US Patent 7129830 Methods and systems for providing security

A security system is described which includes a base station, at least one calibration unit and at least one sensor module having at least one sensor therein. The calibration unit is configured to provide signals to the at least one sensor module. The signals contain data configured to at least partially enable each sensor module to determine its location within a coordinate system. Each sensor module is further configured to transmit module location data, module orientation data, and sensor status from each sensor to the base station.