# Sensors and Communication Simulation for Unmanned Traffic Management
###### Abstract
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{**U1—2019**} & \multicolumn{1}{c}{Electronic drone registration.} \\ \cline{2-3} \multicolumn{1}{c}{VLOS (visual line of sight) operations} & Remote UAVs identification. \\ \cline{2-3} \multicolumn{1}{c}{} & \multicolumn{1}{c}{Provision of static geofences (no drone zones) to users.} \\ \hline \multicolumn{1}{c}{} & Flight plan authorization (including strategical deconfiction of flight plans). \\ \cline{2-3} \multicolumn{1}{c}{} & Drone tracking from multiple information sources. \\ \cline{2-3} \multicolumn{1}{c}{} & Air safety monitoring (no incursion in geofences, terrain avoidance, conflicts between aircraft, etc.). \\ \cline{2-3} \multicolumn{1}{c}{} & Flight plan conformance monitoring (compliance of flight with \\ \multicolumn{1}{c}{} & authorized flightplan). \\ \cline{2-3} \multicolumn{1}{c}{} & Weather provision to operators. \\ \cline{2-3} \multicolumn{1}{c}{} & Access to aeronautic and Air Traffic Control (ATC) data. \\ \cline{2-3} \multicolumn{1}{c}{} & Emergency management. \\ \cline{2-3} \multicolumn{1}{c}{} & Provision to pilots of nearby traffic \\ \cline{2-3} \multicolumn{1}{c}{} & Dynamic (on-board) geofencing. \\ \cline{2-3} \multicolumn{1}{c}{} & Improved interface with Air Traffic Management (ATC/ATM). \\ \cline{2-3} \multicolumn{1}{c}{} & Tactical (in-flight) conflict detection and resolution. \\ \cline{2-3} \multicolumn{1}{c}{} & Drone congestion management. \\ \hline \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \end{tabular}
\end{table} 
Table 1: European U-Space functionalities, expected deployment year, and main functionality deployed in each phase. can be aware of the operations of drones and can guarantee its safety in advance. This process is initiated at the request of the operator by sending the description of an operation or flight plan to the USP. The USP verifies that regulation and airspace requirements are met and that there are no conflicts with other operations. If all conditions are met, the operation is authorized and registered in the UTM system to avoid later simultaneous operations in that area. In addition, all operations are also in-flight monitored. To do so, drones periodically send position information (also known as telemetry) to the USP. Additionally, this information may be merged with data from traditional ATM systems (i.e., radar and other air surveillance sensors tracks) and sensors from different drone surveillance networks. All these data allow to track drones and conflicting aircraft in real time, while monitoring the safety and conformance with the issued authorization and safety rules of all operations, generating alerts in case of deviations or risks. Additionally, non-cooperative drone surveillance sensors may detect drones performing operations that have not been authorized and declared with the UTM ecosystem (non-cooperative drones). This information is key in some use cases, such as detecting unauthorized flights over critical infrastructures or real-time tactical conflict detection with cooperative drones or with manned aircraft. The prototypical example of this type of sensors is radar systems. Although traditional radar systems are not suitable for small aircraft, there are specific adaptations for RPAS (remotely piloted aircraft system) [11]. Moreover, visual techniques can also be used by means of cameras [12], acoustic techniques by means of microphone arrays [13], or radio frequency techniques detecting the emissions generated by the drone's command and control (C2) link [14]. Other surveillance networks are composed by cooperative sensors that detect the position of drones from status messages sent by the aircraft themselves through a broadcast network.