Txhua qhov txuas fiber ntau optic poob qee lub zog kho qhov muag ntawm lub transmitter thiab receiver. Paub yuav ua li cas xam qhov poob ntawd - thiab muab piv nrog cov cuab yeej siv nyiaj siv hluav taws xob - yog qhov sib cais qhov txuas uas ua haujlwm tau ntseeg tau los ntawm ib qho uas ua tsis tau raws li qhov tiag - lub ntiaj teb. Phau ntawv qhia no taug kev los ntawm cov mis laij lej poob fiber ntau, ib kauj ruam -los ntawm- kauj ruam ua haujlwm piv txwv, thiab cov kev kuaj xyuas uas paub txog engineers siv kom tsis txhob muaj feem ntau ntawm kev siv nyiaj yuam kev.
Dab tsi yog Fiber Poob thiab Vim Li Cas Nws Tseem Ceeb?
Fiber poob yog qhov txo qis hauv cov teeb liab optical zog thaum lub teeb mus los ntawm qhov txuas fiber ntau optic. Nyob rau hauv kev xyaum, tag nrho cov poob nyob rau hauv ib qhov txuas los ntawm ntau qhov chaw: lub fiber cable nws tus kheej, mated connector khub, splices, thiab tej yam passive Cheebtsam xws lisplitterslos yog couplers nyob rau hauv txoj kev.
Feem ntau koj yuav pom cov ntsiab lus uas siv nyob rau hauv ntau txoj kev sib txawv me ntsis.Attenuationfeem ntau yog hais txog qhov tsis muaj zog hauv ib chav tsev ntev ntawm cov fiber ntau, qhia hauv dB / km.Insertion poobpiav qhia tag nrho qhov kawg -rau- xaus kev poob ntsuas thoob plaws ib qho txuas, suav nrog tag nrho cov khoom.Link poobyog tus xam los yog ntsuas tag nrho cov passive losses nyob rau hauv lub channel. Cov kev sib txawv no tseem ceeb vim tias kev sib xyaw ua ke ua rau kev siv nyiaj tsis raug - ib qho taw qhia hais txog hauv ob qho tib si Corning'sCov txheej txheem kuaj fiber ntau optic (LAN-1561-AEN)thiab Fiber Optic Association'skev siv nyiaj poob. Rau kev sib piv sib sib zog nqus, saib peb phau ntawv qhiainsertion poob vs rov poob.
Tus lej poob ntawm nws tus kheej qhia koj tsawg heev. Kev nyeem ntawv 3 dB tuaj yeem ua tau zoo kawg nkaus ntawm qhov luv luv multimode tsev kawm ntawv txuas tab sis muaj teeb meem ntawm lub cev ntev singlemode nrog cov ntawv thov nruj. Tias yog vim li cas fiber ntau poob ib txwm ntsuas tawm tsam ob yam: qhov txuas - nyiaj poob haujlwm (qhov kwv yees tag nrho passive poob) thiab cov peev nyiaj siv hluav taws xob ntawm cov khoom siv nquag (qhov sib txawv ntawm cov khoom tso tawm thiab cov neeg txais rhiab heev).
Dab tsi ua rau fiber ntau poob hauv qhov txuas Optical?
Plaub yam tseem ceeb ua rau poob rau hauv ib qho chaw fiber ntau. Kev nkag siab txhua tus pab koj tsim cov peev nyiaj kom raug es tsis txhob kwv yees.
