Ntawm O mus rau L: Evolution ntawm Optical Wavelength Band
Hauv kev kho qhov sib txuas ntawm qhov sib txuas ntawm fiber ntau, ntau cov kev sib txuas xov qes tau txhais thiab ua qauv, los ntawm thawj O-qhab mus rau U / XL-band. E- thiab U / XL-bands feem ntau tau raug zam vim lawv tau muaj kev sib kis ntawm cov cheeb tsam loj. Qhov E-band nruab nrab yog thaj chaw dej ncov, thaum U / XL-band nyob ntawm qhov kawg ntawm lub qhov rais txuas rau silica iav.
Intercity thiab xov tooj nplhaib fiber ntau twb nqa cov teeb liab ntawm ntau lub wavelengths kom nce bandwidth. Fibers nkag mus hauv tsev yuav ntev li qub. Tam sim no muaj ntau hom xov tooj ntawm optical telecom systems tau tsim, qee cov lej faib sij hawm multiplexing (TDM) thiab lwm tus nyob hauv wavelength division multiplexing (WDM), qhov sib qiv ntawm wavelength division multiplexing (DWDM) lossis coarse wavelength division multiplexing (CWDM). Tsab ntawv xov xwm no tuaj yeem sawv cev rau cov evolution ntawm cov kabmob hu ua wavelengths uas yog los ntawm kev piav txog peb cov kev ua haujlwm siab.
Qis Wavelength Division Multiplexing
DWDM systems raug tsim los nrog kev nce cov kev hloov bandwidth ntawm kev sib koom tes kho qaum tes. Qhov nqaim nrug (feem ntau 0.2 nm) ntawm cov hlua txuas nruab nrab ntawm cov kab txuas ntau ntxiv thiab ua rau muaj ntau cov ntaub ntawv ntawm ntau cov Thib Hlis thib ob (Tbps) nyob rau hauv ib lub hauv paus fiber.
Cov tshuab no tau tsim los rau cov teeb meem laser-lub teeb nyob rau hauv C-band, thiab tom qab hauv L-Band, leveraging wavelengths nrog cov nqi qis tshaj plaws hauv cov iav fiber ntau thiab cov kev kho qhov muag optical. Erbium-doped fiber ntau amplifiers (EDFAs, uas ua haujlwm ntawm cov kab txuas no) yog lub tshuab ua haujlwm tseem ceeb rau cov tshuab no. Vim tias cov kab mob WDM siv ntau lub wavelengths tib lub sij hawm, uas yuav ua rau ntau tus attenuation. Vim li no kho qhov tshuab ua kom nrov tau zoo. Raman amplification thiab erbium-doped fiber ntau amplifiers yog ob hom kev siv hauv WDM system.
Yuav kom ua tau raws li qhov kev thov rau "unlimited bandwidth," nws ntseeg tias DWDM yuav tsum tau txuas ntxiv rau ntau pawg. Nyob rau yav tom ntej, txawm li cas los xij, cov L-band kuj tseem yuav qhia tau tias yuav pab tau. Vim tias EDFAs tsawg dua hauv L-band, kev siv cov Raman amplification technology yuav rov qab muab dua, nrog rau kev siv cov wavelengths ze rau 1485 nm.
Kev sib tshuam Wave Division Multiplexing
CWDM yog tus nqi qis tshaj ntawm WDM. Feem ntau cov tshuab tsis muaj zog thiab yog vim li no muaj kev txwv ntau. Lawv feem ntau siv tsawg lub teeb pom kev uas tsis muaj kev kub ntxhov siab. Cov khoob loj dua ntawm cov wavelengths tsim nyog, feem ntau 20 nm. Ntawm chav kawm, qhov no thiaj li muaj cov xaim ntawm cov wavelengths uas yuav siv tau thiab yog li yuav txo tau tag nrho cov qhab-nees bandwidth.
Cov kev siv tam sim no siv cov S-, C- thiab L-band vim hais tias cov nraub qaum qhov chaw nyob thaj av ntawd rau cov qaub pob zeb me me uas tsis muaj qhov muag qis. Txawm hais tias kev txuas mus rau O thiab E-band (1310 nm mus 1450 nm), qhov system tau mus txog (qhov kev deb ntawm lub teeb yuav tuaj yeem nyob rau hauv fiber thiab tseem muaj teebmeem zoo uas tsis muaj kev txhawb zog) yuav raug txom nyem los ntawm kev piam sij los ntawm kev siv lub 1310 nm cheeb tsam nyob rau hauv cov niaj hnub fibers.
Lub sij hawm faib Multiplexing
TDM systems siv ib qho hlua ntev loo los yog ob tug (nrog rau ib tus qhab ntawg mus rau txhua qhov kev taw qhia). TDM cov kev daws tam sim no muaj nyob rau hauv cov tsom teeb nrog rau kev xa xov hluav taws xob ntawm-fiber-home (FTTH) technologies. Ob leeg EPON thiab GPON yog TDM systems. Tus txheej txheem bandwidth allocation rau GPON hais txog 1260 thiab 1360 nm ntws, 1440 txog 1500 nm nqes, thiab 1550 txog 1560 nm rau cable video TV.
Yuav kom ua tau raws li kev xav tau ntawm kev xav tau bandwidth, cov tshuab no yuav tsum tau kho dua tshiab. Qee cov kwv yees tias TDM thiab CWDM (los sis DWDM txawm tias) yuav tsum tau koom tes nrog tib lub fibers network. Kom ua tau raws li qhov no, kev ua hauj lwm yog nyob rau hauv tus qauv hauv lub cev txhawm rau txheeb xyuas cov ntxaij lim dej uas thaiv cov tsis muaj GPIS rau cov neeg tau txais kev pab tam sim no. Qhov no yuav kom lub CWDM tshooj siv wavelength bands deb ntawm cov neeg tseg rau GPON. Yog li ntawd, lawv yuav tsum siv L-Band los yog C-thiab L-band thiab tsis pub siv yees duab.
Xaus
Nyob rau hauv txhua kis, kev ua tau zoo txaus qhia tau tias kom muaj kev ua tau zoo rau hnub no thiab tag kis. Los ntawm tsab xov xwm no, peb paub tias tus thawj O-band tsis tau txaus siab rau txoj kev loj hlob sai ntawm kev siv bandwidth siab dua. Thiab cov evolution ntawm optical wavelength bands xwb txhais tau tias ntau thiab ntau bands yuav tau hu rau. Nyob rau hauv lub neej yav tom ntej, nrog kev loj hlob ntawm kev siv FTTH, tsis muaj kev ntseeg tias C- thiab L-bands yuav ua haujlwm ntxiv thiab tseem ceeb dua nyob rau hauv qhov kev sib tw kho qhov system. FOCC muaj txhua yam khoom siv rau WDM kho qhov muag network, xws li CWDM / DWDM MUX DEMUX thiab EDFA.