Monitoring for unauthorized RF energy emitted or transmitted in a particular zone or portion of a building, etc. Radio frequency energy is received in a region that encompasses a zone in which it is desired to monitor for unauthorized radio frequency energy. At least one characteristic of the received...http://www.google.de/patents/US7142108?utm_source=gb-gplus-sharePatent US7142108 - System and method for monitoring and enforcing a restricted wireless zone
