Raws li txoj kev sib txuas lus zoo uas feem ntau siv.EPON yog siv los ntawm cov neeg siv los txuas rau lub network nkag.Hauv daim ntawv no, cov thev naus laus zis tseem ceeb ntawm EPON tau piav qhia luv luv, thiab daim ntawv thov ntawm EPON hauv kev sib txuas lus kho qhov muag tau qhia meej, thiab nws cov txheej txheem kev tshuaj xyuas.
1.Covikev taw qhiantawm EPON
PON yog ib qho kev cog lus ntawm Passive Optical Network, uas yog kev siv tshuab kho qhov muag tau tsim los txhawb kev siv point-to-multipoint.PON muaj xws li Optical Line Terminal (OLT), Optical Network Unit (ONU) thiab Optical Distribution Network (ODN). Qhov tseem ceeb feature yog ODN yog tag nrho cov tsim los ntawm passive li, thiab lub teeb liab yog dispersed los ntawm ib tug ib tug sib koom kho qhov muag fiber ntau rau txhua tus neeg siv los ntawm ib tug splitter.Qhov system no hu ua Passive Optical Network vim nws txawv ntawm cov tsoos kev twb kev txuas ntawm lub hauv paus. Chaw ua haujlwm thiab cov neeg siv khoom, thiab cov khoom siv hluav taws xob hauv nruab nrab ntawm qhov kev nkag mus rau hauv lub network. Ntxiv rau qhov zoo ntawm kev txuag cov khoom siv fiber ntau, PON tuaj yeem ua kom yooj yim rau kev khiav lag luam thiab kev saib xyuas ntawm lub network, uas yog qhov zoo heev hauv kev txo nqi kev tsim kho thiab kev ua haujlwm. , cov qauv ntawm cov khoom siv kho qhov muag ntshiab thiab pob tshab optical fiber broadband network ua kom muaj kev ruaj ntseg ntawm kev lag luam yav tom ntej.
EPON thev naus laus zis ua ke nrog Ethernet thev naus laus zis nrog PON thev naus laus zis kom paub txog point-to-multipoint high-speed Ethernet fiber ntau nkag mus rau hauv txoj kev yooj yim.Lub point-to-multipoint topology yog cov qauv qauv siv los ntawm EPON, thaum lub sij hawm tshaj tawm hom yog siv rau downlink. thiab TDMA hom yog siv rau upline, uas tuaj yeem paub txog ob txoj kev xa cov ntaub ntawv.
2.Composition ntawm EPON
Raws li ib qho point-to-multipoint fiber ntau nkag tshuab, Passive Optical Network (PON) muaj lub zos Optical Line Terminal (OLT), user-side Optical Network Unit (ONU) thiab Optical Distribution Network (ODN).
2.1 TSI
Feem ntau, OLT tau muab tso rau hauv chav tshuab nruab nrab.Nws muab kev zam txim rau fiber ntau rau kev siv kho qhov muag tsis pom kev nyob rau hauv qhov kev taw qhia downward, GE, 10baes-t, 100base-t, 10gbase-x thiab lwm yam kev cuam tshuam nyob rau sab saud, thiab OLT txhawb EI interface kom paub txog TDM lub suab nkag.
2.2 ONU/ONT
ONU/ONT tau muab tso rau hauv cov neeg siv kawg, feem ntau yog siv Ethernet raws tu qauv kom paub meej kev hloov pauv ntawm cov neeg siv cov ntaub ntawv.Cov ntaub ntawv tuaj yeem xa mus ntawm OLT thiab ONU.
2.3 PAB
Raws li ib tug passive fiber ntau ceg, ODN txuas cov khoom passive ntawm OLT thiab ONU.Lub luag haujlwm tseem ceeb ntawm ODN yog txhawm rau faib cov ntaub ntawv downlink thiab centralize uplink cov ntaub ntawv.Vim tias nws yog kev ua haujlwm dhau los, kev xa tawm passive splitter yog qhov hloov tau yooj yim thiab tsim nyog rau ntau qhov chaw.In common sense, txhua POS muaj qhov sib faib ntawm 8, 16, 32. los yog 64, thiab tuaj yeem txuas nrog ntau theem.
