Txuj ci

Kev sib kis deb tsis yog cov cuab yeej ntawm cable ib leeg. Nws yog qhov tshwm sim ntawm kev siv nyiaj txiag: cov fiber ntau koj nruab, cov ntaub ntawv tus nqi koj khiav nws, lub wavelength koj transceivers siv, poob koj connectors thiab splices ntxiv, thiab dispersion lub teeb liab accumulates ntawm txoj kev. Hloov ib qho ntawm cov no thiab qhov siab tshaj plaws nyob deb hloov nrog nws.

Tias yog vim li cas ob qhov txuas ua ke nrog tib lub cable tuaj yeem coj txawv txawv - ib qho khiav 40 km yam tsis muaj qhov yuam kev, lwm qhov ua tsis tau ntawm 300 m. Phau ntawv qhia no piav qhia txog qhov hloov pauv twg tsim lub qab nthab, yuav ua li cas xam lub qab nthab rau koj tus kheej txuas, thiab seb yuav kuaj xyuas thaum twg qhov txuas poob qis ntawm nws qhov ntsuas ncav cuag.

Qhov deb yog Link Budget, Tsis yog Cable Spec

Ua ntej saib ntawm tus kheej yam, nws yuav pab kom paub seb cov khoom nyob li cas. Rau ib txwm tsim txuas, qhov siab tshaj plaws nyob deb tau txiav txim siab nyob rau hauv qhov kev txiav txim:

• Fiber hom thiab qib- ib leeg- hom lossis multimode, thiab qeb twg hauv txhua
• Cov ntaub ntawv tus nqi thiab optical interface tus qauv- 1G, 10G, 100G, 400G coj txawv txawv ntawm tib lub fiber ntau
• Specification ntawm Transceiver- tso tawm hwj chim, txais rhiab heev, ntsuas ncav cuag
• Tag nrho qhov txuas poob- fiber ntau attenuation ntxiv rau txhua connector, splice thiab splitter nyob rau hauv txoj kev
• Dispersion- modal dispersion ntawm multimode, chromatic dispersion ntawm ib leeg ntev -mode spans
• Ib puag ncig thiab installation zoo- feem ntau yog qhov teeb meem kev ntseeg siab thiab cov npoo, tsis yog thawj zaug - txiav txim qhov deb

Ib puag ncig tej yam kev mob muaj nyob rau hauv daim ntawv no, tab sis tsis nyob rau saum toj. Kub, noo noo thiab mechanical kev ntxhov siab feem ntau erode kojpaj ntaubthiab ntev - kev cia siab rau lub sij hawm. Lawv tsis tshua txiav txim siab seb qhov kev sib txuas tsim nyog mus txog 10 km lossis 40 km.

Fiber Hom thiab Modal Bandwidth

Tib hom - hom fiber ntau nqa ib hom kev nthuav tawm, yog li nws tsis txhob hloov pauv tag nrho thiab tsuas yog qhov kev xaiv tiag tiag tshaj li ob peb puas meters. Multimode fiber ntau muaj ntau hom uas tuaj txog ntawm lub sijhawm sib txawv me ntsis, thiab qhov kev sib kis - tsis attenuation - yog dab tsi caps nws ncav cuag ntawm cov ntaub ntawv siab.

Qhov no yog vim li cas multimode tau teev los ntawmzoo modal bandwidthtsis yog nyob deb. OM3 yog nyob ntawm 2000 MHz ·km ntawm 850 nm thiab OM4 ntawm 4700 MHz ·km; daim duab siab dua yog vim li casOM4 fiber ntautxhawb 10G thiab 100G raws ntev dua OM3 ntawm lwm yam khoom siv zoo tib yam. Yog tias koj tseem tab tom txiav txim siab ntawm ob tsev neeg, kev ua lag luam - tawm ntawm tus nqi, tus nqi transceiver thiab kev hloov kho lub taub hau yog them rau hauv qhov nosingle-mode piv rau multimode sib piv.

