ENERGY HARVESTING ARRIVAL AWARE JOINT SENSING AND TRANSMISSION

According to an aspect, there is provided an apparatus for controlling a terminal device. The apparatus monitors a current charge level of a rechargeable energy storage device of the terminal device and a current energy harvesting state of an energy harvesting device of the terminal device. When the current energy harvesting state corresponds to an energy harvesting state indicative of no energy being harvested, the apparatus causes the terminal device to operate in one of a first, second and third operating modes depending on a value of the current charge level relative to first and second thresholds. The first, second and third operating modes and the first and second thresholds are defined so that the uplink transmission functionality of the terminal device is disabled when the current charge level drops below the first threshold and the downlink transmission functionality of the terminal device is disabled when the current charge level drops below both thresholds.