802.11a/b/g/n/ac Ukuthuthukiswa kanye nokwehluka

802.11a/b/g/n/ac Ukuthuthukiswa Nokwehluka
Kusukela ekukhishweni kokuqala kwe-Wi Fi kubathengi ngo-1997, indinganiso ye-Wi Fi ibilokhu ishintsha njalo, ivame ukwandisa isivinini kanye nokwanda kokumbozwa. Njengoba imisebenzi yengezwe endinganisweni yokuqala ye-IEEE 802.11, yabuyekezwa ngezichibiyelo zayo (802.11b, 802.11g, njll.)

802.11b 2.4GHz
I-802.11b isebenzisa imvamisa efanayo ye-2.4 GHz neyejwayelekile yokuqala ye-802.11. Isekela isivinini esiphezulu sethiyori esingu-11 Mbps kanye nobubanzi obufika kumamitha angu-150. Izingxenye ze-802.11b zishibhile, kodwa le nqubo inesivinini esiphezulu nesihamba kancane phakathi kwazo zonke izindinganiso ze-802.11. Futhi ngenxa ye-802.11b esebenza ku-2.4 GHz, izinto zasekhaya noma amanye amanethiwekhi e-Wi Fi e-2.4 GHz angabangela ukuphazamiseka.

802.11a 5GHz OFDM
Inguqulo ebuyekeziwe ethi “a” yale standard ikhishwa kanyekanye ne-802.11b. Yethula ubuchwepheshe obuyinkimbinkimbi kakhulu obubizwa nge-OFDM (Orthogonal Frequency Division Multiplexing) bokukhiqiza amasignali angenantambo. I-802.11a inikeza izinzuzo ezithile kune-802.11b: isebenza kubhendi yemvamisa ye-5 GHz engaxinene kakhulu futhi ngenxa yalokho ayithinteki kalula. Futhi i-bandwidth yayo iphakeme kakhulu kune-802.11b, enomkhawulo ophezulu wethiyori ongu-54 Mbps.
Kungenzeka ukuthi awukaze uhlangane namadivayisi noma ama-router amaningi e-802.11a. Lokhu kungenxa yokuthi amadivayisi e-802.11b ashibhile futhi aya ngokuya ethandwa emakethe yabathengi. I-802.11a isetshenziswa kakhulu ezinhlelweni zokusebenza zebhizinisi.

802.11g 2.4GHz OFDM
Izinga le-802.11g lisebenzisa ubuchwepheshe obufanayo be-OFDM njengo-802.11a. Njenge-802.11a, lisekela izinga eliphezulu kakhulu lomqondo elingu-54 Mbps. Kodwa-ke, njenge-802.11b, lisebenza kumaza omsindo angu-2.4 GHz aminyene (ngakho-ke lihlushwa izinkinga ezifanayo zokuphazamiseka njengo-802.11b). I-802.11g iyahambisana namadivayisi angu-802.11b: Amadivayisi angu-802.11b angaxhuma ezindaweni zokufinyelela ezingu-802.11g (kodwa ngesivinini esingu-802.11b).
Ngo-802.11g, abathengi benze intuthuko enkulu ekusheshiseni nasekumbozweni kwe-Wi-Fi. Okwamanje, uma kuqhathaniswa nezizukulwane zangaphambilini zemikhiqizo, ama-router angenantambo abathengi aya ngokuya eba ngcono, ngamandla aphezulu kanye nokumbozwa okungcono.

I-802.11n (i-Wi Fi 4) 2.4/5GHz MIMO
Ngezinga le-802.11n, i-Wi Fi isishesha futhi ithembeke kakhulu. Isekela izinga lokudlulisa eliphezulu kakhulu eliyi-300 Mbps (kufika ku-450 Mbps uma usebenzisa ama-antenna amathathu). I-802.11n isebenzisa i-MIMO (Multiple Input Multiple Output), lapho ama-transmitter/ama-receiver amaningi esebenza ngasikhathi sinye noma kokubili kokuphela kwesixhumanisi. Lokhu kungandisa kakhulu idatha ngaphandle kokudinga i-bandwidth ephezulu noma amandla okudlulisa. I-802.11n ingasebenza kuma-frequency band angu-2.4 GHz kanye no-5 GHz.

802.11ac (Wi Fi 5) 5GHz MU-MIMO
I-802.11ac ikhulisa i-Wi Fi, ngesivinini esisukela ku-433 Mbps kuya kuma-gigabit amaningana ngomzuzwana. Ukuze kufezwe lokhu kusebenza, i-802.11ac isebenza kuphela kubhendi yemvamisa ye-5 GHz, isekela imifudlana yesikhala efika kweziyisishiyagalombili (uma kuqhathaniswa nemifudlana emine ye-802.11n), iphinda kabili ububanzi besiteshi ibe yi-80 MHz, futhi isebenzisa ubuchwepheshe obubizwa ngokuthi i-beamforming. Ngokusebenzisa i-beamforming, ama-antenna angadlulisela izimpawu zomsakazo ngokuyisisekelo, ngakho-ke akhombe ngqo kumadivayisi athile.

