Inethiwekhi ye-EPON isebenzisa indlela ye-FTTB ukwenza inethiwekhi, futhi amayunithi ayo enethiwekhi ayisisekeloOLTkanye ne-ONU.I-OLT ihlinzeka ngamachweba amaningi e-PON ukuze imishini yehhovisi elimaphakathi ixhumeke kumishini ye-ONU; i-ONU iyithuluzi lomsebenzisi elihlinzeka ngedatha ehambisanayo nezindawo zokusebenzelana zezwi ukuze kutholakale ukufinyelela kwesevisi yomsebenzisi.Ukwenziwa kokufinyelela ezinsizeni ezahlukene ngokuyinhloko ukusebenzisa amathegi e-VLAN ahlukene abasebenzisi abahlukene namasevisi ahlukene okufanele adluliselwe ngokusobala kuseva yokufinyelela yesevisi ehambisanayo, futhi athumele omaka abahambisanayo be-VLAN kunethiwekhi yenkampani ye-IP ukuze idluliselwe.

1.Isingeniso ku-EPON Network

I-EPON (i-Ethernet Passive Optical Network) iwubuchwepheshe benethiwekhi obusafufusa be-fiber optical, obusebenzisa isakhiwo se-point-to-multipoint, imodi yokudlulisa i-fiber optical passive, esekelwe kupulatifomu ye-Ethernet enesivinini esikhulu kanye ne-TDM yesigaba sokuhlukanisa isikhathi se-MAC (MediaAccessControl) imodi yokulawula ukufinyelela kwemidiya. , Nikeza ubuchwepheshe bokufinyelela ku-broadband ezinhlobonhlobo zezinsizakalo ezihlanganisiwe.Lokho okubizwa ngokuthi "i-passive" kusho ukuthi i-ODN ayiqukethe noma yiziphi izisetshenziswa zikagesi ezisebenzayo kanye nempahla yamandla, futhi yakhiwe ngokuphelele amadivaysi angenzi lutho njengama-optical splitters (Splitter).Isebenzisa ubuchwepheshe be-PON kungqimba olubonakalayo, iphrothokholi ye-Ethernet kungqimba yesixhumanisi, futhi isebenzisa i-PON topology ukuzuza 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.Isistimu ye-EPON yakhiwe ikakhulukaziOLT(itheminali ye-optical line), i-ONU (iyunithi yenethiwekhi ye-optical), i-ONT (itheminali yenethiwekhi ye-optical) kanye ne-ODN (inethiwekhi yokusabalalisa okubonakalayo), Isezingeni lenethiwekhi yokufinyelela yenethiwekhi futhi ilungele kakhulu ukufinyelela kwe-fiber optical kumasevisi e-broadband.

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 yeI-ONUiwukwamukela isignali yokubona bese uyiguqulela kufomethi edingwa umsebenzisi (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 inendawo yokuhlanganisa efinyelela ku-20km, okuqinisekisa ukuthi i-OLT ingathuthukiswa iye endaweni yendabuko ye-metropolitan convergence node kusukela esigabeni sokuqala sokwakhiwa kwenethiwekhi yokufinyelela optical, ngaleyo ndlela kube lula ukwakheka kwenethiwekhi yenethiwekhi yokufinyelela. convergence layer kanye nokulondoloza inani lamahhovisi wokugcina.Ngaphezu kwalokho, 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 kuzuzwe ukudluliswa kwe-bidirectional ye-fiber eyodwa, kusetshenziswa i-1310nm ekhuphuka nomfula i-1490nm yamaza aphansi ukuze idlulise idatha nezwi, futhi izinsizakalo ze-CATV zisebenzisa ubude begagasi obungu-1550nm ukuthwala.I-OLT ibekwe ehhovisi elimaphakathi ukuze kwabe futhi kulawule isiteshi. uxhumano, futhi inokuqapha ngesikhathi sangempela, ukuphatha kanye nemisebenzi yokulungisa.I-ONU ibekwe ohlangothini lomsebenzisi, futhi i-OLT ne-ONU zixhunywe ngendlela engu-1:16/1:32 ngenethiwekhi yokusabalalisa ebonakalayo.

Ukuze uhlukanise amasignali kubasebenzisi abaningi ku-fiber efanayo, izindlela ezimbili ezilandelayo zokuphindaphinda zingasetshenziswa.

1) Ukusakazwa kwedatha okwehlayo 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 anobude obuguquguqukayo.Iphakethe ngalinye lolwazi lineI-EPONunhlokweni wephakethe, okhomba ngokukhethekile ukuthi ingabe iphakethe lolwazi lithunyelwa ku-ONU-1, ONU-2 noma ONU-3.Ingaphinda ikhonjwe njengephakethe lokusakaza elithunyelwa kuwo wonke ama-ONU noma eqenjini elithile le-ONU (iphakethe lokusakaza okuningi).Lapho idatha ifika ku-ONU, i-ONU ithola futhi ihlonze 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 lebanga phakathi kwe-ONU ngayinye futhi sigwema Ukungqubuzana kwe-ONU ngakunye phakathi.