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, nganye i-ONU ingathumela idatha ngaphakathi kwexesha elichaziweyo lefestile.Ngoko ke, i-EPON i-channel ye-upstream ihambisa izibonakaliso zokuqhuma, ezifuna ukusetyenziswa kwezixhobo ze-optical ezixhasa iimpawu zokuqhuma kwii-ONU kunye ne-OLT.
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 zinciphisa inani le-lasers ezifunwa yiofisi ephakathi, kwaye i-OLT yabelwana ngabasebenzisi abaninzi be-ONU.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 ze-ONU, itekhnoloji eziphambili zeEPONumaleko womzimba ugxininiswe kwi-OLT, kubandakanywa: ukulungelelaniswa okukhawulezayo kwezibonakaliso eziqhumayo, ukuvumelanisa kwenethiwekhi, ukulawulwa kwamandla kwiimodyuli ze-transceiver optical, kunye nokwamkelwa okuguquguqukayo.
Ekubeni isibonakaliso esifunyenwe yi-OLT sisignali yokuqhuma kwe-ONU nganye, i-OLT kufuneka ikwazi ukufezekisa ukuvumelanisa kwesigaba 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.Ukongezelela, ngenxa yeendlela ezahlukeneyo ze-ONU nganye ukusuka kwi-OLT, kwimodyuli yokufumana i-OLT, amandla eendawo zokubeka ixesha ezahlukeneyo.Kwizicelo ze-DBA, nokuba amandla exesha elifanayo ahlukile, okubizwa ngokuba yimpembelelo ekufutshane.Ke ngoko, i-OLT kufuneka ikwazi ukulungelelanisa ngokukhawuleza amanqaku ayo "0" kunye ne "1" kwinqanaba lesigqibo.Ukuze kulungiswe "impembelelo esondeleyo", isicwangciso sokulawula amandla sicetywayo, kwaye i-OLT ikwazisa i-ONU yezinga lokuhambisa amandla ngokusebenzisa iipakethi zolawulo kunye nokugcinwa (OAM) emva kokusukela.Ngenxa yokuba esi sikimu siya kwandisa iindleko ze-ONU kunye nobunzima bomgangatho womzimba we-protocol, kwaye unciphise ukuhanjiswa komgca kwinqanaba le-ONU elikude kakhulu ne-OLT, ayizange yamkelwe yiqela elisebenzayo le-EFM.