{"id":6217,"date":"2021-03-24T09:25:22","date_gmt":"2021-03-24T09:25:22","guid":{"rendered":"https:\/\/www.beaconzone.co.uk\/blog\/?p=6217"},"modified":"2021-03-24T09:26:07","modified_gmt":"2021-03-24T09:26:07","slug":"bluetooth-adaptive-frequency-hopping-overcomes-packet-interference","status":"publish","type":"post","link":"https:\/\/www.beaconzone.co.uk\/blog\/bluetooth-adaptive-frequency-hopping-overcomes-packet-interference\/","title":{"rendered":"Bluetooth Adaptive Frequency Hopping Overcomes Packet Interference"},"content":{"rendered":"\n<p>There&#8217;s a recent post by the Bluetooth SIG on <a rel=\"noreferrer noopener\" href=\"https:\/\/www.bluetooth.com\/blog\/how-bluetooth-technology-uses-adaptive-frequency-hopping-to-overcome-packet-interference\" target=\"_blank\">How Bluetooth Technology Uses Adaptive Frequency Hopping to Overcome Packet Interference<\/a>.<\/p>\n\n\n\n<p>When two or more wireless devices transmit on the same frequency, if the transmissions overlap in time then the signal is corrupted. Bluetooth reduces such collisions by using 40 different frequencies called channels. A technique called adaptive frequency hopping (AFH) allows Bluetooth devices to avoid channels that are noisy or busy.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"506\" src=\"https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping-1024x506.png\" alt=\"\" class=\"wp-image-6218\" srcset=\"https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping-1024x506.png 1024w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping-300x148.png 300w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping-768x380.png 768w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping-1200x593.png 1200w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2021\/03\/bluetoothfrequencyhopping.png 1383w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption>Bluetooth channels used by two connected devices<\/figcaption><\/figure><\/div>\n\n\n\n<p>Of the 40 channels defined for use by Bluetooth Low Energy (LE), 37 of these channels are available for use during connected communication.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"904\" height=\"504\" src=\"https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2020\/10\/BluetoothLEAdvertisingChannels.png\" alt=\"\" class=\"wp-image-5683\" srcset=\"https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2020\/10\/BluetoothLEAdvertisingChannels.png 904w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2020\/10\/BluetoothLEAdvertisingChannels-300x167.png 300w, https:\/\/www.beaconzone.co.uk\/blog\/wp-content\/uploads\/2020\/10\/BluetoothLEAdvertisingChannels-768x428.png 768w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption>Channels used for advertising and scanning (in green)<\/figcaption><\/figure><\/div>\n\n\n\n<p>Of the 40 channels, 3 are used for (one way) advertising and 37 for (two way) connections. In the case of <a href=\"https:\/\/www.beaconzone.co.uk\/allbeacons\" target=\"_blank\" rel=\"noreferrer noopener\">beacons<\/a>, they spend most of the time advertising sequentially on channels 37, 38 and 39. Connections and hence AFH are only usually used when setting up the beacons using manufacturers&#8217; apps.<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>There&#8217;s a recent post by the Bluetooth SIG on How Bluetooth Technology Uses Adaptive Frequency Hopping to Overcome Packet Interference. When two or more wireless devices transmit on the same frequency, if the transmissions overlap in time then the signal is corrupted. Bluetooth reduces such collisions by using 40 different frequencies called channels. A technique &hellip; <a href=\"https:\/\/www.beaconzone.co.uk\/blog\/bluetooth-adaptive-frequency-hopping-overcomes-packet-interference\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Bluetooth Adaptive Frequency Hopping Overcomes Packet Interference&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"_links":{"self":[{"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/posts\/6217"}],"collection":[{"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=6217"}],"version-history":[{"count":4,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/posts\/6217\/revisions"}],"predecessor-version":[{"id":6226,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/posts\/6217\/revisions\/6226"}],"wp:attachment":[{"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=6217"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=6217"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.beaconzone.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=6217"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}