Fiber Attenuation dhau deb
Txhua qhov fiber ntau optical absorbs thiab tawg qee lub teeb thaum nws nthuav tawm. Lub attenuation coefficient nyob ntawm fiber ntau thiab wavelength. Raws li ANSI / TIA-568.3-D tus qauv, qhov siab tshaj plaws tso cai rau kev txo qis rau kev npaj yog:
| Hom Fiber | Lub wavelength | Max Attenuation (dB/km) |
|---|---|---|
| 50/125 µm lossis 62.5/125 µm multimode | 850nm ua | 3.5 |
| 50/125 µm lossis 62.5/125 µm multimode | 1 300 nm | 1.5 |
| Singlemode (hauv tsev cable) | 1310nm / 1550nm | 1.0 |
| Singlemode (sab nraum zoov cable) | 1310nm / 1550nm | 0.5 |
Cov no yog cov kev npaj siab tshaj plaws. Manufacturers niaj hnub tsimsinglemode fiber ntaunrog attenuation zoo hauv qab 0.35 dB / km ntawm 1310 nm thiab qis dua 0.25 dB / km ntawm 1550 nm. Yog tias koj muaj cov ntaub ntawv cable tiag tiag, siv cov txiaj ntsig nruj dua - cov qauv pub dawb muaj xws li qhov phem tshaj - cov ntaub ntawv kev nyab xeeb, tsis yog qhov kev kwv yees zoo tshaj plaws.
Connector Pair Poob
Kev poob tshwm sim txhua zaus obfiber ntau optic connectorstau sib yuav. Hauv kev siv nyiaj txiag, koj suav cov khub sib txuas sib txuas, tsis yog ib tus neeg txuas xaus. TIA-568.3-D tus qauv teeb tsa qhov siab tshaj plaws ntawm 0.75 dB ib khub niam txiv, tab sis cov khoom lag luam zoo tshaj plaws (SC, LC, FC hom) feem ntau ua tiav 0.3–0.5 dB ib khub hauv kev xyaum. Qhov no yog ua raws li Corning cov lus pom zoo kom siv cov khoom sib txuas tiag tiag es tsis yog qhov nyiaj pub dawb tshaj plaws thaum twg los tau.
Hauv kev txuas luv luv - hais hauv qab 500 meters - connector poob feem ntau dominates tag nrho cov peev nyiaj ntau dua fiber ntau attenuation. Qhov ntawd yog ib qho laj thawj vim li cas connector zoo thiabconnector hom xaivtseem ceeb heev nyob rau hauv qhov chaw cabling.
Splice Loss
Fusion splices thiab mechanical splices ob leeg ntxiv poob. TIA-568.3-D siab tshaj plaws yog 0.3 dB ib splice. Fusion splices nrog cov tub ntxhais sib raug zoo niaj hnub ua tiav hauv qab 0.1 dB, thaum cov khoom siv sib txuas yuav poob rau hauv 0.2-0.5 dB ntau. Yog tias koj tab tom nrhiav nyiaj txiag rau txoj kev cog ntoo sab nraud nrog ntau lub ntsiab lus sib txuas, cov txiaj ntsig me me ntxiv sai sai rau lub sijhawm ntev.
Khoov, paug, thiab lwm yam
Macrobends thiab microbends nce attenuation tshaj qhov ntsuas qhov ntsuas ntawm cable. Kev kis kab mob ntawm lub ntsej muag kawg ntawm lub ntsej muag yog ib qho ntawm feem ntau ua rau poob qhov kev xav tsis zoo hauv thaj teb - FOA txheeb xyuas cov khoom sib txuas qias neeg ua qhov ua rau qhov kev sim ua tsis tiav. Tight cable routing, tswj cable tsis zoo, thiab kev ntxhov siab ib puag ncig tuaj yeem thawb ntsuas qhov poob siab tshaj qhov kwv yees kwv yees.
Qee qhov txuas kuj suav nrog cov khoom siv passive xws li optical attenuators, WDM couplers, lossisPLC splitters. Txhua yam ntawm no muaj nws tus kheej qhov kev poob qis uas yuav tsum tau ntxiv rau cov peev nyiaj.
