Unmanned Systems Technology 024 | Wingcopter 178 l 5G focus l UUVs insight l CES report l Stromkind KAT l Intelligent Energy fuel cell l Earthsense TerraSentia l Connectors focus l Advanced Engineering report

39 5G communications | Focus trackside to demonstrate high-speed use, for example on a motorway. A neutral-host network is a wholesale network on which anyone can rent capacity. For example, a neutral-host operator would deploy one network along a motorway, and all the local mobile network operators, car makers and others could share it. The AutoAir project will also use a network of 24-60 GHz gigabit nodes to create a V2I network around a high- speed test track and extend this to the 66-71 GHz band for the backhaul links from the nodes to the rest of the network. That is important, as the peak atmospheric oxygen absorption of radio waves occurs at around 60 GHz, so using the higher frequencies can potentially double the range. The backhaul is also important for the data links to the passengers in the vehicle, who all want high-bandwidth links. Using a hyper-dense network, with small cells every few hundred metres along roads and railways rather than single large towers every few kilometres, can provide more capacity and reliability. If wireless networks are used for any applications involving safety, then reliability is of course essential. That reliability can be achieved by ensuring that vehicles are always within range of more than one base station and that the signal strength is consistently good. The mmWave technology will be up and running by the end of 2019 for commercial testing of driverless cars, with plans to roll it out for V2I applications by 2024. Adding in mmWave technology brings higher data rates but also considerable technology challenges for the radio front end. The monolithic microwave integrated circuit (MMIC) modules needed for the front end traditionally need specialist packaging technologies that cannot easily be combined with mainstream surface mount assembly techniques. A 5G radio in a connected car would require up to three high-cost MMICs to cover multiple bands. The MMICs for mmWave 5G systems operating in most of the prime candidate 5G bands include the FCC-licenced 28 GHz band (27.5-28.35 GHz), the 37 GHz band (37-38.6 GHz) and the 39 GHz band (38.6-40 GHz). The 26 GHz (24.25-27.5 GHz) band has been identified by the European Radio Spectrum Policy Group as the ‘pioneer band’ for 5G across continental Europe. A key example of a 28 GHz 5G MMIC in a surface mount plastic package includes a low-noise amplifier, a power amplifier, a transmit power detector and a transmit/receive switch with control logic. It covers the full 28 GHz band and offers a receive sensitivity 3.3 dB with 13.5 dB gain from a current of only 10 mA. One important feature is that it is housed in an over-moulded plastic quad-flat-no-leads (QFN) package suitable for high-volume assembly. Similarly, a 39 GHz power amplifier that covers the 37 and 39 GHz bands in the US is housed in a specialist plastic QFN package that has to include an air cavity in order to operate. This has a 20 dB gain with an output of +40 dBm across both bands. But that is just one component that has to fit into an MMIC module, which highlights the complex challenges of implementing 5G radios cost-effectively. UAVs are also a key application area for 5G of course, but in different ways. For example, governments and disaster-relief organisations expect to use 5G-connected UAVs to help in emergency efforts. UAVs in flight will communicate and share real-time data with each other and teams on the ground, increasing the speed and effectiveness of search- and-rescue missions. That will allow relief managers to dispatch rescue teams safely, quickly estimate structural damage and debris levels, and better distribute resources.   The higher bandwidth of 5G at 2 Gbit/s and above will also allow streaming from 8K cameras on UAVs, which is not possible with current 4G technology, for more detailed inspection applications using standard smartphones. Unmanned Systems Technology | February/March 2019 Different types of millimetre wave front- end modules will be needed for different frequencies (Courtesy of Plextek RFI)