A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

UAV Command and Control, Navigation and Surveillance: A Review of Potential 5G and Satellite Systems

Drones, unmanned aerial vehicles (UAVs), or unmanned aerial systems (UAS) are expected to be an important component of 5G/beyond 5G (B5G) communications. This includes their use within cellular architectures (5G UAVs), in which they can facilitate both wireless broadcast and point-to-point transmissions, usually using small UAS (sUAS). Allowing UAS to operate within airspace along with commercial, cargo, and other piloted aircraft will likely require dedicated and protected aviation spectrum at least in the near term, while regulatory authorities adapt to their use. The command and control (C2), or control and non-payload communications (CNPC) link provides safety critical information for the control of the UAV both in terrestrial-based line of sight (LOS) conditions and in satellite communication links for so-called beyond LOS (BLOS) conditions. In this paper, we provide an overview of these CNPC links as they may be used in 5G and satellite systems by describing basic concepts and challenges. We review new entrant technologies that might be used for UAV C2 as well as for payload communication, such as millimeter wave (mmWave) systems, and also review navigation and surveillance challenges. A brief discussion of UAV-to-UAV communication and hardware issues are also provided.Comment: 10 pages, 5 figures, IEEE aerospace conferenc

System Architecture of Small Unmanned Aerial System for Flight beyond Visual Line-Of-Sight

Small Unmanned Aerial Systems (UAS) have increasingly been used in military application. The application in expanding scope of operations has pushed existing small UAS beyond its designed capabilities. This resulted in frequent modifications or new designs. A common requirement in modification or new design of small UAS is to operate beyond visual Line-Of-Sight (LOS) of the ground pilot. Conventional military development for small UAS adopts a design and built approach. Modification of small Remote Control (RC) aircraft, using Commercial-Off-The Shelf (COTS) equipment, offers a more economical alternative with the prospect of shorter development time compared to conventional approach. This research seeks to establish and demonstrate an architecture framework and design a prototype small UAS for operation beyond visual LOS. The aim is to achieve an effective and reliable development approach that is relevant to the military’s evolving requirements for small UASs. Key elements of the architecture include Failure Mode Effect and Criticality Analysis (FMECA), fail safe design for loss of control or communication, power management, interface definition, and configuration control to support varying onboard payloads. Flight test was conducted which successfully demonstrated a control handoff between local and remote Ground Station (GS) for beyond visual LOS operation

Extending the tactical horizon networking aircraft to enable persistent surveillance and target development for SOF

The NPS Tactical Horizon Extension Project objective is to define and demonstrate a concept by which task force-level commanders and below can obtain a persistent, over-the-horizon surveillance capability for the purpose of target development and other missions without tasking national or theater-level assets. Our goal is to increase the ISR capacity of units who normally would not rate the priority to task a Predator, Global Hawk, or U-2. There are two guiding tenets in developing this concept. First, the equipment and its control should be organic to the SOF unit or task force. Second, utilizing this capability should not require the soldier to carry any additional equipment into the field. Initial research led us to the idea of using networked unmanned aerial systems (UAS's) to generate an over-the-horizon surveillance capability for SOF. We demonstrated the concept by forming a network comprised of a forward ground team, an inexpensive, test-bed UAS equipped with an off-the-shelf video camera, a manned aircraft, and a tactical operations center (TOC). We attained connectivity through an ITT Mesh structure at 2.4 GHz, amplified to 1W. Researchers were from the Defense Analysis, Mechanical and Astronautical Engineering, and Information Sciences Departments. We conducted successful experiments through the USSOCOM-NPS Cooperative Field Experimentation Program.http://archive.org/details/extendingtactica109452582Outstanding ThesisApproved for public release; distribution is unlimited

UAV-Aided Interference Assessment for Private 5G NR Deployments: Challenges and Solutions

Industrial automation has created a high demand for private 5G networks, the deployment of which calls for an efficient and reliable solution to ensure strict compliance with the regulatory emission limits. While traditional methods for measuring outdoor interference include collecting real-world data by walking or driving, the use of unmanned aerial vehicles (UAVs) offers an attractive alternative due to their flexible mobility and adaptive altitude. As UAVs perform measurements quickly and semiautomatically, they can potentially assist in near realtime adjustments of the network configuration and fine-tuning its parameters, such as antenna settings and transmit power, as well as help improve indoor connectivity while respecting outdoor emission constraints. This article offers a firsthand tutorial on using aerial 5G emission assessment for interference management in nonpublic networks (NPNs) by reviewing the key challenges of UAV-mounted radio-scanner measurements. Particularly, we (i) outline the challenges of practical assessment of the outdoor interference originating from a local indoor 5G network while discussing regulatory and other related constraints and (ii) address practical methods and tools while summarizing the recent results of our measurement campaign. The reported proof of concept confirms that UAV-based systems represent a promising tool for capturing outdoor interference from private 5G systems.Comment: 7 pages, 4 figure