Hauv ib hom -, pawg tseem ceeb tsawg dua rau qhov kev ncua deb tshaj li cov neeg xav.G.652.D fiber ntauyog lub ntsiab kev xaiv, teev nyob rau hauvITU-T Kev Pom Zoo G.652nrog cabled attenuation tsis ntau tshaj 0.4 dB / km ntawm 1310 nm thiab 0.3 dB / km ntawm 1550 nm. Khoov- qib G.657 tsis txaus ntseeg, txhais hauvITU-T G.657, tsis txhob kis ntxiv nyob rau hauv ib tug ncaj ncua - lawv tsuas poob tsawg qhov twg txoj kev quab yuam nruj khoov.

Yog li dab tsi tshwm sim yog tias koj xaiv cov fiber ntau tsis raug? Tsis tshua muaj qhov huv si "kev ncua deb". Feem ntau nws yog ib qho ntawm cov no: lub transceiver yuav tsis txuas tag nrho vim tias ib qho -mos module tsis tuaj yeem ua ob peb zoo rau hauv 50 µm core; qhov txuas tuaj tab sis yuam kev nyob rau hauv load vim modal bandwidth tsis txaus rau tus nqi; los yog lub receiver yog overloaded vim hais tias lub ncua sij hawm yog luv luv tshaj lub module tau tsim rau.

Cov ntaub ntawv tus nqi, wavelength thiab dispersion

Tib fiber ntau txhawb kev sib txawv nyob ntawm seb koj khiav nws li cas. Cov cim siab dua txhais tau tias lub sijhawm luv me ntsis, yog li qhov muab cov mem tes sib kis siv ib feem loj ntawm lub qhov muag. Qhov tshwm sim yog tus qauv txhua tus engineer network thaum kawg ceeb toom: ncav cuag ntog raws li tus nqi nce.

Nco ntsoov tias OM4 yuav koj 100 m ntawm 10G tab sis tsuas yog 30 m ntawm 100G. Qib fiber ntau tsis tuaj yeem them nyiaj tsis muaj sijhawm rau tus nqi.

Wavelength ua haujlwm nyob rau hauv ob qho kev qhia ib zaug. Ntawm 1550 nm attenuation yog qis tshaj - feem ntau nyob ib ncig ntawm 0.19–0.21 dB/km ntawm G.652.D tawm tsam 0.32–0.35 dB/km ntawm 1310 nm - uas yog vim li cas ntev -haul thiab DWDM11} nyob hauv C Tab sis 1550 nm kuj yog qhov uas tus qauv ib zaug - hom fiber ntau qhia kwv yees li 17 ps/nm·km ntawmchromatic dispersion, thaum 1310 nm zaum zero -dispersion point. Ntawm 10G lossis 25G txuas yav dhau los txog 60-80 km, kev tawg, tsis muaj zog, dhau los ua qhov kev txwv tsis pub, thiab koj xav tau kev them nyiaj lossis kev sib txuas sib txuas es tsis yog lub tshuab xa hluav taws xob kub.

Optical Power Budget

Qhov no yog kev suav uas hloov qhov kev sib tham saum toj no rau hauv tus lej. Pib nrog dab tsi lub transceiver muab rau koj:

Muaj peev xwm siv hluav taws xob (dB)=yam tsawg kawg nkaus tso zis hluav taws xob (dBm) − receiver rhiab heev (dBm)

Tom qab ntawd rho tawm txhua qhov txuas siv:

• Fiber attenuation: attenuation coefficient (dB/km) × ntev (km)
• Connector poob: tus naj npawb ntawm cov khub sib tw × poob ib khub (feem ntau 0.2-0.5 dB hauv thaj chaw; TIA tso cai txog 0.75 dB)
• Splice poob: tus naj npawb ntawm fusion splices × poob ib splice (feem ntau nyob rau hauv 0.1 dB, nrog 0.3 dB ib qho kev lees paub txwv)
• Passive tivthaiv poob: PON splitters, thaj panels, WDM lim
• Qhov System Margin: 3 dB yog qhov kev tso cai rau kev laus, kho thiab ntsuas qhov tsis paub meej

