastvideoservicesthatuseamulticast
networkdesigntoefficientlymanagenetworkbandwidth.Inthisimplementation,ajoin
messageissentfromtheSTBtothenet
work.