Enye intuthuko ebalulekile ye-802.11ac yi-Multi User (MU-MIMO). Nakuba i-MIMO iqondisa imifudlana eminingi kuklayenti elilodwa, i-MU-MIMO ingaqondisa imifudlana yendawo kumakhasimende amaningi ngasikhathi sinye. Nakuba i-MU-MIMO ingakhulisi isivinini sanoma yiliphi iklayenti ngalinye, ingathuthukisa ukudluliswa kwedatha iyonke yenethiwekhi yonke.
Njengoba ubona, ukusebenza kwe-Wi-Fi kuyaqhubeka nokukhula, ngesivinini esingaba khona kanye nokusebenza okusondelayo kusivinini sezintambo.

I-Wi-Fi 6 engu-802.11ax
Ngo-2018, i-WiFi Alliance yathatha izinyathelo zokwenza amagama ajwayelekile e-WiFi abe lula ukuwabona nokuwaqonda. Bazoshintsha amazinga azayo e-802.11ax abe yi-WiFi6.

I-Wi Fi 6, ikuphi i-6?
Izinkomba eziningana zokusebenza kwe-Wi Fi zifaka phakathi ibanga lokudlulisa, izinga lokudlulisa, umthamo wenethiwekhi, kanye nokuphila kwebhethri. Ngokuthuthuka kobuchwepheshe kanye nezikhathi, izidingo zabantu zesivinini kanye nomkhawulokudonsa ziya ngokuya ziphakama.
Kunezinkinga eziningi ekuxhumaneni kwe-Wi-Fi okuvamile, njengokuminyana kwenethiwekhi, ukumbozwa okuncane, kanye nesidingo sokushintsha njalo ama-SSID.
Kodwa i-Wi Fi 6 izoletha izinguquko ezintsha: ithuthukisa ukusetshenziswa kwamandla kanye namakhono okumboza amadivayisi, isekela ukuvumelana kwesivinini esiphezulu kwabasebenzisi abaningi, futhi ingabonisa ukusebenza okungcono ezimweni ezidinga abasebenzisi abaningi, ngenkathi futhi iletha amabanga amade okudlulisa kanye namazinga aphezulu okudlulisa.
Sekukonke, uma kuqhathaniswa nezandulelayo, inzuzo ye-Wi Fi 6 “iphakeme kabili futhi iphansi kabili”:
Isivinini esiphezulu: Ngenxa yokwethulwa kobuchwepheshe obufana ne-uplink MU-MIMO, i-1024QAM modulation, kanye ne-8 * 8MIMO, isivinini esiphezulu se-Wi Fi 6 singafinyelela ku-9.6Gbps, okuthiwa sifana nesivinini sokushaya.
Ukufinyelela okuphezulu: Ukuthuthukiswa okubaluleke kakhulu kwe-Wi Fi 6 ukunciphisa ukuminyana nokuvumela amadivayisi amaningi ukuthi axhumeke kunethiwekhi. Njengamanje, i-Wi Fi 5 ingaxhumana namadivayisi amane ngesikhathi esisodwa, kuyilapho i-Wi Fi 6 izovumela ukuxhumana namadivayisi afinyelela kwayishumi ngasikhathi sinye. I-Wi Fi 6 isebenzisa futhi ubuchwepheshe be-OFDMA (i-Orthogonal frequency-division multiple access) kanye nobuchwepheshe be-multi-channel signal beamforming obuvela ku-5G ukuthuthukisa ukusebenza kahle kwe-Spectral kanye nomthamo wenethiwekhi ngokulandelana.
Ukubambezeleka okuphansi: Ngokusebenzisa ubuchwepheshe obufana ne-OFDMA kanye ne-SpatialReuse, i-Wi Fi 6 ivumela abasebenzisi abaningi ukuthi badlulisele ngesikhathi esifanayo phakathi nesikhathi ngasinye, isusa isidingo sokuma emgqeni nokulinda, inciphise ukuncintisana, ithuthukise ukusebenza kahle, futhi inciphise ukubambezeleka. Kusukela ku-30ms ye-Wi Fi 5 kuya ku-20ms, kanye nokunciphisa ukubambezeleka okumaphakathi okungu-33%.
Ukusetshenziswa kwamandla aphansi: I-TWT, obunye ubuchwepheshe obusha ku-Wi Fi 6, ivumela i-AP ukuthi ixoxisane ngokuxhumana nama-terminal, inciphise isikhathi esidingekayo ukugcina ukudluliselwa nokusesha amasignali. Lokhu kusho ukunciphisa ukusetshenziswa kwebhethri nokuthuthukisa impilo yebhethri, okuholela ekunciphiseni kuka-30% ekusetshenzisweni kwamandla e-terminal.

Kusukela ngo-2012 | Nikeza amakhompyutha ezimboni enziwe ngokwezifiso kumakhasimende omhlaba wonke!