{"id":84590,"date":"2020-06-09T01:42:40","date_gmt":"2020-06-08T23:42:40","guid":{"rendered":"https:\/\/prohoster.info\/blog\/administrirovanie\/samoe-glavnoe-v-wi-fi-6-net-seryozno"},"modified":"2020-06-09T01:42:40","modified_gmt":"2020-06-08T23:42:40","slug":"samoe-glavnoe-v-wi-fi-6-net-seryozno","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/administrirovanie\/samoe-glavnoe-v-wi-fi-6-net-seryozno","title":{"rendered":"Najd\u00f4le\u017eitej\u0161ie veci o Wi-Fi 6. Nie, naozaj","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Ahoj.<\/p>\n

Ak ver\u00edme v Einsteinovu te\u00f3riu jednoduchosti, kde je hlavn\u00fdm ukazovate\u013eom porozumenia schopnos\u0165 \u010do najjednoduch\u0161ie to vysvetli\u0165, aj v tomto pr\u00edspevku sa pok\u00fasim \u010do najjednoduch\u0161ie a podrobne vysvetli\u0165 fungovanie len jednej s\u00fa\u010diastky nov\u00e9ho \u0161tandardu, ktor\u00fa z nejak\u00e9ho d\u00f4vodu dokonca Wi-Fi Alliance pova\u017euje za nezasl\u00fa\u017eiacu si zmienku v infografike o nov\u00fdch mo\u017enostiach Wi-Fi 6, hoci, ako sa \u010doskoro presved\u010d\u00edme, je ve\u013emi d\u00f4le\u017eit\u00e1 a zauj\u00edmav\u00e1. Tu nie je v\u0161etko dostato\u010dne hlbok\u00e9 a ur\u010dite nie je v\u0161etkoobsahuj\u00face (preto\u017ee tak\u00e9ho slona je \u0165a\u017ek\u00e9 jes\u0165 aj po \u010dastiach), ale d\u00fafam, \u017ee ka\u017ed\u00fd z n\u00e1s si z mojich slovn\u00fdch cvi\u010den\u00ed odnesie nie\u010do nov\u00e9 a zauj\u00edmav\u00e9.<\/p>\n

Ten 802.11ax, ktor\u00fd o\u010dak\u00e1vame zo d\u0148a na de\u0148, minim\u00e1lne u\u017e druh\u00fd rok, nesie so sebou mno\u017estvo nov\u00e9ho a prekvapuj\u00faceho. Pred ka\u017ed\u00fdm, kto chce o \u0148om nie\u010do poveda\u0165, v\u017edy stoj\u00ed vo\u013eba: bu\u010f usporiada\u0165 preh\u013eadov\u00e9 skoky po hlav\u00e1ch, spom\u00ednaj\u00fac vedro skratiek a skratkov\u00fdch pojmov, sna\u017eiac sa nezapadn\u00fa\u0165 do zlo\u017eit\u00fdch mechanizmov v pozad\u00ed ka\u017ed\u00e9ho z nich, alebo zabal\u00ed hodinov\u00fa prezent\u00e1ciu o nie\u010dom jednom, najpr\u00edjemnej\u0161om autorovi. Neboj\u00edm sa \u00eds\u0165 e\u0161te \u010falej: v\u00e4\u010d\u0161ia \u010das\u0165 mojej pozn\u00e1mky bude venovan\u00e1 dokonca nielen nov\u00e9mu!
\n<\/a><\/noindex>
\nTak\u017ee, u\u017e viac ako dvadsa\u0165 rokov sa \u010das\u0165 bezdr\u00f4tov\u00fdch siet\u00ed prenosu d\u00e1t buduje na z\u00e1kladnej kon\u0161trukcii \u0161tandardov z rodiny 802.11 a ako ak\u00fdko\u013evek v\u00e1\u017een\u00fd re\u010dn\u00edk by som mal trochu obnovi\u0165 \u010dasov\u00fa os celej udalostnej re\u0165aze, ktor\u00e1 svetu priniesla miliardy navz\u00e1jom kompatibiln\u00fdch zariaden\u00ed \u2014 ale ako autor, ktor\u00fd si v\u00e1\u017ei \u010ditate\u013ea, sa odv\u00e1\u017eim to predsa len neurobi\u0165. Napriek tomu, nie\u010do by si mali navz\u00e1jom pripomen\u00fa\u0165. <\/p>\n

