An RFID reader communicates with an RFID tag of a masked container in a container group. A power-supply antenna and a link antenna of the RFID reader are spaced apart from the container group, the antennas oriented to transmit signals to a power-supply subset and a data subset, respectively, of the plurality of containers. The RFID reader transmits a power-supply RF signal via the power-supply antenna to the power-supply subset and, while doing so, transmits a data RF signal via the link antenna to the data subset. The containers relay power-supply RF energy in a downstream power-supply direction and relay the data RF signal in upstream and downstream data directions different from the power-supply direction. The data RF signal is relayed by a repeater, which is powered by relayed power-supply RF energy, on each container. The RFID tag responds to the relayed data signal.