Iyini i-GPON?
Ubuchwepheshe be-GPON (Gigabit-Capable PON) yisizukulwane sakamuva se-broadband passive optical integrated access standard based on ITU-TG.984.x standard.Inezinzuzo eziningi ezifana nomkhawulokudonsa ophezulu, ukusebenza kahle okuphezulu, ukumbozwa okukhulu, isixhumi esibonakalayo somsebenzisi esicebile, njll. Iningi labaqhubi liyithatha njengobuchwepheshe obufanele bokufeza uguquko oludidiyelwe lwezinsizakalo zenethiwekhi yokufinyelela.
I-GPON yahlongozwa okokuqala yinhlangano ye-FSAN ngo-September 2002. Ngokusekelwe kulokhu, i-ITU-T yaqeda ukuthuthukiswa kwe-ITU-T G.984.1 kanye ne-G.984.2 ngo-March 2003, futhi yaqeda i-G. ngoFebhuwari nango-June 2004. Ukumiswa kwe-984.3 .Ngakho-ke, ekugcineni kwakhiwa umndeni ojwayelekile we-GPON.
Isakhiwo esiyisisekelo sedivayisi esisekelwe kubuchwepheshe be-GPON sifana naleso se-PON ekhona.Kuphinde kube yi-OLT (i-optical line terminal) yehhovisi elimaphakathi, i-ONT/ONU yesiphetho somsebenzisi (itheminali yenethiwekhi ye-optical noma iyunithi yenethiwekhi yokubona), kanye namadivayisi amabili okuqala axhunywe imodi eyodwa.I-fiber optical (i-SM fibre) kanye ne-passive splitter (Splitter) yakhiwe i-ODN (Optical Distribution Network) kanye nesistimu yokuphatha inethiwekhi.
Kwezinye izindinganiso ze-PON, izinga le-GPON lihlinzeka ngomkhawulokudonsa ophezulu ongakaze ubonwe ngaphambili ngezinga lokuxhumanisa elifinyelela ku-2.5 Gbit/s, futhi izici zalo ezingalingani zifaneleka kakhulu emakethe yesevisi yedatha ye-broadband.Inikeza isiqinisekiso sesevisi esigcwele se-QoS, futhi ithwala amaseli e-ATM kanye/noma ozimele be-GEM.Inezinga elihle lesevisi, isiqinisekiso se-QoS kanye nokufinyelela okugcwele kwenkonzo.Uma uphethe amafreyimu e-GEM, amasevisi e-TDM angenziwa imephu abe ozimele be-GEM, futhi ozimele abajwayelekile abangu-8 kHz (125 μs) bangasekela ngokuqondile amasevisi e-TDM.Njengezinga lobuchwepheshe lesigaba senkampani yenethiwekhi, i-GPON iphinda icacise izindlela zokuvikela futhi iqedele imisebenzi ye-OAM ezingeni lenethiwekhi yokufinyelela.
Ngezinga le-GPON, izinhlobo zezinsizakalo ezidinga ukusekelwa zichazwe ngokucacile: izinsizakalo zedatha (amasevisi e-Ethernet, afaka amasevisi we-IP kanye nokusakaza kwevidiyo ye-MPEG), amasevisi e-PSTN (izinsizakalo ze-POTS, i-ISDN), nemigqa ezinikele (T1, E1, DS3, E3, kanye nezinsiza ze-ATM).) namasevisi wevidiyo (ividiyo yedijithali).Izinsizakalo eziningi ku-GPON zifakwe kumephu kumaseli e-ATM noma amafreyimu e-GEM ukuze adluliselwe, anikeze iziqinisekiso ezihambisanayo ze-QoS zezinhlobo ezahlukene zesevisi.