Uncrewed Systems Technology 048 | Kodiak Driver | 5G focus | Tiburon USV | Skypersonic Skycopter and Skyrover | CES 2023 | Limbach L 2400 DX and L 550 EFG | NXInnovation NX 100 Enviro | Solar power focus | Protegimus Protection

39 responded to a record 3629 call-outs in 2021, up 40% frompre-pandemic levels, withmany more visitors to national parks that do not have cellular coverage. That is driving the demand for airborne base stations using 5G to provide high- bandwidth services such as video. However, this needs a combination of lightweight 5G base station technology and local aircraft traffic management. In Snowdonia, a Dragon UAV has been converted to carry an airborne detect- and-avoid radar, electronic identification and a positioning system that links to a UAV traffic management (UTM) system. The plan is to test the use of the UAV’s base station payload to pick up phone signals on the ground. The system can relay location data from the phones back to base using a 5G NR SA network. The Dragon can be launched to find walkers and provide first responders with essential access information. The trials are exploring how connectivity can provide key support to emergency services so they can respondmore quickly. Having a base station in the sky will allow mountain rescue teams to usemore than just voice calls, enabling picture sharing and video calling that could even help the teams guide people back to safety without having to send themout, saving the teams valuable time and resources. The Dragon can accommodate 5 kg of payload for the base station, either in the nose or a ventral pod for experimental purposes. Its maximum take-off weight is 55 kg, and the endurance for rescue activities will be 2 to 4 hours depending on payload. This 5G data can be usedwith other delivery services. For example, a recent project in Snowdonia also showed proof- of-concept for delivering amini-defibrillator via the Dragon to a remote or rural location that would be difficult to reachwith an ambulance in a timely fashion. High-altitude base stations Another important application for 5G with UAVs is as high-altitude base stations. Flying at altitudes above 18 km (60,000 ft), the UAVs can provide a base station to cover a wide area over days or even months. Applications here include disaster relief operations or to bring 5G broadband to remote areas. The key is developing a low-power base station capability with highly sensitive antenna technology. A radio wave propagation simulator for stratosphere- level wireless comms systems is used to estimate radio wave interference at high altitudes, and enable the design of network area coverage and antenna systems for the UAVs. The base station technology is being tested using high-altitude tethered balloons at a spaceport in a remote part of Japan. A cylindrical multi-element phased array antenna is used to provide stable connectivity regardless of airbornemotion, and is being tested on a high-altitude balloon that can carry a payload of 60 kg. One challenge is that the comms area, or footprint, cannot be fixed, because cells rotate as the aircraft turns, which in turn causes frequent handovers and affects reception strength levels, thereby impacting telecoms quality. By using a cylindrical antenna with digital beamforming control though, the footprint can be fixed by controlling the direction of radio beams as the airborne vehicle rotates. The balloon uses an autopilot system with three tethers andmachine learning (ML) to provide stable positioning. At an altitude of 249m, the systemprovides wide-area network coverage of a few tens of kilometres and stable connection to phones on the ground evenwhen 5G networks | Focus A base station in the sky will allow rescue teams in national parks to guide people back to safety without the need to send the teams out Uncrewed Systems Technology | February/March 2023 A cylindrical multi-element phased array antenna for 5G networks developed for a high-altitude uncrewed base station (Courtesy of HAPS Mobile)