3.Ibkev taw qhiaof key ttshuabof EPON
3.1Dbasfor dynamicbthiab davaqhov chaw nyob
Real-time (ms / us magnitude) hloov qhov uplinking bandwidth mechanism ntawm txhua OUN ntawm EPON, lub npe hu ua dynamic bandwidth allocation algorithm.In EPON, yog hais tias lub bandwidth yog faib statically, ces qhov kis tus nqi kev pab cuam rau cov ntaub ntawv kev sib txuas lus yog heev tsis tsim nyog. bandwidth yog faib nyob rau hauv lub ncov ceev ceev, tag nrho cov system bandwidth yuav tag nrho nyob rau hauv ib tug luv luv lub sij hawm.W tus nqi ntawm bandwidth tsis siab, ntawm qhov tod tes, dynamic bandwidth faib yuav txhim kho lub bandwidth siv system.Sudden kev pab cuam yuav tsum tau ONU tuaj yeem pom tau los ntawm DBA.Dynamic bandwidth hloov ntawm ONU tuaj yeem txhim kho qhov ua tau zoo ntawm PON upline bandwidth.Vim qhov kev txhim kho ntawm kev siv bandwidth efficiency, ntau W cov neeg siv tuaj yeem ntxiv rau ntawm PON uas twb muaj lawm, thiab qhov bandwidth ncov tus nqi uas W cov neeg siv tuaj yeem ncav cuag tau piv rau lossis txawm. tshaj lub bandwidth ntawm cov tsoos uniform faib txoj kev.
Centralized tswj yog ib txoj kev ntawm dynamic bandwidth allocation.Txoj kev no yog rau tag nrho cov ONU uplink lus, yog siv rau OLT rau bandwidth, ces OLT raws li qhov kev thov ntawm lub ONU tso cai raws li qhov cuam tshuam algorithm rau broadband accounted rau W.The Lub tswv yim tseem ceeb ntawm kev faib cov txheej txheem algorithm yog tias txhua ONU lee uplink tuaj yeem faib lub sijhawm faib khoom ntawm tes tuaj txog thiab thov bandwidth.Raws li qhov kev thov ntawm txhua ONU, OLT faib cov bandwidth ncaj ncees thiab tsim nyog, thiab tuav cov txheej txheem ntau dhau, cov ntaub ntawv yuam kev, xov tooj ntawm tes. poob, etc.
3.2Rov qab siv thev naus laus zis ntawm uplink channel
Tam sim no, qhov kev siv tseem ceeb yog lub sij hawm faib ntau yam kev nkag multiplexing (TDMA), uas tuaj yeem siv tib lub sij hawm qhov sib faib lub sij hawm faib multiplexing, statistical time division multi access multiplexing, random access and so on.Txawm li cas los xij, M – time – slot time - faib multiplexing muaj qee qhov shortcomings.Piv txwv li, thaum qee lub sijhawm tsis siv, nws nyob ntawm qee qhov bandwidth, kom lub siab tawg qhov kev pabcuam adaptability tsis muaj zog txaus.Lub ONU xav tau synchronization thiab lwm yam kev nkag mus tsis tau. Qee lub sij hawm nkag mus.Yog li ntawd, kev txheeb xyuas lub sij hawm faib ntau qhov kev nkag multiplexing feem ntau yog siv tom qab sib piv qhov tsis txaus ntawm ob.Thaum lub teeb liab uplink raug xa mus, Ethernet thav duab raug xa mus rau lub sijhawm uas ONU tau faib, thiab qhov loj ntawm cov ntaub ntawv muab los ntawm kev txheeb cais multiplexing yog siv los hloov qhov loj ntawm lub sijhawm.
3.3 OLT qhov sib txawv thiab ncua sij hawm them nyiaj thev naus laus zis thiab ONU plug-and-play thev naus laus zis
Vim tias cov dej ntws ntws ntawm EPON SIV TDMA, ntau lub ntsiab lus nkag ua rau cov ntaub ntawv ncua sij hawm ntawm txhua ONU sib txawv, yog li kev sib tw thiab ncua sij hawm them nyiaj thev naus laus zis tau qhia los tiv thaiv kev sib tsoo ntawm cov ntaub ntawv hauv lub sijhawm. Cov ntaub ntawv sau npe, ntsuas qhov deb thiab lub sijhawm ncua sij hawm them nyiaj thev naus laus zis yuav tsum tau siv los synchronize tag nrho lub sijhawm network sib txawv.Qhov no, cov pob ntawv tuaj txog ntawm lub sijhawm teev tseg raws li DBA algorithm thiab txhawb nqa ntsaws thiab ua si rau ONU.Kev ntsuas qhov deb ntawm txhua qhov. ONU rau OLT kom raug thiab kho qhov kev ncua sij hawm ntawm ONU qhov tseeb tuaj yeem txo qhov ncua sij hawm ntawm kev xa Windows ntawm ONU, txhim kho kev siv uplink channel thiab txo qhov ncua sij hawm.Lub EPON ntau yam yog pib thiab ua tiav tib lub sijhawm uas OLT hla, cim tib lub sijhawm uas lub ntsaws thiab ua si ntawm ONU raug kuaj pom.