Fiber Loss Formula
Cov qauv tseem ceeb rau kev kwv yees tag nrho qhov txuas poob yog ncaj nraim:
Tag Nrho Cov Txuas Txuas Poob (dB)=(Attenuation Coefficient × Fiber Length) + (Number of Connector Pairs × Loss per Pair) + (Number of Splices × Loss per Splice) + Lwm yam Passive Component Poob
Qhov no yog tib cov qauv siv hauv Corning'slink poob nyiaj txiag laij lejthiab hauv FOA txoj kev siv nyiaj txiag. Tom qab ntawd koj muab piv rau tag nrho cov nyiaj siv hluav taws xob ntawm cov khoom siv nquag:
Fais fab nyiaj txiag (dB)=Transmitter Output Fais fab (dBm) − Receiver Sensitivity (dBm)
Kev khiav hauj lwm Margin (dB)=Power Budget − Total Link Poob
Ib qho kev ua haujlwm zoo tshaj plaws txhais tau hais tias qhov txuas yuav tsum ua haujlwm. Cov npoo qis dua li ntawm 3 dB yog suav tias yog qhov pheej hmoo rau lub sijhawm ntev - kev ntseeg tau, vim tias muaj hnub nyoog transmitters, cov khoom sib txuas sib xyaw ua ke, thiab cov splices tuaj yeem degrade yog tias cov cables raug tuav lossis rov qab. FOA pom zoo kom tswj hwm tsawg kawg 3 dB ntawm cov paj los suav rau cov no tiag tiag - ntiaj teb yam.
Ib daim ntawv tseem ceeb:dByog ib chav tsev txheeb ze (nws qhia txog qhov piv), thaumdBm ibyog ib theem zog kiag li (xws li 1 mW). Tsis meej pem ob yog ib qho kev tsis txaus ntseeg uas ua rau tag nrho lub hwj chim - suav nyiaj txawm tias qhov poob kwv yees nws tus kheej yog qhov tseeb.
Yuav ua li cas koj xam fiber ntau poob ib kauj ruam?
Kauj Ruam 1: Sau cov khoom txuas tiag tiag
Ua ntej qhib lub tshuab xam zauv, sau txhua yam hauv cov channel: hom fiber ntau, kev ua haujlwm wavelength, tag nrho txoj kev ntev (tsis yog daim ntawv qhia kev deb - suav nrog kev khiav ntsug, slack loops, thiab routing detours), tus naj npawb ntawm cov khub sib txuas, tus naj npawb ntawm splices, thiab cov khoom siv passive. Feem ntau ntawm kev siv nyiaj yuam kev pib ntawm no, nrog cov suav tsis tiav.
Kauj Ruam 2: Xaiv cov nqi poob
Siv cov khoom tsim cov khoom tshwj xeeb thaum muaj. Poob rov qab rau TIA-568.3-D qhov siab tshaj plaws tsuas yog thaum tsis paub qhov tseeb specs. Raws li Fluke Networks taw qhia hauv lawvphau ntawv qhia kev poob nyiaj txiag, cov qauv muab qhov tsawg kawg nkaus qhov kev ua tau zoo - cov khoom siv tiag tiag feem ntau yog qhov zoo dua, thiab siv cov ntaub ntawv tsim khoom tsim kev kwv yees ntau dua.
Kauj Ruam 3: Xam Xaj Txhua Qhov Tsis Txaus
Muab cov attenuation coefficient los ntawm fiber ntau. Multiply connector khub suav los ntawm poob ib khub. Multiply splice suav los ntawm poob ib splice. Ntxiv ib qho passive tivthaiv poob. Sau txhua yam rau tag nrho cov kwv yees qhov txuas poob.
Kauj Ruam 4: Muab piv rau Cov Nyiaj Siv Hluav Taws Xob
Nrhiav lub transmitter tso zis hwj chim thiab receiver rhiab heev los ntawm cov ntaub ntawv transceiver. Ob tus lej no feem ntau yog teev nyob rau hauv dBm. Qhov txawv yog cov peev nyiaj siv hluav taws xob. Tshem tawm tag nrho qhov txuas poob los ntawm cov peev nyiaj siv hluav taws xob kom tau txais cov nyiaj ua haujlwm. Yog xav paub ntxiv txog cov kev qhia tshwj xeeb ntawm transceiver, saib peb qhov kev sib piv ntawmsinglemode SFP vs multimode SFP.
