[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/www.menas.cz\/wi-fi\/#Article","mainEntityOfPage":"https:\/\/www.menas.cz\/wi-fi\/","headline":"Wi-Fi","name":"Wi-Fi","description":"Jedn\u00e1 se o ozna\u010den\u00ed bezdr\u00e1tov\u00e9 komunikace v\u00a0mobiln\u00edch nebo po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00edch. Pracuje na principu frekven\u010dn\u00edho p\u00e1sma, je to tedy velmi levn\u00e1, ale v\u00fdkonn\u00e1 s\u00ed\u0165, bez toho, ani\u017e by byly pou\u017eity kabely. Jm\u00e9no neboli n\u00e1zev WI-FI je odvozen od Wirelles Fidelity (bezdr\u00e1tov\u00e1 […]","datePublished":"2019-05-15","dateModified":"2023-05-04","author":{"@type":"Person","@id":"https:\/\/www.menas.cz\/author\/#Person","name":"","url":"https:\/\/www.menas.cz\/author\/","identifier":1,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/670235c08005d2f1b80a3d56a421809661de47ce0289bd1c93d0120f6ef211a4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/670235c08005d2f1b80a3d56a421809661de47ce0289bd1c93d0120f6ef211a4?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"menas.cz","logo":{"@type":"ImageObject","@id":"\/logo.png","url":"\/logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/www.menas.cz\/wp-content\/uploads\/img_a345248_w2692_t1558884898.jpg","url":"https:\/\/www.menas.cz\/wp-content\/uploads\/img_a345248_w2692_t1558884898.jpg","height":0,"width":0},"url":"https:\/\/www.menas.cz\/wi-fi\/","wordCount":504,"articleBody":"\tJedn\u00e1 se o ozna\u010den\u00ed bezdr\u00e1tov\u00e9 komunikace v\u00a0mobiln\u00edch nebo po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00edch. Pracuje na principu frekven\u010dn\u00edho p\u00e1sma, je to tedy velmi levn\u00e1, ale v\u00fdkonn\u00e1 s\u00ed\u0165, bez toho, ani\u017e by byly pou\u017eity kabely. Jm\u00e9no neboli n\u00e1zev WI-FI je odvozen od Wirelles Fidelity (bezdr\u00e1tov\u00e1 v\u011brnost).\tWi-Fi nen\u00ed \u017e\u00e1dn\u00e1 novinka. V\u00a0Americe se setkala here\u010dka Hedy Lamarr (vlastn\u00edm jm\u00e9nem Hedwig Eva Maria Kiesler) a hudebn\u00ed skladatel George Antheil a vyslechli na jednom ve\u010d\u00edrku to, \u017ee N\u011bmci vyr\u00e1b\u011bj\u00ed torp\u00e9da \u0159\u00edzen\u00e9 r\u00e1diov\u011b. Spole\u010dn\u011b p\u0159i\u0161li na to, \u017ee pokud by mohli p\u0159eladit vys\u00edla\u010d i p\u0159ij\u00edma\u010d pomoc\u00ed r\u00e1diov\u00e9 cesty, mohli by tyto torp\u00e9da odchylovat z\u00a0dr\u00e1hy. Vyu\u017eili k\u00a0tomu d\u011brnou p\u00e1sku. Antheil slo\u017eil toti\u017e hudbu pro film, kde Lamarr hr\u00e1la a Antheil pot\u0159eboval, aby v\u00a0hudb\u011b hr\u00e1lo synchronn\u011b 16 klav\u00edr\u016f. Nechali si tento vyn\u00e1lez roku 1942 patentovat a bezplatn\u011b ho nab\u00eddky US Navy, kter\u00e1 ale tento patent ve 2.sv\u011btov\u00e9 v\u00e1lce nevyu\u017eila. Ve 20.stolet\u00ed, mezi lety 60.-80. byla tato technologie pou\u017e\u00edvan\u00e1 pouze pro vojensk\u00e9 \u00fa\u010dely. Na po\u010d\u00e1tku 80.let 20.stolet\u00ed bylo umo\u017en\u011bno ve\u0159ejnosti, aby ji tak\u00e9 vyu\u017e\u00edvala.