Nyob rau lub caij nyoog no uas internet loj hlob sai, thev naus laus zis fiber optic tau nkag mus rau hauv txhua yam ntawm peb lub neej. Kev sib txuas network ruaj khov thiab ceev ceev yog qhov tseem ceeb txawm tias koj nyiam saib TV yeeb yaj kiab, ua si hauv tsev, lossis ua lag luam ntau yam hauv lub tuam txhab. Ntawm ntau yam thev naus laus zis rau kev nkag mus rau fiber optic, EPON thiab GPON yog qhov zoo tshaj plaws. Niaj hnub no, cia peb kawm txog qhov sib txawv ntawm ob qho thev naus laus zis no ua ke.
Keeb Kwm ntawm Kev Siv Tshuab thiab Cov Txheej Txheem Txheem
EPON, Ethernet passive optical network yog tsim los ntawm Ethernet technology. Nws ua raws li tus qauv IEEE 802.3ah. Tus qauv no tsim kom muaj kev sib txuas zoo thiab sib ze ntawm EPON thiab Ethernet, vim nws siv cov qauv ntawm Ethernet ncaj qha, zoo li muab Ethernet tso rau ntawm "lub tsho tiv no" ntawm kev nkag mus rau fiber optic. Rau cov neeg uas twb paub txog Ethernet technology, kev saib xyuas cov khoom siv EPON, kev tswj hwm network, thiab lwm yam haujlwm zoo li ua haujlwm hauv ib qho chaw paub, yooj yim kawm thiab yooj yim nkag siab. Piv txwv li, hauv lub network hauv tsev kawm ntawv uas twb tau tso cov kab Ethernet dav dav lawm, yog tias xav tau kev hloov kho mus rau fiber optic, EPON technology tuaj yeem ua tiav kev sib koom ua ke nrog cov khoom siv Ethernet uas twb muaj lawm.
GPON, Tus qauv rau Gigabit Passive Optical Networks yog ITU-T G.984 series. Nws siv cov txheej txheem encapsulation nyuaj dua thiab zoo dua - GEM (GPON Encapsulation Method). GEM zoo li lub thawv "cia" ntse uas tuaj yeem npaj thiab ntim ntau hom kev lag luam. Qhov no ua rau GPON ua tau zoo heev hauv kev nqa lag luam, txawm tias nws yog kev hu xov tooj, kev xa cov ntaub ntawv loj, lossis kev ua si video siab, GPON tuaj yeem teb tau yooj yim thiab yooj yim tswj lawv. Hauv kev sib koom ua ke kev pabcuam network uas muab cov neeg siv kev nkag mus rau hauv Is Taws Nem, IPTV thiab VoIP cov kev pabcuam tib lub sijhawm, GPON tuaj yeem tswj hwm thiab xa cov kev pabcuam sib txawv no hauv txoj kev txiav txim siab los ntawm nws cov peev xwm hloov kho kev pabcuam muaj zog, kom ntseeg tau tias txhua qhov kev pabcuam tuaj yeem ua haujlwm ruaj khov thiab ua haujlwm tau zoo.
Kev ceev thiab bandwidth efficiency
Cov nqi uplink thiab downlink ntawm EPON feem ntau yog symmetrical, nrog rau tus nqi ib txwm ntawm 1.25Gbps. Txawm li cas los xij, nyob rau hauv cov txheej txheem kis tau tus mob hauv network, vim yog qhov overhead ntawm Ethernet thav duab, xws li ntau yam kev tswj hwm cov ntaub ntawv nqa thaum pib thiab thaum kawg ntawm thav duab, txawm hais tias cov ntaub ntawv no tseem ceeb rau kev xa thiab ua cov ntaub ntawv kom raug, lawv kuj siv qee cov peev txheej bandwidth, ua rau qhov bandwidth zoo tiag tiag siv rau kev xa cov ntaub ntawv neeg siv qis dua me ntsis ntawm 1.25Gbps nominal.
GPON tseem zoo dua li qhov ceev, nrog rau qhov ceev downlink txog li 2.488Gbps thiab qhov ceev uplink txog li 1.244Gbps lossis 2.488Gbps. GPON siv lub thav duab ntev ntawm 125 μ s thiab muaj cov txheej txheem faib bandwidth zoo. Zoo li ntawm txoj kev loj, GPON tsis yog tsuas yog nthuav dav txoj kab kev xwb, tab sis kuj tseem ua kom cov cai xa tsheb khiav zoo dua, ua rau cov tsheb (cov ntaub ntawv) mus tau yooj yim dua thiab ua haujlwm tau zoo dua. Ua li no, GPON zoo dua EPON hauv kev ua haujlwm bandwidth thiab tuaj yeem xa ntau cov ntaub ntawv hauv tib lub sijhawm.