Kauj Ruam 5: Txheeb xyuas qhov Margin yog tsim nyog
Ib qho txiaj ntsig zoo yog qhov tsim nyog tab sis tsis tas li txaus. Yog tias cov npoo qis dua 3 dB, qhov txuas yog qhov yooj yim rau degradation los ntawm cov khoom qub, qias neeg lub ntsej muag, ntxiv splices los ntawm kev kho yav tom ntej, los yog qhov kub thiab txias - ntsig txog attenuation hloov. Hauv kev xa tawm, cov engineers uas tsim txoj cai ntawm ntug feem ntau xaus kev daws teeb meem tsis ua haujlwm hauv ib xyoos lossis ob xyoos.
Piv txwv ua haujlwm: 10 km Singlemode Txuas ntawm 1310 nm
Xav txog ib qho sab nraud- cog singlemode txuas khiav 10 km ntawm 1310 nm, nrog ob khub sib txuas sib txuas thiab ib qho fusion splice. Siv TIA-568.3-D npaj qhov tseem ceeb rau sab nraud-cog singlemode cable:
| Cheebtsam | Suav | Loss per Unit | Subtotal (dB) |
|---|---|---|---|
| Fiber ntau attenuation (OS2, 1310nm) | 10km ua | 0.5 dB/km | 5.0 |
| Mated connector khub | 2 | 0.75 dB/pair | 1.5 |
| Fusion splice | 1 | 0.3dB ua | 0.3 |
| Tag nrho kwv yees qhov txuas poob | 6.8 |
Tam sim no xav tias cov ntaub ntawv transceiver qhia tau hais tias lub transmitter tso zis ntawm −15 dBm thiab receiver rhiab heev ntawm −28 dBm:
Lub zog pob nyiaj siv=−15 − (−28) =13dB ib
Kev khiav haujlwm margin=13 − 6.8 =6.2dB ib
Nrog 6.2 dB ntawm cov npoo, qhov txuas no hla tau yooj yim. Txawm tias tom qab khaws 3 dB rau ntev - lub sij hawm degradation, tseem muaj ntau tshaj 3 dB ntawm headroom - txaus los nqus cov kev kho splice yav tom ntej los yog qee qhov kev sib txuas cov laus yam tsis tau poob qis dua qhov kev ntseeg tau.
Yog tias koj siv cov kab tshwj xeeb tiag tiag (hais 0.35 dB / km) thiab qhov sib txuas tsis zoo (hais 0.5 dB / khub), tag nrho yuav poob mus txog 4.8 dB, muab cov npoo loj dua. Tias yog vim li cas siv cov ntaub ntawv tseem ceeb ntawm cov khoom tseem ceeb - tus qauv kev npaj qhov tseem ceeb yog kev txuag los ntawm kev tsim.
Xam lav vs Measured Poob: Thaum twg Txhua Tus Txaus?
Kev xam poob yog qhov kwv yees. Nws muaj txiaj ntsig zoo thaum tsim qauv, hais lus, sib piv txoj hauv kev, thiab ua ntej - txhim kho validation. Tab sis nws tsis zoo ib yam li daim ntawv pov thawj teb.
Rau kev teeb tsa kev sib txuas, kev lag luam tus qauv mus kom ze yog Tier 1 kev sim nrog Optical Loss Test Set (OLTS), uas ncaj qha ntsuas tag nrho qhov kev poob ntawm qhov txuas siv lub teeb pom kev zoo thiab lub ntsuas hluav taws xob. Ob qho tib si TIA-568.3-D tus qauv thiab Corning cov txheej txheem kuaj xyuas txheeb xyuas OLTS kev xeem raws li qhov tseeb tshaj plaws tus yam ntxwv ntawm qhov txuas fiber ntau qhov kev ua tau zoo. Yog tias koj xav nrhiav qhov ua txhaum tshwj xeeb - qhov tsis zoo splice, qhov sib txuas puas, lossis qhov khoov nruj - qhov Optical Time Domain Reflectometer (OTDR) muab cov xwm txheej-qib nthuav dav uas OLTS ua tsis tau. Fluke Networks piav qhia txog kev kuaj OTDR liTier 2 daim ntawv pov thawj, pom zoo nrog OLTS rau kev sim ua tiav.
