Iyo EPON network inoshandisa nzira yeFTTB kugadzira network, uye maintiweki ayo arikoOLTuyeONU. TheOLTinopa akawanda PON ports yepakati hofisi michina yekubatanidza nayoONUmidziyo;ONUChishandiso chemushandisi chekupa zvinoenderana nedata uye manzwi ezwi kuti uone kuwanikwa kwesevhisi yevashandisi.Kuzadzikiswa kwekuwana masevhisi akasiyana kunonyanya kushandisa maVLAN tag akasiyana evashandisi vakasiyana uye masevhisi akasiyana kuendesa pachena kune inoenderana sevhisi yekuwana sevha, uye kutumira iyo inoenderana VLAN tags kune IP mutakuri network yekufambisa.
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 interface 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).OLTmidziyo yakabatana neiyo IP core network kuburikidza neoptical fiber. Iko kuunzwa kweiyo optical access network ine nzvimbo yekuvhara inosvika 20km, iyo inovimbisa kutiOLTinogona kukwidziridzwa kune yechinyakare metropolitan convergence node kubva padanho rekutanga reiyo optical access network yekuvaka, nekudaro kurerutsa iyo network dhizaini 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.OLTinoiswa pahofisi yepakati kugovera nekudzora chiteshi chekubatanidza, uye ine chaiyo-nguva yekutarisa, manejimendi uye kugadzirisa mabasa. TheONUinoiswa parutivi rwemushandisi, uye iyoOLTuyeONUakabatana nenzira ye 1:16/1:32 kuburikidza netiweki yekugovera yekuona.
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 ekudzika kwedhata kufambiswa kubvaOLTkusvika kuwandaONUsinotumirwa nedata nhepfenyuro. Data inotepfenyurwa yakadzika kubva kuOLTkusvika kuwandaONUsmuchimiro chepakati-refu mapaketi.Paketi yega yega yeruzivo ineEPONpacket header, iyo inosarudzika inoratidza kana iyo ruzivo packet inotumirwaONU-1,ONU-2 kanaONU-3. Inogonawo kuzivikanwa sepaketi yekutepfenyura inotumirwa kune veseONUskana kuti kune chaiyoONUboka (multicast packet). Kana data rasvika paONU,theONUinogamuchira uye inoratidza mapakeji eruzivo anotumirwa kwairi kuburikidza nekero yekuenzanisa, uye inorasa mapaketi eruzivo anotumirwa kune mamwe.ONUs. Iyo yakasarudzika LLID inopihwa mushure meiyoONUis registered; theOLTinoenzanisa iyo LLID yekunyoresa runyorwa paunogamuchira data, uye kana iyoONUinogamuchira data, inongogashira mafuremu kana kutepfenyura mafuremu anofanana neyayo LLID.
2) Kuyerera kwedata kunokwira kunotora tekinoroji yeTDMA.
TheOLTinoenzanisa iyo LLID kunyoresa runyorwa usati wagamuchira data; chimwe nechimweONUinotumira furemu yedata munguva yakagoverwa zvakafanana nemidziyo yepakati yehofisiOLT; iyo yakagoverwa nguva slot (kuburikidza nearanging tekinoroji) inotsiva kureba pakati peimwe neimweONUuye anonzvenga mumwe nomumweONUKudhumhana pakati.