As drone-related technologies advance rapidly, a lot of civilian drone applications are also expected to be realised soon in our daily lives. Such applications include disaster prediction and response, delivery of parcels, surveillance, traffic accident and violation monitoring, entertainment, and seeding and cropdusting. Providing high-speed wireless communication through drones is one of the most promising applications for 5G communication systems, and drone-based communication networks provides wireless connectivity for devices without infrastructure coverage due to communication quality deterioration by shadowing or infrastructure damage by natural disasters. Besides, communication support through 4G/5G cellular networks is essential for reliable and stable operation of multiple drones.

Even though the 3rd generation partnership project (3GPP) release 16 deals with providing 5G services for drones, more intensive research and development is still needed for its embodiment in 5G standardisation work. Aviation authorities around the world have been working toward integrating drones into their national airspace, and as a part of such work some promising projects such as UAS Traffic Management (UTM), and Urban Air Mobility (UAM) exhibit the high passion of the industry for unmanned air transportation. However, flight control computers in drones are known to be vulnerable to various attacks such as gyroscope malfunction by sound noise, control signal hacking, Global Navigation Satellite System (GNSS) jamming, and GNSS spoofing. For instance, a successful launch of GNSS spoofing deviates a drone from its designated flight path, and it paralyses the operation of UTM and UAM. Therefore, to facilitate the realisation of unmanned air transportation, it is essential to improve the reliability and security of drone operation as this directly affects human safety onboard and on the ground.

This Special Issue aims to collate original research articles with a focus on communication and security issues for reliable drone operation, ranging from applications to architecture, and from enabling technologies to public safety issue. We welcome research addressing all communication and security issues for reliable drone operations, as well as review articles discussing the current state of the art.

Potential topics include but are not limited to the following:

• 5G communication support for reliable drone operation
• Cross-layer architectures and protocols for drone-based communication network
• Routing and MAC protocols for drone-based communication network
• Beyond radio line of sight communications
• Simulations and testbeds for reliable drone operation
• Navigation in GPS-disabled area
• Ad hoc and mesh network of drones
• Security threats against onboard flight computer and their countermeasures
• Security threats against command and control links and their countermeasures
• Detection and interdiction of flight path deviation
• Security threats against UTM and their countermeasures
• Other security and privacy issues for reliable drone operation