Kev Txheej Txheem Lus Qhia ntawm DWDM Technology thiab DWDM System Cheebtsam
Telecommunications ua dav siv kev kho qhov muag uas cov cab kuj yoj yoog mus rau qhov chaw ua kom pom zoo. Lub nthwv tes taws xob yeem tso cai rau kis ntawm analog lossis digital signals txog li ob peb gigahertz (GHz) los yog gigabits ib feeb (Gbps) rau ib tus neeg sib tw ntawm ntau zaus, feem ntau yog 186 mus rau 196 Thiaj. Qhov tseeb, lub bitrate yuav tau nce ntxiv, siv ntau cov cab kuj tsis uas tsis muaj kev cuam tshuam rau ib tus qauv nkaus xwb. Nws yog pom tseeb tias txhua zaus sib raug mus rau ib qho txawv wavelength. Qis Wavelength Division Multiplexing (DWDM) yog tshwj tseg rau kev sib tshuam zoo heev. Qhov blog no npog cov kev taw qhia txog DWDM kev siv tshuab thiab DWDM cov khoom. Kev khiav haujlwm ntawm txhua feem yog sib tham txog tus kheej thiab tag nrho cov qauv ntawm DWDM txoj kab ke qhia txog qhov kawg ntawm lub blog.
Taw qhia rau DWDM Technology
DWDM tshuab yog kev txuas ntxiv ntawm kev kho qhov muag. DWDM khoom siv (multiplexer, los yog Mux rau luv) muab cov zis los ntawm ob peb qhov kho qhov muag transmitters rau kev sib kis ntawm ib qho fiber ntau optical. Ntawm qhov kawg tau txais, lwm DWDM cov cuab yeej siv (demultiplexer, los yog DeMux rau luv) cais cov kho qhov muag sib xyaw ua ke thiab hla txhua channel mus rau ib qho chaw kho qhov muag. Tsuas yog ib qho fiber ntau qhov siv ntawm DWDM cov khoom siv (ib qho kev xa tawm). Siv cov khoom siv fiber ntau hauv ib qho chaw luam yeeb thiab cov khoom xaib, DWDM pub ntau qhov kev kho qhov muag mus rau ib tus fiber ntau optic cable. Raws li qhia hauv qab no, los ntawm kev siv cov cuab yeej zoo siv AAWG Gaussian technology, FOCC DWDM Mux / Demux qhia txog kev poob qis (3.5dB raug), thiab kev ntseeg siab. Nrog cov qauv kho tshiab, cov DWDM multiplexers thiab demultiplexers tuaj yeem muab kev yooj yim dua.
Ib qho txiaj ntsim tseem ceeb rau DWDM yog tias nws yog tus qauv thiab kev ywj pheej ywj siab. DWDM-based networks yuav xa cov ntaub ntawv hauv IP, ATM, SONET, SDH thiab Ethernet. Yog li, DWDM-based tes hauj lwm muaj peev xwm nqa tau ntau hom tsheb khiav hauv kev sib txawv dua ib qho chaw kho qhov muag. Lub suab sib kis, email, video thiab multimedia ntaub ntawv tsuas yog qee qhov qauv ntawm cov kev pab cuam uas tuaj yeem xa mus rau hauv DWDM systems. DWDM tshuab muaj raws ntawm wavelengths spaced nrog 0.4 nm spacing.
DWDM yog ib hom Kev Sib Hlis Feem Ntau Tshaj Tawm (FDM). Ib qho khoom siv ntawm lub teeb hais tias ib tus neeg lub teeb tsis muaj ntau lub wavelengths yuav coexist nws tus kheej hauv nruab nrab. Lasers muaj peev xwm tsim tsim kom muaj lub teeb ci nrog ib lub qhov kawg ntawm lub wavelength. Txhua tus neeg wavelength ntawm lub teeb tuaj yeem sawv cev ib txoj kab sib txawv ntawm cov ntaub ntawv. Los ntawm sib txuas lub teeb ntawm lub suab pauv ntawm ntau lub wavelengths, muaj ntau txoj kev tuaj yeem kis tau hla ib zaug ib zaug ib txhij. Fiber optic systems siv lub teeb ntsais teeb nyob rau hauv lub khab khab infrared (1 hli mus rau 400 nm wavelength) ntawm tus qauv electromagnetic. Qhov teeb meem ntawm lub teeb nyob rau hauv ntau qhov chaw ntawm qhov kho qhov muag ntawm electromagnetic spectrum feem ntau yog txheeb xyuas los ntawm lawv lub cev ntas, txawm tias muaj ntau zaus (nrug ntawm lambdas) muab ib qho kev qhia ntxiv.
