A small or large area such as a home or office may be remotely monitored by a properly authorized caller using wireless piconet networks between personal wireless piconet identifier devices worn or carried by particular persons and a remotely accessible access monitor base unit. Persons are monitored...http://www.google.de/patents/US20040198448?utm_source=gb-gplus-sharePatent US20040198448 - Access monitoring via piconet connection to telephone
