Qhov sib txawv tseem ceeb ntawm Kev Qhia Xov Xwm thiab Cov Xov Xwm Tsis Muaj Kev Qhia yog tias hauv kev tshaj tawm xov xwm, cov teeb liab taug kev los ntawm lub cev nruab nrab thaum nyob hauv cov xov xwm tsis muaj kev taw qhia, cov teeb liab taug kev los ntawm huab cua.
Hauv kev sib txuas lus cov ntaub ntawv, lub transmitter xa cov teeb liab, thiab tus txais tau txais lawv. Cov xov xwm kis tau tus mob yog txoj kev ntawm lub transmitter thiab receiver. Thiab, muaj ob hom kev sib kis xov xwm. Lawv yog cov tshaj tawm thiab cov xov xwm uas tsis muaj kev taw qhia.
Kev Qhia Media yog dab tsi?
Nyob rau hauv kev tshaj tawm xov xwm, cov teeb liab taug kev los ntawm ib qho khoom nruab nrab. Lub peev xwm kis tau tus mob nyob ntawm yam xws li qhov ntev, qhov nruab nrab, thiab lwm yam. Ob peb piv txwv ntawm cov kev qhia tawm yog cov khub twisted, coaxial cable, thiab fiber ntau optical. Twisted khub cable xa ob qho tib si analog thiab digital signals. Nws muaj ob lub insulated tooj liab hlau nyob rau hauv ib tug kauv qauv. Twisting pab txo qhov cuam tshuam ntawm cov khub uas nyob ib sab ntawm ib lub cable. Ntxiv mus, muaj ob hom twisted khub; lawv yog cov shielded twisted khub (STP) thiab unshielded twisted khub (UDP).
Daim duab 01: Twisted Pair Cables
Cov coaxial cable yog txoj kev sib txuas lus zoo dua vim nws xav tau tus nqi qis. Lub baseband coaxial cable tso cai rau kev sib txuas lus hauv baseband thiab siv cov teeb liab digital. Cov tooj liab hlau muaj ib lub hauv insulated npog thiab ib tug braided txheej conductor. Tsis tas li ntawd, cov yas tiv thaiv npog ib puag ncig tag nrho cov no. Ib tug broadband coaxial cable tso cai rau kis tau tus mob analogue. Nws siv analog signaling. Ib qho nrov coaxial cable yog cable TV rau TV teeb liab faib. Feem ntau, ib lub coaxial cable nqa cov teeb liab ntau zaus dua li cov kab sib tw twisted.
Daim duab 02: Coaxial Cable
Fiber optics xa cov teeb liab hauv daim ntawv ntawm lub teeb. Nws xa lawv los ntawm qhov nruab nrab nyias nyias ua los ntawm silicon lossis iav. Cov tub ntxhais ntawm cov kab no yog cov seem sab hauv, thiab nws muaj ib qho khoom siv dielectric lub tog raj kheej ncig los ntawm lwm cov khoom siv hluav taws xob. Lub reflexive Performance index ntawm cladding yog tsawg dua qhov reflexive index ntawm cov tub ntxhais. Raws li qhov tshwm sim, lub teeb nthuav tawm los ntawm ntau qhov kev xav sab hauv.
Daim duab 03: Fiber Optics
Ntawm qhov zoo, cov khoom siv kho qhov muag txo cov suab nrov, txo qis thiab muab cov bandwidth ntau dua li cov kab sib tw thiab coaxial cable. Txawm hais tias nws muaj ntau qhov zoo, muaj qee qhov tsis zoo thiab. Ntawd yog, tus nqi ntawm kev teeb tsa thiab kev saib xyuas ntawm fiber ntau yog kim.
Cov Media Unguided yog dab tsi?
Kev sib txuas lus wireless siv cov xov xwm tsis muaj kev taw qhia uas cov teeb liab hla huab cua. Txoj kev yog ntshaw nyob rau hauv qhov chaw uas nws yog ib qho nyuaj rau khiav ib lub cev cable ntawm ob qhov kawg. Xov tooj cua nthwv dej, microwaves, thiab infrared nthwv dej yog ob peb yam piv txwv ntawm cov xov xwm tsis muaj kev qhia.
Daim duab 04: Microwave Transmission
Xov tooj cua tsis tshua muaj suab nrov thiab nthuav tawm hauv txhua qhov kev qhia. Yog li ntawd, nws tsis yog qhov tsim nyog los ua kom cov xaim xaim thiab txais cov kav hlau txais xov. Txawm li cas los xij, nws tsim nyog rau kev tshaj tawm mus ntev.
Ntawm qhov tod tes, microwave muaj zaus ntau dua li xov tooj cua. Tab sis, qhov kev ncua deb ntawm lub teeb liab tuaj yeem taug kev nyob ntawm qhov siab ntawm lub kav hlau txais xov. Tsis tas li ntawd, lub microwave xav tau kab ntawm kev pom kev sib kis. Cov xov tooj ntawm tes, satellite networks, thiab wireless LANs siv microwaves.
Cov nthwv dej infrared tsis tuaj yeem hla ntau yam teeb meem. Yog li ntawd, lawv siv rau kev sib txuas lus luv luv. Cov khoom siv xws li TV cov chaw taws teeb tswj thiab VCR siv infrared nthwv dej.
Dab tsi yog qhov sib txawv ntawm Kev Qhia Xov Xwm thiab Cov Xov Xwm Tsis Qhia?
Guided Media vs Unguided Media |
|
| Kev tshaj tawm yog qhov nruab nrab uas xa cov cim los ntawm txoj hauv kev ntawm lub cev. | Unguided media yog qhov nruab nrab uas xa cov teeb liab los ntawm qhov chaw dawb. |
| Kev taw qhia | |
| Muaj ib qho kev taw qhia tshwj xeeb xa cov cim. | Tsis muaj kev taw qhia tshwj xeeb xa tawm. |
| Siv hauv kev xa xov xaim | Pab xa xov wireless |
| Piv txwv | |
| Twisted khub, coaxial cable, thiab fiber optics | xov tooj cua, microwave, thiab infrared |
Summary – Guided Media vs Unguided Media
Kev tshaj tawm thiab kev tshaj tawm tsis qhia yog ob hom kev sib kis. Qhov txawv ntawm Guided Media thiab Unguided Media yog tias nyob rau hauv kev tshaj tawm xov xwm, cov teeb liab taug kev los ntawm lub cev nruab nrab thaum nyob rau hauv unguided media, cov teeb liab taug kev los ntawm huab cua.
