3G vs 4G Network Technology | LTE thiab WiMAX | 3G vs 4G Ceev, zaus thiab nta piv | Roj teeb Lub neej ntau dua hauv 3G
3G thiab 4G yog cov kev sib txuas lus wireless sib cais los ntawm qee cov qauv thiab cov qauv ntsuas. Nyob rau hauv evolution ntawm lub xov tooj ntawm tes cov qauv tsim rau 3G thiab 4G network tau revolutionized tiam tom ntej mobile muaj peev xwm ntawm cov neeg siv khoom. Ob qho tib si cov qauv yog tsom rau kev muab cov ntaub ntawv siab uas yog qhov tseem ceeb tshaj plaws rau ntau yam kev siv yav tom ntej thiab cov neeg siv xav tau xws li multimedia, streaming, conferencing thiab lwm yam. Tab sis qhov tseeb muaj ntau qhov sib txawv ntawm ob tus qauv thiab cov thev naus laus zis siv rau txhua qhov tshwj xeeb thiab cov khoom siv tes ua. siv. Yog li lawv xa highspeed wireless txuas, lawv qee zaum hu ua wireless broadband technologies. Nws yog qhov tseem ceeb uas 3GPP tau ua lub luag haujlwm tseem ceeb hauv kev hloov pauv ntawm ntau tiam neeg hauv cov xov tooj ntawm tes thiab nws yog kev sib koom tes ntawm cov koom haum hauv xov tooj los ntawm ntau lub teb chaws thiab cheeb tsam hauv ntiaj teb txhawm rau txhawm rau muab cov qauv siv 3G thoob ntiaj teb raws li GSM systems.
3G Wireless Communication Technology
Nov yog tiam thib peb ntawm cov xov tooj ntawm tes uas yog tsom rau cov ntaub ntawv siab rau cov ntawv thov xws li kev hu xov tooj, streaming video thiab suab, video conferencing thiab multimedia applications thiab lwm yam hauv ib puag ncig mobile. Muaj ob qhov kev sib koom tes muaj xws li 3GPP thiab 3GPP2 tom kawg yog ib qho kev tsim qauv rau 3G raws li CDMA thev naus laus zis. Raws li ITU (International Telecommunications Union) cov kev cai hauv qab no yuav tsum tau ua raws li txhua lub network kom raug hu ua 3G network raws li tau hais los ntawm 3GPP.
– Cov ntaub ntawv hloov pauv tus nqi (txuas txuas) ntawm 144Kbps yam tsawg kawg nkaus rau kev txav ntawm tes thiab 384Kbps rau cov neeg taug kev.
– 2Mbps hauv tsev sab hauv rau downlink.
– Ntawm kev thov bandwidth thiab 2Mbps broadband internet nkag tau kuj tau teev tseg los ntawm 3GPP.
Cov txheej txheem tseem ceeb ntau yam siv los ntawm 3G tes hauj lwm yog CDMA variations. Rau CDMA networks uas twb muaj lawm rau GSM yuav pib siv WCDMA (Wide band CDMA) uas siv 5 MHz channel band dav muaj peev xwm muab 2Mbps cov ntaub ntawv tus nqi. Tsis tas li lwm yam CDMA thev naus laus zis xws li CDMA2000, CDMA2000 1x EV-DO tau siv ntau qhov chaw thoob ntiaj teb rau 3G tes hauj lwm.
4G Wireless Communication Technology
Nov yog tiam tom ntej ntawm cov xov tooj ntawm tes raws li tau teev tseg los ntawm ITU thiab tus thawj coj ntawm 3G tes hauj lwm. Tam sim no muaj ob lub thev naus laus zis tau txais txiaj ntsig tau txiav txim siab thaum tham txog kev txav mus rau 4G vim nws cov ntaub ntawv siab zoo li 100Mbps hauv cov chaw txawb siab thiab 1Gbps hauv qhov chaw nyob ruaj khov. WiMAX (Kev Sib Tham Thoob Ntiaj Teb rau Microwave Access) thiab LTE (ntev Lub Sijhawm Evolution) yog cov thev naus laus zis tau txiav txim siab.
Ua raws li cov lus qhia tshwj xeeb yuav tsum tau ntsib los ntawm txhua lub network kom suav tias yog 4G:
– 100Mbps cov ntaub ntawv tus nqi hauv cov chaw txawb siab thiab 1Gbps hauv qhov chaw nyob ruaj khov
– Network ua haujlwm ntawm IP pob ntawv (Txhua tus IP network)
– Kev faib tawm dynamic nrog channel bandwidth txawv ntawm 5MHz txog 20 MHz raws li qhov xav tau los ntawm daim ntawv thov
– Soft hand over capability.
Qhov txawv ntawm 3G thiab 4G Network Technologies
1. Downlink cov ntaub ntawv tus nqi rau 3G nyob ib ncig ntawm 2Mbps nyob rau hauv hom chaw nres tsheb whilst 4G specifications nws yuav tsum yog 1 Gbps thiab nyob rau hauv heev mobile puag ncig 3G downlink ceev yuav tsum nyob ib ncig ntawm 384Kbps thiab 100 Mbps nyob rau hauv 4G tes hauj lwm.
2. Ntau cov txheej txheem nkag mus siv los ntawm 3G yog CDMA thiab nws cov kev hloov pauv thiab hauv 4G ob lub thev naus laus zis (LTE thiab WiMAX) siv OFDMA (Orthogonal Frequency Division Multiple Access) hauv downlink.
3. Nyob rau hauv lub uplink LTE siv SC – FDMA (Tib neeg Carrier FDMA) thiab WiMAX txuas ntxiv siv OFDMA thaum 3G tes hauj lwm siv CDMA variations.
