Lub sijhawm no, cov neeg uas mob siab rau kev tsim kho ntawm IEEE802.3 yuav tsis muaj teeb meem ntxiv los ntawm qhov tsis muaj kev sib kis, vim tias ntau ntau ntawm cov kev sib tw daws tau tam sim no tau tsim lossis qauv. Tam sim no xav txog yav dhau los: tsis yog txhua txoj kev daws teeb meem tuaj yeem ua tiav kev lag luam tiav.
Nyob rau hauv thaj chaw ib puag ncig no, cov neeg siv zoo li muaj "tos thiab pom" tus cwj pwm vim tias nws tsis tuaj yeem piav qhia yog vim li cas cov leeg qaum tseem tseem khiav ntawm ib ncig 10G. Lub tshuab no nyuam qhuav hloov pauv txij xyoo 2002. Ua tsaug rau txoj kev txhim kho ntawm cov thev naus laus zis tshiab, lub caj qaum network txuas thaum kawg tuaj yeem hloov-los ntawm txoj kev faib wavelength faib multiplexing technology ntawm multimode fiber. Hauv qab no yuav piav qhia qhov kev cia siab ntawm cov thev naus laus zis tshiab.
Peb puas muaj lub network kho qhov muag cov nyiaj tau los?
Cov ntaub ntawv tooj liab, uas feem ntau pom tias muaj peev xwm xa cov khoom hluav taws xob tsawg, tseem nrov: nws tsis tsuas yog siv tag nrho lub tsev LAN ua qhov IT infrastructure, tab sis kuj muab wireless LAN nkag mus rau cov chaw thiab txuas kev faib tsim siv thev naus laus zis rau hauv lub network tsuas yog qhov ntawd, nws kuj tseem siv tau rau POE fais fab mov. Lub chaw ua haujlwm hauv cheeb tsam tam sim no tau tsim rau 10G (EA hom), uas yog 10GBase-T cov qauv thev naus laus zis txij li xyoo 2006.
Txawm li cas los xij, feem ntau ntawm cov khoom siv kho qhov muag fiber ntau thiab thaj chaw hauv cheeb tsam uas muab cov qauv kab rov tav no tsuas yog ua haujlwm ntawm 10G qib, uas yog, 10GBase-SR txheej txheem thev naus laus zis txij xyoo 2002. Qhov no tsis sib xws nrog lub cav ntawm Ethernet LAN: rau lub hom phiaj ntawm kev nyab xeeb kev khiav haujlwm, caj qaum network yuav tsum nyob rau hauv "theem" sai dua ntawm kev hais tau nrawm dua nws nkag mus siv network. Qhov no xav kom ua tiav qhov tseeb ntawm 40GBase-SR4 thev naus laus zis qauv txij li xyoo 2010.
Tam sim no, 40G transceivers yog siv dav hauv cov chaw loj lossis cov chaw qaum, siv hloov 4-txoj kev 10G transceivers. Hom no tsis nce rau kab kev xav tau ntawm txhua lub fiber ntau. Qhov no ua rau kev nkag siab ntawm kev lag luam, tab sis kev thev naus laus zis nws yog qhov ntsuas pa.
Kev taw qhia ntawm 8 multimode fiber ntau parallel cables (nrog plaub txoj kev taw qhia 10Gb / s channel) yog lub thev naus laus zis thev naus laus zis. Txhawb kev siv cov thev naus laus zis ob zaug siv tshuab fiber ntau yuav ua rau muaj kev nyuaj ntau dua thiab tsis muaj kev ua haujlwm thiab kev saib xyuas, uas tsis tuaj yeem ua tau ntev ntawm cov kev ua tau zoo ntawm MPO kev siv tshuab. Ib qho ntxiv, lwm qhov teeb meem yog qhov tsis txaus siv nyiaj. Lub sijhawm ntawm 40G kev xa tawm tau loj hlob, tsis yog tsuas yog vim cov hierarchical tus qauv ntawm lub network, tab sis kuj vim tias 40G transceiver tau mus txog tus nqi tsim nyog, tsim lub hauv paus rau cov kev nqis peev no.
Tam sim no peb yuav tsum lees tias peb lub peev xwm tsim kho thev naus laus zis tau pom muaj qhov cuam tshuam. Piv txwv li, siv cov cim taw qhia thiab tus txais ntawm ib khub ntawm cov kho qhov muag tsis tuaj yeem txuas ntxiv cov ntaub ntawv ntawm ntau dua 100G. Qhov tseeb, peb siv ntau lub channel sib txuas kev sib txuas rau cov txheej txheem. Ntxiv nrog rau ntau-txheej ua tiav txoj kev sib kis (kho qhov muag cable-txais) version, kuj muaj kev daws teeb meem rau kev sib txuas ntawm cov kab xa hluav taws xob sib txuas rau cov kab hluav taws xob nyob hauv txhua qhov kev qhia. Nov yog WDM (Wavelength Division Multiplexing) tus qauv uas tau siv hauv thaj tsam ntawm thaj chaw xa xov tooj rau ntau dua 15 xyoos. Cov thev naus laus zis no siv 1550 nanometers ua qhov nruab nrab ntawm qhov nruab nrab thiab ntev ib ntus ntawm 50Ghz lossis 100Ghz ntawm txhua nthwv dej. Tsis ntev los no, WDM thev naus laus zis tau txhim kho qee qhov luv luv ntawm 850nm-950nm, tseem hu ua (Shortwave-CWDM) lossis SWDM.