Siv xam thaum:koj tab tom tsim txoj hauv kev tshiab, sib piv cov kev xaiv txuas, lossis tshawb xyuas tias cov cuab yeej siv hluav taws xob yuav tsum txaus ua ntej kev teeb tsa.
Siv kev ntsuas thaum:koj tau lees paub qhov txuas txuas rau kev lees paub, teeb meem daws teeb meem kev ua haujlwm tsis txaus ntseeg, lossis tshawb xyuas qhov ntsuas qhov poob poob hauv cov peev nyiaj suav.
Hauv kev xyaum, nws yog ib qho uas ntsuas qhov poob txawv me ntsis los ntawm kev kwv yees. Yog tias ntsuas qhov poob siab ntau dua li cov peev nyiaj, thawj yam uas yuav tsum tau kuaj xyuas yog qhov kawg ntawm connector -fim contamination, incorrect connector khub suav, thiab npaj txhij txog khoov los yog cable puas nyob rau hauv txoj kev.
Dab tsi yog Kev Pom Zoo Fiber Poob?
Tsis muaj ib lo lus teb thoob ntiaj teb - qhov kev poob qis yog nyob ntawm qhov txuas tshwj xeeb thiab cov cuab yeej ua haujlwm ntawm nws. Txawm li cas los xij, muaj cov lus qhia siv tau:
Qhov txuas dhau qhov kev sim nyiaj poob yog tias tag nrho cov kev ntsuas qhov poob qis yog nyob ntawm lossis qis dua qhov suav nyiaj siv rau qhov txuas tshwj xeeb. Qhov txuas dhau qhov kev sim nyiaj siv hluav taws xob yog tias tseem muaj cov txiaj ntsig kev ua haujlwm zoo tom qab rho tawm tag nrho cov nyiaj poob los ntawm cov cuab yeej siv hluav taws xob. Rau lub sijhawm ntev - kev ntseeg siab, kev ua haujlwm ntawm qhov tsawg kawg nkaus 3 dB siab tshaj qhov tsawg kawg nkaus tau txais kev nkag siab zoo tau pom zoo.
Rau kev siv ceev ceev, cov kev npaj ua kom muaj nuj nqis los ntawm TIA-568.3-D tus qauv yog: multimode fiber ntau ntawm 850 nm yuav tsum tsis pub tshaj 3.5 dB / km; singlemode sab nraum zoov cable ntawm 1310 nm yuav tsum tsis pub tshaj 0.5 dB / km; thiab connector khub yuav tsum tsis pub tshaj 0.75 dB txhua. Yog tias koj qhov ntsuas qhov tseem ceeb ntawm ib feem yog zoo nyob rau hauv cov kev txwv no thiab tag nrho cov kev txuas poob yog nyob rau hauv cov peev nyiaj siv hluav taws xob nrog cov npoo txaus, qhov txuas feem ntau tau txais.
Qhov twg los nrhiav Tx Fais Fab thiab Rx rhiab heev ntawm Daim Ntawv Qhia Transceiver
Ob tus lej koj xav tau rau kev suav nyiaj siv hluav taws xob - transmitter output power (Tx) thiab receiver rhiab heev (Rx) - tau teev nyob rau hauv daim ntawv teev cov transceiver module, feem ntau yog nyob rau hauv ib lub rooj sau npe "Optical Characteristics" los yog "Transmitter/Receiver Parameters." Nrhiav:
- Transmitter tso zis zog (min / max):muab hauv dBm. Siv tus nqi yam tsawg kawg nkaus rau qhov phem tshaj - kev siv nyiaj txiag.