Ib qho piv txwv ua haujlwm rau 10 km ib zaug -mode txuas ntawm 1310 nm, siv tus sawv cev datasheet qhov tseem ceeb - ib txwm hloov cov duab los ntawm koj tus kheej module datasheet:

• Transmitter yam tsawg kawg nkaus tso zis: -8.0 dBm; Txais rhiab heev: −18.0 dBm →pob nyiaj siv 10.0 dB
• Fiber ntau: 10 km × 0.36 dB/km=3.6 dB
• Connectors: 4 khub niam txiv × 0.5 dB=2.0 dB
• Qhov loj me: 2 × 0.1 dB=0.2 dB
• Tag nrho qhov txuas poob=5.8 dB; seem npoo=4.2 dB

Tshaj 3 dB ntawm cov npoo, qhov txuas yog suab. Hauv qab no, koj yog ib qho khoom siv qias neeg lossis ib qho kev kho splice kom deb ntawm qhov yuam kev. Thiab yog tias kev suav dhau mus tab sis qhov txuas tseem ua tsis tiav, qhov txwv tsis yog lub zog - saib ntawm kev sib cais lossis ntawm tus nqi / qhov cuam tshuam tsis sib haum.

Connectors, Splices thiab dabtsi yog khoov

Nyob rau hauv ib lub chaw soj nstuam, fiber ntau dominates cov nyiaj txiag poob. Hauv thaj teb, cov xwm txheej tsis sib xws feem ntau ua. Plaub connector khub ntawm 0.5 dB txhua tus nqi tib yam li 5.5 km ntawm G.652.D fiber ntau ntawm 1310 nm - thiab connector suav yog qhov sib txawv feem ntau underestimated nyob rau theem tsim.

Peb hom kev ua tsis tiav suav rau feem ntau ntawm qhov tsis txaus ntawm kev suav thiab ntsuas qhov poob:

• Cov ntsej muag uas tsis huv.Ib qho me me ntawm ib qho ferrule tuaj yeem ntxiv txhua yam los ntawm ib feem ntawm dB kom ua tiav qhov txuas tsis ua haujlwm, thiab nws yog thawj zaug los tshuaj xyuas ntawm txhua qhov txuas uas degraded yam tsis muaj lub cev hloov pauv.
• Tsis zoo fusion splices.Core misalignment, cleave lub kaum sab xis yuam kev thiab kev sib kis tag nrho tshwm sim li siabsplice poob. Ib qho kev sib txuas tsis tu ncua saum 0.3 dB yuav tsum tau rov ua dua - ua dua tsis tau txais.
• Khoov.Macrobending - ib lub cable rub ib ncig ntawm lub tais ces kaum nruj dua li nws qhov tsawg kawg nkaus khoov lub vojvoog - zoo nkaus li cov kauj ruam hauv cheeb tsam ntawm OTDR kab thiab muaj zog wavelength - nyob ntawm, phem dua ntawm 1550 nm dua li ntawm 1310 nm. Microbending los ntawm crushing los yog tshaj - nruj cable ties yog ntau diffuse thiab nyuaj rau localise. Covkhoov poob tus cwj pwm ntawm G.657 fiber ntauyog dab tsi ua rau nws tsim nyog teev rau hauv - tsev thiab FTTH txoj hauv kev uas cov neeg nruab tsis tuaj yeem lav qhov dav dav radii.