\t\t\u00a0\tPojmy, kter\u00e9 souvisej\u00ed s\u00a0Wi-Fi\t\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Access Point \u2013 p\u0159\u00edstupov\u00fd bod (AP), ur\u010den k\u00a0\u0159\u00edzen\u00ed komunikace mezi za\u0159\u00edzen\u00edmi Wi-Fi\t\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Firewall \u2013 zamezuje p\u0159\u00edstupu na po\u010d\u00edta\u010d nebo s\u00ed\u0165 nepovolan\u00fdm osob\u00e1m\t\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Home gateway \u2013 je to br\u00e1na, kter\u00e1 spojuje dv\u011b r\u016fzn\u00e9 s\u00edt\u011b, sm\u011bruje router\t\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 WISP\u2013 kombinuje p\u0159\u00edjem dat a nastavuje router pro LAN v\u00fdstupy\t\u00a0\tProbl\u00e9m Wi-Fi je takov\u00fd, \u017ee se \u0161\u00ed\u0159\u00ed i mimo objekt \u010di budovu, a proto je mo\u017en\u00e9 se na ni p\u0159ipojit pod podvodn\u00fdm heslem. Zabezpe\u010den\u00ed s\u00edt\u011b se vyv\u00edjelo postupn\u011b a n\u011bkter\u00e9 star\u0161\u00ed s\u00edt\u011b, maj\u00ed pouze omezen\u00e9 zabezpe\u010den\u00ed. U takov\u00fdch p\u0159\u00edpad\u016f se vyu\u017e\u00edv\u00e1 nap\u0159. Virtu\u00e1ln\u00ed priv\u00e1tn\u00ed s\u00ed\u0165.\t\u00a0\tZabezpe\u010den\u00ed bezdr\u00e1tov\u00fdch s\u00edt\u00ed bych rozd\u011blila do dvou skupin: \u0160IFROV\u00c1N\u00cd a AUTORIZACE.\t\u00a0\tVz\u00e1jemn\u00fd soulad za\u0159\u00edzen\u00ed zaji\u0161\u0165uje IEEE 802.11\t\t\t\tStandart\t\t\t\tOzna\u010den\u00ed\t\t\t\tP\u00e1smo\t\t\t\tMax. rychlost Mbit\/s\t\t\t\tVrstva\t\t\t\tIEEE 802.11\t\t\t\t\u00a0\t\t\t\t2,4\t\t\t\t2\t\t\t\tDSSS\t\t\t\tIEEE 802.11 a\t\t\t\tWi-Fi 1\t\t\t\t5\t\t\t\t54\t\t\t\tOFDM\t\t\t\tIEEE 802.11 b\t\t\t\tWi-Fi 2\t\t\t\t2,4\t\t\t\t11\t\t\t\tDSSS\t\t\t\tIEEE 802.11 g\t\t\t\tWi-Fi 3\t\t\t\t2,4\t\t\t\t54\t\t\t\tOFDM\t\t\t\tIEEE 802.11 n\t\t\t\tWi-Fi 4\t\t\t\t2,4 nebo 5\t\t\t\t600*\t\t\t\tOFDM, MIMO\t\t\t\tIEEE 802.11 ac \t\t\t\tWi-Fi 5\t\t\t\t2,4 nebo 5\t\t\t\t1800\t\t\t\tOFDM, MIMOV dne\u0161n\u00ed dob\u011b se za\u010dala vyu\u017e\u00edvat Wi-Fi 5, kter\u00e1 p\u0159ekon\u00e1v\u00e1 st\u00e1vaj\u00edc\u00ed s\u00ed\u0165 Wi-Fi 4, tedy 4G (LTE). Jde vlastn\u011b o zv\u00fd\u0161en\u00ed p\u0159enosov\u00e9 rychlosti, m\u011bla by b\u00fdt pou\u017e\u00edv\u00e1na jak mobiln\u00edmi telefony, chytr\u00fdmi auty, roboty nebo na p\u0159enos holografick\u00fdch telefon\u00e1t\u016f \u010di konferenc\u00ed.Je ale i zraniteln\u011bj\u0161\u00ed ne\u017e 4G.\u00a0Bezdr\u00e1tov\u00e1 s\u00ed\u0165 m\u00e1 velmi bohatou minulost i sou\u010dasnost. Ka\u017ed\u00fd den ji vyu\u017eije ka\u017ed\u00fd z\u00a0n\u00e1s a je jedno, jestli se jen tak bloum\u00e1te internetem anebo hrajete po\u010d\u00edta\u010dov\u00e9 hry.                                                                                                                                                                                                                                                                                                                                                                                        3.7\/5 - (8 votes)        "},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Wi-Fi","item":"https:\/\/www.menas.cz\/wi-fi\/#breadcrumbitem"}]}]