Txawm li cas los xij lub zej zog uas muaj kev kaj siab thuam TV rau nws qhov tsis zoo rau kev nco qab, txawm li cas los xij, lub teeb liab TV muaj nyob hauv yuav luag txhua qhov chaw nyob (thiab ntau qhov chaw tsis nyob hauv tsev). Hauv cov nroog loj, qhov no yuav luag txhua lub TV cable, txawm tias txhua tus nyob ib puag ncig lawv ib txwm hu nws "antenna". Thiab yog hais tias lub terrestrial TV txais system yog heev pom tseeb (txawm hais tias nws kuj yuav txawv los ntawm ib txwm horned kav hlau txais xov nyob rau windowsill, kuv yuav mas tham txog qhov no tom qab), ces lub cable TV system yuav zoo li poob nthav tsis yooj yim rau nws cov hauj lwm thiab architecture. Kuv nthuav tawm ib tsab xov xwm hais txog qhov no. Kuv xav qhia cov neeg txaus siab rau cov hauv paus ntsiab lus ntawm kev ua haujlwm ntawm CATV tes hauj lwm, nrog rau lawv txoj haujlwm thiab kev kuaj mob.
- Part 1: General CATV network architecture
- Ntu 2: Cov teeb liab muaj pes tsawg leeg thiab cov duab
- Part 3: Analog Signal Component
- Ntu 4: Cov Khoom Siv Hluav Taws Xob Digital
- Ntu 5: Coaxial faib network
- Ntu 6: RF Signal Amplifiers
- Ntu 7: Optical receivers
- Part 8: Optical backbone network
- Ntu 9: Headend
- Ntu 10: Kev daws teeb meem ntawm CATV network
Kuv tsis ua txuj sau ib phau ntawv nyeem, tab sis kuv yuav sim nyob rau hauv lub moj khaum ntawm kev tshawb fawb thiab tsis overload cov ntawv nrog cov qauv thiab cov lus piav qhia ntawm technologies. Qhov no yog vim li cas kuv thiaj li tso "ntse" cov lus nyob rau hauv cov ntawv nyeem yam tsis tau piav qhia; los ntawm googling lawv koj tuaj yeem nkag mus tob npaum li koj xav tau. Tom qab tag nrho, txhua yam tau piav qhia zoo ib tus zuj zus, tab sis kuv tsuas yog yuav qhia koj li cas nws tag nrho ntxiv rau cable TV system. Nyob rau hauv thawj qhov chaw, kuv yuav superficially piav qhia txog tus qauv ntawm lub network, thiab tom qab ntawd kuv yuav tshuaj xyuas kom meej ntxiv cov ntsiab lus ntawm kev ua haujlwm ntawm tag nrho cov system.
Lub cable TV network muaj cov qauv ntoo. Lub teeb liab yog tsim los ntawm lub taub hau chaw nres tsheb, uas sau cov teeb liab los ntawm ntau qhov chaw, tsim lawv rau hauv ib qho (raws li ib qho kev npaj ntau zaus) thiab xa lawv mus rau lub network faib loj hauv daim ntawv xav tau. Niaj hnub no, lub caj qaum network yog, ntawm chav kawm, kho qhov muag thiab lub teeb liab mus rau hauv coaxial cable tsuas yog nyob rau hauv lub kawg lub tsev.
Lub taub hau chaw nres tsheb
Cov khoom siv hluav taws xob rau lub taub hau tuaj yeem yog cov kav hlau txais xov satellite (uas tuaj yeem muaj lub kaum os) lossis cov kwj digital xa ncaj qha los ntawm TV raws lossis lwm tus neeg siv xov tooj. Kom tau txais thiab sib sau ua ke cov cim los ntawm ntau qhov chaw, ntau qhov kev pabcuam ntau tus decoders / modulators yog siv, uas yog khib-mount chassis nrog ntau daim npav nthuav dav uas muab kev sib txuas rau ntau qhov sib cuam tshuam, nrog rau kev txiav txim siab, hloov kho thiab tsim cov teeb liab xav tau. .
Ntawm no, piv txwv li, peb pom 6 modules rau tau txais satellite tshaj tawm xov xwm thiab ob DVB-C tso zis modulators.
Thiab lub chassis no yog koom nrog hauv descrambling lub teeb liab. Koj tuaj yeem pom CAM modules, tib yam uas tau muab tso rau hauv TVs kom tau txais cov kab hluav taws xob kaw.
