PON yog cov lus luv ntawm passive optical network, uas tsuas yog siv cov tshuaj fiber thiab passive zoo li fiber ntau splitter thiab combiner. EPON （Ethernet PON) thiab GPON (Gigabit PON) yog qhov tseem ceeb tshaj plaws ntawm cov phiaj xwm kho qhov muag, siv dav rau kev nkag mus rau hauv Internet, lub suab hla Internet raws tu qauv (VoIP), thiab digital TV xa tawm hauv cov nroog loj. Hnub no peb yuav los tham txog qhov sib txawv ntawm EPON thiab GPON.
Tshuab Sib Piv ntawm EPON thiab GPON
EPON ua raws li Ethernet tus qauv 802.3 tuaj yeem txhawb qhov nrawm ntawm 1.25 Gbit / s hauv ob qho tib si hauv nqes thiab nqes los. Nws yog qhov paub zoo tias kev daws teeb meem rau "thawj mais" qhov kho qhov muag txuas network. Thaum GPON, raws li Gigabit thev naus laus zis, tau xaiv raws li ITU-T G.983 uas tuaj yeem muab rau 622 Mbit / s nqes dej thiab 155 Mbit / s ntws los. GPON yog txoj kev tseem ceeb los ua kom muaj kev pabcuam nkag tau rau cov kev pabcuam. Nws cov kev cai tau tsim los ntawm pab pawg Full Service Access Network (FASN), uas tom qab tau txais los ntawm ITU-T ua G.984.x tus qauv – ntxiv rau ITU-T kev pom zoo, G.983, uas paub meej broadband PON ( BPON).
Raws li seem ntawm PON, lawv muaj qee yam sib xws. Piv txwv li, nkawd ob leeg tuaj yeem lees txais raws li thoob ntiaj teb cov qauv, npog tib lub network topology txoj kev siv thiab FTTx kev siv, thiab siv WDM (wavelength-division multiplexing) nrog tib lub ntsej muag sib xws nrog lwm tus sab nraud wavelength; thiab muab triple-ua si, Internet Protocol TV (IPTV) thiab cable TV (CATV) cov kev pabcuam video.
Cov Nqi Sib Piv
Tsis muaj teeb meem nyob rau hauv GPON lossis hauv EPON, qhov kho qhov muag kab davhlau ya nyob twg (OLT), optical network unit (ONU) thiab optical faib network (ODN) yog qhov tsis muaj qhov tseem ceeb, uas yog qhov txiav txim siab ntawm tus nqi ntawm GPON thiab EPON kev faib tawm.
Tus nqi ntawm OLT thiab ONT yog pawg los ntawm ASIC (thov kev siv hluav taws xob tshwj xeeb) thiab optic module. Tsis ntev los no, cov chipsets ntawm GPON feem ntau yog ua raws FPGA (thaj chaw-programmable rooj vag array), uas yog kim tshaj EPON MAC txheej ASIC. Ntawm qhov tod tes, optic module tus nqi ntawm GPON kuj tseem siab dua EPON's. Thaum GPON mus txog theem kev xa tawm, kwv yees tus nqi ntawm GPON OLT yog 1.5 mus rau 2 zaug siab dua EPON OLT, thiab tus nqi kwv yees GPON ONT yuav yog 1.2 rau 1.5 npaug siab dua ntawm EPON ONT.
Peb txhua tus paub tias ODN yog tsim los ntawm fiber ntau cable, txee, kho qhov muag splitter, txuas, thiab lwm yam. Nyob rau hauv cov ntaub ntawv ntawm kev xa cov paib mus rau tib tus naj npawb ntawm cov neeg siv, tus nqi ntawm EPON thiab GPON yuav zoo ib yam.
Ntsiab lus
Tam sim no, vim ntau tus kws tshaj lij muaj cov kev xav sib txawv ntawm EPON thiab GPON. Yog li, tsis muaj lus teb meej meej los txiav txim seb qhov twg zoo dua. Tab sis ib qho yog qhov tseeb: PON, uas muaj cov nqi qis ntawm qhov sib txig sib luag, tau ua rau muaj zog loj uas tau tsav los ntawm qhov kev xav tau nce zuj zus mus rau kev siv Is Taws Nem sai dua thiab muaj video ntau. Tsis tas li, kev siv fiber ntau yuav txuas ntxiv nthuav dav ntawm kev siv tooj liab, raws li cov neeg siv khoom xav tau "ua peb zaug ua si" (yeeb yaj kiab, suab thiab cov ntaub ntawv) loj hlob.