Iyo EPON network inoshandisa nzira yeFTTB kugadzira network, uye maintiweki ayo arikoOLTuye ONU.Iyo OLT inopa akawanda maPON ports kuti midziyo yepakati yehofisi ibatane neONU midziyo; ONU ndiyo mushandisi midziyo yekupa zvinoenderana nedata uye manzwi ekuona kuti mushandisi kuwana masevhisi. vashandisi vakasiyana uye masevhisi akasiyana kuendesa pachena kune inoenderana sevhisi yekuwana sevha, uye tumira inoenderana VLAN tags kune IP mutakuri network kuti itumirwe.
1. Nhanganyaya kuEPON Network
EPON (Ethernet Passive Optical Network) inobuda optical fiber yekuwana network tekinoroji, iyo inotora point-to-multipoint chimiro, passive optical fiber transmission mode, yakavakirwa pahigh-speed Ethernet papuratifomu uye TDM nguva yekupatsanura MAC (MediaAccessControl) midhiya yekuwana yekudzora maitiro. , Ipai teknolojia yekuwana Broadband yemhando dzakasiyana-siyana dzakabatanidzwa.Iyo inonzi "passive" inoreva kuti ODN haina chero zvigadzirwa zvemagetsi zvinoshanda uye magetsi, uye inoumbwa zvachose nemagetsi emagetsi akadai se optical splitters (Splitter).Inoshandisa tekinoroji yePON pachikamu chemuviri, Ethernet protocol padanho rekubatanidza, uye inoshandisa iyo PON topology kuwana Ethernet yekuwana.Naizvozvo, inosanganisa zvakanakira zvePON tekinoroji uye Ethernet tekinoroji: mutengo wakaderera, wakakwira bandwidth, yakasimba scalability, inochinjika uye nekukurumidza sevhisi kurongazve, kuenderana neiyo iripo Ethernet, nyore manejimendi, zvichingodaro.
EPON inogona kuona kubatanidzwa kwezwi, data, vhidhiyo, uye nharembozha.Iyo EPON system inonyanya kuumbwa neOLT(Optical line terminal), ONU (optical network unit), ONT (optical network terminal) uye ODN (optical distribution network), Iri padanho rekuwana network yetiweki uye inonyanya kukodzera kuwana fiber optical yemasevhisi ebroadband.
Active network midziyo inosanganisira yepakati hofisi rack michina (OLT) uye optical network unit (ONU).Iyo optical network unit (ONU) inopa vashandisi chimiro pakati pe data, vhidhiyo, uye nhare network nePON.Basa rekutanga reONUndiko kugamuchira chiratidzo chemaziso uye wochishandura kuita chimiro chinodiwa nemushandisi (Ethernet, IP nhepfenyuro, runhare, T1/E1, nezvimwewo).OLT midziyo yakabatana neiyo IP core network kuburikidza neoptical fiber.Iko kuunzwa kweiyo optical access network ine nzvimbo yekuvhara inosvika 20km, iyo inovimbisa kuti OLT inogona kukwidziridzwa kuenda kune yechinyakare metropolitan convergence node kubva padanho rekutanga rekuvakwa kweiyo optical access network, nekudaro kurerutsa network yetiweki yekuwana network. convergence layer uye kuchengetedza huwandu hwemahofisi ekupedzisira.Pamusoro pezvo, hunhu hweiyo optical access network yakakura, yakakwirira yekuwana bandwidth, kuvimbika kwepamusoro, uye akawanda-sevhisi QoS level tsigiro yaitawo shanduko yetiweki yekuwana kune yakabatana, yakabatanidzwa, uye inoshanda mutakuri chikuva.
2.Basic Principles yeEPON Network
Iyo EPON system inoshandisa tekinoroji yeWDM kuti iwane imwe-fiber bidirectional transmission, ichishandisa kumusoro kwe1310nm uye yakadzika 1490nm wavelengths kutumira data nezwi, uye masevhisi eCATV anoshandisa 1550nm wavelength kutakura.OLT inoiswa pahofisi yepakati kuti igove uye idzore chiteshi. kubatanidza, uye ine chaiyo-nguva yekutarisa, manejimendi uye kugadzirisa mabasa.Iyo ONU inoiswa kudivi remushandisi, uye OLT neONU zvakabatanidzwa nenzira ye1:16/1:32 kuburikidza neine passive optical distribution network.
Kuti uparadzanise masaini kubva kune vakawanda vashandisi pane imwechete fiber, nzira mbiri dzinotevera dzemultiplexing dzinogona kushandiswa.
1) Iyo yakadzika data rwizi inotora tekinoroji yekutepfenyura.
MuEPON, maitiro ekufambisa data kubva kuOLT kuenda kune akawanda ONU anotumirwa nekutepfenyura data.Data inotepfenyurwa zvichidzika kubva kuOLT kuenda kune akawanda ONU nenzira yemapaketi akareba-akareba.Paketi yega yega yeruzivo ineEPONpacket header, iyo inotaridza kuti pakiti yeruzivo yakatumirwa kuONU-1, ONU-2 kana ONU-3.Inogonawo kuzivikanwa sepaketi yekutepfenyura inotumirwa kune ese maONU kana kune chaiyo ONU boka (multicast packet).Kana iyo data yasvika paONU, ONU inogamuchira uye inozivisa mapaketi eruzivo anotumirwa kwairi kuburikidza nekero yekuenzanisa, uye inorasa mapaketi eruzivo anotumirwa kune mamwe maONU.LLID yakasarudzika inopihwa mushure mekunge ONU yanyoreswa;iyo OLT inoenzanisa iyo LLID yekunyoreswa runyorwa kana ichigamuchira data, uye kana ONU yagamuchira data, inongogashira mafuremu kana kutepfenyura mafuremu anofanana neLLID yayo.
2) Kuyerera kwedata kunokwira kunotora tekinoroji yeTDMA.
Iyo OLT inoenzanisa iyo LLID yekunyoresa runyorwa isati yagamuchira data;ONU yega yega inotumira data furemu munguva yenguva yakagoverwa zvakafanana nepakati hofisi midziyo OLT;iyo yakagoverwa nguva slot (kuburikidza neinongedzo tekinoroji) inotsiva chinhambwe chinhambwe pakati peONU yega yega uye inodzivirira yega yega ONU Collision pakati.