Unmanned Systems Technology 033 l SubSeaSail Gen6 USSV l Servo actuators focus l UAVs insight l Farnborough 2020 update l Transforma XDBOT l Strange Development REVolution l Radio telemetry focus

83 The more mature technology is the IEEE 802.11p standard, also called Digital Short Range Communications. It is a modification of 802.11a wi-fi technology operating in the 5.9 GHz band without the need for a base station. It is designed to work with fast-changing multi-path reflections and doppler shifts generated by relative speeds as high as 500 kph with a typical line-of-sight range of 1 km. The multiple access mechanism (the Carrier Sense Multiple Access protocol with Collision Avoidance protocol) efficiently handles high- density use cases when combined with Distributed Congestion Control. However, this requires dedicated infrastructure to be built on roads to receive the data from the cars, and this data has to be fed back into the network. The competing technology is based on the next-generation cellular phone standards developed by the 3GPP standards group. The current 4G (also called LTE-V2V) technology does not have the capacity or latency needed for such telemetry links to vehicles. However, the latest versions of the 3GPP standard for 5G specifically address this. The 5G New Radio specification in 3GPP rev 15 allows higher performance links and is now undergoing trials in the US, Europe and Asia. The resulting 5G cellular vehicle-to everything, or V2X (C-V2X), standards were approved in January, leading to three chipset suppliers and seven module makers developing products to automotive quality. These will be available for production designs during 2022. However, many chip and module makers also have 802.11p implementations. The upcoming 3GPP Release 16 adds extensions for ultra-reliable and low- latency comms, as well as lower power consumption and support for multiple antennas. It is expected to be agreed by the end of this year. All this allows telemetry from cars to use the 5G networks that are now being rolled out, prioritising telemetry packets from driverless vehicles to minimise the latency. However, there are predictions that autonomous vehicles will use up to 4 Tbytes of telemetry data per day, which is not feasible with a 30-40 MHz band at 5.9 GHz. That is driving the need to use the same digital architectures over links in the millimetre band, from 59 to 71 GHz, for links of even higher bandwidth. WiFi6 The next generation of wi-fi is also giving significant advantages for unmanned systems, particularly in the air. WiFi6 (which is the IEEE 802.11ax standard) adds significant power efficiency enhancements that will be an advantage for UAVs. Some already use a 2.4 or 5 GHz link, and WiFi6 will also give the opportunity to use the 6 GHz band. New technologies added to WiFi6 to boost data rates and reliability also lend themselves to low-power operation to mix telemetry and payload data over line- of-sight links. Radio telemetry | Focus It is predcted that autonomous vehicles will use up to 4 Tbytes of telemetry data per day, which is not feasible on a 30-40 MHz band Unmanned Systems Technology | August/September 2020 A 5G New Radio prototype system for testing on a car (Courtesy of Qualcomm)