802.11a/b/g/n/ac Kukula ndi kusiyanitsa

802.11a/b/g/n/ac Kukula ndi Kusiyanitsa
Kuyambira pomwe Wi Fi idatulutsidwa koyamba kwa ogula mu 1997, muyezo wa Wi Fi wakhala ukusintha nthawi zonse, nthawi zambiri umawonjezera liwiro komanso kufalikira kwa intaneti. Pamene ntchito zinawonjezeredwa ku muyezo woyambirira wa IEEE 802.11, zinasinthidwa kudzera mu zosintha zake (802.11b, 802.11g, ndi zina zotero)

802.11b 2.4GHz
802.11b imagwiritsa ntchito ma frequency ofanana a 2.4 GHz ndi muyezo woyambirira wa 802.11. Imathandizira liwiro lalikulu kwambiri la 11 Mbps ndi kutalika kwa mamita 150. Zida za 802.11b ndizotsika mtengo, koma muyezo uwu uli ndi liwiro lapamwamba kwambiri komanso lochedwa kwambiri pakati pa miyezo yonse ya 802.11. Ndipo chifukwa cha 802.11b yomwe imagwira ntchito pa 2.4 GHz, zida zapakhomo kapena ma netiweki ena a 2.4 GHz Wi Fi angayambitse kusokoneza.

802.11a 5GHz OFDM
Mtundu wosinthidwa wa "a" wa muyezo uwu watulutsidwa nthawi imodzi ndi 802.11b. Umayambitsa ukadaulo wovuta kwambiri wotchedwa OFDM (Orthogonal Frequency Division Multiplexing) wopanga ma siginecha opanda zingwe. 802.11a imapereka zabwino zina kuposa 802.11b: imagwira ntchito mu gulu la ma frequency la 5 GHz losadzaza kwambiri ndipo motero silingathe kusokonezedwa kwambiri. Ndipo bandwidth yake ndi yayikulu kwambiri kuposa 802.11b, yokhala ndi malire opitilira 54 Mbps.
Mwina simunakumanepo ndi zipangizo zambiri za 802.11a kapena ma rauta. Izi zili choncho chifukwa zipangizo za 802.11b ndizotsika mtengo ndipo zikutchuka kwambiri pamsika wa ogula. 802.11a imagwiritsidwa ntchito makamaka pa ntchito zamabizinesi.

802.11g 2.4GHz OFDM
Muyezo wa 802.11g umagwiritsa ntchito ukadaulo womwewo wa OFDM monga 802.11a. Monga 802.11a, umathandizira liwiro lalikulu la 54 Mbps. Komabe, monga 802.11b, umagwira ntchito pama frequency a 2.4 GHz odzaza (ndipo motero umakumana ndi mavuto ofanana ndi 802.11b). 802.11g imagwirizana ndi zida za 802.11b: Zipangizo za 802.11b zimatha kulumikizidwa ku malo olowera a 802.11g (koma pa liwiro la 802.11b).
Ndi 802.11g, ogula apita patsogolo kwambiri pa liwiro la Wi Fi komanso kufalikira kwa intaneti. Pakadali pano, poyerekeza ndi mibadwo yakale ya zinthu, ma rauta opanda zingwe a ogula akukhala bwino kwambiri, ndi mphamvu zambiri komanso kufalikira kwa intaneti kwabwino.

802.11n (Wi Fi 4) 2.4/5GHz MIMO
Ndi muyezo wa 802.11n, Wi Fi yakhala yachangu komanso yodalirika. Imathandizira kufalikira kwa ma 300 Mbps (mpaka 450 Mbps pogwiritsa ntchito ma antenna atatu). 802.11n imagwiritsa ntchito MIMO (Multiple Input Multiple Output), komwe ma transmitter/receiver ambiri amagwira ntchito nthawi imodzi kumapeto amodzi kapena onse awiri a ulalo. Izi zitha kuwonjezera kwambiri deta popanda kufunikira bandwidth yayikulu kapena mphamvu yotumizira. 802.11n imatha kugwira ntchito mu ma frequency band a 2.4 GHz ndi 5 GHz.

802.11ac (Wi Fi 5) 5GHz MU-MIMO
802.11ac imawonjezera mphamvu ya Wi Fi, ndi liwiro kuyambira 433 Mbps mpaka ma gigabit angapo pa sekondi. Kuti izi zitheke, 802.11ac imagwira ntchito mu band ya 5 GHz yokha, imathandizira mitsinje ya malo asanu ndi atatu (poyerekeza ndi mitsinje inayi ya 802.11n), imawirikiza kawiri m'lifupi mwa njira kufika pa 80 MHz, ndipo imagwiritsa ntchito ukadaulo wotchedwa beamforming. Ndi beamforming, ma antenna amatha kutumiza ma signali a wailesi, kotero amaloza mwachindunji kuzipangizo zinazake.

