What if sensors could move?

Up to now, we have considered sensors to be either fixed or subject to mobility. Indeed, when animals are equipped with sensors, the sensor has no way of predicting its trajectory and suffers the animal's mobility. Now let's consider that these sensors have additional faculties that enable them not only to perceive their environment, but also to act upon it. For example, if a sensor detects a fire, it can activate fire hoses. These are called actuators. If these sensors have the ability to move, they become small robots with controlled mobility, which can make a major contribution to the sensor network. This also raises new challenges, such as how do robots move themselves? How can their mobility benefit routing? These are the questions we'll address in this section.