1.1 I-Passive Optical splitter
I-Passive Optical splitter iyingxenye ebalulekile yenethiwekhi ye-PON. Umsebenzi we-passive optical splitter ukuhlukanisa amandla okubona esignali eyodwa yokubona okokufaka kokuphumayo okuningi. Ngokuvamile, isihlukanisi sizuza ukuhlukaniswa okukhanyayo kusuka ku-1:2 kuya ku-1:32 noma ngisho no-1:64. Isici se-passive optical splitter ukuthi ayidingi ukunikezwa kwamandla futhi inokuguquguquka okuqinile kwemvelo. Njengoba isiteshi esikhuphuka nomfula i-EPON sihlukanisa isikhathi siphindaphindwa yibo bonkeI-ONUs, ngamunyeI-ONUingathumela idatha phakathi newindi lesikhathi esishiwo. Ngakho-ke, isiteshi esikhuphuka nomfula i-EPON sidlulisa amasignali okuqhuma, okudinga ukusetshenziswa kwamadivayisi okubona asekela amasignali okuqhumaAma-ONUfuthiOLTs.
Izihlukanisi ze-Passive Optical kumanethiwekhi we-PON ngokuvamile zihlukaniswa zibe izinhlobo ezimbili: isihlukanisi se-fusion taper esivamile kanye nesihlukanisi se-waveguide sokukhanya esisanda kuvela.
1.2 I-Physical topology
Inethiwekhi ye-EPON yamukela isakhiwo se-point-to-multipoint topology esikhundleni se-point-to-point structure, esisindisa kakhulu inani le-fiber optical kanye nezindleko zokuphatha. I-PONOLTimishini inciphisa inani lama-lasers adingwa yihhovisi eliphakathi, kanyeOLTyabelwa abaningiI-ONUabasebenzisi. Ngaphezu kwalokho, i-EPON isebenzisa ubuchwepheshe be-Ethernet nozimele be-Ethernet abajwayelekile ukuze baphathe isevisi yamanje evamile—isevisi ye-IP ngaphandle kwanoma yikuphi ukuguqulwa.
1.3 Ukuvumelanisa okuqhume kwesendlalelo esibonakalayo se-EPON
Ukuze kuncishiswe izindleko zeI-ONU, ubuchwepheshe obubalulekile be-I-EPONungqimba ngokomzimba bagxileOLT, okuhlanganisa: ukuvumelanisa okusheshayo kwezimpawu zokuqhuma, ukuvumelanisa kwenethiwekhi, ukulawulwa kwamandla amamojula we-transceiver optical, nokwamukela okuguquguqukayo.
Kusukela isignali etholwe yi-OLTiyisignali yokuqhuma ngayinyeI-ONU, iOLTkufanele ikwazi ukuzuza ukuvumelanisa kwesigaba ngesikhathi esifushane, bese yamukela idatha. Ukwengeza, ngenxa yokuthi isiteshi se-uplink samukela imodi ye-TDMA, kanye nobuchwepheshe besinxephezelo sokubambezeleka kokudlulisa i-fiber engu-20km bubona ukuvumelanisa kweskhathi senethiwekhi yonke, amaphakethe wedatha afika ngesikhathi esinqunywa i-algorithm ye-OBA. Ngaphezu kwalokho, ngenxa yamabanga ahlukene ngamunyeI-ONUukusukaOLT, okwemojula yokwamukela yeOLT, amandla ezikhala zesikhathi ezahlukene ahlukile. Kuzinhlelo zokusebenza ze-DBA, ngisho namandla e-slot yesikhathi esifanayo ahlukile, okubizwa ngokuthi umphumela oseduze-kude. Ngakho-ke, i-OLTkufanele ikwazi ukulungisa ngokushesha amaphuzu ayo ezinqumo "0" kanye "no-"1" . Ukuze kuxazululwe "umphumela oseduze", uhlelo lokulawula amandla luhlongozwayo, futhiOLTyazisa iI-ONUwezinga lamandla okudlulisa ngokusebenzisa amaphakethe okusebenza nokuphatha (OAM) ngemva kokulinganisa. Ngoba lolu hlelo luzokhuphula izindleko ze-ONU kanye nobunkimbinkimbi bephrothokholi yesendlalelo somzimba, futhi kukhawulele ukusebenza komugqa wokudluliselaI-ONUizinga elikude kakhulu neOLT, ayizange yamukelwe iqembu elisebenzayo le-EFM.