802.11a/b/g/n/ac Kev loj hlob thiab kev sib txawv

802.11a/b/g/n/ac Kev loj hlob thiab kev sib txawv
Txij li thaum thawj zaug tso tawm Wi Fi rau cov neeg siv khoom hauv xyoo 1997, Wi Fi tus qauv tau hloov zuj zus mus tas li, feem ntau nce nrawm thiab nthuav dav.Raws li cov haujlwm tau ntxiv rau tus qauv IEEE 802.11 thawj, lawv tau hloov kho los ntawm nws cov kev hloov kho (802.11b, 802.11g, thiab lwm yam).

802.11b 2.4 GHz
802.11b siv tib zaus 2.4 GHz raws li tus qauv 802.11 qub.Nws txhawb qhov siab tshaj plaws theoretical ceev ntawm 11 Mbps thiab ntau txog 150 ko taw.802.11b Cheebtsam yog pheej yig, tab sis tus qauv no muaj qhov siab tshaj plaws thiab qeeb tshaj plaws ntawm tag nrho cov qauv 802.11.Thiab vim yog 802.11b ua haujlwm ntawm 2.4 GHz, cov khoom siv hauv tsev lossis lwm yam 2.4 GHz Wi Fi tes hauj lwm yuav ua rau muaj kev cuam tshuam.

802.11a 5GHz OFDM
Qhov hloov kho version "a" ntawm tus qauv no tau tso tawm ib txhij nrog 802.11b.Nws qhia txog kev siv tshuab ntau dua hu ua OFDM (Orthogonal Frequency Division Multiplexing) rau kev tsim cov teeb liab wireless.802.11a muab qee qhov zoo dua 802.11b: nws ua haujlwm hauv qhov tsawg tsawg 5 GHz zaus band thiab yog li tsis tshua muaj kev cuam tshuam.Thiab nws cov bandwidth yog siab dua 802.11b, nrog rau qhov theoretical siab tshaj plaws ntawm 54 Mbps.
Tej zaum koj yuav tsis tau ntsib ntau 802.11a li lossis routers.Qhov no yog vim 802.11b cov khoom siv pheej yig dua thiab ua nrov nrov hauv cov neeg siv khoom lag luam.802.11a feem ntau yog siv rau kev lag luam.

802.11g 2.4GHz OFDM
Tus qauv 802.11g siv tib OFDM thev naus laus zis li 802.11a.Zoo li 802.11a, nws txhawb qhov siab tshaj plaws theoretical tus nqi ntawm 54 Mbps.Txawm li cas los xij, zoo li 802.11b, nws ua haujlwm hauv congested 2.4 GHz zaus (thiab yog li raug kev txom nyem los ntawm cov teeb meem cuam tshuam tib yam li 802.11b).802.11g yog rov qab sib xws nrog 802.11b cov khoom siv: 802.11b cov khoom siv tuaj yeem txuas rau 802.11g cov ntsiab lus nkag (tab sis ntawm 802.11b nrawm).
Nrog 802.11g, cov neeg siv khoom tau ua tiav tseem ceeb hauv Wi-nkaus ceev thiab kev pab them nqi.Lub caij no, piv rau cov tiam dhau los ntawm cov khoom lag luam, cov neeg siv khoom siv wireless routers tau zoo dua thiab zoo dua, nrog lub zog ntau dua thiab kev pab cuam zoo dua.

802.11n (Wi-Fi 4) 2.4 / 5GHz MIMO
Nrog tus qauv 802.11n, Wi Fi tau ua sai dua thiab txhim khu kev qha.Nws txhawb qhov siab tshaj plaws theoretical kis tus nqi ntawm 300 Mbps (txog 450 Mbps thaum siv peb lub kav hlau txais xov).802.11n siv MIMO (Multiple Input Multiple Output), qhov twg ntau lub transmitters/receivers ua haujlwm ib txhij ntawm ib lossis ob qho kawg ntawm qhov txuas.Qhov no tuaj yeem ua rau cov ntaub ntawv nce ntxiv yam tsis tas yuav tsum muaj ntau dua bandwidth lossis lub zog xa mus.802.11n tuaj yeem ua haujlwm hauv 2.4 GHz thiab 5 GHz zaus bands.

802.11ac (Wi-Fi 5) 5GHz MU-MIMO
802.11ac boosts Wi Fi, nrog ceev xws li 433 Mbps mus rau ob peb gigabits ib ob.Txhawm rau ua tiav qhov kev ua tau zoo no, 802.11ac ua haujlwm tsuas yog hauv 5 GHz zaus band, txhawb nqa txog yim spatial kwj (piv rau plaub kwj ntawm 802.11n), muab ob npaug rau qhov dav ntawm 80 MHz, thiab siv lub tshuab hu ua beamforming.Nrog beamforming, kav hlau txais xov tuaj yeem xa xov tooj cua teeb liab, yog li lawv ncaj qha mus rau cov khoom siv tshwj xeeb.