DWDM System Cheebtsam
Ib qho DWDM system feem ntau muaj tsib yam: Optical Transmitters / Receivers, DWDM Mux / DeMux Cov Ntxaij, Optical Ntxiv / Tawm Multiplexers (OADMs), Optical Amplifiers, Transponders (Wavelength Converters).
Optical Transmitters / Receivers
Transmitters yog piav raws li DWDM cov khoom vim lawv muab cov cim qhov teeb meem uas yog muab ntau dua. Cov yam ntxwv ntawm cov khoom siv kho tshuab siv hauv DWDM systems yog qhov tseem ceeb heev rau cov qauv tsim. Ntau yam kho qhov muag pom tau siv los ua cov teeb pom kev hauv DWDM. Cov khoom hluav taws xob hauv cov khoom tuaj (0 los sis 1) ua rau cov kev hloov ntawm lub teeb nrig (piv txwv, lub teeb ntawm lub teeb = 1, qhov tsis muaj teebmeem = 0). Lasers tsim teeb meem ntawm lub teeb. Txhua lub teeb mem ntawm lub teeb muaj ib lub sijhawm pes tsawg (lambda) qhia hauv nanometers (nm). Nyob hauv ib qho chaw kho qhov muag, cov kwj ntawm cov ntaub ntawv raug xa mus rau lub cev txheej ntaus ntawv, nws cov zis yog lub teeb pom kev (ib qho LED lossis laser) uas cuam tshuam cov fiber ntau fiber ntau. Cov cuab yeej no hloov cov teeb duab digital los ntawm hluav taws xob (electrons) mus rau optical (photons) daim ntawv (hluav taws xob kom kho qhov muag, EO). Cov khoom siv hluav taws xob thiab zeroes ua rau lub teeb ci ntsi xws li lub teeb ci (xws li, lub teeb = 1, me me los sis tsis muaj teeb ci = 0) lub teeb rau hauv qhov tseem ceeb ntawm cov khoom siv fiber ntau. EO hloov dua siab tshiab yog tsis-tsheb cuam tshuam. Lub hom phiaj ntawm cov teebmeem ntawm lwm yam yog tsis hloov. Pulses ntawm lub teeb propagate thoob plaws lub fiber ntau qhov muag los ntawm txoj kev ntawm tag nrho cov sab hauv. Ntawm qhov kawg tau txais, lwm qhov kev kho qhov muag sensor (photodiode) ntes cov xim pulses thiab hloov cov teeb khoom siv hluav taws xob rov tuaj rau hluav taws xob daim ntawv. Ib nkawm fibers feem ntau txuas ob qho khoom siv (ib qho khoom sib kis, ib leeg tau txais fiber ntau).
DWDM systems yuav tsum muaj qhov teeb meem ntawm lub teeb ntom nti ntawm lub teeb kom tsis muaj kev cuam tshuam nrog kev cuam tshuam los yog kev cuam tshuam. Muaj ntau tus neeg laser raug siv los tsim cov tib neeg raws hauv DWDM. Txhua lub laser koomtxoos ntawm qhov txawv ntawm qhov txawv me ntsis. Niaj hnub nimno tshuab ua haujlwm nrog 200, 100, thiab 50-GHz spacing. Kev txhawb zog tshiab 25-GHz spacing thiab 12.5-GHz spacing yog tshawb xyuas. Feem ntau, DWDM kev sib txuas lus (DWDM SFP, DWDM SFP, DWDM XFP, thiab lwm yam) khiav haujlwm ntawm 100 thiab 50 GHz tuaj yeem nrhiav tau ntawm lub khw niaj hnub no.