Transceiver ncav cuag thiab Compatibility

Qhov kev ncua deb luam tawm ntawm qhov kho qhov muag module yog qhov ntsuas qhov system tau los ntawm tus qauv interface, tsis yog lus cog tseg txog koj txoj hauv kev. Nws xav tias ib hom fiber ntau, ib lub wavelength tshwj xeeb, thiab ib qho channel nkag tsis tau tus qauv txhais. Peb daim tshev ua ntej koj cog lus:

• Fiber hom thiab wavelength yuav tsum sib phim ntawm ob qhov kawg.Ib qho 850 nm module thiab ib qho - hom span tsuas yog tsis sib xws, thiab 1310 nm module yuav tsis cuam tshuam nrog 1550 nm ib qho.
• Koj qhov kev xam qhov txuas poob yuav tsum tau zaum hauv qab ntawm lub interface lub channel tso nyiaj poob nyiaj, uas tau teev tseg rau PHY hom los ntawmIEEE 802.3 Pawg Ua Haujlwm.
• Kos lub receiver overload point, tsis yog rhiab heev.Muab 40 km ER module rau ntawm qhov txuas 500 m tuaj yeem ua rau cov neeg txais thiab tsim cov kev ua yuam kev uas zoo ib yam li kev poob ntau dhau. Haum rau lub attenuator.

Rau kev yuav khoom, txoj cai siv tau yog nug cov neeg muag khoom rau peb tus lej uas tso cai rau koj txheeb xyuas qhov kev thov koj tus kheej: yam tsawg kawg nkaus tso zis hluav taws xob transmitter, receiver rhiab heev, thiab rated channel insertion poob. Ib qho "20 km module" uas tsis muaj cov lej no tuaj yeem kuaj xyuas koj txoj kev.

Environmental thiab Installation Conditions

Ib puag ncig cuam tshuam kev deb ntawm kev ncaj qha, los ntawm kev noj cov npoo thiab los ntawm kev degrading lub cable dhau sijhawm. Cov kab hluav taws xob sab nraum zoov xav tau dej- thaiv, UV- tiv taus thiab cov khoom siv hluav taws xob zoo vim tias cov dej noo nkag mus rau hauv lub plhaub puas lossis qhov sib txuas kaw, thiab tsoo cov khoom thauj uas ua rau microbending, yog dab tsi thawb qhov txuas tawm ntawm cov nyiaj xyoo tom qab ua haujlwm. Cyclic kub siab heev tseem ceeb nyob rau hauv ciam teb ntawm qhov kev khiav hauj lwm ntau yam thiab los ntawm ntev - lub sij hawm laus, tsis raws li ib hnub- mus rau - hnub nyob deb variable.

Ib qho kev kho tsim nyog ua kom meej meej, vim nws tshwm sim tas li hauv cov ntaub ntawv cable:nplaim taws-retardant thiab hluav taws kub- cov qhab nia tiv thaiv tsis ntev kev sib kis.Lawv muaj los ua kom txaus siab rau cov cai hluav taws xob hauv tsev, txwv cov nplaim taws sib kis thiab tswj cov pa taws thiab halogen emission. Flexibility thiab khoov kev ua tau zoo tiag tiag cuam tshuam rau kev poob; nplaim taws ntsuas tsis tau. Qhia ob qho tib si, tab sis tsis txhob confuse ob.

Cov lus nug nquag

- hom fiber ntau tuaj yeem xa mus deb npaum li cas?

Nws nyob ntawm qhov interface, tsis yog fiber ntau. Standard Ethernet interfaces ntawm ib qho - hom ncua 10 km (LR), 40 km (ER) thiab 80 km (ZR-chav kawm, tus neeg muag khoom- qhia). Nrog rau kev nthuav dav thiab kev sib faib nyiaj, submarine thiab ntev -haul systems khiav ntau txhiab mais ntawm tib hom fiber ntau. Cov fiber ntau yuav luag tsis muaj qhov txwv.

Vim li cas tib lub fiber ntau txhawb nqa qhov deb ntawm cov ntaub ntawv ntau dua?

