Iyo EPON system ine akawanda optical network units (ONU), an optical line terminal (OLT), uye imwe kana akawanda optical network (ona Mufananidzo 1).Munzira yekuwedzera, chiratidzo chinotumirwa neOLT chinotepfenyurwa kune ese maONU.8h Shandura fomati yefomati, tsanangurazve chikamu chepamberi, uye wedzera iyo nguva uye zvine musoro chiziviso (LLID)).Iyo LLID inozivisa ONU yega yega muPON system, uye iyo LLID inotsanangurwa panguva yekuwana maitiro.
(1) Kukura
Muhurongwa hweEPON, chinhambwe chenyama pakati peONU yega yega neOLT mugwara rekufambisa mashoko hachina kuenzana.Yese EPON system inotaura kuti chinhambwe chakareba pakati peONU neOLT i20km, uye chinhambwe chipfupi i0km.Uyu mutsauko wechinhambwe uchakonzera kunonoka kusiyanisa pakati pe0 ne200 isu.Kana pasina gaka rakakwana rekuzviparadzanisa nevamwe, masaini kubva kumaONU akasiyana anogona kusvika kumagumo ekugamuchira kweOLT panguva imwe chete, izvo zvinozokonzera kupokana kwezviratidzo zvekumusoro.Iko kukakavara kunokonzeresa kuwanda kwekukanganisa uye kurasikirwa kwekuyananisa, nezvimwe, zvichikonzera kuti sisitimu itadze kushanda zvakajairika.Uchishandisa nzira yekufamba, tanga wayera nhambwe yemuviri, uye wozogadzirisa ese maONU kuenda kune imwechete inonzwisisika chinhambwe seOLT, uye wozoita nzira yeTDMA kuti uwane kudzivirira kusawirirana.Parizvino, nzira dzakasiyana-siyana dzinoshandiswa dzinosanganisira kupararira-kutenderera, kunze-kwe-bhendi kubva uye mu-bhendi-kuvhura hwindo.Semuyenzaniso, iyo time tag kubva nzira inoshandiswa kutanga kuyera chiratidzo chekunonoka kunonoka kubva kune yega yega ONU kuenda kuOLT, uye wozoisa chaiyo yakaenzana kunonoka Td kukosha kune yega yega ONU, kuitira kuti loop yekunonoka nguva yeONU yese mushure mekuisa Td. (Inonzi equalization loop delay value Tequ) yakaenzana, mhedzisiro yacho yakafanana neiyo ONU yega yega inotamiswa kuenda kune imwechete inonzwisisika chinhambwe seOLT, uye ipapo furemu inogona kutumirwa nemazvo zvinoenderana neTDMA tekinoroji pasina kupokana..
(2) Kuwana nzira
OLT inoona kuti ONU muPON system inotumira Gate MPCP meseji nguva nenguva.Pakugamuchira meseji yeGedhi, iyo ONU isina kunyoreswa ichamirira nguva isina kurongeka (kudzivisa kunyoreswa panguva imwe chete yeONU dzakawanda), uyezve kutumira Register meseji kuOLT.Mushure mekubudirira kunyoreswa, OLT inopa LLID kuONU.
(3) Ethernet OAM
Mushure mekunge ONU yanyoresa neOLT, Ethernet OAM paONU inotanga nzira yekutsvaga uye inosimbisa hukama neOLT.Ethernet OAM inoshandiswa paONU/OLT links kutsvaga zvikanganiso zviri kure, kukonzeresa kure kure, uye kuona mhando yekubatanidza.Nekudaro, Ethernet OAM inopa rutsigiro rweakagadziridzwa OAM PDUs, ruzivo mayuniti uye nguva mishumo.Vazhinji vagadziri veONU/OLT vanoshandisa maOAM ekuwedzera kuseta akakosha mabasa eONU.Chishandiso chakajairika ndechekudzora bandwidth yevashandisi vekupedzisira neiyo yekumisikidza bandwidth modhi yakawedzerwa muONU.Iyi isiri-standard application ndiyo kiyi yebvunzo uye inova chipingamupinyi pakutaurirana pakati peONU neOLT.
