Uthungelwano lwe-EPON lusebenzisa indlela ye-FTTB ukwenza uthungelwano, kunye neeyunithi zayo zenethiwekhi ezisisisekoOLTkwayeI-ONU. IOLTibonelela ngamazibuko e-PON amaninzi kwizixhobo ze-ofisi ezisembindini ukudibanisa kuzoI-ONUizixhobo;I-ONUsisixhobo somsebenzisi ukubonelela ngedatha ehambelanayo kunye nojongano lwelizwi ukuqonda ukufikelela kwenkonzo yomsebenzisi.Ukuqonda ukufikelela kwiinkonzo ezahlukeneyo ikakhulu kukusebenzisa iithegi ezahlukeneyo zeVLAN kubasebenzisi abohlukeneyo kunye neenkonzo ezahlukeneyo ukuhambisa ngokuphandle kwiseva yofikelelo yenkonzo ehambelanayo, kwaye uthumele i iithegi ezihambelanayo zeVLAN kuthungelwano lomthwali we-IP ukuhanjiswa.
1.Intshayelelo kwi-EPON Network
I-EPON (i-Ethernet Passive Optical Network) yiteknoloji ye-fiber ephumayo yokufikelela kwi-fiber network, eyamkela i-point-to-multipoint structure, i-passive optical fiber transmission mode, esekelwe kwi-platform ye-Ethernet ye-high-speed kunye ne-TDM ixesha lokwahlula i-MAC (MediaAccessControl) indlela yokulawula ukufikelela kwimidiya. , Ukubonelela ngeteknoloji yokufikelela kwi-broadband kwiinkonzo ezahlukeneyo ezidibeneyo.Okubizwa ngokuthi "i-passive" ithetha ukuba i-ODN ayinayo nayiphi na i-electronic device esebenzayo kunye nezixhobo zombane, kwaye iqulethwe ngokupheleleyo izixhobo ezingabonakaliyo ezifana ne-optical splitters (Splitter). Isebenzisa itekhnoloji ye-PON kumaleko womzimba, iprotocol ye-Ethernet kumaleko wekhonkco, 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 yenethiwekhi ye-optical) kunye ne-ODN (inethiwekhi yokusabalalisa i-optical), Ikwinqanaba lokufikelela kwinethiwekhi yothungelwano kwaye ilungele kakhulu ukufikelela kwi-fiber optical kwiinkonzo ze-broadband.
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 linendawo yokugubungela ukuya kuthi ga kwi-20km, eqinisekisa ukubaOLTinokuphuculwa ukuya kwindawo yesiqhelo yokudibana kwemetropolitan ukusuka kwinqanaba lokuqala lolwakhiwo lwenethiwekhi yofikelelo olubonayo, ngaloo ndlela lwenza lula ubume bothungelwano lofikelelo lonxibelelwano umaleko kunye nokugcina inani leeofisi zokuphela. Ukongeza, iimpawu zenethiwekhi yokufikelela kumandla amakhulu, i-bandwidth ephezulu yokufikelela, ukuthembeka okuphezulu, kunye neenkonzo ezininzi ze-QoS zenkxaso yezakhono ziye zenza ukuvela kothungelwano lokufikelela kwiqonga elidibeneyo, elidibeneyo, nelisebenzayo.
2.Imigaqo esisiseko ye-EPON Network
Inkqubo ye-EPON isebenzisa iteknoloji ye-WDM ukufikelela kwi-fiber-fiber bidirectional transmission, isebenzisa i-1310nm enyukayo kunye ne-1490nm ye-wavelengths esezantsi yokuhambisa idatha kunye nezwi, kwaye iinkonzo ze-CATV zisebenzisa i-1550nm wavelength ukuthwala.OLTibekwe kwi-ofisi ephakathi ukuze yabe kwaye ilawule uqhagamshelo lwejelo, kwaye inokubeka iliso ngexesha lokwenyani, imisebenzi yolawulo kunye nokugcinwa kwayo. II-ONUibekwe kwicala lomsebenzisi, kwaye iOLTkwaye iI-ONUziqhagamshelwe ngendlela ye-1:16/1:32 ngothungelwano losasazo lwe-passive optical.
Ukuze ukwahlula imiqondiso kubasebenzisi abaninzi kwifayibha enye, ezi ndlela zimbini zilandelayo zokuphindaphinda zinokusetyenziswa.
1) Umjelo wedatha osezantsi wamkela iteknoloji yosasazo.
Kwi-EPON, inkqubo yokuhanjiswa kwedatha ezantsi ukusukaOLTukuphindaphindaIi-ONUithunyelwa ngokusasazwa kwedatha. Idatha isasazwa ezantsi ukusuka kwiOLTukuphindaphindaIi-ONUngohlobo lweepakethi ezinobude obuguquguqukayo.Ipakethi yolwazi nganye ineEPONiheader yepakethe, echonga ngokukodwa ukuba ipakethi yolwazi ithunyelwe kuyoI-ONU-1,I-ONU-2 okanyeI-ONU-3. Isenokuchongwa njengepakethi yosasazo ethunyelwa kubo bonkeIi-ONUokanye kwinto ethileI-ONUiqela (iipakethi ezininzi). Xa idatha ifika kwiI-ONU,iI-ONUifumana kwaye ichonge iipakethi zolwazi ezithunyelwe kuyo ngokuthelekisa idilesi, kwaye ilahle iipakethe 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.
I-2) Ukuhamba kwedatha ephezulu kwamkela iteknoloji ye-TDMA.
IOLTuthelekisa uluhlu lobhaliso lwe-LLID ngaphambi kokufumana idatha; nganyeI-ONUithumela isakhelo sedatha kwixesha elibekiweyo ngokulinganayo elabelwe izixhobo zeofisi ephakathiOLT; ixesha elibekiweyo (ngokusebenzisa itekhnoloji eqalayo) ihlawulela umgama womgama phakathi kwendawo nganyeI-ONUkwaye uphepha nganyeI-ONUUkungqubana phakathi.