US Patent 9794753 System and method for establishing real-time location

A communication system with a master device configured to determine location information in real-time with respect to a portable device. The master device may direct one or more monitor devices to monitor communications that occur over a primary communication link. The monitor devices may sense characteristic information about the signal from the portable device, and communicate this characteristic information to the master device via an auxiliary communication link. The communication system may determine location of the portable device, authenticate the portable device, determine whether the portable device is authorized to allow or initiate an action, and command or enable an action with respect to equipment.