Qhov sib piv ntawm spectral
Qhov piv ntawm kev faib tawm yog ib qho cim qhia tseem ceeb rau kev ntsuas qhov muaj peev xwm ntawm cov thev naus laus zis fiber optic nkag mus thiab tus naj npawb ntawm cov neeg siv. Nws hais txog qhov sib piv ntawm cov chaw sib txuas lus optical network (ONUs) uas lub davhlau ya nyob twg optical kab (OLT) tuaj yeem txuas rau.
Qhov sib piv ntawm EPON feem ntau yog 1:32, thiab nrog kev kho kom zoo tshwj xeeb, nws tuaj yeem ncav cuag txog 1:64. Qhov no txhais tau tias hauv EPON network, ib lub cuab yeej OLT tuaj yeem txuas mus txog 32, thiab hauv cov xwm txheej hnyav, 64 ONU cov neeg siv khoom. Piv txwv li, hauv kev tsim kho kev nkag mus rau fiber optic hauv thaj chaw nyob, yog tias siv EPON thev naus laus zis thiab qhov sib piv sib cais yog 1:32, ces ib lub cuab yeej OLT tsuas tuaj yeem muab cov kev pabcuam nkag mus rau network rau qhov siab tshaj plaws ntawm 32 tsev neeg.
GPON muaj qhov zoo dua ntawm qhov sib cais piv, nrog rau qhov sib cais piv txog li 1:64, thiab txawm tias nyob rau hauv qee qhov chaw tsim kho thiab ua kom zoo, nws tuaj yeem ua tiav qhov sib cais piv ntawm 1:128. Qhov sib cais piv loj dua ua rau GPON ua tau zoo dua ntawm qhov ntau thiab tsawg ntawm cov neeg siv txuas nrog. Piv txwv li, vim lawv thaj chaw dav thiab kev faib tawm ntawm cov neeg siv sib txawv, yog tias GPON thev naus laus zis raug saws, siv nws cov yam ntxwv optical piv siab, ib lub cuab yeej OLT tuaj yeem muab kev pabcuam rau ntau tus neeg siv, txo cov nqi peev khoom siv thiab txo qhov nyuaj ntawm kev tsim kho network thiab kev saib xyuas.
Tus nqi khoom siv thiab kev sib xws
Cov khoom siv EPON muaj qee qhov zoo ntawm tus nqi vim lawv vam khom rau cov thev naus laus zis Ethernet laus. Nws cov nqi khoom siv qis heev, uas yog qhov zoo heev rau cov haujlwm tsim kho network nrog cov peev nyiaj tsawg thiab kev nkag siab txog tus nqi. Piv txwv li, hauv kev tsim kho network ntawm qee lub lag luam me lossis cov haujlwm kho dua tshiab network ntawm cov chaw nyob qub, vim muaj nyiaj tsawg, qhov zoo ntawm tus nqi qis ntawm cov khoom siv EPON tuaj yeem pom tag nrho. Ntxiv mus, vim muaj kev sib raug zoo zoo ntawm EPON thiab Ethernet, cov khoom siv EPON tuaj yeem yooj yim koom ua ke nrog cov khoom siv network uas twb muaj lawm hauv ib puag ncig uas Ethernet siv dav, tsis tas yuav hloov cov khoom siv loj, txo cov nqi ntawm kev txhim kho network.
Cov khoom siv GPON, vim lawv cov thev naus laus zis nyuaj heev, muaj cov nqi tshawb fawb thiab tsim khoom siab rau cov khoom tseem ceeb xws li cov chips, ua rau cov nqi khoom siv tag nrho siab heev. Txawm li cas los xij, cov khoom siv GPON, nrog lawv cov kev ua tau zoo thiab muaj peev xwm txhawb nqa kev lag luam nplua nuj, tau ua pov thawj tias muaj txiaj ntsig zoo hauv qee qhov xwm txheej uas xav tau kev ua haujlwm siab heev hauv network thiab kev lag luam ntau yam. Piv txwv li, hauv cov chaw lag luam loj, nws yog qhov tsim nyog los ua kom tau raws li cov kev xav tau nkag mus rau hauv network ceev ceev ntawm ntau tus tub luam, muab cov kev pabcuam wireless network ruaj khov rau cov neeg siv khoom, thiab ua tiav ntau yam haujlwm lag luam xws li kev tswj hwm lub tsev ntse. Cov khoom siv GPON tuaj yeem muab kev txhawb nqa txhim khu kev qha rau cov kev xav tau kev lag luam nyuaj no nrog lawv cov kev ua tau zoo heev thiab kev ywj pheej.
Lub sijhawm tshaj tawm: Plaub Hlis-17-2025