{"id":1119,"date":"2007-04-23T17:42:46","date_gmt":"2007-04-23T15:42:46","guid":{"rendered":"http:\/\/www.randform.org\/blog\/?p=1119"},"modified":"2007-04-23T17:42:46","modified_gmt":"2007-04-23T15:42:46","slug":"musical-chairs","status":"publish","type":"post","link":"https:\/\/www.randform.org\/blog\/?p=1119","title":{"rendered":"Musical chairs"},"content":{"rendered":"

\"Pigeons-in-holes.jpg\"
\nimage source wikipedia<\/a><\/p>\n

new scientist reported <\/a> about tests performed on a recent conference<\/a> in which radio networks are used for wireless communication, a feature commonly called cognitive radio<\/a>. <\/p>\n


\n
\nCognitive radio could plainly mean that radio (and TV) frequencies are used for wireless communication, but it could also mean that certain properties of the radio networks are included into consideration. In particular it could mean that temporarily unused frequencies (which premises that one detects these properly) are used dynamically. <\/p>\n

Cognitive radio reminds of using the Vertical blanking interval<\/a> of a TV for teletext or multiplexing<\/a> in phone communication where several phone calls may be transferred using one wire. However the “detection-of-a-free-space-and-
\nfitting-the-signal-into-it problem” may be not so easy – if one e.g. thinks of the game “musical chairs”<\/a>…:). (On the game side there are luckily some less-darwinian<\/a> variants like “A Cold Wind Blows<\/a> or Fruit Basket Turnover<\/a>…)<\/p>\n

The musical chair game refers mathematically to the socalled Pigeonhole principle<\/a> whose extention to infinite sets<\/a> brings the real fun in…:-O<\/p>\n

Another variant -this time from computer science- which is used to control the multiplexing of data packages (and transport in networks in general) is the OSI model <\/a> which is related to the well-known tcp-ip internet protocol <\/a>. The tcp-ip protocoll allows for a large variety of physical media as can be seen in this example<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

image source wikipedia new scientist reported about tests performed on a recent conference in which radio networks are used for wireless communication, a feature commonly called cognitive radio.<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[15,26,2,7,6],"tags":[],"_links":{"self":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1119"}],"collection":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1119"}],"version-history":[{"count":0,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1119\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1119"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1119"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1119"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}