1. Isingeniso senethiwekhi ye-EPON
I-EPON(I-Ethernet Passive Optical Network) ubuchwepheshe benethiwekhi obusafufusa be-fiber optical, obusebenzisa isakhiwo se-point-to-multipoint, imodi yokudlulisa i-fiber optical passive, esekelwe ku-high-speed Ethernet platform kanye ne-TDM time division MAC (MediaAccessControl) imodi yokulawula ukufinyelela kwemidiya, Nikeza ngezinhlobonhlobo zobuchwepheshe bokufinyelela ku-broadband ukuze uthole izinsiza ezihlanganisiwe.Okubizwa ngokuthi "i-passive" kusho ukuthi i-ODN ayinazo izisetshenziswa zikagesi ezisebenzayo kanye nempahla yamandla, futhi konke kuqukethe amadivaysi angenayo njengama-optical splitters (Splitter).Isebenzisa ubuchwepheshe be-PON kungqimba ebonakalayo, iphrothokholi ye-Ethernet kungqimba yesixhumanisi, futhi isebenzisa i-PON topology ukuze ifinyelele ukufinyelela kwe-Ethernet.Ngakho-ke, ihlanganisa izinzuzo zobuchwepheshe be-PON nobuchwepheshe be-Ethernet: izindleko eziphansi, umkhawulokudonsa ophezulu, ukuqina okuqinile, ukuhlelwa kabusha kwesevisi okuguquguqukayo nokushesha, ukuhambisana ne-Ethernet ekhona, ukuphathwa okulula, njalonjalo.
I-EPON ingabona ukuhlanganiswa kwezwi, idatha, ividiyo, namasevisi eselula.Uhlelo lwe-EPON lwakhiwe ikakhulukazi i-OLT (itheminali yomugqa wokukhanya),I-ONU(iyunithi yenethiwekhi ye-optical), i-ONT (itheminali yenethiwekhi ye-optical) kanye ne-ODN (inethiwekhi yokusabalalisa optical).Isezingeni lenethiwekhi yokufinyelela yenethiwekhi futhi ilungele kakhulu ukuxhumana kwe-fiber optical yezinsizakalo ze-broadband.Ingene.
Imishini yenethiwekhi esebenzayo ihlanganisa imishini yokubeka emaphakathi yehhovisi (OLT) kanye neyunithi yenethiwekhi ye-optical (ONU).Iyunithi yenethiwekhi yokubona (i-ONU) inikeza abasebenzisi ukuxhumana phakathi kwedatha, ividiyo, namanethiwekhi ocingo kanye ne-PON.Indima yokuqala ye-ONU ukuthola isignali ye-optical bese uyiguqula ibe yifomethi edingwa ngumsebenzisi (i-Ethernet, ukusakaza kwe-IP, ucingo, i-T1/E1, njll.).Imishini ye-OLT ixhunywe kunethiwekhi eyinhloko ye-IP nge-fiber optical.Ukwethulwa kwenethiwekhi ye-optical access ifinyelela ku-20km, okuqinisekisa ukuthiOLTingathuthukiswa iye endaweni yendabuko ye-metropolitan convergence node kusukela esigabeni sokuqala sokwakhiwa kwenethiwekhi yokufinyelela optical, ngaleyo ndlela kube lula ukwakheka kwenethiwekhi ye-convergence layer yenethiwekhi yokufinyelela kanye nokulondoloza Inombolo yamahhovisi okugcina.Ukwengeza, izici zomthamo omkhulu wenethiwekhi yokufinyelela okubonakalayo, umkhawulokudonsa ophezulu wokufinyelela, ukwethembeka okuphezulu, namandla okusekelwa kwezinga le-QoS lezinsizakalo eziningi nakho kwenze ukuvela kwenethiwekhi yokufinyelela kufinyelele endaweni yesikhulumi esihlangene, esihlanganisiwe, nesisebenzayo saba ngokoqobo.
2. Izimiso Eziyisisekelo ze-EPON Network
Uhlelo lwe-EPON lusebenzisa ubuchwepheshe be-WDM ukuze lubone ukudluliswa kwe-bidirectional ye-fiber eyodwa, kusetshenziswa ubude begagasi obungu-1310nm obukhuphuka nomfula obungu-1490nm obungezansi ukuze budlulise idatha nezwi, futhi izinsiza ze-CATV zisebenzisa ubude beza beza obungu-1550nm ukuze buthwale.I-OLT ibekwe ehhovisi elimaphakathi ukuze isabalalise futhi ilawule ukuxhunywa kwesiteshi, futhi inemisebenzi yokuqapha, yokuphatha kanye nokunakekela ngesikhathi sangempela.I-ONU ibekwe ohlangothini lomsebenzisi, futhi i-OLT ne-ONU zixhunywe ngendlela engu-1:16/1:32 ngenethiwekhi yokusabalalisa ebonakalayo.Ukuze kuhlukaniswe amasignali kubasebenzisi abaningi ku-fiber efanayo, izindlela ezimbili ezilandelayo zokuphindaphinda zingasetshenziswa.
(1) Ukusakaza kwedatha engezansi kusebenzisa ubuchwepheshe bokusakaza.Ku-EPON, inqubo yokudluliswa kwedatha ezansi komfula isuka ku-OLT iye kuma-ONU amaningi ithunyelwa ngokusakazwa kwedatha.Idatha isakazwa phansi komfula isuka ku-OLT iye kuma-ONU amaningi ngendlela yamaphakethe olwazi obude obuguquguqukayo.Iphakethe ngalinye lolwazi linombhalo wephakethe we-EPON, okhomba ngokukhethekile ukuthi iphakethe lolwazi lithunyelwa ku-ONU-1, ONU-2 noma ku-ONU-3.Ingase futhi imakwe njengephakethe lolwazi lokusakaza elithunyelwa kuwo wonke ama-ONU noma eqenjini elithile le-ONU (iphakethe lolwazi lokusakaza okuningi).Lapho idatha ifika ku-ONU, i-ONU ithola futhi ibone amaphakethe olwazi athunyelwe kuyo ngokufaniswa kwekheli, futhi ilahla amaphakethe olwazi athunyelwe kwamanye ama-ONU.I-LLID ehlukile inikezwa ngemva kokubhaliswa kwe-ONU;i-OLT iqhathanisa uhlu lokubhaliswa kwe-LLID lapho ithola idatha, futhi lapho i-ONU ithola idatha, ithola kuphela ozimele noma ozimele abasakazayo abafana ne-LLID yayo.
(2) Ukugeleza kwedatha okukhuphukayo kusebenzisa ubuchwepheshe be-TDMA.I-OLT iqhathanisa uhlu lokubhalisa lwe-LLID ngaphambi kokuthola idatha;I-ONU ngayinye ithumela uhlaka lwedatha endaweni yesikhathi eyabiwe ngokulinganayo yimishini yehhovisi emaphakathi OLT;isikhathi esabiwe (ngokusebenzisa ubuchwepheshe obuhlukahlukene) sinxephezela igebe ebangeni le-ONU ngayinye futhi sigwema Ukungqubuzana kwe-ONU ngakunye phakathi.
