Iyini i-GPON?
Ubuchwepheshe be-GPON (Gigabit-Capable PON) yisizukulwane sakamuva se-broadband passive optical integrated access standard based on the ITU-TG.984.x standard.Inezinzuzo eziningi ezifana nomkhawulokudonsa ophezulu, ukusebenza kahle okuphezulu, ukumbozwa okukhulu, nokuxhumana okucebile komsebenzisi.Iningi lama-opharetha likuthatha njengobuchwepheshe obufanele ukubona i-broadband kanye noshintsho oluphelele lwezinsiza zenethiwekhi.
I-GPON yahlongozwa okokuqala yinhlangano ye-FSAN ngoSepthemba 2002. Ngalesi sisekelo, i-ITU-T yaqeda ukwakhiwa kwe-ITU-T G.984.1 kanye ne-G.984.2 ngo-March 2003, futhi yaqeda i-G.984.1 kanye ne-G.984.2 ngoFebhuwari nangoJuni. 2004. 984.3 ukumiswa.Ngakho ekugcineni wakha umndeni ojwayelekile we-GPON.
Isakhiwo esiyisisekelo semishini esekelwe kubuchwepheshe be-GPON sifana ne-PON ekhona.Iphinde yakhiwe nge-OLT (itheminali yomugqa wokukhanya) ehhovisi elimaphakathi kanye ne-ONT/ONU (itheminali yenethiwekhi yokubona noma ebizwa ngokuthi i-optical network unit) ohlangothini lomsebenzisi.I-ODN (Optical Distribution Network) yenziwe nge-SM fiber kanye ne-passive splitter (Splitter) kanye nohlelo lokuphatha inethiwekhi.
Kwezinye izindinganiso ze-PON, izinga le-GPON lihlinzeka ngomkhawulokudonsa ophezulu ongakaze ubonwe ngaphambili, ngezinga eliphansi lomfula elifika ku-2.5Gbit/s, futhi izici zalo ezilinganayo zingavumelana kangcono nemakethe yesevisi yedatha ye-broadband.Ihlinzeka ngesiqinisekiso sesevisi esigcwele se-QoS, futhi iphatha amaseli e-ATM kanye (noma) namafreyimu e-GEM ngesikhathi esifanayo.Inekhono elihle lokuhlinzeka ngamazinga esevisi, isiqinisekiso sokusekela i-QoS kanye nokufinyelela kwesevisi okugcwele.Uma uphethe ozimele be-GEM, amasevisi e-TDM angenziwa imephu kumafreyimu e-GEM, futhi ozimele abajwayelekile abangu-8kHz (125μs) bangasekela ngokuqondile amasevisi e-TDM.Njengezinga lobuchwepheshe lezinga lokuxhumana ngocingo, i-GPON iphinda icacise indlela yokuvikela futhi iqedele imisebenzi ye-OAM ezingeni lenethiwekhi yokufinyelela.
Ezingeni le-GPON, izinhlobo zezinsizakalo ezidinga ukusekelwa zihlanganisa izinsizakalo zedatha (izinsizakalo ze-Ethernet, ezihlanganisa izinsizakalo ze-IP kanye nokusakaza kwevidiyo ye-MPEG), amasevisi e-PSTN (i-POTS, amasevisi e-ISDN), imigqa ezinikele (T1, E1, DS3, E3, kanye nezinsiza ze-ATM).) Nezinsizakalo zevidiyo (ividiyo yedijithali).Izinsizakalo eziningi ku-GPON zifakwe kumephu kumaseli e-ATM noma amafreyimu e-GEM ukuze adluliselwe, anganikeza iziqinisekiso ezihambisanayo ze-QoS zezinhlobo zesevisi ezihlukahlukene.