A sensor device may use battery power to operate a sensor node by taking
sensor readings and transferring data into or out of a set of queues. A
radio frequency identification (RFID) tag may be used to wirelessly
communicate data into and/or out of the sensor device without using power
from the battery. The sensor node may be placed in a low-power mode
without respect whether the RFID tag is communicating. In some
embodiments, the sensor device may be used as a store-and-forward node
for other devices by placing data received from one RFID reader into the
set of queues and later transmitting the data from the set of queues in
response to a poll from another RFID reader.