Cov tuam txhab sib txuas lus tau pib siv Fiber rau Tsev (FTTH) ua qhov tseem ceeb
Thoob plaws ntiaj teb, ua rau cov thev naus laus zis tsim kho sai. Cov tes hauj lwm kho qhov muag nquag (AON) thiab cov tes hauj lwm kho qhov muag tsis siv neeg (PON) yog ob lub tshuab tseem ceeb uas ua rau kev sib txuas FTTH broadband ua tau. PON uas tuaj yeem muab cov kev daws teeb meem pheej yig dua yog qhov muaj ntau dua hauv feem ntau ntawm FTTH kev xa tawm. ABC ntawm PON yuav raug qhia hauv tsab xov xwm no, uas feem ntau cuam tshuam nrog cov khoom yooj yim thiab cov thev naus laus zis cuam tshuam suav nrog OLT, ONT, ONU, thiab ODN.
Piav Qhia Txog PON: Kev Txhais, Cov Qauv thiab Cov Txiaj Ntsig
Lub network optical passive yog hais txog lub network fiber-optic siv cov topology taw tes-rau-multipoint thiab optical splitters los xa cov ntaub ntawv los ntawm ib qho chaw xa mus rau ntau tus neeg siv kawg. Sib piv rau AON, ntau tus neeg siv khoom txuas nrog ib qho transceiver los ntawm kev siv cov ceg ntoo ntawm cov fibers thiab passive splitter / combiner units, ua haujlwm tag nrho hauv thaj chaw optical thiab tsis muaj hwj chim hauv PON architecture. Muaj ob qho tseem ceeb PON qauv tam sim no: Gigabit Passive Optical Network (GPON) thiab Ethernet Passive Optical Network (EPON). Lawv cov qauv topology yeej zoo ib yam. Raws li qhov kev xaiv thawj zaug hauv ntau qhov xwm txheej FTTH xa tawm, PON kev daws teeb meem muaj ntau qhov txiaj ntsig zoo:
Kev Siv Hluav Taws Xob Tsawg Dua
Qhov Chaw Xav Tau Tsawg Dua
Bandwidth siab dua
Kev Ruaj Ntseg Qib Siab Dua
Yooj yim dua rau nruab thiab nthuav dav
Txo Cov Nqi Ua Haujlwm thiab Kev Tswj Xyuas
PON Cov Qauv thiab Cheebtsam
Hauv Gigabit Ethernet Passive Optical Network (GEPON) system, muaj ib lub optical line terminal (OLT) ntawm lub chaw ua haujlwm hauv nruab nrab ntawm tus neeg muab kev pabcuam thiab ntau lub optical network units (ONUs) lossis optical network terminals (ONTs) ze rau cov neeg siv kawg, nrog rau lub optical splitter (SPL). Tsis tas li ntawd, lub optical distribution network (ODN) kuj tseem siv thaum lub sijhawm xa ntawm OLT thiab ONU/ONT.
Lub Rooj Sib Tham Txog Kab Optical (OLT)
OLT yog qhov pib rau lub network passive optical, uas txuas nrog lub core switch los ntawm Ethernet cables. Lub luag haujlwm tseem ceeb ntawm OLT yog hloov, thav duab, thiab xa cov teeb liab rau PON network thiab los sib koom tes cov optical network terminals multiplexing rau kev sib koom upstream transmission. Feem ntau, cov khoom siv OLT muaj rack, CSM (Control and Switch Module), ELM (EPON Link Module, PON card), redundancy protection -48V DC power supply modules, lossis ib qho 110/220V AC power supply module, thiab kiv cua. Hauv cov khoom no, daim npav PON thiab lub zog txhawb nqa hot-swap thaum lwm lub module tau tsim sab hauv. OLT muaj ob txoj kev taw qhia: upstream (tau txais kev faib tawm ntau hom ntaub ntawv thiab suab tsheb los ntawm cov neeg siv) thiab downstream (tau txais cov ntaub ntawv, suab, thiab video tsheb los ntawm lub network metro lossis los ntawm lub network ntev thiab xa mus rau txhua lub ONT modules ntawm ODN.) Qhov deb tshaj plaws txhawb nqa rau kev xa hla ODN yog 20 km.
