1.1 I-Passive Optical splitter
I-Passive optical splitter yinxalenye ebalulekileyo yenethiwekhi yePON. Umsebenzi we-passive optical splitter kukwahlula amandla optical optical signal enye igalelo kwiziphumo ezininzi. Ngokwesiqhelo, i-splitter ifezekisa ukwahlula ukukhanya ukusuka ku-1:2 ukuya ku-1:32 okanye nakwi-1:64. Uphawu lwe-passive optical splitter kukuba ayifuni ukunikezelwa kwamandla kwaye inokulungelelaniswa okunamandla kokusingqongileyo. Ukusukela ukuba itshaneli ye-EPON ephezulu yolwahlulo lwexesha luphindaphindwe ngabo bonkeI-ONUs, nganyeI-ONUingathumela idatha phakathi kwexesha elichaziweyo lefestile. Ke ngoko, itshaneli ye-EPON enyukayo ihambisa imiqondiso yokugqabhuka, efuna ukusetyenziswa kwezixhobo zokukhanya ezixhasa imiqondiso egqabhukileyoIi-ONUkwayeOLTs.
Izahluli ze-Passive optical kuthungelwano lwe-PON zihlala zohlulwe zibe ziindidi ezimbini: isahlukanisi setape esidityanisiweyo esiqhelekileyo kunye neplani esandula kuhluma i-waveguide waveguide splitter.
1.2 I-Physical topology
Inethiwekhi ye-EPON ithatha i-point-to-multipoint topology structure endaweni ye-point-to-point structure, egcina kakhulu inani le-fiber optical kunye neendleko zokulawula. I-PONOLTizixhobo kunciphisa inani lasers ezifunwayo yi-ofisi central, kunyeOLTkwabelwana ngayo ngabaninziI-ONUabasebenzisi. Ukongezelela, i-EPON isebenzisa iteknoloji ye-Ethernet kunye nezakhelo eziqhelekileyo ze-Ethernet ukuthwala inkonzo yangoku yenkonzo-inkonzo ye-IP ngaphandle kokuguqulwa.
1.3 Ungqamaniso lweBurst lwe-EPON umaleko womzimba
Ukuze kuncitshiswe iindleko zeI-ONU, iitekhnoloji eziphambili zeEPONUmaleko womzimba zigxile kwiOLT, kubandakanywa: ukuvumelanisa ngokukhawuleza kwezibonakaliso ezigqabhukileyo, ukuvumelanisa kwenethiwekhi, ukulawula amandla kwiimodyuli ze-transceiver optical, kunye nokwamkelwa okuguquguqukayo.
Ukusukela umqondiso ofunyenwe yiOLTluphawu olugqabhukileyo lwento nganyeI-ONU, iOLTkufuneka ikwazi ukufezekisa ungqamaniso lwesigaba ngexesha elifutshane, kwaye emva koko ifumane idatha. Ukongezelela, ngenxa yokuba i-channel ye-uplink ithatha imodi ye-TDMA, kunye ne-20km i-fiber optical transmission yokulibaziseka iteknoloji yembuyekezo iyaqaphela ixesha lokuvumelanisa kwinethiwekhi yonke, iipakethi zedatha zifika kwixesha elinqunywe yi-algorithm ye-OBA. Ukongeza, ngenxa yemigama eyahlukileyo nganyeI-ONUisuka eOLT, yemodyuli yokwamkela yeOLT, amandla eendawo zokubeka ixesha ezahlukeneyo ahlukile. Kwizicelo ze-DBA, nokuba amandla exesha elifanayo ahlukile, okubizwa ngokuba yimpembelelo ekufutshane. Ngoko ke, iOLTkufuneka ikwazi ukulungelelanisa ngokukhawuleza amanqaku ayo "0" kunye "1" nenqanaba lesigqibo. Ukuze kulungiswe "impembelelo ekufutshane", inkqubo yokulawula amandla iye yacetywa, kunye neOLTikwazisa iI-ONUyenqanaba lokuhambisa amandla ngokusebenza kunye nolawulo lolondolozo (OAM) iipakethi emva kokusukela. Ngenxa yokuba esi sikimu siya kwandisa iindleko ze-ONU kunye nobunzima bomgangatho womzimba we-protocol, kunye nokunciphisa ukuhanjiswa komgca kwintsebenzo.I-ONUinqanaba elikude ukusuka kwiOLT, ayizange yamkelwe liqela elisebenzayo le-EFM.