Standard WLAN 802.11ad se naz\u00fdv\u00e1 Wireless Gigabit, zkr\u00e1cen\u011b WiGig. Na tento standard ji\u017e navazuje standard IEEE 802.11ay, kter\u00fd m\u00e1 odstranit st\u00e1vaj\u00edc\u00ed nep\u0159esnosti v definici standardu a zajistit dal\u0161\u00ed zv\u00fd\u0161en\u00ed p\u0159enosov\u00e9 rychlosti. Tento standard byl vyvinut ve spolupr\u00e1ci organizace Wireless Gigabit Alliance, kterou tvo\u0159\u00ed \u0159ada v\u00fdrobc\u016f po\u010d\u00edta\u010d\u016f a po\u010d\u00edta\u010dov\u00e9ho softwaru (Intel, Microsoft, Dell, Panasonic), a organizace Wi-Fi Alliance.<\/p>\n
C\u00edlem je vyvinout technologii, jej\u00ed\u017e pou\u017e\u00edv\u00e1n\u00ed nevy\u017eaduje licenci a kter\u00e1 zvy\u0161uje rychlost bezdr\u00e1tov\u00e9ho p\u0159ipojen\u00ed na \u00farove\u0148 n\u011bkolika gigabit\u016f. Zde se pou\u017e\u00edv\u00e1 nelicencovan\u00e9 p\u00e1smo 60\u00a0GHz. Tento standard v\u0161ak nen\u00ed typickou s\u00edt\u00ed WLAN s p\u0159\u00edstupov\u00fdm bodem a mnoha klienty WLAN, ale pou\u017e\u00edv\u00e1 se sp\u00ed\u0161e v bezdr\u00e1tov\u00e9 komunikaci ve spojen\u00ed \u201epoint-to-point\u201c mezi dv\u011bma za\u0159\u00edzen\u00edmi s vysok\u00fdmi p\u0159enosov\u00fdmi rychlostmi v rozsahu gigabit\u016f. Pro dosa\u017een\u00ed t\u011bchto vysok\u00fdch po\u017eadavk\u016f na rychlost p\u0159enosu dat je zru\u0161ena zp\u011btn\u00e1 kompatibilita se v\u0161emi p\u0159edchoz\u00edmi standardy WLAN.<\/p>\n
Jak\u00e9 jsou mo\u017en\u00e9 oblasti pou\u017eit\u00ed WiGig?<\/strong><\/p>\n Typick\u00fdmi aplikacemi jsou p\u0159ipojen\u00ed typu \u201epoint-to-point\u201c v oblasti dom\u00e1c\u00ed z\u00e1bavy, kter\u00e1 vy\u017eaduj\u00ed vysokou \u0161\u00ed\u0159ku p\u00e1sma bez zprost\u0159edkuj\u00edc\u00edho sm\u011brova\u010de, nap\u0159\u00edklad pro VR headsety (virtu\u00e1ln\u00ed realita), dokovac\u00ed stanice nebo 4k video za\u0159\u00edzen\u00ed 4. Oblast\u00ed pou\u017eit\u00ed tedy nen\u00ed vz\u00e1jemn\u00e9 propojen\u00ed n\u011bkolika po\u010d\u00edta\u010d\u016f, ale ad hoc spojen\u00ed mezi po\u010d\u00edta\u010di a perifern\u00edmi za\u0159\u00edzen\u00edmi.<\/p>\n V \u00favahu p\u0159ich\u00e1zej\u00ed n\u00e1sleduj\u00edc\u00ed p\u0159\u00edklady pou\u017eit\u00ed:<\/p>\n V \u010dem p\u0159esn\u011b se li\u0161\u00ed od \u201enorm\u00e1ln\u00edho\u201c standardu WLAN?