Exfo EXpert IPTV Test Tools (FTB-200v2) Instrukcja Użytkownika Pobierz pdf (Strona 72)

72

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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.

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Exfo EXpert IPTV Test Tools (FTB-200v2) Instrukcja Użytkownika Strona 72