The object of the invention is a method where a first communications device (10) and a second communications device (20), previously unknown to each other, communicate with each other wirelessly using short-range RF technology, said second communications device being at a certain moment of time in a...http://www.google.com.tw/patents/US20020197956?utm_source=gb-gplus-share專利 US20020197956 - Hiding a device