V\u0161etky iter\u00e1cie Wi-Fi kladli na prv\u00e9 miesto spo\u013eahlivos\u0165, ale nie maximaliz\u00e1ciu prenosovej kapacity. To vypl\u00fdva z mechanizmu pr\u00edstupu k m\u00e9diu (CSMA\/CA), ktor\u00fd nie je z poh\u013eadu vy\u017em\u00fdkania posledn\u00fdch kilobitov za sekundu z prenosov\u00e9ho m\u00e9dia najoptim\u00e1lnej\u0161\u00ed (podrobnej\u0161ie o nedokonalosti sveta vo v\u0161eobecnosti a Wi-Fi najm\u00e4 si m\u00f4\u017eete pre\u010d\u00edta\u0165 v \u010dl\u00e1nku m\u00f4jho b\u00fdval\u00e9ho kolegu. skhomm<\/a><\/noindex> tu je<\/a><\/noindex>), ale neuverite\u013ene odoln\u00e9ho takmer v ak\u00fdchko\u013evek podmienkach. Naozaj, m\u00f4\u017eete poru\u0161i\u0165 takmer v\u0161etky z\u00e1klady projektovania Wi-Fi siet\u00ed \u2014 a aj tak bude v tejto sieti prebieha\u0165 v\u00fdmena \u00fadajov! Na zabezpe\u010denie toho, \u010do sa v anglickom jazyku ozna\u010duje ako \u0165a\u017eko prelo\u017eite\u013en\u00e9 slovo technokratick\u00e9ho zafarbenia, robustness, je zameran\u00fd cel\u00fd mechanizmus, pod\u013ea ktor\u00e9ho klienti Wi-Fi siete z\u00edskavaj\u00fa mo\u017enos\u0165 pren\u00e1\u0161a\u0165 a\/alebo prij\u00edma\u0165 svoje porcie \u00fadajov. Cel\u00e1 vrstva nanesen\u00e1 na zlep\u0161enie modul\u00e1ci\u00ed, agreg\u00e1ci\u00ed r\u00e1mcov s \u00fadajmi (nie \u00faplne tak, ale nech to je!) na\u010falej funguje u\u017e po dvoch z\u00e1kladn\u00fdch princ\u00edpoch 802.11, ktor\u00e9 zabezpe\u010duj\u00fa t\u00fato bezkonkuren\u010dn\u00fa spo\u013eahlivos\u0165:<\/p>\n

    \n
  1. \u201eK\u00fdm hovor\u00ed jeden \u2014 ostatn\u00ed ml\u010dia\u201c;<\/li>\n
  2. \u201eV\u0161etko okrem \u00fadajov sa hovor\u00ed pomaly a zrozumite\u013ene\u201c.<\/li>\n<\/ol>\n

    \nDruh\u00fd bod sp\u00f4sobuje sie\u0165ovej kapacite ove\u013ea v\u00e4\u010d\u0161ie \u0161kody, ako by sa na prv\u00fd poh\u013ead mohlo zda\u0165. Tu je skvel\u00fd obr\u00e1zok, ilustruj\u00faci jeden odoslan\u00fd k\u00fasok \u00fadajov v sieti Wi-Fi:<\/p>\n

    \"Najd\u00f4le\u017eitej\u0161ie
    \n
    \nPo\u010fme sa pozrie\u0165, \u010do to znamen\u00e1 pre be\u017en\u00fdch \u013eud\u00ed, ktor\u00ed nevedia, ko\u013eko str\u00e1nok je v \u0161tandarde 802.11-2016. R\u00fdchlos\u0165 prenosu \u00fadajov, ktor\u00fa v vlastnostiach bezdr\u00f4tovej siete uv\u00e1dza syst\u00e9m a ktor\u00fa na obaloch pr\u00edstupov\u00fdch bodov vykres\u013euj\u00fa market\u00e9ri ak\u00e9hoko\u013evek v\u00fdrobcu (no ur\u010dite ste to u\u017e videli \u2014 1,7 Gb\/s! 2,4 Gb\/s! 9000 Gb\/s!), nie je len vrcholn\u00e1 a maxim\u00e1lna pri 100% vy\u0165a\u017een\u00ed prenosu, ale je aj r\u00fdchlos\u0165ou, pri ktorej sa bude odosiela\u0165 iba modr\u00e1 \u010das\u0165 na tomto kr\u00e1snom grafe. V\u0161etko ostatn\u00e9 sa bude pren\u00e1\u0161a\u0165 r\u00fdchlos\u0165ou, ktor\u00e1 sa po anglicky naz\u00fdva management rate (a po rusky tie\u017e, preto\u017ee preklada\u0165 tak\u00e9to v\u00fdrazy hroz\u00ed \u010fal\u0161\u00edm neporozumen\u00edm medzi in\u017einiermi), a t\u00e1to r\u00fdchlos\u0165 je ni\u017e\u0161ia nielen o nieko\u013ekon\u00e1sobne, ale o STO<\/b> n\u00e1sobkov. Napr\u00edklad, bez ak\u00fdchko\u013evek dodato\u010dn\u00fdch nastaven\u00ed sie\u0165 na 802.11ac, ktor\u00e1 m\u00f4\u017ee pracova\u0165 s klientmi na kan\u00e1lovej r\u00fdchlosti 1300 Mb\/s, pren\u00e1\u0161a v\u0161etky slu\u017eobn\u00e9 inform\u00e1cie (v\u0161etko, \u010do nie je modr\u00e9 na na\u0161om \u010doraz stra\u0161nej\u0161om grafe) na management rate 6 Mb\/s. Viac ako dvesto kr\u00e1t pomal\u0161ie! <\/p>\n

