ADSL vs Broadband
Broadband sawv cev rau qee hom kev sib txuas lus cov ntaub ntawv thev naus laus zis uas tso cai rau cov ntaub ntawv hloov pauv ntau dua piv rau cov qauv sib txuas. Nws kuj sawv cev rau ntau hom DSL (Digital Subscriber Line) technologies whereas ADSL (Asynchronous Digital Subscriber Line) yog ib daim ntawv ntawm nws. ADSL siv tooj liab txuas xov tooj sib txuas los muab cov ntaub ntawv ceev ceev, tso cai rau tib lub sijhawm xa cov suab thiab cov ntaub ntawv.
ADSL
ADSL (Asymmetric Digital Subscriber Line) yog ib daim ntawv uas nrov heev ntawm DSL thev naus laus zis. Raws li lub npe qhia, ADSL yog 'asymmetric' nyob rau hauv cov nqe lus ntawm upload thiab download ceev nws muab. Qhov no yog ib qho ntawm cov laj thawj tseem ceeb rau nws qhov muaj koob meej txij li ADSL muab ntau dua downstream zaus bandwidth (138 kHz - 1104 kHz) piv rau upstream zaus bandwidth (26.075 kHz - 137.825 kHz).
Feem ntau, ADSL yog muab los siv tib qhov chaw siv rau kev sib txuas suab; yog li, nws yuav tsum muaj ADSL splitter rau kev ntxub ntxaug ob lub suab thiab cov ntaub ntawv bandwidths. Lub splitter feem ntau yog txuas nrog ntawm cov neeg siv khoom, thiab cov ntaub ntawv sib cais tau muab pub rau hauv ADSL modem lossis router, rau lub hom phiaj ntawm kev hloov kho thiab demodulation. Lub ntsiab drawback ntawm ADSL yog qhov attenuation ntawm cov teeb liab hla kev ncua deb.
ADSL feem ntau tuaj yeem muab faib ua luv luv ntawm kev sib pauv xov tooj mais kawg; Qhov no feem ntau txawv ntawm 4 mus rau 5 km. Rau sab kev sib pauv, nws xaus nrog cov neeg siv digital kab nkag mus rau multiplexer (DSLAM), uas yog lwm hom zaus splitter uas cais lub suab band teeb liab ntawm lub xov tooj. Tom qab ntawd, cov ntaub ntawv raug xa mus hla lub tuam txhab xov tooj cov ntaub ntawv network, thiab thaum kawg nws mus txog cov ntaub ntawv nraub qaum raws li Internet Protocol.
ADSL yog tag nrho duplex cov ntaub ntawv kev sib txuas lus kev daws teeb meem thiab feem ntau yog siv los ntawm ib khub ntawm cov xov hlau (Copper), raws li cov zaus faib duplex (FDD), lub sij hawm faib duplex (TDD), lossis ncha-tso duplex (ECD) technologies. Muaj ntau ntau hom ADSL technologies muaj hnub no, xws li ADSL 2 thiab ADSL 2+. Cov hom no tau hloov zuj zus nrog cov ntaub ntawv ntau dua. ADSL2 muaj ceev txog li 12,000kbps thiab ADSL 2+ nrog ceev txog li 24,000 kbps.
Broadband
Broadband tau pib pib ua qhov sib txawv ntawm kev pabcuam hu xovtooj thiab muab ntau dua 'bandwidth' dua li cov thev naus laus zis nqaim. Nws tuaj yeem yog hom DSL lossis Cable. Lub International Telecommunications Union (ITU) tau txhais broadband raws li kev sib txuas uas muab cov nqi siab dua tus qauv tus nqi ntawm 1.5Mbps.
Ntxiv mus, broadband kis tau tus mob thev naus laus zis tau npaj los siv cov bandwidth loj uas muab los ntawm fiber ntau optics. Broadband muab kev nkag mus rau qhov zoo tshaj plaws Internet kev pab cuam rau streaming media, gaming, VoIP (Internet xov tooj), thiab kev sib tham sib pab. Broadband kev sib txuas ua kom muaj kev nkag tau sai sai rau ntau yam ntawm cov ntaub ntawv online, email, instant messaging, thiab lwm yam kev pabcuam kev sib txuas lus uas muaj nyob hauv internet. Ntau qhov kev pabcuam tam sim no thiab tsim tshiab yuav tsum tau hloov pauv cov ntaub ntawv ntau dua uas tsis muaj peev xwm ua tau nrog kev pabcuam kev sib txuas.
Hnub no, ntau hom kev pabcuam digital subscriber line (DSL) muaj xws li SDSL (symmetric Digital Subscriber Line), HDSL (High-bit-rate Digital Subscriber Line). Lub hauv paus ntawm tag nrho cov thev naus laus zis no ua kom ntseeg tau tias cov ntaub ntawv digital raug xa mus rau cov kab hluav taws xob siab-bandwidth.
Dab tsi yog qhov txawv ntawm ADSL thiab Broadband?
• ADSL yog hom kev daws teeb meem dav dav; yog li ob leeg muaj cov yam ntxwv zoo sib xws hauv cov ntsiab lus ntawm lub network architecture.
• ADSL kev sib txuas yog qhov zoo tshaj plaws siv nyob rau hauv cov xwm txheej uas muaj kev thov siab heev rau cov dej ntws qis, qhov broadband tuaj yeem muab kev daws teeb meem rau ntau yam kev xav tau ywj pheej los ntawm kev txwv bandwidth rau sab sauv thiab qis.
• Broadband muaj ntau haiv neeg nyob rau hauv ntau yam kis tau tus mob technologies xws li cable, DSL, Txawb/wireless, tab sis ADSL siv tsuas yog DSL technology uas khiav ntawm tooj liab cables.
• ADSL tej zaum yuav tsis muaj nyob rau hauv txhua qhov chaw, vim qhov kev ncua deb ntawm qhov kev sib pauv mais kawg, tab sis Broadband muab kev pabcuam siv ntau hom kev siv tshuab xws li cable, satellite, uas tuaj yeem ua haujlwm txawm tias nyob deb. txwv.
