Sisitemu ya EPON igizwe nibice byinshi bya optique (ONU), umurongo wa optique (OLT), hamwe numuyoboro umwe cyangwa byinshi (reba Ishusho 1).Mu cyerekezo cyo kwagura, ibimenyetso byoherejwe na OLT byerekanwa kuri ONU zose.8h Hindura imiterere yikadiri, ongera usobanure igice cyimbere, hanyuma wongere umwanya nibiranga logique (LLID)).LLID igaragaza buri ONU muri sisitemu ya PON, kandi LLID isobanurwa mugihe cyo kuvumbura.
(1) Guhindagurika
Muri sisitemu ya EPON, intera igaragara hagati ya buri ONU na OLT murwego rwo hejuru rwohereza amakuru ntabwo aringana.Sisitemu rusange ya EPON iteganya ko intera ndende hagati ya ONU na OLT ari 20km, naho intera ngufi ni 0km.Itandukaniro ryintera rizatera gutinda guhinduka hagati ya 0 na 200 natwe.Niba nta cyuho gihagije cyo kwigunga, ibimenyetso biva muri ONU zitandukanye birashobora kugera kumpera yakira ya OLT icyarimwe, bizatera amakimbirane yibimenyetso byo hejuru.Amakimbirane azatera amakosa menshi no gutakaza syncronisation, nibindi, bitera sisitemu kunanirwa gukora bisanzwe.Ukoresheje uburyo butandukanye, banza upime intera ifatika, hanyuma uhindure ONU zose kurugero rumwe rwumvikana na OLT, hanyuma ukore uburyo bwa TDMA kugirango ugere ku makimbirane.Kugeza ubu, uburyo bwakoreshwaga bukoreshwa burimo gukwirakwiza-gukwirakwiza ibintu, hanze ya bande no muri bande idirishya rifungura.Kurugero, igihe cyateganijwe uburyo bwakoreshejwe mukubanza gupima ibimenyetso bya loop gutinda kuva kuri buri ONU kugeza kuri OLT, hanyuma ugashyiramo uburinganire bwihariye bwo gutinza Td agaciro kuri buri ONU, kugirango loop itinde igihe cya ONU zose nyuma yo gushyiramo Td ..
(2) Inzira yo kuvumbura
OLT isanga ONU muri sisitemu ya PON yohereza ubutumwa bwa Gate MPCP buri gihe.Iyo wakiriye ubutumwa bw Irembo, ONU itiyandikishije izategereza igihe cyateganijwe (kugirango wirinde icyarimwe kwiyandikisha kuri ONU nyinshi), hanyuma wohereze ubutumwa bwanditse kuri OLT.Nyuma yo kwiyandikisha neza, OLT igenera LLID kuri ONU.
(3) Ethernet OAM
ONU imaze kwiyandikisha muri OLT, Ethernet OAM kuri ONU itangira inzira yo kuvumbura igashyiraho isano na OLT.Ethernet OAM ikoreshwa kumurongo wa ONU / OLT kugirango ubone amakosa ya kure, utere kure, kandi umenye ubuziranenge bwihuza.Nyamara, Ethernet OAM itanga inkunga kubikorwa byihariye bya OAM PDUs, ibice byamakuru na raporo zigihe.Benshi mubakora ONU / OLT bakoresha umugereka wa OAM kugirango bashireho imirimo yihariye ya ONU.Porogaramu isanzwe ni ukugenzura umurongo wabakoresha ba nyuma hamwe nuburyo bugaragara bwagutse muri ONU.Iyi porogaramu itari isanzwe nurufunguzo rwikizamini kandi iba inzitizi yimikoranire hagati ya ONU na OLT.
(4) Kugenda kumanuka
Iyo OLT ifite traffic yohereza ONU, izatwara amakuru ya LLID yerekanwe ONU mumodoka.Kubera ibiranga gutangaza PON, amakuru yoherejwe na OLT azashyikirizwa ONU zose.Tugomba cyane cyane gutekereza kumiterere aho traffic traffic yohereza amashusho ya serivise.Bitewe nuburyo bwo gutangaza sisitemu ya EPON, mugihe umukoresha yihitiyemo porogaramu ya videwo, izashyikirizwa abakoresha bose, ikoresha umurongo mugari cyane.OLT mubisanzwe ishyigikira IGMP Snooping.Irashobora guhisha IGMP Kwinjira Gusaba ubutumwa no kohereza amakuru menshi kubakoresha bijyanye niri tsinda aho gutangaza kubakoresha bose, kugabanya traffic muri ubu buryo.
