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://thebrickes.shop/product-category/vase/