(4) Kuyerera kwemvura yakadzika
Kana OLT iine traffic yekutumira ONU, inotakura iyo LLID ruzivo rwekwainoenda ONU mutraffic.Nekuda kwekutepfenyura kwePON, data inotumirwa neOLT ichatepfenyurwa kune ese maONU.Isu tinofanirwa kunyanya kufunga nezvemamiriro ezvinhu apo traffic yakadzika inofambisa vhidhiyo sevhisi hova.Nekuda kwekutepfenyura kweiyo EPON sisitimu, kana mushandisi akagadzirisa chirongwa chevhidhiyo, chinozotepfenyurwa kune vese vashandisi, iyo inodya yakadzika bandwidth zvakanyanya.OLT inowanzo tsigira IGMP Snooping.Inogona snoop IGMP Join Chikumbiro meseji uye kutumira multicast data kune vashandisi vane hukama neboka iri pane kutepfenyura kune vese vashandisi, kuderedza traffic neiyi nzira.
(5) Kuyerera kwemvura
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 ichipindura ONU, ichiudza iyo ONU nguva yekutanga yekufambisa kunotevera OLT inofanirwa kukwanisa kubata bandwidth zvinodiwa kune ese maONU, uye inofanirwa kukoshesa mvumo yekufambisa.Maererano nekutanga kwemutsara uye kuenzanisa zvikumbiro zveONU dzakawanda, OLT inofanirwa kukwanisa. kubata bandwidth inodiwa kune ese maONU.Dynamic kugovera yekumusoro bandwidth (kureva DBA algorithm).
2.2 Zvinoenderana nehunyanzvi hunhu hweEPON system, matambudziko ebvunzo akatarisana neEPON system
(1) Tichifunga nezve chiyero cheEPON system
Kunyange zvazvo IEEE802.3ah isingatsananguri nhamba yepamusoro muhurongwa hweEPON, nhamba huru inotsigirwa neEPON system inobva pa16 kusvika pa128. ONU yega yega inopinda muEPON system inoda nguva yeMPCP neOAM.Sezvo mamwe masaiti ajoinha EPON, njodzi yekukanganisa kwehurongwa ichawedzera.Semuyenzaniso, yega yega ONU inoda kuburitsazve maitiro, kupinda mukati uye kutanga OAM chikamu.Nokudaro, nguva yekudzorera yehurongwa hwose ichawedzera nehuwandu hweONU.
(2) Dambudziko rekupindirana kwemidziyo
Izvi zvinotevera zvinhu zvinonyanya kutariswa kune intercommunication yemidziyo:
● The dynamic bandwidth algorithm (DBA) inopiwa nevagadziri vakasiyana yakasiyana.
●Vamwe vagadziri vanoshandisa “Organization Specific Elements” yeOAM kutara maitiro chaiwo.
●Kuti kugadzirwa kweMPCP protocol kunoenderana here.
●Kuti nzira dzekuyera kureba dzakagadzirwa nevagadziri vakasiyana dzinoenderana nekugadzirisa wachi.
(3) Njodzi dzakavanzwa mukufambiswa kwemasevhisi ekutamba katatu muEPON system
Nekuda kwehunhu hwekutapurirana hweEPON, dzimwe njodzi dzakavanzika dzinozounzwa kana uchitumira katatu masevhisi ekutamba:
● Kuderera kwemvura kunoparadza zvakawanda zvebhanwidth: EPON system inoshandisa nhepfenyuro yekufambisa nzira mumhepo yakadzika: imwe neimwe ONU ichagamuchira huwandu hwakawanda hwemotokari inotumirwa kune mamwe maONU, ichiparadza zvakawanda zvepasi.
●Kunonoka kwekumusoro kwakakura: Kana ONU ichitumira data kuOLT, inofanira kumirira mukana wekutumira wakagoverwa neOLT.Naizvozvo, iyo ONU inofanirwa kuvharira huwandu hukuru hwetraffic inokwira, izvo zvinokonzeresa kunonoka, jitter, uye kurasikirwa kwepaketi.
3 EPON bvunzo tekinoroji
Muedzo weEPON unonyanya kusanganisira zvinhu zvakati wandei senge interoperability test, protocol test, system transmission performance test, sevhisi uye basa rekuona.Iyo yakajairwa test topology inoratidzwa muMufananidzo 2. Zvigadzirwa zveIXIA zveIxN2X zvinopa kadhi rekuedza reEPON rakatsaurirwa, EPON test interface, inogona kutora nekuongorora maprotocol eMPCP neOAM, inogona kutumira EPON traffic, inopa chirongwa chekuyedza otomatiki, uye inogona kubatsira vashandisi kuyedza. DBA algorithms.