Lwm qhov kev nce qib tseem ceeb ntawm 802.11ac yog Multi User (MU-MIMO).Txawm hais tias MIMO coj ntau tus kwj mus rau ib tus neeg siv khoom, MU-MIMO tuaj yeem coj ncaj qha mus rau ntau tus neeg siv khoom.Txawm hais tias MU-MIMO tsis nce qhov nrawm ntawm txhua tus neeg siv khoom, nws tuaj yeem txhim kho tag nrho cov ntaub ntawv dhau los ntawm tag nrho lub network.
Raws li koj tuaj yeem pom, Wi-nkaus kev ua tau zoo txuas ntxiv mus, nrog rau qhov muaj peev xwm ceev thiab kev ua tau zoo nce mus txog qhov nrawm.

802.11ax Wi-Fi 6
Hauv 2018, WiFi Alliance tau ntsuas los ua kom WiFi tus qauv npe yooj yim dua kom paub thiab nkag siab.Lawv yuav hloov tus qauv 802.11ax yav tom ntej rau WiFi6

Wi-Fi 6, 6 qhov twg?
Ntau qhov ntsuas kev ua tau zoo ntawm Wi Fi suav nrog kev sib kis deb, tus nqi sib kis, lub peev xwm network, thiab roj teeb lub neej.Nrog rau kev txhim kho thev naus laus zis thiab lub sijhawm, tib neeg cov kev xav tau ntawm kev ceev thiab bandwidth tau nce siab.
Muaj ntau cov teeb meem hauv kev sib txuas Wi-Fi ib txwm muaj, xws li kev sib txuas hauv network, kev pabcuam me me, thiab qhov yuav tsum tau hloov SSIDs tas li.
Tab sis Wi Fi 6 yuav coj cov kev hloov tshiab: nws ua kom zoo dua qhov kev siv hluav taws xob thiab kev pab them nqi ntawm cov khoom siv, txhawb nqa ntau tus neeg siv kev sib raug zoo siab, thiab tuaj yeem ua kom pom kev ua tau zoo dua hauv cov neeg siv cov xwm txheej hnyav, thaum tseem coj cov kev sib kis ntev dua thiab kev sib kis ntau dua.
Zuag qhia tag nrho, piv rau nws cov thawj coj, qhov zoo ntawm Wi Fi 6 yog "dual siab thiab dual qis":
Kev kub ceev: Ua tsaug rau kev qhia txog cov thev naus laus zis xws li uplink MU-MIMO, 1024QAM kev hloov kho, thiab 8 * 8MIMO, qhov siab tshaj plaws ntawm Wi Fi 6 tuaj yeem ncav cuag 9.6Gbps, uas tau hais tias zoo ib yam li kev mob stroke.
Kev nkag siab siab: Qhov kev txhim kho tseem ceeb tshaj plaws ntawm Wi Fi 6 yog kom txo qis kev sib tsoo thiab tso cai rau ntau lub cuab yeej txuas rau lub network.Tam sim no, Wi Fi 5 tuaj yeem sib txuas lus nrog plaub lub cuab yeej ib txhij, thaum Wi Fi 6 yuav tso cai rau kev sib txuas lus nrog ntau txog kaum ob lub cuab yeej ib txhij.Wi Fi 6 kuj tseem siv OFDMA (Orthogonal zaus-kev faib ntau yam nkag) thiab ntau lub teeb liab teeb liab beamforming thev naus laus zis tau los ntawm 5G los txhim kho Spectral efficiency thiab network peev feem.
Tsis tshua muaj latency: Los ntawm kev siv cov thev naus laus zis xws li OFDMA thiab SpatialReuse, Wi Fi 6 ua rau ntau tus neeg siv xa mus rau tib lub sijhawm, tshem tawm qhov xav tau ntawm queuing thiab tos, txo kev sib tw, txhim kho kev ua haujlwm, thiab txo latency.Los ntawm 30ms rau Wi Fi 5 txog 20ms, nrog qhov nruab nrab latency txo ntawm 33%.
Kev siv hluav taws xob tsawg: TWT, lwm lub thev naus laus zis tshiab hauv Wi Fi 6, tso cai rau AP sib tham nrog cov khoom siv hluav taws xob, txo lub sij hawm xav tau los tswj kev sib kis thiab tshawb nrhiav cov teeb liab.Qhov no txhais tau hais tias txo cov roj teeb siv thiab txhim kho lub roj teeb lub neej, ua rau 30% txo qis hauv lub zog siv hluav taws xob.

Txij xyoo 2012 |Muab cov khoos phis tawj kho kom haum rau cov neeg siv khoom thoob ntiaj teb!