    Logick\u00e1 ot\u00e1zka \u2013 ktor\u00e9ho, prep\u00e1\u010dte, d\u0148a ktor\u00e9ho mesiaca sa tak\u00e1 \u0161kodliv\u00e1 my\u0161lienka mohla v\u00f4bec dosta\u0165 do \u0161tandardu, pod\u013ea ktor\u00e9ho dnes pracuj\u00fa miliardy zariaden\u00ed na celom svete? Logick\u00e1 odpove\u010f \u2013 kompatibilita, kompatibilita, kompatibilita! Sie\u0165 na najnov\u0161om pr\u00edstupovom bode by mala zabezpe\u010di\u0165 mo\u017enos\u0165 pr\u00e1ce pre zariadenia star\u00e9 desa\u0165 alebo dokonca p\u00e4tn\u00e1s\u0165 rokov, a pr\u00e1ve vo v\u0161etk\u00fdch t\u00fdchto \"ne-modr\u00fdch\" k\u00faskoch sa pren\u00e1\u0161a inform\u00e1cia, ktor\u00fa pomal\u0161ie star\u00e9 zariadenia prijm\u00fa, spr\u00e1vne pochopia a nebud\u00fa sa pok\u00fa\u0161a\u0165 po\u010das superr\u00fdchlych d\u00e1tov\u00fdch prenosov odosiela\u0165 svoje. Robustnos\u0165 si vy\u017eaduje obete!<\/p>\n

    Teraz som pripraven\u00fd poskytn\u00fa\u0165 ka\u017ed\u00e9mu zainteresovan\u00e9mu neocenite\u013en\u00fd n\u00e1stroj na to, aby sa ohromene str\u00e1cal v s\u00fa\u010dasnom Wi-Fi potenci\u00e1lne pren\u00e1\u0161an\u00fdch megabitov \u2013 to je u\u017e nevyhnutn\u00e9 na \u0161t\u00fadium v pr\u00edslu\u0161n\u00fdch in\u017einierskych kruhoch. WiFi AirTime Calculator<\/b> autorstvom n\u00f3rskeho nad\u0161enca 802.11 Gjermunda Raaena. Je dostupn\u00fd na tento odkaz<\/a><\/noindex> \u2013 v\u00fdsledok jeho pr\u00e1ce vyzer\u00e1 pribli\u017ene takto:<\/p>\n

    \"Najd\u00f4le\u017eitej\u0161ie
    \n
    \nRiadok 1 \u2013 \u010das potrebn\u00fd na odoslanie paketu \u00fadajov s d\u013a\u017ekou 1512 bajtov zariaden\u00edm 802.11n v \u0161\u00edrke kan\u00e1la 20 MHz.<\/p>\n

    Riadok 2 \u2013 \u010das potrebn\u00fd na odoslanie rovnak\u00e9ho paketu zariaden\u00edm so shodnou ant\u00e9nou, ale pracuj\u00facim u\u017e pod\u013ea \u0161tandardu 802.11ac v kan\u00e1li s \u0161\u00edrkou 80 MHz.<\/p>\n

    Ako je to mo\u017en\u00e9 \u2013 \"pokazen\u00e9\" o \u0161tyrikr\u00e1t viac priestoru, maxim\u00e1lna modul\u00e1cia sa skomplikovala z 64QAM na 256QAM, kan\u00e1lov\u00e1 r\u00fdchlos\u0165 je vy\u0161\u0161ia o \u0160ES\u0164<\/b> kr\u00e1t (433 Mb\/s namiesto 72 Mb\/s), a vyhralo sa maxim\u00e1lne 25% \u010dasu obsadenia priestoru? <\/p>\n

    Kompatibilita a dva princ\u00edpy 802.11, pam\u00e4t\u00e1te si?<\/p>\n

    Dobre, ako m\u00f4\u017eeme opravi\u0165 tak\u00fa nespravodlivos\u0165 a plytvanie \u2013 op\u00fdtame sa, ako si to zrejme kl\u00e1dli v\u0161etky pracovn\u00e9 skupiny IEEE, ktor\u00e9 sa pustili do tvorby \u0161tandardu? Prich\u00e1dza nieko\u013eko logick\u00fdch ciest:<\/p>\n

