The impact of video encoding parameters on QoE of simulated FPV drone control

Applications of Unmanned Aerial Systems (UAS) have become increasingly diverse and advanced over the years. While initial applications targeted strictly military applications, with a rapid decrease in cost and increase in availability to consumers, applications such as surveillance, journalism, agriculture, film-making, entertainment, etc. have begun to flourish. One of these applications is an immersive drone-piloting modality known as First-person view (FPV) piloting. This method of flying leads to the challenge of streaming video and transmitting control information at very low latencies to enable proper real-time control. FPV technology most commonly relies on implementing video streaming through analog technology due to strict latency requirements. In this paper, we present our research directed toward developing a digital alternative to this technology. We report on two user studies designed to assess the Quality of Experience (QoE) of an FPV system, coupled with a cloud-based drone flight simulator, with the objective to evaluate the impact of various video encoding parameters, namely bitrate, resolution, and frame rate. Two user studies with the same core test methodology were conducted: the first involved University students and staff at the Univ. of Zagreb, while the second study involved Spanish Air Force Academy flight students and instructors with (unlike the first study group) significant prior experience in piloting manned aircraft and experience in the use of a flight simulator for military pilot training. The primary motivation of conducting the second user study was thus to investigate quality perception involving users with different prior experience as compared to our first study. Obtained results indicate that video encoding parameters have a significant impact on user perceived QoE, with only a slight impact of prior piloting experience on quality ratings. Furthermore, our findings highlight the relevance of simulator sickness in this kind of system.