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 suav nrog Optical Line Terminal (OLT), Optical Network Unit (ONU) thiab Optical Distribution Network (ODN).Nws tseem ceeb feature yog tias ODN yog tag nrho cov tsim ntawm passive li, thiab cov 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 yog qhov sib txawv ntawm cov kev sib txuas ib txwm nyob ntawm lub hauv paus chaw ua haujlwm thiab cov neeg siv khoom, thiab cov khoom siv hluav taws xob yog nyob nruab nrab ntawm qhov kev nkag mus rau hauv lub network. Ntxiv rau qhov zoo ntawm kev txuag fiber ntau, PON tuaj yeem ua kom yooj yim rau kev khiav hauj lwm thiab kev saib xyuas lub network, uas yog zoo heev hauv kev txo cov nqi tsim kho thiab kev ua haujlwm.Ntxiv mus, cov qauv ntawm cov ntshiab optical media 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 qhov point-to-multipoint fiber ntau nkag tshuab, Passive Optical Network (PON) muaj cov kab hluav taws xob hauv cheeb tsam Optical Line Terminal (OLT), user-side Optical Network Unit (ONU) thiab Optical Distribution Network (ODN).
2.1OLT
Feem ntau,OLTyog muab tso rau hauv lub hauv paus tshuab chav tsev. Nws muab kev zam txim rau fiber ntau rau kev sib txuas lus kho qhov muag nyob rau hauv nqe lus nqes, GE, 10baes-t, 100base-t, 10gbase-x thiab lwm yam kev cuam tshuam nyob rau hauv kev nce siab, thiabOLTtxhawb EI interface kom paub TDM lub suab nkag.
2.2ONU/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 ntawmOLTthiabONU.
2.3 PAB
Raws li ib tug passive fiber ceg, ODN txuas cov khoom passive ntawmOLTthiabONU. 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 kev siv ntawm lub system.Sudden kev pab cuam yuav tsum tau.ONUtuaj yeem pom tau los ntawm DBA. Dynamic bandwidth hloov ntawmONUtuaj 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 muab ntxiv rau ntawm PON uas twb muaj lawm, thiab qhov bandwidth ncov tus nqi uas W cov neeg siv tuaj yeem ncav cuag tuaj yeem sib piv los yog ntau tshaj qhov bandwidth ntawm lub txoj kev faib nyiaj ib txwm siv.
Centralized tswj yog ib txoj kev ntawm dynamic bandwidth faib.Qhov no yog rau tag nrho covONUuplink lus, yog siv rauOLTrau bandwidth, cesOLTraws li kev thov ntawm lubONUkev tso cai raws li qhov cuam tshuam algorithm rau broadband suav nrog W.Lub tswv yim tseem ceeb ntawm kev faib cov txheej txheem algorithm yog tias txhua ONU lee uplink tuaj yeem faib lub sijhawm faib ntawm cov xov tooj ntawm tes tuaj txog thiab thov bandwidth.Raws li qhov kev thov ntawm txhua tus.ONU, OLTallocates bandwidth ncaj ncees thiab tsim nyog, thiab tswj cov txheej txheem overload, ntaub ntawv yuam kev code, cell poob, thiab lwm yam.
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 lub sijhawm, nws nyob ntawm qee qhov bandwidth, kom lub siab tawg qhov kev pabcuam adaptability tsis muaj zog txaus.ONUxav tau synchronization thiab lwm yam random access txoj kev yam tsis muaj lub sij hawm nkag tau yooj yim.Yog li ntawd, statistical time division multi access multiplexing feem ntau yog siv tom qab sib piv qhov tsis txaus ntawm ob.Thaum lub teeb liab uplink kis tau, Ethernet thav duab raug xa mus rau hauv lub sij hawm slot rau qhov twg. tusONUyog 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 ntau thiab ncua kev them nyiaj thev naus laus zis thiabONUplug-and-play technology
Vim tias cov dej ntws ntws ntawm EPON siv TDMA, ntau qhov kev nkag mus ua rau cov ntaub ntawv ncua sij hawm ntawm txhua tusONUsib txawv, yog li qhov sib txawv 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 sau npe.Yuav kom tsis txhob muaj kev sib tsoo ntawm lub sijhawm sau cov ntaub ntawv, kev ntsuas qhov deb thiab lub sij hawm ncua sij hawm them nyiaj thev naus laus zis yuav tsum tau siv los synchronize tag nrho lub sijhawm sib txawv network. Ua li no, pob ntawv tuaj txog ntawm lub sijhawm teev tseg raws li DBA algorithm thiab txhawb nqa ntsaws thiab ua si rauONU.Kev ntsuas qhov deb ntawm txhua qhovONUto OLTraug thiab kho qhov kis tau tus mob ncua ntawmONUprecisely tuaj yeem txo lub sijhawm nruab nrab ntawm qhov xa Windows ntawmONU, txhim kho kev siv cov uplink channel thiab txo qhov ncua sij hawm.Qhov kev sib tw EPON yog pib thiab ua tiav tib lub sijhawm uas covOLTdhau, cim tib lub sijhawm uas lub ntsaws thiab ua si ntawm lubONUkuaj pom.
3.4Xa thiab tau txais cov teeb liab tawg
Txij li thaum lub teeb liab tawg ntawm txhua tusONUtau txais los ntawmOLT, OLTyuav tsum tau paub txog theem synchronization rau ib lub sij hawm ntawm lub sij hawm 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 txhawb nqa cov teeb liab tawg hauvONUthiabOLT.Feem ntau cov khoom siv kho qhov muag tsis tuaj yeem ua tau raws li qhov yuav tsum tau ua, thiab ib qho me me ntawm qhov tawg hom kho qhov muag muaj qhov ua haujlwm ceev ntawm li 155M, uas yog tus nqi siab heev.Yog li ntawd, txhawm rau kom paub qhov tawg hom tau zoo dua, cov txheej txheem tshwj xeeb yog siv rau cov khoom siv kho qhov muag. txais kawg. 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
CovONUtuaj 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 hauv tsevhloov.
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.