DWDM Mux / DeMux Lim
Ntau lub wavelengths (tag nrho cov nyob rau hauv 1550 nm band) tsim los ntawm ntau yam kev sib tw thiab kev khiav hauj lwm ntawm nyias fibers yog chav ua ke rau ib qho fiber ntau los ntawm kev ntawm ib qho kev xaiv lim (Mux lim). Lub teeb liab tso tawm ntawm qhov kev tshaj lij ntawm cov zauv tau raug xa mus ua ib qho teeb liab sib txuas. Ntawm qhov kawg tau txais, ib qho kev hloov kho qhov muag lim (DeMux lim) cais tag nrho ntawm cov tib neeg cov wavelengths ntawm cov teeb liab sib txuas mus rau tus neeg fibers. Tus fibers tus kheej kis tau cov kab nrig ntawm cov dej ntws mus rau ntau li ntau tshaj qhov muag. Feem ntau, Mux thiab DeMux (sib faib thiab txais) cov khoom muaj nyob rau hauv ib qho chaw nkaum. Optical Mux / DeMux li yuav ua tau zoo. Tshaj Plaws Pib Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws Tshaj Plaws. Daim duab hauv qab no yog kev ua haujlwm DWDM kev ua haujlwm. N lub teeb pulses ntawm N txawv wavelengths nqa ntawm N txawv fibers yog chav ua ke los ntawm DWDM Mux . Cov cim N yog multiplexed rau hauv ob sab fiber ntau qhov muag. Ib qho DWDM DeMux tau txais cov teeb liab sib txuas thiab cais txhua tus N cim kev teeb liab thiab xa txhua tus mus rau ib qho fiber ntau. Cov xa tawm thiab tau txais cov cim teeb liab sawv cev cov khoom siv sab nraud. Qhov no yuav tsum tau siv ib tug khub optical fibers; ib qho rau xa, ib qho rau tau txais.
Optical Ntxiv / Tshem Tawm Multiplexers
Optical ntxiv / poob multiplexers (piv txwv li OADMs) muaj qhov txawv ntawm "Add / Drop", piv nrog Mux / DeMuxfilters. Ntawm no yog ib daim duab uas qhia txog kev khiav haujlwm ntawm 1-channel OADM. Qhov OADM no yog tsim los tsuas ntxiv lossis poob muag kho qhov muag nrog ib qho kev txhawj xeeb. Los ntawm sab laug mus rau sab xis, ib qho teeb liab sib sau ua ke tau tawg mus rau hauv ob qho chaw, poob thiab dhau-dhau. Cov OADM dauv tsuas yog xim liab qhov muag hluav taws xob. Cov kwj hluav taws xob nqos tawm mus rau lub receiver ntawm tus neeg siv khoom. Tshaj qhov laj thawj uas pom tau tias dhau los ntawm OADM yog multiplexed nrog ntxiv lub teeb liab ntxiv. Lub OADM ntxiv ib qho xim tshiab kho qhov muag hluav taws xob, uas ua haujlwm ntawm tib lub wavelength raws li teeb liab. Cov kauj ruam kho qhov muag tshiab yog nrog cov kev sib tw dhau los ua ib qho teeb meem tshiab.
OADM tsim rau kev khiav hauj lwm ntawm DWDM wavelengths yog hu ua DWDM OADM , thaum ua haujlwm ntawm CWDM wavelengths hu ua CWDM OADM . Ob ntawm lawv tuaj yeem nrhiav tau ntawm kev ua lag luam tam sim no.