      \n
    1. Ur\u00fdchli\u0165 prenos d\u00e1t v \"zelenom\" k\u00fasku grafu.<\/i><\/b> To sa deje pri ka\u017edom vydan\u00ed \u0161tandardu, preto\u017ee ve\u013ek\u00e9 \u010d\u00edsla pekne vyzeraj\u00fa na krabiciach. V praxi, ako sme si pr\u00e1ve v\u0161imli, d\u00e1va kone\u010dn\u00fd n\u00e1rast \u2013 aj keby sme ur\u00fdchlili r\u00fdchlos\u0165 kan\u00e1la na sto tis\u00edc mili\u00f3nov gigab\u00edt za nanosekundu, v\u0161etky ostatn\u00e9 \u010dasti grafu nikam nezmizn\u00fa. Preto odpor\u00fa\u010dam v v\u0161etk\u00fdch rozpr\u00e1vaniach o v\u0161etk\u00fdch nov\u00fdch \u0161tandardoch 802.11 vynecha\u0165 odseky, kde sa spom\u00ednaj\u00fa megabity za sekundu.<\/li>\n
    2. Zr\u00fdchlite v\u0161etky ostatn\u00e9 \u010dasti diagramu.<\/i><\/b> Naozaj, ak aspo\u0148 zdvojn\u00e1sob\u00edme r\u00fdchlos\u0165, ktorou sa pren\u00e1\u0161a v\u0161etko 'nezelen\u00e9' (alebo 'nesiv\u00e9', ak sa st\u00e1le pozer\u00e1te na predch\u00e1dzaj\u00faci obr\u00e1zok), z\u00edskame nie\u010do menej ako 50% n\u00e1rast skuto\u010dnej priepustnosti \u2014 pravda, za cenu straty kompatibility s zariadeniami a \u010fal\u0161\u00edmi aspektmi, o ktor\u00fdch sa dozviete, ke\u010f sa budete pripravova\u0165 na sk\u00fa\u0161ku na hrd\u00fd titul CWNA \ud83d\ude42 Spoiler: nemus\u00ed sa v\u00e1m to v\u017edy podari\u0165, a silno zv\u00e1\u017ete, kam to povedie. V skuto\u010dnosti to poru\u0161uje jeden z dvoch princ\u00edpov 802.11, tak\u017ee s t\u00fdm treba by\u0165 ve\u013emi opatrn\u00fd!<\/li>\n
    3. Slepi\u0165 dokopy nieko\u013eko tak\u00fdchto r\u00e1mcov so zelen\u00fdmi \u010das\u0165ami.<\/i><\/b> \u010c\u00edm dlh\u0161ia je zelen\u00e1 \u010das\u0165, t\u00fdm efekt\u00edvnej\u0161ie funguje zv\u00fd\u0161enie kan\u00e1lovej r\u00fdchlosti. \u00c1no, je to celkom funk\u010dn\u00e1 strat\u00e9gia, ktor\u00e1 sa objavila u\u017e v 802.11n a je jedn\u00fdm z nieko\u013ek\u00fdch z\u00e1kladn\u00fdch kame\u0148ov jej revolu\u010dnosti. Probl\u00e9m je v tom, \u017ee, po prv\u00e9, mno\u017estvo aplik\u00e1ci\u00ed m\u00e1 na tak\u00fato agreg\u00e1ciu \u010distej starosti (napr\u00edklad ten krvila\u010dn\u00fd Voice over Wi-Fi), po druh\u00e9, mno\u017estvo zariaden\u00ed na \u0148u tie\u017e ka\u0161le (raz som sa pok\u00fasil zachyti\u0165 aspo\u0148 nieko\u013eko such\u00fdch agregovan\u00fdch r\u00e1mcov v skuto\u010dnej sieti spolo\u010dnosti, v ktorej pracujem, ale medzi >500k 'zachyten\u00fdmi' sn\u00edmkami boli agregovan\u00e9 presne nula. Pravdepodobne je probl\u00e9m v mojej metodol\u00f3gii zbierania d\u00e1t, ale r\u00e1d by som ju prediskutoval s ka\u017ed\u00fdm, kto m\u00e1 z\u00e1ujem, niekde v osobnej diskusii!). <\/li>\n
    4. Poru\u0161i\u0165 a prv\u00fd z dvoch princ\u00edpov 802.11, za\u010da\u0165 hovori\u0165, ke\u010f hovor\u00ed niekto in\u00fd.<\/i><\/b> A tu prich\u00e1dza na pomoc 802.11ax.<\/li>\n<\/ol>\n

      \nAko skvel\u00e9, kone\u010dne som vo svojom rozpr\u00e1van\u00ed o Wi-Fi 6 dospel k samotn\u00e9mu Wi-Fi 6! Ak to st\u00e1le \u010d\u00edtate, bu\u010f to mus\u00edte robi\u0165 z nejak\u00e9ho d\u00f4vodu, alebo v\u00e1s to naozaj zauj\u00edma. Tak, aj ke\u010f 802.11ax ded\u00ed obrovsk\u00fa \u010das\u0165 predch\u00e1dzaj\u00facej pr\u00e1ce cel\u00e9ho rodiny 802.11 (a nielen, mimochodom \u2014 niektor\u00e9 skvel\u00e9 veci sa objavili v\u00f4bec v 802.16, zn\u00e1my ako WiMAX), nie\u010do v \u0148om predsa len je \u010derstv\u00e9 a origin\u00e1lne. Obvykle na t\u00fdchto slov\u00e1ch vznikne tak\u00fdto obr\u00e1zok, dostupn\u00fd na str\u00e1nke Wi-Fi Alliance:<\/p>\n