- Receiver rhiab heev:muab hauv dBm. Qhov no yog lub teeb liab uas tsis muaj zog tshaj plaws uas tus receiver tuaj yeem ntes tau thaum tuav tus nqi me ntsis yuam kev.
- Receiver overload (los yog siab tshaj input zog):lub teeb liab muaj zog tshaj tus receiver tuaj yeem ua yam tsis muaj qhov yuam kev. Qhov no tseem ceeb ntawm qhov txuas luv luv uas qhov poob tsawg tsawg.
Cov peev nyiaj siv hluav taws xob yog qhov sib txawv ntawm qhov tsawg kawg nkaus tso zis thiab Rx rhiab heev. Yog tias daim ntawv teev cov ntaub ntawv teev −8.2 dBm yam tsawg kawg Tx thiab −14.4 dBm Rx rhiab heev, cov peev nyiaj siv hluav taws xob yog 6.2 dB - tawm ntau qhov chaw tsawg dua rau kev sib txuas tsis ntev dua - ncav cuag module nrog 13 dB pob nyiaj siv. Xaiv qhov zoo transceiver rau qhov txuas qhov deb yog thawj kauj ruam mus rau kev siv nyiaj txiag. Yog xav paub ntxiv, saib peb tsab xov xwm ntawmtransceivers vs transponders.
Common Fiber Loss xam yuam kev
Suav Connectors Hloov Pairs Connector
Txoj kev siv nyiaj suav suav cov khub sib txuas sib txuas - ob qhov txuas txuas ua ke - tsis yog ib tus neeg xaus. Yog tias koj suav txhua qhov kev sib txuas xoob kawg, koj yuav overestimate lossis underestimate qhov poob nyob ntawm seb koj siv tus nqi li cas rau ib -unit value. Corning cov lus qhia kev xeem tau qhia meej txog qhov no.
Tsis meej pem dB thiab dBm
dB yog tus txheeb ze piv. dBm yog qib siab zog. Yog tias koj rho tawm tus nqi dBm los ntawm tus nqi dB, lossis sib piv lawv ncaj qha, koj cov txiaj ntsig nyiaj txiag yuav tsis muaj nuj nqis. Khaws cov txiaj ntsig poob hauv dB thiab qib zog hauv dBm, thiab tsuas yog muab lawv los ntawm cov qauv raug.
Siv Standard Maximums thaum muaj Specs tiag tiag
TIA kev npaj qhov tseem ceeb yog qhov phem tshaj - cov nyiaj pub dawb, tsis yog tus nqi ib txwm. Yog tias koj muaj cov chaw tsim khoom siv cable thiab cov khoom siv tshwj xeeb, siv cov lej nruj dua. Tshaj - kev cia siab rau tus qauv siab tshaj plaws tuaj yeem ua rau dhau - engineering (kev xaj siab dua- lub zog transceivers koj tsis xav tau) lossis, qhov phem dua, npog qhov teeb meem tiag tiag vim tias qhov nyiaj pub dawb tshuav nyiaj txiag saib "zoo."
Tsis muaj Cheebtsam hauv Channel
Patch panels, optical attenuators, couplers, WDM cov ntxaij lim dej, thiab lwm qhov kev txiav tawm tag nrho ua rau poob. Nws yog ib qho yooj yim kom tsis nco qab lub thaj vaj huam sib luag txuas taw tes lossis ib qho attenuator uas tau ntxiv los tiv thaiv cov neeg txais khoom ntau dhau. Taug kev ntawm txoj kev, tshawb xyuas raws li - tsim cov duab kos, thiab suav txhua yam.
