# Research Trends in Collaborative Drones
###### Abstract  
The last decade has seen an explosion of interest in drones--introducing new networking technologies, such as 5G wireless connectivity and cloud computing. The resulting advancements in communication capabilities are already expanding the ubiquitous role of drones as primary solution enablers, from search and rescue missions to information gathering and parcel delivery. Their numerous applications encompass all aspects of everyday life. Our focus is on networked and collaborative drones. The available research literature on this topic is vast. No single survey article could do justice to all critical issues. Our goal in this article is not to cover everything and include everybody but rather to offer a personal perspective on a few selected research topics that might lead to fruitful future investigations that could play an essential role in developing drone technologies. The topics we address include distributed computing with drones for the management of anonymity, countering threats posed by drones, target recognition, navigation under uncertainty, risk avoidance, and cellular technologies. Our approach is selective. Every topic includes an explanation of the problem, a discussion of a potential research methodology, and ideas for future research. d rone; distributed computing; countering drone threats; target recognition; navigation; risk avoidance; cellular technologies; management of anonymity +
Footnote †: journal:  
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photo recordings of protected areas, it can also lead to the release of dangerous materials in the proximity of critical infrastructures. Examples include attacks carried out in military missions and flying drones in proximity to airport areas. According to [10], only in 2017, there were more than 300 reported incidents involving small drones. Similar issues are even more popular in the public media [11]. While specific drone applications have countless benefits, others may be a real threat to safety and security. There is a need to develop a science for countering drone threats. The following three problems we address relate to specific algorithms for collaborative drone applications. First, we explore algorithms for target recognition from the air at a certain altitude. We establish the foundations of a probabilistic framework. Ideas for future work building on this framework are discussed. Second, we establish foundations for drone navigation in GPS-denied environments in the face of decision-making uncertainties. We discuss how these foundations can lead to future research. We complement the previous approach by exploring a formal framework for risk avoidance by flying drones. Within this framework, we introduce ideas for further investigation. The final problem that we address relates to cellular technologies in networked collaborative drone applications. While early generations of drones required line-of-sight communications with a ground station to maintain control and push data, such as a video stream, the latest drone generations may benefit from the use of Beyond Visual Line of Sight (BVLOS). BVLOS lifts the pilot-drone line-of-sight constraint [12]. It expands the range of operation of drones and types of applications considerably. However, for safe operation, BVLOS requires reliable and real-time command and control. Connections may also serve other purposes, such as data communication and collaboration between drones. Various questions deserve attention, such as the use of cellular technology to network drones, making drones integral parts of the network infrastructure, such as base station-drone or relay, drones pushing information to the cloud, such as location-related signal strength data, or drones pulling information from the cloud, such as flight awareness data. Networking elevates drones' capabilities to another level. The outline of this article is as follows. The management of anonymity in the context of distributed computing is explored in Section 2.