      \"Najd\u00f4le\u017eitej\u0161ie
      \n
      \nAko som na za\u010diatku spomenul, v r\u00e1mci jedn\u00e9ho preh\u013eadn\u00e9ho \u010dl\u00e1nku m\u00f4\u017eeme rozobera\u0165 len jeden z t\u00fdchto k\u013e\u00fa\u010dov\u00fdch bodov, a to konkr\u00e9tne ani jeden z t\u00fdch, ktor\u00e9 s\u00fa zn\u00e1zornen\u00e9 na obr\u00e1zku (prekvapenie!). Som si ist\u00fd, \u017ee ste u\u017e \u010d\u00edtali mili\u00f3n r\u00fdchlych opisov ka\u017ed\u00e9ho z t\u00fdchto \u00f4smich k\u013e\u00fa\u010dov\u00fdch prvkov, ja v\u0161ak budem pokra\u010dova\u0165 vo svojom zd\u013ahavom rozpr\u00e1van\u00ed o tom, \u010do vypl\u00fdva z OFDMA \u2013 o viacer\u00fdch pr\u00edstupe k m\u00e9diu (MU-access control), ktor\u00fd, ako vid\u00edme, sa na infografike v\u00f4bec neobjavil. A to je naozaj \u0161koda!<\/p>\n

      Viacer\u00fd pr\u00edstup je to, bez \u010doho by delenie kan\u00e1la na podnosn\u00edky v\u00f4bec stratilo zmysel. Pre\u010do sa sna\u017ei\u0165 presk\u00fama\u0165 r\u00f4zne k\u00fasky spektra, ak neexistuje mechanizmus, ktor\u00fd by don\u00fatil klientov novej siete Wi-Fi 6 poru\u0161i\u0165 jedno z doteraz nemenn\u00fdch pravidiel a za\u010da\u0165 hovori\u0165 s\u00fa\u010dasne? A samozrejme, tak\u00fd mechanizmus sa nemohol vyhn\u00fa\u0165 vzniku \u2013 a zn\u00ed\u017ei\u0165 vplyv probl\u00e9mu \"dlhej\" na rozdiel od \u00fadajov riadiacej inform\u00e1cie. Ako? Ve\u013emi jednoducho: nech \u201epomal\u00e1\u201c servisn\u00e1 \u010das\u0165 je distribuovan\u00e1 rovnako ako predt\u00fdm, ale \u201er\u00fdchlu\u201c \u010das\u0165, v ktorej id\u00fa samotn\u00e9 \u00fadaje, po\u0161leme s\u00fa\u010dasne z nieko\u013ek\u00fdch (alebo na nieko\u013eko) zariaden\u00ed na pokyn! Vyzer\u00e1 to pribli\u017ene takto:<\/p>\n

      \"Najd\u00f4le\u017eitej\u0161ie
      \n
      \nNa poh\u013ead to m\u00f4\u017ee vyzera\u0165 zlo\u017eito, no v podstate je to dos\u0165 \u013eahko vysvetlite\u013en\u00e9: pr\u00edstupov\u00fd bod pomocou \u0161peci\u00e1lneho r\u00e1mca, ktor\u00fd je zrozumite\u013en\u00fd pre v\u0161etky (aj nie Wi-Fi 6!) zariadenia, oznamuje, \u017ee je pripraven\u00fd pren\u00e1\u0161a\u0165 \u00fadaje s\u00fa\u010dasne pre STA1 a STA2. Ke\u010f\u017ee \"hlavi\u010dka\" tohto r\u00e1mca je \u00faplne jasn\u00e1 aj pre ve\u013emi star\u00fdch klientov, robia spr\u00e1vny z\u00e1ver, \u017ee \u00e9ter bude obsaden\u00fd po\u010das ur\u010dit\u00e9ho \u010dasu prenosom inform\u00e1ci\u00ed in\u00fdm klientom siete, a za\u010dn\u00fa odpo\u010d\u00edtava\u0165 \u010das do konca tohto obdobia (vlastne, ako to robili v\u017edy v Wi-Fi). Zariadenia STA1 a STA2 v\u0161ak rozumej\u00fa, \u017ee teraz im bud\u00fa \u00fadaje pren\u00e1\u0161an\u00e9 u\u017e nov\u00fdm sp\u00f4sobom, naraz, ka\u017ed\u00e9mu na svojom k\u00fasku kan\u00e1la, a odpovedaj\u00fa pr\u00edstupov\u00e9mu bodu tie\u017e naraz, pri\u010dom rovnako synchronne potvrdzuj\u00fa prijatie r\u00e1mca (ka\u017ed\u00fd so svojou porciou \u00fadajov!), a m\u00e9dium je znovu uvo\u013enen\u00e9. \"Zospodu nahor\" funguje to pribli\u017ene takto:<\/p>\n