SWDM qhov broadband multimode fiber
Niaj hnub no, OM3 thiab OM4 multimode fiber (MMF) yog qhov nruab nrab ntawm kev xaiv rau Ethernet thiab Fiber Channel thov (NRZ tes taws los piav ua haujlwm ntawm 850 nm). Yog tias koj xav nce cov ntaub ntawv tus nqi, qhov kev qhia tau zoo kev txwv yog txwv los ntawm MMF cov qauv kev faib tawm thiab VCSEL bandwidth tsawg. Yuav kom kov yeej cov kev txwv no, cov kab hluav taws xob sib txuas ua ke ntawm kev khiav haujlwm ntawm 10G thiab 25 Gbps kab nrawm yog xav tau los ua kom muaj peev xwm ntxiv. Txawm li cas los xij, txoj hauv kev no yuav tsum muaj cov kev tsim vaj tse raws li cov cuab yeej siv sib txuas fiber ntau (MPO). Txhawm rau txuas ntxiv siv cov pov thawj ob-fiber qauv, kev daws teeb meem ntawm 100 Gbps thiab siab dua, ib qho MMF yuav muab tau qhov muaj feem thib ua ntej. Hauv qhov no, WDM thev naus laus zis tuaj yeem siv. Hauv kev sib piv, OM4-MMF muaj ntau dua li cov qauv siv bandwidth, tab sis nws qhov ntev ntawm yoj ntev yog qhov nqaim qis, tsuas yog 850 nm, uas txwv nws WDM muaj peev xwm. Hom kev siv nyiaj tsawg tshaj ntawm kev ua haujlwm rau tsawg kawg plaub WDM channel (txhua channel 25 Gbps) yuav tsum muaj qhov loj-dav dav MMFs nrog qhov ntev ntawm qhov ntev ntawm 100 nanometers. Xav txog kev rov qab ua tsis tau zoo, qhov ntev ntawm 850 nanometers tseem tsis hloov, yog li lub qhov rais ua haujlwm ntawm 850 txog 950 nanometers tshwm (saib Daim Duab 1). Kev ua tau zoo ntawm MMF hauv qhov system muaj feem xyuam rau cov kev ua kom tau txais txiaj ntsig zoo, uas cuam tshuam los ntawm cov kev ua tau zoo ntawm bandwidth (EMB) thiab kev tawg. 
Txhawm rau kom paub tseeb txog qhov ua tau zoo ntawm bandwidth ntawm 2000 MHz * km, EMB yuav tsum yog 4.700 MHz * km ntawm 850 nm thiab tsis pub tsawg tshaj 2.700 MHz * km ntawm 950 nm (saib Daim Duab 2). Los ntawm kev ua kom zoo ntawm cov tub ntxhais qhov tseem ceeb thiab ua kom zoo dua the ntsuas hauv GI tub ntxhais iav, lub ncov EMB yog hloov dua siab rau 880 nm, thiab broadband MMFs uas ua tau raws li cov lus qhia no tau lees paub.
Cov txheej txheem thev naus laus zis ntawm broadband MMFs tau ntsuas qhov siv cov tunable titanium sapphire laser nyob rau ntau qhov ntev ntawm 850 txog 950 nanometers. Qhov tshwm sim feem EMB yog qhia hauv Daim Duab 2 thiab piv nrog OM4-MMF. Qhov nkhaus qhia tau nce siab tshaj plaws EMB ntawm 875 nm optimized broadband MMFs, thaum OM4 tus qauv MMF nthuav tawm qhov nqaim EMB xa ntawm 850 nm. Yog li, broadband MMFs ua tau raws li cov cai ntawm EMB kev cai, thaum tus qauv OM4-MMF tsis tuaj yeem ua tau raws li cov cai ntawm txog 900 nanometers. 
Txhawm rau qhia WDM peev txheej ntawm broadband MMFs hauv cov kab ke tshiab uas twb muaj lawm thiab yav tom ntej, kev ntsuam xyuas BER tau ua tiav ntawm 850 thiab 980 nanometers thiab 28 Gbps. Kev txheeb xyuas qhov yuam kev me ntsis (BER) qhia tau hais tias lub zog hluav taws xob yuav tsum tau tom qab 100m kis tau mus txog. Tsis tas li ntawd, BER tau ntsuas qhov siv coj los ua lag luam muaj 40 Gbps duplex transceiver nrog 2 WDM channel (20 Gbps), kev khiav haujlwm ntawm 850 thiab 980 nanometers, feem. Yog li ntawd, qhov kev ua yuam kev tsis raug rau qhov siab txog li 300m (BER <10-12) tuaj="" yeem="" muab="" tau="" los="" ntawm="" dav="" dav="" mmf,="" uas="" yog="" sib="" npaug="" rau="" ob="" txoj="" kab="" sib="" chaws="" ntawm=""> Nyob hauv qhov ntau ntawm 850 txog 980 nanometers, 4 WDM channel (25.8 Gbps) nrog qhov deb ntawm 30 nanometers thiab lub peev xwm ntawm 100G tuaj yeem ua tiav kev ua yuam kev tsis raug ntawm 200m.