Chav Optical Network (ONU) / Chaw Nres Tsheb Optical Network (ONT)
ONU hloov cov teeb liab pom kev uas xa los ntawm cov fibers mus rau cov teeb liab hluav taws xob. Cov teeb liab hluav taws xob no ces raug xa mus rau cov neeg sau npe ib leeg. Feem ntau, muaj qhov deb lossis lwm qhov kev nkag mus rau hauv network ntawm ONU thiab cov neeg siv kawg lub tsev. Ntxiv mus, ONU tuaj yeem xa, sib sau ua ke, thiab kho ntau hom ntaub ntawv los ntawm cov neeg siv khoom thiab xa nws mus rau OLT. Kev kho kom zoo yog cov txheej txheem uas ua kom zoo dua thiab rov kho cov ntaub ntawv kom nws xa tau zoo dua. OLT txhawb nqa kev faib bandwidth uas tso cai rau kev xa cov ntaub ntawv kom du mus rau OLT, uas feem ntau tuaj txog hauv bursts los ntawm cov neeg siv khoom. ONU tuaj yeem txuas nrog ntau txoj hauv kev thiab hom cable, zoo li twisted-pair tooj liab hlau, coaxial cable, optical fiber, lossis los ntawm Wi-Fi.
Cov khoom siv kawg rau cov neeg siv kuj tseem yuav raug xa mus rau lub davhlau ya nyob twg optical network (ONT). Qhov tseeb, ONT zoo ib yam li ONU hauv qhov tseem ceeb. ONT yog lo lus ITU-T, thaum ONU yog lo lus IEEE. Koom nrog cov qauv sib txawv, lawv ob leeg xa mus rau cov khoom siv sab neeg siv hauv GEPON system. Tab sis hauv kev xyaum, muaj qhov sib txawv me ntsis ntawm ONT thiab ONU raws li lawv qhov chaw nyob.
Kev Sib Txuas Lus Txog Kev Faib Khoom Siv Optical (ODN)
ODN, yog ib feem tseem ceeb ntawm lub kaw lus PON, muab cov khoom siv xa hluav taws xob rau kev sib txuas ntawm ONUs rau OLTs nrog 20 km lossis deb dua. Hauv ODN, cov xov hlau fiber optic, cov khoom sib txuas fiber optic, cov khoom sib cais passive optical, thiab cov khoom pabcuam koom tes ua ke. ODN muaj tsib ntu uas yog cov fiber feeder, qhov chaw faib khoom optical, qhov chaw faib khoom fiber, qhov chaw nkag mus rau optical, thiab qhov chaw poob fiber. Cov fiber feeder pib los ntawm lub thav duab faib khoom optical (ODF) hauv chav sib txuas lus hauv chaw ua haujlwm hauv chaw ua haujlwm thiab xaus rau ntawm qhov chaw faib khoom optical rau kev them nqi ntev. Cov fiber faib khoom los ntawm qhov chaw faib khoom optical mus rau qhov chaw nkag mus rau optical faib cov fiber rau thaj chaw ib sab ntawm nws. Cov fiber poob txuas qhov chaw nkag mus rau optical rau cov davhlau ya nyob twg (ONTs), ua tiav cov fiber poob rau hauv cov tsev neeg siv. Tsis tas li ntawd, ODN yog txoj hauv kev tseem ceeb rau kev xa cov ntaub ntawv PON thiab nws qhov zoo cuam tshuam ncaj qha rau kev ua tau zoo, kev ntseeg siab, thiab kev nthuav dav ntawm PON system.
Xaus lus
OLT, ONU lossis ONT, thiab ODN yog cov khoom tseem ceeb hauv GEPON system, uas tau siv dav hauv FTTH daim ntawv thov los ntawm deb. Cov khoom siv cabling txo qis (tsis muaj cov khoom siv nquag) thiab kev xa xov xwm yooj ywm pab txhawb rau cov tes hauj lwm optical passive zoo tagnrho rau kev siv Is Taws Nem hauv tsev, suab, thiab video. Tsis tas li ntawd, cov tes hauj lwm optical passive kuj tseem tuaj yeem siv rau hauv cov tsev kawm qib siab thiab cov chaw ua lag luam, muab cov kev daws teeb meem pheej yig. Raws li PON thev naus laus zis tau txuas ntxiv txhim kho, cov ntawv thov muaj peev xwm tau nthuav dav thiab.
Lub sijhawm tshaj tawm: Lub Rau Hli-14-2022