{"id":2170,"date":"2020-04-02T16:13:33","date_gmt":"2020-04-02T13:13:33","guid":{"rendered":"https:\/\/blog.3kgroup.ee:443\/?p=2170"},"modified":"2020-05-11T16:39:22","modified_gmt":"2020-05-11T13:39:22","slug":"suururitusel-2-4-ghz-wi-fi-seadmetega-tood-teha-on-riskantne-2","status":"publish","type":"post","link":"https:\/\/blog.3kgroup.ee:443\/?p=2170&lang=en","title":{"rendered":"Working with 2.4 GHz Wi-Fi devices at a major event is risky."},"content":{"rendered":"\n<p>Here are some measurements in the 2.4GHz and 5GHz coverage area from the Saku Great Hall at Robotex 2019 competition. The following 2.4 GHz graphs clearly show that the latency (measured on a wi-fi network from an AP to a client) reaches up to 480ms and the median is 81ms, which means that in half of the cases the latency is greater than 81ms. This situation is caused by 2.4 GHz Wi-Fi devices.<\/p>\n\n\n\n<p>The number of users in the hall was 650-700, depending on the movement of people.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"832\" height=\"617\" src=\"https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/2.4GHz-health.png\" alt=\"\" class=\"wp-image-1689\" srcset=\"https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/2.4GHz-health.png 832w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/2.4GHz-health-300x222.png 300w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/2.4GHz-health-768x570.png 768w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/2.4GHz-health-600x445.png 600w\" sizes=\"auto, (max-width: 832px) 100vw, 832px\" \/><figcaption>5 GHz<\/figcaption><\/figure>\n\n\n\n<p>In the 5GHz frequency band, the quality of signal is much better for 700 users. The median latency is 24ms, the median air occupancy is only 5%, so in half of the cases the occupancy is even less than 5%.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"777\" height=\"619\" src=\"https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/5GHz-health.png\" alt=\"\" class=\"wp-image-1690\" srcset=\"https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/5GHz-health.png 777w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/5GHz-health-300x239.png 300w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/5GHz-health-768x612.png 768w, https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/5GHz-health-600x478.png 600w\" sizes=\"auto, (max-width: 777px) 100vw, 777px\" \/><figcaption>2.4 GHz <\/figcaption><\/figure>\n\n\n\n<p>A positive example from Robotex, where robots already use the 5 GHz Wi-Fi frequency to transmit images. A separate SSID was created for the competition, wich had a higher priority than public networks.<\/p>\n\n\n\n<figure class=\"wp-block-video\"><video height=\"1280\" style=\"aspect-ratio: 720 \/ 1280;\" width=\"720\" controls src=\"https:\/\/blog.3kgroup.ee:443\/wp-content\/uploads\/2019\/11\/animal-rescue2.mov\"><\/video><figcaption>Starship competition robots event on a virtual Wi-Fi network at 5 GHz. The robot receives points for each animal found, the image of which is uploaded to the server.<\/figcaption><\/figure>\n\n\n\n<p>However, a busy and high latency network means slow speeds and often no internet connection. The graphs are taken from the <a href=\"http:\/\/3kgroup.ee\/tag\/smartzone\/\">SmartZone management system<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Here are some measurements in the 2.4GHz and 5GHz coverage area from the Saku Great Hall at Robotex 2019 competition. The following 2.4 GHz graphs clearly show that the latency [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":1688,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[462],"tags":[486],"class_list":["post-2170","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wifi-on-events","tag-events"],"acf":[],"_links":{"self":[{"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/posts\/2170","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2170"}],"version-history":[{"count":7,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/posts\/2170\/revisions"}],"predecessor-version":[{"id":2182,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/posts\/2170\/revisions\/2182"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=\/wp\/v2\/media\/1688"}],"wp:attachment":[{"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2170"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2170"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.3kgroup.ee:443\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2170"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}