A system including a detector, a reader, and a tag. The detector includes a sensor to detect a user event, and a communication circuitry to communicate at a first frequency band. The reader includes communication circuitry to communicate at a second frequency band. The tag includes a first communication circuitry to communicate at the first frequency band and a second communication circuitry to communicate at the second frequency band. The detector is to communicate with the tag via the communication circuitry of the detector. The detector is to determine whether to associate the tag with the user event. The detector is to communicate the determined association. The tag is to communicate using the second communication circuitry of the tag with the reader.