      \"Najd\u00f4le\u017eitej\u0161ie
      \n
      \nHlavn\u00fd a n\u00e1padn\u00fd rozdiel \u2014 pr\u00edstupov\u00fd bod, ktor\u00fd v tejto situ\u00e1cii informuje stanice schopn\u00e9 komunikova\u0165 s\u00fa\u010dasne, kedy za\u010da\u0165 prenos, pomocou \u0161peci\u00e1lneho r\u00e1mca, ktor\u00fd sa naz\u00fdva \u2014 Trigger. Toto je v podstate nov\u00fd \u201esp\u00fa\u0161\u0165a\u010d\u201c cel\u00e9ho mechanizmu viacn\u00e1sobn\u00e9ho s\u00fa\u010dasn\u00e9ho pr\u00edstupu k prostrediu, ktor\u00fd pova\u017eujem za jednu z najd\u00f4le\u017eitej\u0161\u00edch inov\u00e1ci\u00ed \u201epod kapotou\u201c nov\u00e9ho \u0161tandardu. Pr\u00e1ve v \u0148om klienti dost\u00e1vaj\u00fa \u201erozvrh\u201c, ako si rozdelia jeden frekven\u010dn\u00fd kan\u00e1l; pr\u00e1ve v \u0148om klienti s\u00fa\u010dasne informuj\u00fa pr\u00edstupov\u00fd bod, \u017ee dostali svoje d\u00e1vky \u00fadajov a dok\u00e1zali ich spracova\u0165. V \u0148om pr\u00edstupov\u00fd bod informuje v\u0161etk\u00fdch, ktor\u00ed m\u00f4\u017eu \u201ehovori\u0165\u201c s\u00fa\u010dasne, o za\u010diatku prenosu \u00fadajov \u2014 v \u0148om pr\u00edstupov\u00fd bod tie\u017e sp\u00fa\u0161\u0165a odoslanie po\u017eadovan\u00fdch \u00fadajov. Nov\u00fd mechanizmus Trigger frame v podstate umo\u017e\u0148uje zn\u00ed\u017ei\u0165 nezmyseln\u00e9 vyu\u017e\u00edvanie obsadenosti spektra \u2014 a to tak efekt\u00edvne, ako ve\u013ea klientov m\u00f4\u017ee tento mechanizmus pou\u017e\u00edva\u0165 a spr\u00e1vne ho prij\u00edma\u0165!<\/p>\n

      A teraz formulujeme hlavn\u00e9 t\u00e9zy, ktor\u00e9 vypl\u00fdvaj\u00fa z tohoto dlh\u00e9ho rozpr\u00e1vania a maj\u00fa amb\u00edcie na TL;DR: <\/p>\n