<\/strong><\/p>\n Nejd\u016fle\u017eit\u011bj\u0161\u00edm rozd\u00edlem mezi standardem 802.11ad a b\u011b\u017en\u00fdmi standardy WLAN 802.11ac (vyu\u017eit\u00ed frekven\u010dn\u00edho p\u00e1sma 5 GHz) a 802.11ax (vyu\u017eit\u00ed frekven\u010dn\u00edho p\u00e1sma 2,4 GHz a 5 GHz) je pou\u017eit\u00fd frekven\u010dn\u00ed rozsah.\u00a0 D\u00edky p\u0159echodu na p\u00e1smo 60 GHz, kter\u00e9 pokr\u00fdv\u00e1 frekven\u010dn\u00ed rozsah od 57 do 66\u00a0GHz, m\u00e1 WiGig k dispozici mnohem \u0161ir\u0161\u00ed p\u00e1smo kan\u00e1l\u016f ne\u017e v p\u00e1smech 2,4 a 5\u00a0GHz. Zde je k dispozici celkov\u00e1 \u0161\u00ed\u0159ka p\u00e1sma p\u0159ibli\u017en\u011b 8,5\u00a0GHz, rozd\u011blen\u00e1 do 4 kan\u00e1l\u016f, ka\u017ed\u00fd o \u0161\u00ed\u0159ce p\u00e1sma 2,16\u00a0GHz. Pro srovn\u00e1n\u00ed, 802.11ac a 802.11ax poskytuj\u00ed maxim\u00e1ln\u00ed \u0161\u00ed\u0159ku p\u00e1sma 80 MHz v p\u00e1smu 2,4 GHz a 160 MHz v p\u00e1smu 5 GHz.<\/p>\n Dal\u0161\u00ed z\u00e1sadn\u00ed rozd\u00edl spo\u010d\u00edv\u00e1 v oblastech pou\u017eit\u00ed popsan\u00fdch standard\u016f WLAN. Na rozd\u00edl od standard\u016f 802.11ac a 802.11ax nen\u00ed WiGig ur\u010den pro s\u00edt\u011b s v\u00edce u\u017eivateli, kter\u00e9 pokr\u00fdvaj\u00ed v\u00edce m\u00edstnost\u00ed, ale poskytuje \u0159e\u0161en\u00ed pro \u0161irokop\u00e1smov\u00e1 bezdr\u00e1tov\u00e1 p\u0159ipojen\u00ed typu \u201epoint-to-point\u201c na kr\u00e1tk\u00e9 vzd\u00e1lenosti. Pou\u017eit\u00ed p\u00e1sma 60 GHz m\u00e1 za n\u00e1sledek vy\u0161\u0161\u00ed \u00fatlum sign\u00e1lu ve voln\u00e9m prostoru a p\u0159es objekty nebo st\u011bny, co\u017e v\u00fdrazn\u011b omezuje maxim\u00e1ln\u00ed dosa\u017eiteln\u00fd dosah r\u00e1diov\u00fdch sign\u00e1l\u016f. Atmosf\u00e9rick\u00fd kysl\u00edk zp\u016fsobuje \u00fatlum p\u0159ibli\u017en\u011b 20\u00a0dB na 1\u00a0km. P\u0159edm\u011bty, p\u0159ek\u00e1\u017eky (nap\u0159. tak\u00e9 lid\u00e9), st\u011bny a stropy nav\u00edc zeslabuj\u00ed sign\u00e1ly, co\u017e znamen\u00e1, \u017ee nejlep\u0161\u00ed mo\u017en\u00fd p\u0159enos sign\u00e1lu lze realizovat pouze mezi za\u0159\u00edzen\u00edmi s p\u0159\u00edmou viditelnost\u00ed bez ztr\u00e1t propustnosti. WiGig tak nach\u00e1z\u00ed uplatn\u011bn\u00ed v bezdr\u00e1tov\u00e9 komunikaci v r\u00e1mci m\u00edstnosti a v okruhu maxim\u00e1ln\u011b deseti metr\u016f. D\u00edky tomu mohou b\u00fdt ostatn\u00ed p\u0159ipojen\u00ed WLAN v budov\u011b provozov\u00e1na ve stejn\u00e9m frekven\u010dn\u00edm rozsahu, ani\u017e by se vz\u00e1jemn\u011b ru\u0161ila kv\u016fli velmi omezen\u00e9mu dosahu.