User-in-the-Loop (UIL) refers to the notion that a technology (e.g., network) can improve a performance objective by engaging its human users (Layer 8). The idea can be applied in various technological fields. UIL assumes that human users of a network are among the smartest but also most unpredictable units of that network. Furthermore, human users often have a certain set of (input) values that they sense (more or less observe, but also acoustic or haptic feedback is imaginable: imagine a gas pedal in a car giving some resistance, like for a speedomat). Both elements of smart decision-making and observed values can help towards improving the bigger objective.