Lub peev xwm tuaj yeem raug txuas ntxiv nce ntxiv los ntawm kev siv cov qauv kev hloov kho qib siab (xws li PAM-4). Hauv chav kuaj, 180 Gbps kis tau los ntawm broadband MMF tau ua tiav (nrog plaub 45 Gbps PAM-4 WDM teeb liab), thiab nws qhov BER siab tshaj 300m, thaum nyob rau OM4-MMF qhov siab tshaj tsuas tau 150m. Cov txiaj ntsig no qhia tau tias broadband MMFs ua tiav cov ntaub ntawv kev ua tau zoo ntawm 40, 100, lossis 200 Gbps yam tsis tas yuav muaj kev sib txig sib luag hauv cov fiber ntau.
Nqi sib piv
Rau 40GBase-x, cov neeg siv muaj ntau txoj hauv kev nyob hauv cov haujlwm network. Vim yog ua cov qauv QSFP + plhaub hom, cov nqi sib txuam ntau dua tuaj yeem tuaj yeem ntsaws thiab ua si raws li kev sib kis sib txawv. Ib qho qauv tau pom zoo:
Ntawm tib cov ntaub ntawv nqi, tus nqi ntawm SM transceiver (40Gbase-LR4) yog 200% rau 400% siab dua tus nqi ntawm MM transceiver (40Gbase-SR4).
Qhov sib txawv ntawm ob lub transceivers yog tsawg kawg € 600, uas yog ob zaug tus nqi ntawm tag nrho cov hluav taws xob passive (txuas).
Yog li no, yog hais tias txheej txheem ua tau, MMF-based fiber qaum yog kev daws teeb meem ntau dua.
Qee cov neeg siv kev txhawj xeeb tias SWDM thev naus laus zis ntawm transceiver yuav tsim ntau cov nqi ntxiv. Kev sib piv yooj yim (Daim Duab 3) qhia tias qhov pib ntawm tus nqi yooj yim yog cov tiaj lossis tseem muaj nyiaj txiag ntau hauv qee qhov chaw. 
Hauv qhov xwm txheej no, thawj zaug ntawm kev lag luam SWDM transceiver tau dhau los ua lub ntsiab lus ntawm kev saib xyuas. Lawv tsis tsuas yog nthuav dav txoj kev xaiv ntawm transceivers los ntawm kev txhim kho ntxiv, tab sis kuj tau tso cai siv kev siv cov ntsaws pov thawj LC kom tswj tau 2-MMF cov txheej txheem ntawm 40G thiab 100G qib zog.
xaus lus
Muaj cov neeg siv twb npaj yuav nce mus rau 40GbE thiab sab saud Ethernet. Feem ntau ntawm cov kev thov yog caj qaum-chaw nres nkoj rau cov chaw nres nkoj. Ob-fiber ntau OM3 ntawm txhua kab tau thov nyob rau hauv ntau qhov xwm txheej, thiab txoj kev txhim kho txoj kab ke feem ntau yog ua tiav ib qib zuj zus. Qhov tau hais tseg rau hauv broadband MMF tau rov qab los txuas nrog yav dhau los OM2, OM3 thiab txawm tias OM4 MMFs, thiab nws tsis muaj lwm yam kev xav tau rau kev sib txuas nrog cov khoom siv dua li qub thev naus laus zis, uas yog qhov muaj txiaj ntsig loj. Qhov no tso cai rau broadband MMF rau kev lag luam hloov pauv ntawm 10G tes hauj lwm kom raug nqi 40G thiab 100G tes hauj lwm, thiab tuaj yeem hloov kho rau 200G yav tom ntej. Nyob rau tib lub sijhawm, broadband MMF tau pom tias yog MMF txuas ntxiv los ntawm IEEE802.3, thiab yuav raug txhawb nqa hauv kev tsim cov qauv network yav tom ntej.
Rau cov neeg uas tsis tuaj yeem tsis quav ntsej cov nqi ntawm LAN thiab DC lub network qaum, MM fiber yog qhov hloov tsis tau. Lub tshuab broadband MMF tshiab muab cov nqi xa khoom kom zoo dua qub uas ua rau LC duplex cov teeb meem kev txhim kho tau yooj yim dua. Broadband MMF tau dhau los ua qauv MM fiber raws li cov kev cai ntawm IEC thiab TIA, thiab yuav tau txhais raws li OM5 optical cable qeb hauv kev kho dua tshiab ntawm ISO / IEC11801. Nws thawj cov khoom lag luam muaj nyob rau tom khw.