*2.4. Tasks*

Tasks are generated by actual users or artificial intelligent agents that require data or images that can only be collected by drones due to the location or danger to human safety. Since we can assume that our tasks will be periodically requested, it is feasible to estimate an arrival rate based on factors around the area, such as population density. The tasks in terms of a facility location problem are known as the customers that must be served by some facility. In terms of drone demand, we can apply different degrees of energy requirements to complete a task. For example, a task may require *v* units of energy to perform a task, so, therefore, there must be *v* units of energy available in the drone's battery to complete the task.

In Figure 2, we illustrate that a drone can only land and take off at its own drone port, in the case of a single drone at a drone port.

**Figure 2.** An example of a distributed drone port system.
