Reliable Multi-Link Framework for Command and Control Communication in Remotely Piloted Aircraft Systems

Unmanned Aerial Vehicles (UAVs) have created new opportunities for various applications in civil airspace. One critical aspect of a successful operation is to establish reliable communication between a UAV and the remote pilot in a Ground Control Station in Remotely Piloted Aircraft Systems. The effectiveness of this communication, known as C2 communication, depends on the underlying network technology (LTE/5G, Satellite, etc.) and the specific application telemetry protocol. A single C2 link using cellular or satellite communication technology fails to satisfy the ICAO C2 performance requirements [1]. Therefore, a multi-link framework for C2 communication is widely adopted. However, the homogeneous cellular-based multi-link [2] experimental solutions have limitations concerning the geographical location of Beyond Visual Line-of-Sight (BVLOS) operations. Additionally, simulation analysis of the heterogeneous multi-link [3] solution, using cellular and GEO-satellite communication, is inadequate to conclude the link performance requirements (bandwidth and latency) for the telemetry protocol. Therefore, we propose a heterogeneous 5G and LEO-satellite Iridium multi-link network architecture for C2 communication. Our quantitative analysis of the link technology present in this architecture demonstrates (i) the required logical Link Quality Indicator for C2 communication, and (ii) the possible solutions for C2 telemetry protocol to utilize the link capabilities in this architecture. We demonstrate that a cellular link can provide a throughput of 3.5, 8.5 Mbps and 30 ms latency for 5G, whereas an Iridium satellite link can provide 22, 88 kbps (uplink, downlink) throughput and 750 ms latency sufficient for reliable C2 communication.