Ob qho laj thawj. Cov nqi siab dua ua rau lub sijhawm me ntsis, yog li tus nqi ruaj khov ntawm cov mem tes sib kis los ntawm kev sib cais siv feem ntau ntawm lub qhov muag. Thiab siab dua - tus nqi txais feem ntau xav tau lub zog kho qhov muag ntau dua rau tib qhov kev ua yuam kev, uas ua rau lub zog siv nyiaj tsawg. Ob qho kev cuam tshuam thawb rau tib qho kev taw qhia.

Puas yog 1310nm lossis 1550nm zoo dua rau kev ncua deb?

1550nm muaj qis qis qis, yog li nws yeej ntawm cov peev nyiaj siv hluav taws xob ntev ntev. Tab sis 1310 nm zaum zero-kev sib cais wavelength ntawm tus qauv ib zaug- hom fiber ntau, yog li nws muaj kev zam siab dua rau siab - tus nqi txuas. Rau qhov poob - txwv ncua, xaiv 1550 nm; rau ib qho dispersion- txwv ib qho, 1310 nm lossis qhov cuam tshuam nrog kev them nyiaj dispersion.

Kuv qhov txuas tau zoo nyob rau hauv lub module qhov ntsuas qhov deb tab sis tseem ua yuam kev. Vim li cas?

Feem ntau yog vim li cas, nyob rau hauv kev txiav txim: contaminated connector kawg lub ntsej muag, ntau connector khub nyob rau hauv txoj kev tshaj li cov peev nyiaj xav, ib tug siab - poob splice, ib tug khoov ua txhaum lub vojvoog yam tsawg kawg nkaus, los yog receiver overload ntawm ib tug luv luv txuas nrog ib tug ntev - mus txog module. Ntsuas qhov poob ua ntej - nws cais cov teeb meem fais fab ntawm txhua yam.

Puas tsawg - poob lossis "premium" cables txuas ntxiv qhov kev ncua deb?

Qee lub sij hawm, tab sis cov nyhuv yog bounded thiab yuav tsum tau quantified. Tsiv ntawm 0.35 dB / km mus rau 0.19 dB / km ntawm 1550 nm txuag 1.6 dB tshaj 10 km - tiag, tab sis me dua peb qhov txuas txuas. Ultra-qis- poob fiber ntau khwv tau nws tus nqi ntawm qhov ntev tsis rov ua dua, tsis nyob hauv tsev kawm ntawv txuas. Nco ntsoov nug seb lub wavelength twg ib daim duab attenuation hais txog, thiab nco ntsoov tias lub transceiver qhov ntsuas qhov ncav cuag tseem caps qhov txuas txawm tias qhov fiber ntau zoo npaum li cas.

Cov ntsiab lus

Fiber optic kis tau tus mob nyob deb yog teem los ntawm ib tug system, tsis yog los ntawm ib tug cable. Txhim kho cov ntaub ntawv tus nqi thiab tus qauv interface ua ntej, tom qab ntawd hom fiber ntau thiab qib, tom qab ntawd suav cov peev nyiaj siv hluav taws xob tiv thaiv koj cov khoom sib txuas tiag tiag thiab suav cov splice, thiab thaum kawg xyuas cov dispersion ntev lossis siab - tus nqi spans. Kho ib puag ncig tshwj xeeb raws li kev ntseeg siab thiab kev txiav txim siab margin - tsim nyog, tab sis cov lus nug txawv ntawm kev ncav cuag.

Yog tias koj tab tom qhia txog cable rau txoj hauv kev uas paub ntev thiab tus nqi, cov kauj ruam tom ntej tseem ceeb yog ua haujlwm rov qab: nqa lub interface lub channel tso qhov poob nyiaj, rho tawm 3 dB ntawm cov npoo, rho koj cov khoom txuas thiab cov nyiaj sib txuas, thiab saib seb qhov coefficient txo qis qhov seem ntawm cov fiber ntau xav tau. Tus lej ntawd, tsis yog kev lag luam nyob deb, yog qhov yuav tsum tau tsav qhov tshwj xeeb.