One or more surfaces within a facility are equipped with devices having several segments, each segment with an antenna. Segments may be grouped together into a cluster. Each segment within a cluster is associated with a particular timeslot. A transmitter at the device transmits on a specific frequency. During the particular timeslot for that segment, a signal at the specific frequency is transmitted and radiated from the antenna for that segment. An object electromagnetically couples to one or more antennas of the device, acting as a signal path for the signal. A receiver in a second segment detects the signal, and information about the timeslot for the signal and relative signal strength is generated. By using this information, a location and path of the object may be determined. Receivers in shelves may also be used to facilitate disambiguation of one user from another when interacting with items on those shelves.