A portable wireless alarm system includes at least two alarm devices each of which includes a signal generator for generating an action signal, wherein the alarm devices are communicatively networked with each other by means of radio frequency to contribute a security network in such a manner that, within...http://www.google.fr/patents/US6946959?utm_source=gb-gplus-shareBrevet US6946959 - Wireless alarm system for contributing security network
Wireless alarm system for contributing security network