<\/p>\n WiGig tedy v \u017e\u00e1dn\u00e9m p\u0159\u00edpad\u011b nem\u00e1 nahradit b\u011b\u017en\u00e9 standardy WLAN, ale pouze otev\u0159\u00edt dal\u0161\u00ed oblasti pou\u017eit\u00ed s vy\u0161\u0161\u00edmi p\u0159enosov\u00fdmi rychlostmi. Standard je vhodn\u00fd nap\u0159\u00edklad pro bezdr\u00e1tov\u00fd p\u0159enos videosign\u00e1l\u016f s vysok\u00fdm rozli\u0161en\u00edm 4K nebo srovnateln\u00fdch sign\u00e1l\u016f z oblasti dom\u00e1c\u00ed z\u00e1bavy, \u010d\u00edm\u017e WiGig p\u0159\u00edmo konkuruje bezdr\u00e1tov\u00fdm protokol\u016fm a standard\u016fm, jako je Wireless HDMI (WHDMI).<\/p>\n Jak\u00e9 jsou hlavn\u00ed technick\u00e9 vlastnosti WiGig?<\/strong><\/p>\n Vzhledem k pou\u017eit\u00ed p\u00e1sma 60\u00a0GHz a z toho plynouc\u00ed v\u011bt\u0161\u00ed celkov\u00e9 \u0161\u00ed\u0159ce p\u00e1sma a 4 jednotliv\u00fdch kan\u00e1l\u016f, nejsou modula\u010dn\u00ed postupy pro dosa\u017een\u00ed vysok\u00fdch p\u0159enosov\u00fdch rychlost\u00ed tak slo\u017eit\u00e9 jako u standard\u016f 802.11ac a 802.11ax. WiGig pou\u017e\u00edv\u00e1 metodu SC-OFDM (Single Carrier Orthogonal Frequency Division Multiplex). V kombinaci s technologi\u00ed Beamforming pro vyrovn\u00e1n\u00ed vyza\u0159ovac\u00edho diagramu ant\u00e9n dosahuje standard 802.11ad rychlosti p\u0159enosu dat 6,76\u00a0Gb\/s. Pro dosa\u017een\u00ed srovnateln\u011b vysok\u00fdch p\u0159enosov\u00fdch rychlost\u00ed v ni\u017e\u0161\u00edch frekven\u010dn\u00edch p\u00e1smech (802.11ac a 802.11ax) se pou\u017e\u00edvaj\u00ed sofistikovan\u011bj\u0161\u00ed metody multiplexov\u00e1n\u00ed a modulace, jako je OFDMA (Orthogonal Frequency Division Multiple Access) a 256-QAM nebo 1024-QAM.<\/p>\n Dal\u0161\u00edmi vlastnostmi WiGig jsou jednak re\u017eim \u00faspory energie pro za\u0159\u00edzen\u00ed nap\u00e1jen\u00e1 z bateri\u00ed, jednak mo\u017enost rozli\u0161ovat mezi dv\u011bma re\u017eimy (vysoce v\u00fdkonn\u00fd p\u0159enos dat s vysokou p\u0159enosovou rychlost\u00ed a robustn\u00ed p\u0159enos dat s ni\u017e\u0161\u00ed p\u0159enosovou rychlost\u00ed).<\/p>\n Krom\u011b toho ji\u017e existuj\u00ed t\u0159\u00edp\u00e1smov\u00e1 za\u0159\u00edzen\u00ed, kter\u00e1 podporuj\u00ed v\u0161echna zde uveden\u00e1 p\u00e1sma r\u016fzn\u00fdch standard\u016f WLAN (2,4\u00a0GHz, 5\u00a0GHz, 60\u00a0GHz).<\/p>\n\n