1. Gabatarwar hanyar sadarwa ta EPON
EPON(Ethernet Passive Optical Network) fasaha ce ta hanyar sadarwa ta hanyar sadarwa ta fiber mai tasowa, wacce ke ɗaukar tsari-zuwa-multipoint tsarin, yanayin watsa fiber na gani mai ƙarfi, dangane da dandamalin Ethernet mai sauri da Rarraba lokaci MAC (MediaAccessControl) yanayin ikon sarrafa kafofin watsa labarai, Samar da fasahohin samun dama ga hanyoyin sadarwa iri-iri don ayyukan haɗin gwiwa.Abin da ake kira "passive" yana nufin cewa ODN ba ta ƙunshi kowane na'urorin lantarki masu aiki da kayan wuta ba, kuma duk sun ƙunshi na'urori marasa amfani kamar masu rarraba gani (Splitter).Yana amfani da fasahar PON a Layer na jiki, ka'idar Ethernet a layin haɗin gwiwa, kuma yana amfani da PON topology don samun damar Ethernet.Sabili da haka, yana haɗuwa da fa'idodin fasaha na PON da fasahar Ethernet: ƙananan farashi, babban bandwidth, haɓaka mai ƙarfi, daidaitawa da sake tsara sabis na sauri, dacewa tare da Ethernet data kasance, gudanarwa mai dacewa, da sauransu.
EPON na iya gane haɗin murya, bayanai, bidiyo, da sabis na wayar hannu.Tsarin EPON ya ƙunshi OLT (tashar layin gani na gani),ONU(Naúrar cibiyar sadarwa na gani), ONT (Tsarin hanyar sadarwa ta gani) da ODN (cibiyar rarrabawar gani).Yana a matakin hanyar sadarwa na hanyar sadarwa kuma ya fi dacewa da haɗin fiber na gani na sabis na broadband.Ciki
Kayan aikin cibiyar sadarwa mai aiki sun haɗa da kayan tara kayan ofis na tsakiya (OLT) da naúrar cibiyar sadarwa ta gani (ONU).Naúrar hanyar sadarwa ta gani (ONU) tana ba masu amfani da mu'amala tsakanin bayanai, bidiyo, da cibiyoyin sadarwar tarho da PON.Matsayin farko na ONU shine karɓar siginar gani sannan a canza shi zuwa tsarin da mai amfani ke buƙata (Ethernet, watsawar IP, tarho, T1/E1, da sauransu).An haɗa kayan aikin OLT zuwa cibiyar sadarwar IP ta hanyar fiber na gani.Gabatarwar hanyar sadarwa ta hanyar sadarwa tana da ɗaukar hoto har zuwa 20km, wanda ke tabbatar da cewaOLTza a iya inganta zuwa ga gargajiya metropolitan convergence kumburi daga farkon mataki na Tantancewar damar cibiyar sadarwa yi, don haka sauƙaƙa da cibiyar sadarwa tsarin na convergence Layer na samun damar cibiyar sadarwa da kuma ajiye Adadin karshen ofisoshin.Bugu da kari, halayen babbar hanyar sadarwa ta hanyar sadarwa ta gani, babban damar isa ga bandwidth, babban abin dogaro, da damar tallafin matakin QoS masu yawan ayyuka sun kuma sanya juyin halittar hanyar sadarwa zuwa ga hadadden dandamali, hadewa, da ingantaccen dandamali mai daukar kaya.
2. Ka'idoji na asali na EPON Network
Tsarin EPON yana amfani da fasahar WDM don gane watsawar fiber guda ɗaya, ta yin amfani da 1310nm na sama da 1490nm na ƙasa don watsa bayanai da murya, kuma sabis na CATV suna amfani da tsawon tsayin 1550nm don ɗauka.An sanya OLT a cikin ofishin tsakiya don rarrabawa da sarrafa haɗin tashar tashar, kuma yana da kulawa na ainihi, gudanarwa da ayyukan kulawa.Ana sanya ONU a gefen mai amfani, kuma OLT da ONU ana haɗa su a cikin hanyar 1:16/1:32 ta hanyar hanyar sadarwa mai rarraba kayan gani.Domin raba sigina daga masu amfani da yawa akan fiber iri ɗaya, ana iya amfani da waɗannan dabaru iri-iri biyu masu zuwa.
(1) Rafin bayanan da ke ƙasa yana ɗaukar fasahar watsa shirye-shirye.A cikin EPON, ana aika tsarin watsa bayanan ƙasa daga OLT zuwa ONU masu yawa ta hanyar watsa bayanai.Ana watsa bayanai a ƙasa daga OLT zuwa ONU masu yawa a cikin nau'i na fakitin bayanai masu tsayi.Kowane fakitin bayanin yana da kan fakitin EPON, wanda ke nuna musamman ko an aika fakitin bayanin zuwa ONU-1, ONU-2 ko ONU-3.Hakanan ana iya yiwa alama alama azaman fakitin bayanan watsa shirye-shirye da aka aika zuwa duk ONUs ko zuwa takamaiman rukunin ONU (fakitin bayanai da yawa).Lokacin da bayanan suka isa ONU, ONU tana karɓar kuma ta gane fakitin bayanan da aka aika zuwa gare ta ta hanyar daidaita adireshin, kuma ta watsar da fakitin bayanan da aka aika zuwa wasu ONUs.An ware LLID na musamman bayan an yi rajistar ONU;OLT yana kwatanta lissafin rajistar LLID lokacin karɓar bayanai, kuma lokacin da ONU ya karɓi bayanai, kawai yana karɓar firam ko firam ɗin watsa shirye-shiryen da suka dace da nasa LLID.
(2) kwararar bayanai na sama suna ɗaukar fasahar TDMA.OLT yana kwatanta lissafin rajista na LLID kafin karɓar bayanai;kowane ONU yana aika da firam ɗin bayanai a cikin ramin lokaci daidai da abin da babban ofishin kayan aikin OLT ya keɓe;Ramin lokacin da aka keɓe (ta hanyar fasahar kewayon) yana rama ratar da ke tsakanin kowane ONU kuma yana guje wa kowane ONU karo tsakanin.
