1. EPON network sumo
EPON(Ethernet Passive Optical Network) inobuda optical fiber access network tekinoroji, iyo inotora point-to-multipoint chimiro, passive optical fiber transmission mode, yakavakirwa pakakwirira-speed Ethernet papuratifomu uye TDM nguva kupatsanura MAC (MediaAccessControl) midhiya yekudzora nzira, Ipa akasiyana siyana eBroadband kuwana matekinoroji emasevhisi akabatanidzwa. Izvo zvinonzi "passive" zvinoreva kuti ODN haina chero zvigadzirwa zvemagetsi zvinoshanda uye magetsi emagetsi, uye zvese zvine zvigadziriso zvakadai semagetsi emagetsi (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). Iyo iri padanho retiweki retiweki uye inonyanya kukodzera optical fiber yekubatanidza yebroadband masevhisi. Into.
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 kufukidzwa kunosvika 20km, iyo inovimbisa kutiOLTinogona kukwidziridzwa kune yechinyakare metropolitan convergence node kubva padanho rekutanga reiyo optical access network yekuvaka, nekudaro kurerutsa iyo network chimiro cheiyo convergence layer yekuwana network uye kuchengetedza Nhamba yekupera mahofisi. Pamusoro pezvo, hunhu hweiyo optical access network yakakura, yakakwirira yekupinda bandwidth, yakakwirira kuvimbika, uye akawanda-sevhisi QoS level tsigiro yaitawo shanduko yetiweki yekuwana kune yakabatana, yakabatanidzwa, uye inoshanda mutakuri chikuva.
2. Basic Principles yeEPON Network
Iyo EPON sisitimu inoshandisa tekinoroji yeWDM kuona kutapurirana-fiber bidirectional, uchishandisa kumusoro 1310nm nekudzika 1490nm wavelengths kufambisa data nezwi, uye masevhisi eCATV anoshandisa 1550nm wavelength kutakura. TheOLTinoiswa muhofisi yepakati kugovera uye kutonga kubatana kwechiteshi, 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 zviratidzo kubva kune vakawanda vashandisi pane imwechete fiber, nzira mbiri dzinotevera dze multiplexing dzinogona kushandiswa.
(1) Iyo yakadzika data rwizi inotora tekinoroji yekutepfenyura. MuEPON, maitiro ekudzika kwedhata kufambisa kubva kuOLTkusvika kuwandaONUsinotumirwa nedata nhepfenyuro. Data inotepfenyurwa yakadzika kubva kuOLTkusvika kuwandaONUsmuchimiro chekusiyanisa-kureba ruzivo mapaketi. Packet yega yega yeruzivo ine EPON packet header, inotaridza kuti ruzivo rwacho rwakatumirwaONU-1,ONU-2 kanaONU-3. Inogona zvakare kumakwa sepakeji yeruzivo rwenhepfenyuro inotumirwa kune veseONUskana kuti kune chaiyoONUboka (multicast information packet). Kana data rasvika paONU, ivoONUinogamuchira uye inoziva mapaketi 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 nerange tekinoroji) inotsiva gaka riri chinhambwe chechimwe nechimweONUuye anonzvenga mumwe nomumweONUKudhumhana pakati.
