1. Intshayelelo yenethiwekhi ye-EPON
EPON(i-Ethernet Passive Optical Network) yiteknoloji ye-fiber ephumayo yokufikelela kwi-fiber, eyamkela i-point-to-multipoint structure, i-passive optical fiber transmission mode, esekelwe kwi-high-speed Ethernet platform kunye ne-TDM ixesha lokwahlula i-MAC (MediaAccessControl) indlela yokulawula ukufikelela kwimidiya, Ukubonelela ngeendlela ezahlukeneyo zobuchwepheshe bokufikelela kwiinkonzo ezihlangeneyo.Okubizwa ngokuba "yi-passive" kuthetha ukuba i-ODN ayinayo nayiphi na i-electronic device esebenzayo kunye nombane, kwaye zonke ziqulethe izixhobo ezingabonakaliyo ezifana ne-splitter optical (Splitter).Isebenzisa iteknoloji ye-PON kwinqanaba lomzimba, i-Ethernet protocol kwi-link layer, kwaye isebenzisa i-PON topology ukufikelela kwi-Ethernet.Ngoko ke, idibanisa iingenelo zeteknoloji ye-PON kunye nobuchwepheshe be-Ethernet: ixabiso eliphantsi, i-bandwidth ephakamileyo, i-scalability enamandla, ukulungelelaniswa okuguquguqukayo kunye nokukhawuleza kwenkonzo, ukuhambelana ne-Ethernet ekhoyo, ulawulo olufanelekileyo, njalo njalo.
I-EPON inokuqonda ukudityaniswa kwelizwi, idatha, ividiyo, kunye neenkonzo zeselfowuni.Inkqubo ye-EPON yenziwe ikakhulu yiOLT (itheminali yomgca wokukhanya),I-ONU(iyunithi yenethiwekhi ye-optical), i-ONT (i-terminal ye-optical network) kunye ne-ODN (inethiwekhi yokusabalalisa i-optical).Ikwinqanaba lofikelelo lwenethiwekhi yothungelwano kwaye ilungele ikakhulu uqhagamshelo lwefiber optical yeenkonzo zebroadband.Into.
Izixhobo zenethiwekhi ezisebenzayo ziquka izixhobo zokubeka i-ofisi ephakathi (OLT) kunye neyunithi yenethiwekhi ye-optical (ONU).Iyunithi yenethiwekhi ye-optical network (ONU) ibonelela abasebenzisi nge-interface phakathi kwedatha, ividiyo, kunye neenethiwekhi zefowuni kunye nePON.Indima yokuqala ye-ONU kukufumana umqondiso we-optical kwaye emva koko uyiguqule kwifomathi efunwa ngumsebenzisi (i-Ethernet, ukusasazwa kwe-IP, ifowuni, T1 / E1, njl.).Izixhobo ze-OLT ziqhagamshelwe kwinethiwekhi engundoqo ye-IP ngefiber optical.Ukwaziswa kothungelwano lwe-optical access lufikelela kuma-20km, nto leyo eqinisekisa ukubaOLTinokuthi iphuculwe kwindawo yesiqhelo ye-metropolitan convergence node ukusuka kwinqanaba lokuqala lolwakhiwo lwenethiwekhi yofikelelo olubonayo, ngaloo ndlela ilula ubume bothungelwano lomaleko wokuhlangana wofikelelo womnatha kunye nokugcina inani leeofisi zokuphela.Ukongeza, iimpawu zenethiwekhi yokufikelela kwi-optical umthamo omkhulu, i-bandwidth ephezulu yokufikelela, ukuthembeka okuphezulu, kunye neenkonzo ezininzi ze-QoS zenkxaso yezakhono zenze ukuba i-evolution yenethiwekhi yokufikelela kwiqonga elidibeneyo, elidibeneyo, nelisebenzayo libe yinyani.
2. Imigaqo esisiseko ye-EPON Network
Inkqubo ye-EPON isebenzisa iteknoloji ye-WDM ukuqonda ukuhanjiswa kwe-bidirectional ye-fiber enye, usebenzisa i-1310nm ephezulu kunye ne-downstream 1490nm wavelengths ukuhambisa idatha kunye nezwi, kunye neenkonzo ze-CATV zisebenzisa i-1550nm wavelength ukuthwala.I-OLT ibekwe kwi-ofisi ephakathi ukuze isasaze kwaye ilawule uxhulumaniso lwejelo, kwaye inomsebenzi wangempela wokubeka iliso, ulawulo kunye nokugcinwa.I-ONU ibekwe kwicala lomsebenzisi, kwaye i-OLT kunye ne-ONU zidityaniswe ngendlela ye-1:16/1:32 ngokusebenzisa inethiwekhi yokusabalalisa i-passive optical.Ukuze ukwahlula imiqondiso kubasebenzisi abaninzi kwifiber enye, ezi ndlela zimbini zilandelayo zokuphindaphinda zingasetyenziswa.
(1) Umjelo wedatha osezantsi wamkela iteknoloji yosasazo.Kwi-EPON, inkqubo yokuhanjiswa kwedatha esezantsi ukusuka kwi-OLT ukuya kwii-ONU ezininzi ithunyelwa ngokusasazwa kwedatha.Idatha isasazwa ezantsi ukusuka kwiOLT ukuya kwii-ONU ezininzi ngohlobo lweepakethi zolwazi oluguquguqukayo.Ipakethe nganye yolwazi inesihloko sepakethe ye-EPON, echonga ngokukodwa ukuba ipakethi yolwazi ithunyelwe ku-ONU-1, ONU-2 okanye ONU-3.Isenokuphawulwa njengepakethe yolwazi losasazo oluthunyelwe kuzo zonke ii-ONU okanye kwiqela elithile le-ONU (ipakethi yolwazi losasazo oluninzi).Xa idatha ifika kwi-ONU, i-ONU ifumana kwaye ibone iipakethi zolwazi ezithunyelwe kuyo ngokuhambelana nedilesi, kwaye ilahle iipakethi zolwazi ezithunyelwe kwezinye ii-ONU.I-LLID eyodwa yabelwa emva kokuba i-ONU ibhalisiwe;i-OLT ithelekisa uluhlu lobhaliso lwe-LLID xa ifumana idatha, kwaye xa i-ONU ifumana idatha, ifumana kuphela izakhelo okanye izakhelo zokusasaza ezihambelana ne-LLID yayo.
(2) Ukuhamba kwedatha ephezulu kwamkela iteknoloji yeTDMA.I-OLT ithelekisa uluhlu lobhaliso lwe-LLID ngaphambi kokufumana idatha;i-ONU nganye ithumela isakhelo sedatha kwixesha elibekiweyo ngokulinganayo elabelwe izixhobo zeofisi ephakathi OLT;ixesha elabelwe ixesha elibekiweyo (ngokusebenzisa itekhnoloji eqalayo) ihlawulela umsantsa kumgama we-ONU nganye kwaye inqanda ukungqubana kwe-ONU nganye phakathi.