Optical Amplifiers
Optical amplifiers txhawb lub amplitude lossis ntxiv qhov nce mus rau optical teeb liab dhau ntawm ib lub tshuab fiber ntau los ntawm kev ncaj qha rau lub photons ntawm lub teeb liab nrog ntxiv zog. Lawv yog cov cuab yeej hauv "fiber". Optical amplifiers nrov ua qhov muag ntsig txog qhov thoob ntau ntawm wavelengths. Qhov no tseem ceeb heev rau DWDM qhov kev thov. Erbium-Doped Fiber Amplifiers (EDFAs) yog hom uas siv ntau hom fiber ntau hauv tshuab hlwb hlau. EDFAs siv hauv DWDM systems qee zaum hu ua DWDM EDFA, piv rau cov siv hauv CATV lossis SDH. Koj yuav tau txais txhua yam ntawm Optical Amplifiers hauv Fiberstore, xws li DWDM EDFA, CATV EDFA, SDH EDFA, EYDFA, thiab Raman Amplifier thiab lwm yam. (Ntawm no yog ib daim duab uas qhia txog kev lag luam ntawm ib DWDM EDFA.)
Transponders (Wavelengths Converters)
Transponders hloov optical Pib ntsais koj teeb ntawm ib qho wavelength mus rau lwm lub wavelength uas haum rau DWDM kev siv. Transponders yog Optical-hluav taws xob-Optical (OEO) wavelength converters. Ib tus neeg txuas lus tau ua haujlwm OEO los hloov wavelengths of light, yog li qee cov neeg hu ua "OEO" rau luv luv. Tsis pub dhau DWDM system tus neeg tuaj yeem hloov cov neeg siv khoom siv hluav taws xob (OE) thiab rov ua haujlwm 2R (Reamplify, Reshape) los yog 3R (Reamplify, Reshape, and Retime). Daim duab hauv qab no qhia txog kev khiav haujlwm ntawm tus neeg txuas ob tog. Tus neeg txuas lus yog nyob nruab nrab ntawm tus neeg siv khoom siv thiab lub DWDM system. Los ntawm sab laug mus rau sab xis, tus neeg txais kev pom zoo tau txais ib qho me me dig muag kev khiav dej num ntawm ib qho kev tshuav (1310 nm). Tus neeg hloov ua thev naus laus zuj zus ntawm qhov kev khiav lag luam ntawm lub lag luam mus rau ITU-raws li wavelength. Nws xa nws qhov tso tawm mus rau DWDM qhov system. Nyob rau sab txais (sab laug mus rau sab laug), txheej txheem yog ntxeev siab. Lub transponder tau txais ib qho ITU-raws li qhov me me thiab hloov cov teeb meem rov qab mus rau lub wavelength uas siv los ntawm tus neeg siv khoom.
Transponders feem ntau yog siv hauv WDM systems (2.5 txog 40 Gbps), suav nrog tsis yog DWDM systems, tab sis aslo CWDM systems. Fiberstore muaj ntau hom WDM transponders (OEO converters) nrog ntau qhov chaw sib txawv (SFP rau SFP, SFP + rau SFP +, XFP rau XFP, thiab lwm yam).
Yuav ua li cas DWDM System Cheebtsam Ua Haujlwm Nrog DWDM Technology
Raws li DWDM qhov kev tsim muaj li ntawm tsib yam, lawv ua haujlwm li cas? Cov kauj ruam nram qab no qhia tawm cov lus teb (xws li koj tuaj yeem pom txhua tus qauv DWDM cov kab ke hauv qab):
Siv DWDM technology, DWDM systems muab qhov bandwidth rau ntau cov ntaub ntawv. Qhov tseeb, lub peev xwm ntawm DWDM systems loj hlob tuaj li kev yees duab yees uas cia kom ze zus, thiab yog li ntau dua, ntawm wavelengths. Tab sis DWDM kuj tsiv dhau kev thauj mus los ua lub hauv paus ntawm tag nrho cov kho qhov muag nrog qhov paab ntu nruab ntom thiab kev tiv thaiv hauv nruab siab. Hloov ntawm cov qauv ntawm photonic yuav ua kom qhov kev hloov evolution, xws li yuav ua raws li cov txheej txheem uas tso cai rau cov teeb pom kev mus rau hauv kev sib koom ua ke hauv ntau txoj kev zoo li kev sib cog lus virtual ua hnub no. Nrog rau kev tsim kho cov technologies, DWDM systems yuav xav tau ntau yam ntxiv los mus ua kom tau qhov zoo dua.