In energy harvesting Internet of Things (IoT) systems. the age of information (AoI) should be maintained at a low level to guarantee the accuracy and reliability of derived decisions. In this paper. we design an information freshness-guaranteed and energy-efficient data generation control system (IFE-DGCS) where an IoT gateway with a directional antenna determines the polling frequenc... https://www.nacrack.com/flash-pick-7-5ft-Heavy-Duty-Gold-Metal-Round-Wedding-Arch-Photo-Backdrop-Stand-top-grab/