Tsis quav ntsej txog qhov kawg -Face Contamination
Dirty connector kawg lub ntsej muag yog ib qho ntawm feem ntau yog vim li cas vim li cas kev ntsuas poob ntau tshaj qhov suav nyiaj siv. Cov plua plav microscopic tuaj yeem ua rau qhov poob qis thiab rov qab xav tau zoo heev. FOA, Corning, thiab Fluke Networks txhua tus hais txog kev tshuaj xyuas thiab kev tu vaj tse raws li qhov yuav tsum tau ua ua ntej kev ntsuas kev poob. Hauv ntau qhov tiag tiag -kev daws teeb meem hauv ntiaj teb, kev ntxuav lub ntsej muag kawg daws qhov teeb meem yam tsis muaj kev rov qab -spling lossis hloov cable.
Muab xam cov peev nyiaj hla tab sis ntsuas poob tsis tau - Tam sim no Dab tsi?
Thaum tus lej hais tias qhov txuas yuav tsum ua haujlwm tab sis OLTS hais tias nws tsis ua, feem ntau yuav ua rau yog: cov khoom sib kis tsis zoo, cov khoom sib txuas tsis raug suav nrog hauv cov peev nyiaj, ib qho tsis suav nrog splice lossis thaj vaj huam sib luag, kev khoov ntau dhau, lossis kev puas tsuaj cable uas tsis pom thaum lub sijhawm teeb tsa. Pib nrog kev tshuaj xyuas cov khoom sib txuas, tom qab ntawd txheeb xyuas cov khoom suav, thiab siv OTDR txhawm rau txheeb xyuas qhov kev poob tshwj xeeb yog tias kev ntxuav tsis daws qhov sib txawv.
Singlemode vs Multimode: Qhov txawv tseem ceeb rau kev poob nyiaj txiag
Singlemode thiab multimode fiber ntau muaj qhov sib txawv attenuation yam ntxwv, sib txawv kev khiav hauj lwm wavelengths, thiab sib txawv qhov txuas txuas mus - tag nrho cov uas cuam tshuam rau kev siv nyiaj txiag.
Multimode fiber ntau (OM1-OM5)ua haujlwm ntawm 850 nm thiab 1300 nm nrog ntau dua attenuation ib kilometer tab sis feem ntau yog siv rau luv luv txuas hauv tsev thiab tsev kawm ntawv. Cov peev nyiaj siv hluav taws xob rau siab -cov ntawv thov multimode ceev (xws li 10GBASE-SR) tuaj yeem nruj heev - qee zaum tsuas yog 2-3 dB - uas txhais tau tias yuav luag tsis muaj chaw rau cov khoom txuas ntxiv lossis lub ntsej muag qias neeg.
Singlemode fiber ntau (OS1/OS2)ua haujlwm ntawm 1310 nm thiab 1550 nm nrog qis qis qis, ua rau nws xaiv tus qauv rau cov pob txha hauv tsev kawm ntawv, cov xov tooj hauv metro, thiab ntev - kev sib txuas. Cov peev nyiaj siv hluav taws xob feem ntau yog qhov loj dua, tab sis qhov kev ncua ntev txhais tau tias muaj ntau cov fiber ntau attenuation thiab feem ntau ntau splices, yog li cov peev nyiaj tseem tuaj yeem nruj ntawm txoj kev txuas ntxiv.
Ib txwm phim cov attenuation coefficient rau qhov tseeb fiber ntau hom thiab wavelength. Siv tus nqi multimode nyob rau hauv ib qho kev siv nyiaj singlemode (los yog vice versa) yog qhov yuam kev uas yooj yim xav tsis thoob thaum hloov ntawm cov haujlwm.
Cov lus nug nquag
Yuav ua li cas koj xam fiber optic link poob?
Ntxiv qhov poob ntawm fiber ntau attenuation (dB / km × ntev), connector khub (suav × poob ib khub), splices (suav × poob ib splice), thiab lwm yam passive Cheebtsam. Cov nyiaj tau los yog koj qhov kwv yees tag nrho qhov txuas poob. Muab piv rau cov cuab yeej siv hluav taws xob los txiav txim seb qhov txuas yuav tsum ua haujlwm li cas.
