4G vs LTE
4G, hu ua 4 thtiam ntawm kev sib txuas lus ntawm tes, thiab LTE (Long Term Evolution) yog 3GPP cov lus qhia rau cov xov tooj ntawm tes broadband. Lub sijhawm sib txawv ntawm kev sib txuas lus ntawm tes tau muab faib ua ntau tiam neeg xws li 1G, 2G, 3G, thiab 4G, qhov twg txhua tiam neeg muaj ntau cov thev naus laus zis xws li LTE. ITU (International Telecommunication Union) txiav txim siab LTE-Advanced raws li tus qauv 4G tiag tiag, thaum nws tseem lees txais LTE raws li tus qauv 4G.
4G
ITU suav tias IMT-Advanced (International Mobile Telecommunication) technologies raws li 4G qauv tseeb. Raws li cov lus txhais, IMT-Advanced yuav tsum muaj peev xwm xa qhov siab tshaj plaws download ceev ntawm 1Gbps nyob rau hauv ib puag ncig nyob ruaj ruaj, thaum 100Mbps nyob rau hauv high mobile ib puag ncig. Thaum pib, ITU ua tiav qhov kev ntsuam xyuas ntawm 6 tus neeg sib tw wireless mobile broadband qauv rau cov qauv 4G. Thaum kawg, 2 thev naus laus zis, LTE Advanced thiab WirelessMAN-Advanced tau lees paub lub npe hu ua IMT-Advanced. Txawm hais tias, LTE Advanced tau suav tias yog tus qauv 4G tiag tiag, ITU kuj tau tso cai siv HSPA +, WiMax thiab LTE li 4th tiam thev naus laus zis. Raws li IMT-Advanced specification ncov spectral efficiency yuav tsum yog 15bps / Hz rau downlink thiab 6.75bps / Hz rau uplink. Qhov kev ua tau zoo spectral no thiab lwm yam IMT-Advanced yuav tsum tau ua tiav los ntawm 3GPP Tso Tawm 10 (LTE-Advanced).
LTE
LTE tau pib nrog 3GPP Tso Tawm 8 (Txias thaum Lub Peb Hlis 2008), thiab hloov zuj zus ntxiv hauv 9 thiab 10 tawm. Kev ua haujlwm siab spectral yog ib qho tseem ceeb ntawm LTE uas tau ua tiav siv Orthogonal Frequency Division Multiple Access (OFDMA) nrog 64-QAM (Quadrature Amplitude Modulation) cov txheej txheem. Kev siv MIMO (Multiple Input Multiple Output) cov tswv yim kav hlau txais xov yog lwm lub ntsiab lus tseem ceeb uas txhim kho qhov ua tau zoo ntawm LTE rau 15bps / Hz. LTE yuav tsum muaj peev xwm txhawb nqa txog 300Mbps downlink thiab 75Mbps hauv uplink raws li 3GPP specification. Kev tsim vaj tsev ntawm LTE yog qhov yooj yim dua thiab tiaj tus thaum piv nrog 3GPP kev tshaj tawm dhau los. eNode-B txuas ncaj qha nrog System Architecture Evolution Gateway (SAE-GW) rau kev hloov ntaub ntawv, thaum nws txuas nrog Mobile Management Entity (MME) rau kev taw qhia raws li LTE architecture. Qhov yooj yim eUTRAN architecture tso cai rau kev siv cov peev txheej zoo dua, uas thaum kawg xaus nrog OPEX thiab CAPEX cov nyiaj khaws cia rau tus muab kev pabcuam.
Qhov txawv ntawm 4G thiab LTE yog dab tsi?
¤ LTE Advanced, uas tseem hu ua tus qauv 4G tiag, yog kev hloov pauv ntawm LTE tus qauv. Yog li, LTE thiab LTE Advanced muaj kev sib raug zoo, qhov twg LTE davhlau ya nyob twg tuaj yeem ua haujlwm hauv LTE Advanced network, thiab LTE Advanced Terminal tuaj yeem ua haujlwm hauv LTE network.
¤ Muaj peev xwm ntawm cov qauv 4G muaj tseeb ntau dua thaum piv nrog LTE. LTE txhawb nqa mus txog qhov siab tshaj plaws ntawm 2.7 bps / Hz / cell, thaum LTE Advanced (True 4G) muaj peev xwm ntawm 3.7 bps / Hz / cell. Txawm hais tias, ob qho tib si LTE thiab LTE-Advanced (qhov tseeb 4G) txhawb nqa tib lub spectral efficiency hauv downlink, uplink spectral efficiency ntau dua nrog qhov tseeb 4G.
¤ Ob leeg LTE thiab 4G tau tsom mus rau kev txhim kho cov ntaub ntawv tus nqi. Peak downlink cov ntaub ntawv tus nqi ntawm LTE yog 300Mbps, thaum official 4G txhais yuav tsum 1Gbps downlink cov ntaub ntawv tus nqi. Yog li, qhov tseeb 4G muaj cov ntaub ntawv ntau dua thaum piv nrog LTE, hauv ob qho tib si uplink thiab hauv downlink.
¤ LTE yog lub npe hu ua 3GPP tso tawm 8, thaum qhov tseeb 4G suav tias yog 3GPP tso tawm 10, uas yog kev hloov pauv ntawm thawj LTE thev naus laus zis.
¤ LTE tes hauj lwm tau raug xa mus thoob ntiaj teb tam sim no, thaum muaj tseeb 4G tes hauj lwm tseem tab tom tos rau kev sim. Qhov no tsuas yog vim kev ruaj ntseg ntawm LTE thaum piv nrog LTE-Advanced. Thawj cov qauv LTE tau luam tawm thaum Lub Peb Hlis 2008, thaum pib theem ntawm LTE-Advanced (Tseeb 4G) tau tsim qauv hauv lub Peb Hlis 2010.
¤ 4G yog tiam tom ntej ntawm kev sib txuas lus mobile broadband, whereas LTE yog lub hauv paus rau 4G technologies tseeb xws li LTE-Advanced.
