EPON Thiab GPON Ntawm Passive Optical Network
PON (Passive Optical Network) yog hais txog lub tshuab xa khoom hluav taws xob tsis muaj cov khoom siv hluav taws xob thiab lub zog siv hluav taws xob, cov faib hluav taws xob (ODN) tag nrho los ntawm cov kho qhov muag thiab lwm qhov sib xyaw, tsis tas yuav siv cov khoom siv hluav taws xob kim, yog ib hom kev fiber ntau-optic nkag network. PON txo cov nqi ntawm cov khoom siv fiber ntau thiab cov chaw ua haujlwm hauv chaw ua haujlwm nruab nrab piv nrog cov taw tes-taw qhia.
Ib qho PON muaj qhov kho qhov muag kab davhlau ya nyob twg (OLT) ntawm qhov chaw pabcuam chaw ua haujlwm thiab tus lej ntawm cov network kho qhov muag (ONUs) ze rau cov neeg siv tag. Hauv OLT / ONU nruab nrab ntawm cov khoos phib tawj faib tawm muaj xws li cov fiber ntau thiab passive optical splitter lossis Fiber Optic Coupler.
OLT
Ib qho OLT, feem ntau Ethernet hloov, router, lossis multimedia hloov chaw, yog nyob rau hauv lub hauv paus chaw ua haujlwm (CO) ua cov khoom tseem ceeb ntawm EPON system los muab cov ntaub ntawv tseem ceeb thiab video-to-phone network cuam tshuam rau EPON thiab kev pabcuam chaw muab kev pab.
ONU
ONUs yog siv los txuas cov khoom lag luam rau cov neeg siv khoom, xws li PCs, lub npov saum txheej (STBs), thiab cov ntsuas hloov. Feem ntau tso rau ntawm cov qhua tuaj noj mov hauv tsev, txoj kev hauv tsev, lossis txoj kev tsheb, ONUs yog lub luag haujlwm tseem ceeb rau kev xa cov ntaub ntawv uplink xa los ntawm cov khoom siv khoom thauj khoom (los ntawm ONU rau OLT) thiab xaiv tau txais kev tshaj tawm xov tooj cua xa mus los ntawm OLTs (los ntawm OLT rau ONU).
ODN
Ib qho ODN muaj cov khoom siv kho qhov muag, ib lossis ntau qhov kev sib txuas ntawm qhov kho qhov muag (POSs), thiab lwm yam passive kho qhov muag. ODNs muab cov phiaj xwm xa khoom sib kis ntawm OLTs thiab ONUs. Lub POS tuaj yeem ua ke yplink cov ntaub ntawv mus rau hauv ib qho ntawm cov fiber ntau thiab faib cov ntaub ntawv downlink rau cov ONUs.
Muaj ob lub tshuab pa hluav taws xob (passive optical network technologies): Ethernet PON (EPON) thiab gigabit PON (GPON). EPON thiab GPON tau thov nyob rau qee lub sijhawm sib txawv, thiab txhua tus nyias muaj nyias qhov zoo hauv kev nkag mus rau cov neeg siv khoom. EPON tsom rau kev thov FTTH thaum GPON tsom rau tag nrho cov kev pabcuam kev pabcuam, suav nrog cov kev pabcuam tshiab thiab cov kev pabcuam qub uas muaj nyob rau hauv xws li ATM thiab TDM.
EPON yog qhov Passive Optical Network uas nqa Ethernet thav ntawv encapsulated hauv 802.3 tus qauv. Nws yog kev sib txuas ntawm Ethernet thev naus laus zis thiab PON thev naus laus zis ua raws IEEE 802.3ah tus qauv tso tawm thaum Lub Rau Hli, 2004. Ib qho qauv EPON li qub muaj peb ntu: EPON OLT, EPON ONU thiab EPON ODN. Nws muaj ntau yam zoo, xws li kev ua haujlwm qis thiab txij nkawm nqi, kom deb ntawm qhov ntev thiab ntau daim bandwidth.
GPON siv cov ntsiab lus-rau-ntau sib xws. GPON cov qauv sib txawv ntawm lwm PON cov qauv hauv qhov ntawd nws ua tiav ntau dua cov kab thiab cov peev txheej siab dua uas siv cov ntim loj, kuj sib txawv thiab ntev. Thiab GPON feem ntau suav tias yog tus neeg muaj zog tshaj plaws rau kev faib tawm ntau. GPON muaj qhov nqes hauv qab ntawm 2.488 Gb / s thiab qhov peev xwm nce ntawm 1.244 Gbp / s uas tau sib koom nrog cov neeg siv.
Tseem muaj ntau yam sib txawv ntawm EPON thiab GPON. EPON, raws li Ethernet thev naus laus zis, ua tau raws IEEE 802.3ah Ethernet hauv thawj Mile txuj uas tam sim no sib koom ua ke rau IEEE Txuj 802.3-2005. Nws yog txoj kev daws teeb meem rau "thawj mais" qhov kho qhov muag siv tau. Ntawm qhov tod tes GPON, yog qhov kev qhia tseem ceeb los ua kom muaj kev pabcuam puv ntoob rau kev koom tes. Nws cov kev xav tau raug tsim los ntawm pab pawg Full Service Access Network (FASN), uas tom qab tau txais los ntawm ITU-T ua G.984.x cov qauv – ntxiv rau ITU-T kev pom zoo, G.983, uas paub meej broadband PON ( BPON).
Ob EPON thiab GPON tau lees txais raws li cov qauv thoob ntiaj teb. Lawv npog tib lub network topology cov hau kev thiab FTTx kev siv, sib xyaw ua ke WDM thev naus laus zis, xa tib lub yoj yob ob qho tib si ntws tawm sab hauv thiab sab saud ua ke nrog rau lwm tus neeg thib peb lub yoj. PON thev naus laus zis muab kev ua si peb zaug, Kev Tshaj Tawm Internet TV (IPTV) thiab TV cable (CATV) cov kev pabcuam video.