        \n
      1. Pr\u00edstupov\u00e9 body nov\u00e9ho \u0161tandardu 802.11ax, aj ke\u010f s\u00fa zalo\u017een\u00e9 len na jednej z mnoh\u00fdch noviniek, za\u010dn\u00fa zvy\u0161ova\u0165 celkov\u00fa priepustnos\u0165 celej siete u\u017e so mal pr\u00edstup pomocou prihlasovac\u00edch \u00fadajov a hesla.<\/b> kompatibiln\u00fdm klientsk\u00fdm zariaden\u00edm! Hne\u010f ako sa objavia aspo\u0148 dvaja klienti, ktor\u00ed dok\u00e1\u017eu hovori\u0165 s\u00fa\u010dasne, tak pri rovnak\u00fdch podmienkach (nem\u00e1m \u017eiadny d\u00f4vod predpoklada\u0165, \u017ee ovl\u00e1da\u010de pre klientsk\u00e9 r\u00e1diov\u00e9 moduly bud\u00fa lep\u0161ie ako predt\u00fdm, a teda, \u017ee agreg\u00e1cia \u201eu\u017eito\u010dn\u00fdch\u201c \u010dast\u00ed r\u00e1mcov, ako aj mnoh\u00e9 in\u00e9 klientsky z\u00e1visl\u00e9 funkcie bud\u00fa na\u010falej \u201ev priemere po zoo\u201c fungova\u0165 nie celkom ide\u00e1lne) u\u017e zv\u00fd\u0161ia priemern\u00fa priepustnos\u0165. Tak\u017ee ak uva\u017eujete o novej sieti Wi-Fi \u2014 m\u00e1 zmysel hne\u010f zv\u00e1\u017ei\u0165 najnov\u0161ie a najlep\u0161ie pr\u00edstupov\u00e9 body, preto\u017ee aj ke\u010f teraz pre ne je e\u0161te m\u00e1lo klientov \u2014 situ\u00e1cia tak dlho nevydr\u017e\u00ed.<\/li>\n
      2. V\u0161etky triky a finty, ktor\u00e9 m\u00e1 dnes na\u0161a pohotov\u00e1 bezdr\u00f4tov\u00e1 in\u017einierka, e\u0161te dlh\u00e9 roky ostan\u00fa aktu\u00e1lne \u2014 pr\u00edstupov\u00fd mechanizmus sa s\u00edce prekvapivo posunul, poru\u0161uj\u00fac viac ako 20 rokov platn\u00e9 z\u00e1kladn\u00e9 princ\u00edpy, ale st\u00e1le kladie d\u00f4raz na kompatibilitu. Na\u010falej je potrebn\u00e9 vyl\u00fa\u010di\u0165 \"pomal\u00e9\" management rates (a st\u00e1le je potrebn\u00e9 ch\u00e1pa\u0165, pre\u010do a kedy), na\u010falej je potrebn\u00e9 spr\u00e1vne pl\u00e1nova\u0165 fyzick\u00fa vrstvu, preto\u017ee \u017eiaden mechanizmus na \u00farovni kan\u00e1la nezafunguje, ak bud\u00fa probl\u00e9my na fyzickej \u00farovni. Pr\u00e1ve sa objavila mo\u017enos\u0165 robi\u0165 e\u0161te lep\u0161ie<\/i>.<\/li>\n
      3. Takmer v\u0161etky rozhodnutia vo Wi-Fi 6 prij\u00edma pr\u00edstupov\u00fd bod. Ako vid\u00edme, spravuje pr\u00edstup klientov k prostrediu t\u00fdm, \u017ee sp\u00e1ja zariadenia do \"obdob\u00ed\" s\u00fa\u010dasnej prev\u00e1dzky. Ak sa na chv\u00ed\u013eu odklon\u00edme \u2014 fungovanie TWT m\u00e1 tie\u017e plne na pleciach pr\u00edstupov\u00fd bod. Teraz mus\u00ed AP nielen \"vysiela\u0165 sie\u0165\" a uchov\u00e1va\u0165 prev\u00e1dzku v frontoch, ale aj sledova\u0165 v\u0161etk\u00fdch klientov, pl\u00e1nuj\u00fac, ako ich najefekt\u00edvnej\u0161ie spoji\u0165 na z\u00e1klade ich priepustnost\u00ed a po\u017eiadaviek na prev\u00e1dzku, ich bat\u00e9ri\u00ed a mnoho \u010fal\u0161\u00edch faktorov \u2014 naz\u00fdvam tento proces \"orchestr\u00e1ciou\". Algoritmy, pod\u013ea ktor\u00fdch pr\u00edstupov\u00fd bod urob\u00ed v\u0161etky tieto rozhodnutia, nie s\u00fa regulovan\u00e9, a teda skuto\u010dn\u00e1 kvalita a \u0161truktur\u00e1lny pr\u00edstup v\u00fdrobcov sa uk\u00e1\u017ee presne pri v\u00fdvoji algoritmov orchestr\u00e1cie. \u010c\u00edm presnej\u0161ie pr\u00edstupov\u00e9 body predpovedaj\u00fa potreby klientov, t\u00fdm lep\u0161ie a rovnomernej\u0161ie ich dok\u00e1\u017eu organizova\u0165 do skup\u00edn viacn\u00e1sobn\u00e9ho pr\u00edstupu \u2014 a teda, t\u00fdm efekt\u00edvnej\u0161ie bud\u00fa vyu\u017e\u00edva\u0165 zdroje \u00e9teru a vy\u0161\u0161ia bude kone\u010dn\u00e1 priepustnos\u0165 tak\u00e9ho pr\u00edstupov\u00e9ho bodu. Algoritmus \u2014 posledn\u00e1 hranica!<\/li>\n
      4. Prechod z Wi-Fi 5 na Wi-Fi 6 je svojou podstatou a v\u00fdznamom revolu\u010dn\u00fd rovnako ako prechod z 802.11g na 802.11n. Vtedy sme z\u00edskali viacero tokov a agreg\u00e1ciu \u201eu\u017eito\u010dn\u00e9ho za\u0165a\u017eenia\u201c \u2014 teraz z\u00edskavame s\u00fa\u010dasn\u00fd pr\u00edstup k prostrediu a kone\u010dne funguj\u00face MU-MIMO a Beamforming (po prv\u00e9, ako vieme, to s\u00fa takmer to ist\u00e9; po druh\u00e9, diskusia o tom, \u201epre\u010do MU-MIMO v 802.11ac vymysleli, ale nedok\u00e1zali ho spusti\u0165\u201c \u2014 to je t\u00e9ma pre samostatn\u00fd ve\u013ek\u00fd \u010dl\u00e1nok \ud83d\ude42 ). Obe, 802.11n a Wi-Fi 6, funguj\u00fa v oboch p\u00e1smach (2,4 GHz a 5 GHz), na rozdiel od \u201emedzi-\u010dasu\u201c predchodcov \u2014 naozaj, \u201e\u0161es\u0165 je nov\u00e1 \u0161tyri\u201c!<\/li>\n<\/ol>\n