3.4Xa thiab tau txais cov teeb liab tawg
Txij li thaum lub teeb liab tawg ntawm txhua ONU tau txais los ntawm OLT, OLT yuav tsum paub txog theem synchronization rau lub sijhawm thiab tom qab ntawd tau txais cov ntaub ntawv.Qhov no yuav tsum tau siv cov khoom siv kho qhov muag uas muaj peev xwm los txhawb cov teeb liab tawg hauv ONU thiab OLT.Feem ntau cov khoom siv kho qhov muag tsis tuaj yeem ntsib. qhov yuav tsum tau muaj, thiab ib tug me me ntawm burst hom optical pab kiag li lawm muaj ib tug ua hauj lwm ceev ntawm txog 155M, uas yog kuj siab nyob rau hauv nqe. Yog li ntawd, thiaj li yuav paub burst hom zoo dua, tshwj xeeb cov tswv yim yog siv rau qhov kawg tau txais.Lub optical tawg kis tau tus mob yuav tsum tau kaw thiab qhib sai heev thiab tsim cov teeb liab sai sai.Yog li ntawd, cov tsoos electro-optical conversion module siv tsis siv neeg lub hwj chim tswj nrog tawm tswv yim yog tsis tsim nyog rau kev siv, tab sis yuav tsum tau lasers nrog ceev teb. txais qhov kawg tau txais lub teeb liab lub teeb lub zog ntawm txhua tus neeg siv yog qhov sib txawv thiab txawm tias ntau qhov sib txawv.Yog li ntawd, nyob rau hauv qhov tawg tau txais Circuit Court, qhov tau txais qib (threshold) yuav tsum tau hloov kho txhua zaus tau txais lub teeb liab tshiab.
4.Application ntawm fiber optic kev sib txuas lus hauv cell
ONU tuaj yeem teeb tsa rau ntawm tus neeg siv khoom (FTTH) lossis ntawm txoj kev hauv tsev (FTTB), tab sis qhov no yog nyob rau hauv cov ntaub ntawv nkag mus.In FTTH hom, tus naj npawb ntawm cov neeg siv tsis paub meej.Nyob rau hauv rooj plaub no, txhawm rau txhim kho qhov kev siv ntawm cov khoom siv, txo cov nqi thiab ua kom yooj yim txij nkawm.Qhov chaw ntawm cov khoom siv kho qhov muag yog qhov tseem ceeb, thiab kev siv cov qib ntawm lub teeb faib, qhov chaw ntawm ntau yam hauv lub computer. chav tsev ntawm lub zej zog los yog lub zej zog nyob rau hauv lub teeb handover box.Tom qab kev tsim kho nyob rau hauv xws li ib txoj kev, tsis hais tus naj npawb ntawm cov neeg siv nce los yog txo, kev siv cov cuab yeej siv tau ntau tshaj.Txawm li cas los xij, thaum tus naj npawb ntawm cov neeg siv loj, qhov kev xav tau rau kev nkag mus rau optical fiber ntau kuj yuav nce ntau.Thaum nyob rau hauv FTTB hom, OMU tau teeb tsa rau hauv txoj kev hauv tsev, thiab cov optical splitter tau teeb tsa tib yam li FTTH.Hom kev nkag no feem ntau yog ua nyob rau hauv txoj kev hloov pauv.
Xaus
EPON thev naus laus zis muaj ntau yam zoo, xws li kev siv dav dav ntawm cov neeg siv, kev kub ceev ntawm cov dej ntws thiab qis qis, cov yam ntxwv ntawm kev sib kis tau zoo, txuag cov khoom siv fiber ntau los ntawm taw tes mus rau ntau qhov kev sib txuas lus thiab lwm yam -theem kev ua haujlwm tsim qauv tsim qauv, tab sis kuj muaj qhov tsis zoo, tsis muaj hluav taws xob hluav taws xob hluav taws xob txuag hluav taws xob thiab kev tiv thaiv ib puag ncig.Raws li kev sib txuas lus kho qhov muag, EPON thev naus laus zis yog qhov tseem ceeb. ntawm qhov muaj zog adaptability rau qhov chaw xa mus, muaj kev ntseeg siab thiab tsis muaj kev saib xyuas, dhau los ua qhov kev xaiv zoo tshaj plaws rau kev tsim kho ntawm cov tiam tom ntej broadband nkag network.