Qhov tshwm sim ntawm kev ua haujlwm ntawm cov cuab yeej no yog lub teeb liab tso tawm uas muaj tag nrho cov channel uas peb yuav muab rau cov neeg siv khoom, npaj los ntawm zaus raws li ib qho kev npaj ntau zaus. Hauv peb lub network, qhov no yog qhov ntau ntawm 49 txog 855 MHz, muaj ob qho tib si analog thiab digital channels hauv DVB-C, DVB-T thiab DVB-T2 hom:
Tso cov teeb liab spectrum.
Lub teeb liab generated yog pub rau hauv ib qho optical transmitter, uas yog qhov tseem ceeb tshaj tawm xov xwm hloov pauv thiab hloov peb cov channel mus rau hauv qhov nruab nrab ntawm qhov nruab nrab ntawm lub TV ib txwm wavelength ntawm 1550 nm.
Optical transmitter.
Lub cev faib khoom network
Cov teeb liab kho qhov muag tau txais los ntawm lub taub hau yog nthuav dav siv qhov kho qhov muag erbium amplifier (EDFA), paub txog txhua tus kws tshaj lij kev sib txuas lus.
Ob peb kaum ntawm dBm ntawm cov teeb liab theem coj los ntawm lub tshuab hluav taws xob tso tawm tuaj yeem muab faib thiab xa mus rau ntau qhov chaw. Kev faib yog nqa tawm los ntawm passive dividers, kom yooj yim, muab tso rau hauv lub tsev ntawm khib-mount cross-connects.
Optical divider nyob rau hauv ib chav tsev optical cross-connect.
Lub teeb liab sib faib mus txog cov khoom uas, yog tias tsim nyog, nws tuaj yeem ua kom nrov nrov siv tib lub amplifiers, lossis faib ntawm lwm yam khoom siv.
Qhov no yog qhov chaw nyob hauv cheeb tsam node yuav zoo li. Nws suav nrog lub tshuab hluav taws xob kho qhov muag, lub teeb liab divider nyob rau hauv rackmount vaj tse, thiab kev faib khoom kho qhov muag, los ntawm cov fibers raug faib rau cov khoom siv kho qhov muag.
Cov neeg siv khoom faib network
Optical receivers, zoo li lub transmitter, yog nruab nrab converters: lawv hloov cov tau txais optical teeb liab mus rau ib tug coaxial cable. OPs tuaj nyob rau hauv ntau yam thiab los ntawm txawv manufacturers, tab sis lawv functionality feem ntau yog tib yam: qib kev soj ntsuam thiab yooj yim teeb liab hloov, uas kuv yuav tham nyob rau hauv kom meej nyob rau hauv cov lus hauv qab no.
Optical receivers siv nyob rau hauv peb lub network.
Nyob ntawm lub tsev architecture (tus naj npawb ntawm cov plag tsev, tus naj npawb ntawm lub tsev thiab lub qhov rooj, thiab lwm yam), lub optical receiver tuaj yeem nyob rau ntawm qhov pib ntawm txhua tus riser, los yog tej zaum ib qho ntawm ob peb (qee zaum txawm nyob nruab nrab ntawm lub tsev tsis muaj ib qho kev pom zoo. optical, tab sis ib coaxial cable nteg), nyob rau hauv cov ntaub ntawv no, lub inevitable attenuation ntawm lub dividers thiab txoj kev loj yog compensated los ntawm amplifiers. Zoo li qhov no, piv txwv li:
CATV teeb liab amplifier Teleste CXE180RF
Cov neeg siv khoom faib tawm yog tsim los ntawm ntau hom coaxial cable thiab ntau qhov sib faib, uas koj tuaj yeem pom hauv cov vaj huam sib luag qis tam sim no ntawm koj lub staircase.
Cables nkag mus rau hauv chav tsev yog txuas nrog cov outputs ntawm cov neeg siv khoom splitters.
Ntawm chav kawm, feem ntau, muaj ntau lub TV nyob rau hauv txhua chav tsev thiab lawv txuas nrog ntxiv splitters, uas kuj qhia attenuation. Yog li ntawd, qee zaum (thaum muaj ntau lub TV hauv chav tsev loj), nws yog ib qho tsim nyog yuav tsum tau nruab cov teeb liab amplifiers ntxiv rau hauv chav tsev, uas rau cov hom phiaj no yog me me thiab tsis muaj zog tshaj qhov tseem ceeb.
Tau qhov twg los: www.hab.com