        <\/p>\n

        Nie\u010do o p\u00f4vode tohto \u010dl\u00e1nku<\/b>
        \n \u010cl\u00e1nok bol nap\u00edsan\u00fd pre s\u00fa\u0165a\u017e, ktor\u00fa usporiadala spolo\u010dnos\u0165 Huawei (p\u00f4vodne bol zverejnen\u00fd         tu<\/a><\/noindex>). V mnohom som sa pri jeho p\u00edsan\u00ed opieral o svoju vlastn\u00fa prezent\u00e1ciu na konferencii \u201eBezdr\u00f4tov\u00fd svet\u201c, ktor\u00e1 sa konala v roku 2019 v Petrohrade (z\u00e1znam vyst\u00fapenia si m\u00f4\u017eete pozrie\u0165 na YouTube<\/a><\/noindex>, len majte na pam\u00e4ti \u2014 zvuk je tam, povedzme, nie je najlep\u0161\u00ed, napriek petrohradskej povahy videa!).
        \n
        Zdroj:         habr.com<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

        \u041f\u0440\u0438\u0432\u0435\u0442. \u0415\u0441\u043b\u0438 \u0432\u0435\u0440\u0438\u0442\u044c \u0442\u0435\u043e\u0440\u0438\u0438 \u043f\u0440\u043e\u0441\u0442\u043e\u0442\u044b \u042d\u0439\u043d\u0448\u0442\u0435\u0439\u043d\u0430, \u0433\u043b\u0430\u0432\u043d\u044b\u0439 \u043f\u043e\u043a\u0430\u0437\u0430\u0442\u0435\u043b\u044c \u043f\u043e\u043d\u0438\u043c\u0430\u043d\u0438\u044f \u043f\u0440\u0435\u0434\u043c\u0435\u0442\u0430 \u2014 \u044d\u0442\u043e \u0441\u043f\u043e\u0441\u043e\u0431\u043d\u043e\u0441\u0442\u044c \u043c\u0430\u043a\u0441\u0438\u043c\u0430\u043b\u044c\u043d\u043e \u043f\u0440\u043e\u0441\u0442\u043e \u0435\u0433\u043e \u043e\u0431\u044a\u044f\u0441\u043d\u0438\u0442\u044c, \u0442\u043e \u0438 \u0432 \u044d\u0442\u043e\u043c \u043f\u043e\u0441\u0442\u0435 \u044f \u043f\u043e\u0441\u0442\u0430\u0440\u0430\u044e\u0441\u044c \u043c\u0430\u043a\u0441\u0438\u043c\u0430\u043b\u044c\u043d\u043e \u043f\u0440\u043e\u0441\u0442\u043e \u0438 \u043f\u043e\u0434\u0440\u043e\u0431\u043d\u043e \u043e\u0431\u044a\u044f\u0441\u043d\u0438\u0442\u044c \u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0435 \u0432\u0441\u0435\u0433\u043e \u043e\u0434\u043d\u043e\u0439 \u0434\u0435\u0442\u0430\u043b\u0438 \u043d\u043e\u0432\u043e\u0433\u043e \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u0430, \u043a\u043e\u0442\u043e\u0440\u0443\u044e \u043f\u043e\u0447\u0435\u043c\u0443-\u0442\u043e \u0434\u0430\u0436\u0435 Wi-Fi Alliance \u0441\u0447\u0438\u0442\u0430\u0435\u0442 \u043d\u0435\u0434\u043e\u0441\u0442\u043e\u0439\u043d\u043e\u0439 \u0443\u043f\u043e\u043c\u0438\u043d\u0430\u043d\u0438\u044f \u0432 \u0438\u043d\u0444\u043e\u0433\u0440\u0430\u0444\u0438\u043a\u0435 \u043e \u043d\u043e\u0432\u044b\u0445 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044f\u0445 Wi-Fi 6, \u0445\u043e\u0442\u044f \u043e\u043d\u0430, \u043a\u0430\u043a \u043c\u044b \u0441\u043a\u043e\u0440\u043e […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":84591,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[688],"tags":[],"class_list":["post-84590","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-administrirovanie"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Najd\u00f4le\u017eitej\u0161ie v Wi-Fi 6. Nie, v\u00e1\u017ene | ProHoster","description":"Ahoj. Ak ver\u00edme te\u00f3rii jednoduchosti Einsteina, hlavn\u00fd ukazovate\u013e porozumenia predmetu \u2014 je schopnos\u0165 maxim\u00e1lne jednoducho ho vysvetli\u0165, tak aj v tomto pr\u00edspevku sa pok\u00fasim maxim\u00e1lne jednoducho a podrobne vysvetli\u0165.","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/administrirovanie\/samoe-glavnoe-v-wi-fi-6-net-seryozno","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sk_SK","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u0421\u0430\u043c\u043e\u0435 \u0433\u043b\u0430\u0432\u043d\u043e\u0435 \u0432 Wi-Fi 6. \u041d\u0435\u0442, 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