Dab tsi yog pob nyiaj siv fiber ntau txuas?
Ib pob nyiaj siv fiber ntau (lossis txuas- pob nyiaj poob) yog qhov kwv yees kwv yees ntawm tag nrho cov kev poob qis thoob plaws qhov txuas fiber ntau. Nws suav nrog tag nrho cov khoom poob - fiber ntau, connectors, splices, thiab passive devices. FOA piav qhia nws raws li qhov kwv yees uas tau muab piv rau cov cuab yeej siv nyiaj siv hluav taws xob txhawm rau txheeb xyuas qhov txuas qhov muaj peev xwm thiab tawm tsam cov txiaj ntsig kev sim kom paub meej tias kev teeb tsa kom raug.
Dab tsi yog qhov txawv ntawm qhov poob thiab attenuation?
Attenuation yog hais txog lub zog kho qhov muag poob ib kilometer ntawm fiber ntau vim yog nqus thiab tawg hauv iav. Insertion poob yog qhov dav dua, kawg -rau- xaus kev ntsuas ntawm tag nrho cov kev poob ntawm qhov txuas txuas, suav nrog fiber ntau attenuation ntxiv rau tag nrho cov connector, splice, thiab cov khoom poob. Rau cov ncauj lus kom ntxaws, nyeem peb tsab xov xwm ntawmkev poob qis hauv fiber ntau.
Dab tsi yog qhov lees txais fiber ntau poob rau ib qhov txuas?
ANSI/TIA-568.3-D tus qauv tso cai rau qhov siab tshaj plaws ntawm 0.75 dB rau ib khub sib txuas. Txawm li cas los xij, zoo-ua Hoobkas-polished connectors feem ntau ua tiav 0.3-0.5 dB. Siv cov khoom sib txuas tiag tiag es tsis yog qhov nyiaj pub dawb tshaj plaws ua rau muaj peev xwm ntau dua.
Npaum li cas yuav tsum muaj fiber ntau txuas?
Yam tsawg kawg ntawm 3 dB ntawm kev khiav hauj lwm margin yog ib qho kev ua raws li kev lag luam dav dav. Qhov no suav rau kev laus ntawm cov khoom siv hluav taws xob, kev sib txuas ntawm cov khoom sib kis thaum lub sij hawm, kev kho cov splice yav tom ntej, thiab qhov kub thiab txias - cuam tshuam txog kev hloov pauv. Cov kev sib txuas uas tsim los nrog tsawg dua 3 dB npoo feem ntau yuav xav tau kev saib xyuas lossis ua tsis tiav ntxov.
Dab tsi yog cov cuab yeej siv los ntsuas qhov poob fiber ntau?
Ib qho Optical Loss Test Set (OLTS), suav nrog lub teeb pom kev zoo thiab lub zog ntsuas hluav taws xob, yog tus qauv ntsuas rau Tier 1 daim ntawv pov thawj ntawm tag nrho qhov txuas poob. Ib qho OTDR yog siv rau Tier 2 xeem - nws muab qhov kev ncua deb -mapped kab uas qhia qhov poob ntawm txhua qhov kev tshwm sim (connector, splice, khoov) raws cov fiber ntau.
Cov ntawv nyeem thiab nyeem ntxiv
- Fiber Optic Association - xam nyiaj Fiber Optic Poob nyiaj
- Corning - Pom zoo Fiber Optic Test Guidelines (LAN-1561-AEN)
- Corning - Link Loss Budget Calculator
- Fluke Networks - Fiber Optic Link Poob nyiaj suav nyiaj
- Fluke Networks - OLTS + OTDR: Ua tiav Fiber Optic Test Strategy
- ANSI/TIA-568.3-D - Optical Fiber Cabling thiab Components Standard (muaj los ntawmTIA)