Kupita patsogolo kwina kwakukulu kwa 802.11ac ndi Multi User (MU-MIMO). Ngakhale kuti MIMO imatsogolera mitsinje ingapo kwa kasitomala m'modzi, MU-MIMO imatha kutsogolera mitsinje ya malo kwa makasitomala angapo nthawi imodzi. Ngakhale kuti MU-MIMO siwonjezera liwiro la kasitomala aliyense payekha, imatha kusintha kuchuluka kwa deta yonse ya netiweki yonse.
Monga mukuonera, magwiridwe antchito a Wi-Fi akupitilirabe kusintha, ndipo liwiro lomwe lingakhalepo komanso magwiridwe antchito akuyandikira liwiro la waya.

802.11ax Wi Fi 6
Mu 2018, WiFi Alliance idachitapo kanthu kuti mayina a WiFi omwe akupezeka azizindikirika mosavuta. Asintha muyezo wa 802.11ax womwe ukubwera kukhala WiFi6.

Wi Fi 6, kodi 6 ili kuti?
Zizindikiro zingapo za magwiridwe antchito a Wi Fi zikuphatikizapo mtunda wotumizira mauthenga, kuchuluka kwa mauthenga, mphamvu ya netiweki, ndi moyo wa batri. Chifukwa cha kupita patsogolo kwa ukadaulo ndi nthawi, zosowa za anthu pa liwiro ndi bandwidth zikukwera kwambiri.
Pali mavuto angapo pa maukonde achikhalidwe a Wi Fi, monga kudzaza kwa netiweki, kuchepa kwa malo ofikira, komanso kufunikira kosintha ma SSID nthawi zonse.
Koma Wi Fi 6 ibweretsa kusintha kwatsopano: imakonza kugwiritsa ntchito mphamvu ndi kuphimba zipangizo, imathandizira ogwiritsa ntchito ambiri kuthamanga kwambiri, ndipo imatha kuwonetsa magwiridwe antchito abwino pazochitika zomwe ogwiritsa ntchito amagwiritsa ntchito kwambiri, komanso kubweretsa mtunda wautali wotumizira mauthenga komanso kuchuluka kwa mauthenga otumizira mauthenga.
Ponseponse, poyerekeza ndi zakale, ubwino wa Wi Fi 6 ndi "wapamwamba kawiri ndi wotsika kawiri":
Liwiro lapamwamba: Chifukwa cha kuyambitsidwa kwa ukadaulo monga uplink MU-MIMO, 1024QAM modulation, ndi 8 * 8MIMO, liwiro lalikulu la Wi Fi 6 limatha kufika 9.6Gbps, zomwe zimanenedwa kuti ndizofanana ndi liwiro la stroke.
Kufikira pa intaneti: Chinthu chofunika kwambiri pa Wi Fi 6 ndikuchepetsa kuchulukana kwa anthu ndikulola zipangizo zambiri kulumikizana ndi netiweki. Pakadali pano, Wi Fi 5 imatha kulumikizana ndi zipangizo zinayi nthawi imodzi, pomwe Wi Fi 6 imalola kulumikizana ndi zipangizo zambiri nthawi imodzi. Wi Fi 6 imagwiritsanso ntchito OFDMA (Orthogonal frequency-division multiple access) ndi ukadaulo wa multi-channel signal beamforming wochokera ku 5G kuti apititse patsogolo magwiridwe antchito a Spectral komanso mphamvu ya netiweki motsatana.
Kuchedwa kochepa: Pogwiritsa ntchito ukadaulo monga OFDMA ndi SpatialReuse, Wi Fi 6 imalola ogwiritsa ntchito ambiri kutumiza mauthenga nthawi imodzi mkati mwa nthawi iliyonse, kuchotsa kufunikira kokhala pamzere ndi kudikira, kuchepetsa mpikisano, kukonza magwiridwe antchito, komanso kuchepetsa kuchedwa. Kuyambira 30ms ya Wi Fi 5 mpaka 20ms, ndi kuchepa kwapakati kwa kuchedwa kwa 33%.
Kugwiritsa ntchito mphamvu zochepa: TWT, ukadaulo wina watsopano mu Wi Fi 6, umalola AP kulumikizana ndi ma terminal, kuchepetsa nthawi yofunikira kuti ipititse patsogolo kutumiza ndi kusaka ma signali. Izi zikutanthauza kuchepetsa kugwiritsa ntchito batri ndikukweza moyo wa batri, zomwe zimapangitsa kuti kugwiritsa ntchito mphamvu ya terminal kuchepe ndi 30%.

Kuyambira 2012 | Perekani makompyuta a mafakitale okonzedwa mwamakonda kwa makasitomala apadziko lonse lapansi!