Unmanned Systems Technology 014 | Quantum Tron | Radio links and telemetry | Unmanned Aerial Vehicles | Protonex fuel cell | Ancillary systems | AUVSI 2017 Show report

32 W ireless links are increasingly important for unmanned and autonomous systems in the air and on the ground, and play a key role in handling identification and traffic management, control, telemetry and payload data. These functions can be carried out in different ways using a range of frequency bands and protocols, and increasingly require high levels of security. Efforts are also now underway to consolidate the technologies behind them in a low-power, lightweight implementation. In addition, the increasing use of swarms of ground- based or airborne systems is driving the need for more sophisticated radio communications systems. There is an argument that the growth in autonomy means there is less need for external links, as all the data from sensors around the system is processed internally. However there is a mounting need for UGVs to share mapping, location and telemetry data, while the cameras on unmanned aircraft need to feed video streams back to the user – wherever they may be – in order to control the craft. The UAVs may also need to feed back ultra-high definition (UHD, also known as 4K) video from a camera in the payload. The technologies used to link to unmanned systems therefore have a wide range of implementations. Custom analogue radio links and low-power wide area networks using low frequencies such as 915 MHz in Europe and 868 MHz in the US can be used for long- distance control systems and some telemetry data from the UAV itself such as system health, but cannot handle the 4K video requirements. Using a long-range control technology when all that is needed is a short-range, high-bandwidth payload link can be a case of overkill, so system designers are converging increasingly on using the same comms technology for control, telemetry and payload links. This simplifies system design and avoids the need for multiple radios, but puts a strain on radio subsystem designers to deliver low power, long range, long battery life and high performance. There are also issues with craft that travel beyond visual line of sight (BVLOS). Current regulations in North America and Europe prohibit BVLOS operation for airborne and marine craft. Satellite transceivers with smaller antennas are now able to fit into larger UAV platforms, and can be used for ground vehicles operating in out-of-the- Nick Flaherty compares the various radio frequency bands and technologies for managing unmanned systems Well connected June/July 2017 | Unmanned Systems Technology The Sharp Intellos UGV uses a kinetic mesh radio system to link ground and air systems together (Courtesy of Rajant Technology)