# Communication Manager for Hyper-Connected RPAS Environments
## 1 Introduction  
Nowadays, Remotely Piloted Aircraft (RPA) operations in the civilian sphere mainly include a single vehicle that performs reconnaissance missions by sending telemetry parameters that different onboarded sensors have acquired (e.g., video, temperature, air quality) to a Remote Pilot Station (RPS). Despite their apparent simplicity, single-RPA applications are employed in many different and significant fields (e.g., surveillance of livestock [1], monitoring of power lines [2], traffic monitoring [3], or search and rescue [4], among many others). Over the past few years, implementing more complex services integrated into the urban environment based on multiple RPAS operating collaboratively (the so-called RPA swarms) has been profusely investigated. It has led to new scenarios that have not yet been adequately deployed, such as package delivery [5], monitoring of crowds such as concerts or demonstrations [6], communications coverage extension [7], or support to emergency services in cities such as firefighters, police, and hospitals [8]. However, there are still several critical challenges before we can see these applications integrated into our daily lives. On the one hand, these challenges have to do with the regulation field. For example, the European Union has recently released a new single European regulation (EASA: [[https://www.easa.europa.eu/domains/civil-drones](https://www.easa.europa.eu/domains/civil-drones)]([https://www.easa.europa.eu/domains/civil-drones](https://www.easa.europa.eu/domains/civil-drones)) (accessed on 14 January 2023)) (which is applicable as of 31 December 2020), which affects all Remotely Piloted Aircraft Systems (RPASs) regardless of the weight and size of the RPA and whether they are used forprofessional or recreational purposes. Some significant rules to comply with the new European regulation are (i) registering as an RPAS operator, (ii) accrediting RPA pilot training, or (iii) meeting the different restrictions/regulations imposed by local airspace authorities for each possible flight area. On the other hand, solving the challenges involves the technological field itself (described below). This article will address the latter perspective, although its relationship with air traffic management will also be discussed. In particular, we handle one of the challenges RPAs will face in the hyper-connected environment already present in the current 5G communications ecosystem and even more so in the upcoming 6G scene, looking towards all-to-all connectivity scenarios. In the first place, near-future-RPAs will need to transmit many more information streams. In addition to the traditional video stream, RPAs may need to transmit, for instance, (i) data related to aeronautical telemetry (e.g., pressure, temperature, speed, GPS position), (ii) telemetry from different onboard sensors (e.g., air quality, smoke detection), (iii) control information for U-Space Unmanned Aircraft System Traffic Management (UTM) [9], (iv) control information for their RPS, (v) control information between RPAs for swarm management, (vi) information from new applications they may support (e.g., VoIP provisioning for remote users, loudspeaker service for emergencies) or traffic related to the many service-provisioning technologies that are being included more and more within the software payload of the RPAs ranging from virtual machines to containers or light containers that can be remotely handled. In the second place, RPAs will have many alternatives for data transmission. These alternatives include traditional radio frequency links for Control and Non-Payload Communications (CNPC) (also known as Command and Control (C2)) and payload (usually in separate bands), to which will be added different backup links that may eventually be considered as primary links based on cellular technology (either 3G, 4G/LTE, 5G), satellite technology, proprietary line-of-sight links, millimeter wave, visible light communications, Wi-Fi links, or Bluetooth links.