(5) Inzira yo hejuru
ONU imwe yonyine irashobora kohereza traffic mugihe runaka.ONU ifite imirongo myinshi yibanze (buri murongo uhuye nurwego rwa QoS. ONU yohereza ubutumwa bwa OLT kugirango isabe amahirwe yo kohereza, isobanura uko buri murongo uhagaze. OLT yohereza ubutumwa bw Irembo busubiza ONU, ibwira ONU igihe cyo gutangiriraho ubutaha itaha OLT igomba kuba ishobora gucunga umurongo mugari wa ONU zose, kandi igomba gushyira imbere uruhushya rwo kohereza. Ukurikije ibyihutirwa byumurongo kandi ugahuza ibyifuzo bya ONU nyinshi, OLT igomba kuba ishobora gucunga umurongo wa enterineti ibisabwa kuri ONU zose. Gutanga imbaraga zidasanzwe zo hejuru (ni ukuvuga DBA algorithm).
2.2 Ukurikije ibimenyetso bya tekiniki biranga sisitemu ya EPON, ibibazo byikizamini byahuye na sisitemu ya EPON
(1) Urebye igipimo cya sisitemu ya EPON
Nubwo IEEE802.3ah idasobanura umubare ntarengwa muri sisitemu ya EPON, umubare ntarengwa ushyigikiwe na sisitemu ya EPON ni kuva kuri 16 kugeza 128. Buri ONU yinjira muri sisitemu ya EPON isaba MPCP hamwe na OAM.Mugihe imbuga nyinshi zifatanije na EPON, ibyago byamakosa ya sisitemu biziyongera.Kurugero, buri ONU ikeneye kongera kuvumbura inzira, kwinjira no gutangira isomo rya OAM.Kubwibyo, igihe cyo kugarura sisitemu yose kiziyongera hamwe numubare wa ONU.
(2) Ikibazo cyo gutumanaho ibikoresho
Ibice bikurikira birasuzumwa cyane cyane muguhuza ibikoresho:
Dyn Dynamic bandwidth algorithm (DBA) itangwa nababikora batandukanye iratandukanye.
● Bamwe mubakora bakoresha "OrganizaTIon Ibintu Byihariye" bya OAM kugirango bashireho imyitwarire yihariye.
● Niba iterambere rya protokole ya MPCP rihuye rwose.
● Niba intera yo gupima intera yakozwe nababikora batandukanye ihuye nogutunganya amasaha.
(3) Ibyago byihishe mugukwirakwiza serivisi eshatu zo gukina muri sisitemu ya EPON
Bitewe no kwanduza ibiranga EPON, ibyago bimwe byihishe bizatangizwa mugihe cyohereza serivise eshatu zo gukina:
● Downstream isesagura umurongo mwinshi: sisitemu ya EPON ikoresha uburyo bwo kohereza amakuru muburyo bwo hasi: buri ONU izakira umubare munini wimodoka yoherejwe kurindi ONU, isesagura umurongo mwinshi wo hasi.
Gutinda gutembera hejuru ni binini: Iyo ONU yohereje amakuru kuri OLT, igomba gutegereza amahirwe yo kohereza yatanzwe na OLT.Kubwibyo, ONU igomba guhagarika umubare munini wimodoka yo hejuru, bizatera gutinda, jitter, no gutakaza paki.
3 Ikoranabuhanga rya EPON
Ikizamini cya EPON gikubiyemo ahanini ibintu byinshi nkikizamini cyimikoranire, ikizamini cya protocole, ikizamini cyo kohereza sisitemu, serivisi no kugenzura imikorere.Ikizamini gisanzwe cya topologiya cyerekanwe mubishushanyo 2. Ibicuruzwa bya IXN2X bya IXIA bitanga ikarita yikizamini cyabigenewe ya EPON, interineti yikizamini cya EPON, irashobora gufata no gusesengura protocole ya MPCP na OAM, irashobora kohereza traffic traffic, gutanga porogaramu yikizamini cyikora, kandi irashobora gufasha abakoresha kwipimisha. DBA algorithms.
