1. Nhanganyaya
Nekukurumidza kuvandudza tekinoroji yekuwana Broadband, matekinoroji akasiyana ari kusimukira eBroadband akabuda mushure mekunaya kwemvura.Mushure mePON tekinoroji ndeyeDSL tekinoroji uye tambo tekinoroji, imwe yakanakira kuwana chikuva, PON inogona kupa zvakananga masevhisi ekuona kana FTTH masevhisi.EPON imhando nyowani yefiber access network tekinoroji, ichishandisa mapoinzi kune akawanda-point chimiro, sourceless light transmission, inopa akasiyana Ethernet masevhisi.Inoshandisa PON's topology kushandisa Ethernet kuwana, uye PON tekinoroji inoshandiswa mune yemuviri layer mune yemuviri layer.Nokudaro, inobatanidza zvakanakira zvePON teknolojia uye teknolojia yeEthernet: mari shoma;high bandwidth;ine simba scalability, inoshanduka uye nekukurumidza sevhisi kugadziridza;kuwirirana neEthernet iripo;nyore manejimendi, etc. EPON bvunzo yakasiyana zvakanyanya neyechinyakare Ethernet midziyo.Ichi chinyorwa chinotarisa nezve EPON bvunzo tekinoroji.
2 EPON tekinoroji sumo uye bvunzo dambudziko
TheEPONsisitimu inoumbwa neakawanda emagetsi network mayunitsi, mwenje terminal (OLT), uye imwe kana kupfuura inotaridzika (ona Mufananidzo 1).Munzira yedownlink, chiratidzo chinotumirwa neOLT chinotepfenyurwa pamaONU ese.Munzira yekukwira kumusoro, TDMA akawanda-channel matekiniki anoshandiswa, uye iyo uplink ruzivo rwemaONU akawanda anoita TDM ruzivo kune OLT.802.3AH Shandura Ethernet furemu fomati, tsanangura patsva chikamu chekare, wedzera zvitambi zvenguva uye zvine musoro link identifiers (LLID).LLID inozivisa yega yega ONU yePON system uye inotsanangura iyo LLID panguva yekutsvaga maitiro.
3 Kiyi tekinoroji muPON system
Muhurongwa hweEPON, chinhambwe chenyama pakati peONU yega yega neOLT mugwara rekufambisa mashoko hachina kuenzana.Kazhinji, EPON system inotaura kuti chinhambwe chakareba kubva kuONU kuenda kuOLT i20km, uye chinhambwe chipfupi i0km.Musiyano uyu uri chinhambwe unokonzera kunonoka kusiyanisa pakati pe0 ne200 isu.Kana pasina gaka rakakwana rekuzviparadzanisa nevamwe, masaini kubva kumaONU akasiyana anogona kusvika kumagumo ekugamuchira kweOLT panguva imwe chete, zvichikonzera kupokana kwezviratidzo zvekumusoro.Kusawirirana kunogona kukonzera kuwanda kwekukanganisa uye kurasikirwa kwekuyananisa, nezvimwewo, zvichikonzera kuti sisitimu isashande nemazvo.Uchishandisa nzira yekufamba, tanga wayera nhambwe yemuviri, wozogadzirisa ese maONU kune chinhambwe chine musoro seOLT, uye woita nzira yeTDMA kudzivirira kupokana.Idzo dziri kushandiswa parizvino nzira dzekusiyana dzinosanganisira kupararira-spectrum kubva, kunze-kwe-bhendi kubva uye mu-bhendi hwindo-kuvhura kubva.Semuenzaniso, uchishandisa nzira yekufamba-nguva, tanga wayera nguva yekunonoka kwechiratidzo kubva kune imwe neimwe ONU kuenda kuOLT, wobva waisa chaiyo yakaenzana kunonoka Td kukosha kune yega yega ONU, kuitira kuti loop inonoke yeONU yese mushure mekuisa Td inogona. kuwanikwa Nguva (inonzi yakaenzana loop kunonoka kukosha Tequ) yakaenzana, uye mhedzisiro yakafanana nekufambisa imwe neimwe ONU kuenda kune imwechete inonzwisisika chinhambwe seOLT, uyezve kutumira furemu nenzira kwayo zvinoenderana neTDMA tekinoroji pasina kudhumhana.
Iyo OLT inoona kuti ONU muPON system inopota ichitumira Gate MPCP meseji.Mushure mekunge ONU isina kunyoreswa yawana meseji yeGedhi, ichamirira nguva isina kurongeka (kudzivisa kunyoreswa panguva imwe chete yeONU dzakawanda), uyezve kutumira Register meseji kuOLT.Mushure mekubudirira kunyoreswa, OLT inopa LLID kuONU.
Mushure mekunge ONU yanyoresa neOLT, Ethernet OAM paONU inotanga nzira yekutsvaga uye inosimbisa hukama neOLT.Ethernet OAM inoshandiswa kuona zvikanganiso zviri kure paONU/OLT link, kukonzeresa loopback iri kure, uye kuona kunaka kwelink.Nekudaro, Ethernet OAM inopa rutsigiro rwetsika OAM PDUs, mayuniti eruzivo, uye mishumo yenguva.Vazhinji vagadziri veONU/OLT vanoshandisa maOAM ekuwedzera kuseta akakosha mabasa eONU.Chishandiso chakajairika ndechekudzora bandwidth yevashandisi vekupedzisira kuburikidza neiyo yakawedzera gadziriso bandwidth modhi muONU.Iyi isiri-standard application ndiyo kiyi yebvunzo uye inova chipingamupinyi pakutaurirana pakati peONU neOLT.
Kana OLT iine traffic yekutumira ONU, inotakura iyo LLID ruzivo rwekwainoenda ONU mutraffic.Nekuda kwemaitiro ekutepfenyura ePON, data rakatumirwa neOLT richatepfenyurwa kune ese maONU.Kunyanya, mamiriro ezvinhu apo iyo yakadzika traffic inofambisa vhidhiyo sevhisi rwizi inofanira kutariswa.Nekuda kwemaitiro ekutepfenyura eiyo EPON system, kana mushandisi akagadzirisa chirongwa chevhidhiyo, chinozotepfenyurwa kune vese vashandisi, iyo inodya yakawanda yakadzika bandwidth.OLT inowanzo tsigira IGMP Snooping.Inogona kutarisa IGMP Join Chikumbiro meseji uye kutumira multicast data kune vashandisi vane hukama neboka pane kutepfenyura kune vese vashandisi, nekudaro ichidzikisa traffic.
Imwe chete ONU inogona kutumira traffic pane imwe nguva.ONU ine mitsetse yakawanda yakakosha (mutsetse wega wega unoenderana nedanho reQoS. ONU inotumira Report message kuOLT ichikumbira mukana wekutumira, inodonongodza mamiriro emutsara wega wega. OLT inotumira meseji yeGedhi kuONU kuti iudze ONU. nguva yekutanga yekufambisa kunotevera kuenda kuOLT Inofanirwa kugona kubata bandwidth zvinodiwa zveONU dzese, uye inofanira kupa pamberi kune chiremera chekutapurirana.Maererano nekutanga kwemutsara, kuenzanisa zvikumbiro zveONU dzakawanda.OLT inofanira kuva inokwanisa kubata bandwidth zvinodiwa zveese maONU uye zvine simba kugovera kumusoro bandwidth (kureva DBA algorithm).