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 iqulunqwe ikakhuluOLT(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.
Isixhobo sothungelwano esisebenzayo siquka izixhobo zokuvala zeofisi esembindini (OLT) kunye neyunithi yenethiwekhi yamehlo (I-ONU). Iyunithi yenethiwekhi yamehlo (I-ONU) ibonelela abasebenzisi ngonxibelelwano phakathi kwedatha, ividiyo, kunye neenethiwekhi zefowuni kunye nePON. Indima yokuqala yeI-ONUkukufumana umqondiso we-optical kwaye emva koko uyiguqule kwifomathi efunwa ngumsebenzisi (i-Ethernet, ukusasazwa kwe-IP, umnxeba, i-T1 / E1, njl.).OLTizixhobo 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 yokufikelela kwi-optical, ngaloo ndlela lula ulwakhiwo lothungelwano lwe-convergence layer yokufikelela kuthungelwano 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. IOLTibekwe kwi-ofisi ephakathi ukuze isasaze kwaye ilawule ukudityaniswa kwejelo, kwaye inomsebenzi wokubeka iliso ngexesha langempela, ulawulo kunye nokugcinwa. II-ONUibekwe kwicala lomsebenzisi, kwaye iOLTkwaye iI-ONUziqhagamshelwe ngendlela ye-1:16/1:32 ngothungelwano losasazo lwe-passive optical. Ukuze ukwahlula imiqondiso kubasebenzisi abaninzi kwifiber efanayo, ezi ndlela zimbini zilandelayo zokuphindaphinda zinokusetyenziswa.
(1) Umjelo wedatha osezantsi wamkela iteknoloji yosasazo. Kwi-EPON, inkqubo yokuhanjiswa kwedatha ezantsi ukusuka kwiOLTukuphindaphindaIi-ONUithunyelwa ngokusasazwa kwedatha. Idatha isasazwa ezantsi ukusuka kwiOLTukuphindaphindaIi-ONUngohlobo lweepakethi zolwazi oluguquguqukayo. Ipakethe nganye yolwazi inesihloko sepakethe ye-EPON, echonga ngokukodwa ukuba ipakethi yolwazi ithunyelweI-ONU-1,I-ONU-2 okanyeI-ONU-3. Isenokuphawulwa njengepakethi yolwazi losasazo ethunyelwa kubo bonkeIi-ONUokanye kwinto ethileI-ONUiqela (ipakethi yolwazi losasazo oluninzi). Xa idatha ifika kwiI-ONU, iI-ONUifumana kwaye ibone iipakethi zolwazi ezithunyelwe kuyo ngokuthelekisa idilesi, kwaye ilahle iipakethi zolwazi ezithunyelwe kwezinyeIi-ONU. I-LLID eyodwa yabelwa emva kweI-ONUibhalisiwe; iOLTuthelekisa uluhlu lobhaliso lwe-LLID xa ufumana idatha, kwaye xa iI-ONUifumana idatha, ifumana kuphela izakhelo okanye izakhelo zosasazo ezihambelana ne-LLID yayo.
(2) Ukuhamba kwedatha ephezulu kwamkela iteknoloji yeTDMA. IOLTuthelekisa uluhlu lobhaliso lwe-LLID ngaphambi kokufumana idatha; nganyeI-ONUithumela isakhelo sedatha kwixesha elibekiweyo ngokulinganayo elabelwe izixhobo zeofisi ephakathiOLT; ixesha elibekiweyo (ngokusebenzisa itekhnoloji eqalayo) ibuyekeza isithuba esikumgama ngamnyeI-ONUkwaye uphepha nganyeI-ONUUkungqubana phakathi.
