Unmanned aircraft systems (UAS) and their uses are becoming more and more popular across industries.  The safe operation of UAS and related systems that control this traffic in both controlled and uncontrolled skies depend on reliable communication. Airbus and M1 Limited started a 5G network connectivity trial with IMDA in order to innovate, enable, and find new ways to make the operation of UAS flying in the lower airspace more efficient and reliable.

This trial’s objective was to determine whether 5G networks will be an effective primary method of communication for UAS operations. The arrangement was made with a two-pronged strategy in mind. The first is to assess whether 5G can support the networking and communication systems for UAVs. The second was to assist in the design and creation of the first standalone 5G modem to be certified for use in aviation and maritime applications, with the goal of speeding the growth of the 5G ecosystem.

The testing began in 2019, when 5G standalone architecture (SA) was still in its infancy, and Airbus was one of the forerunners in conducting such a trial. It was conducted at the Maritime Drone Estate, which was established by IMDA, and is also Airbus’ first 5G SA testing. There have been some delays in this trial study, which will be finished this year, because of the epidemic.

It was only reasonable for Airbus to concentrate their trial on measuring characteristics that give an indicator of the failure likelihood given that safety considerations are of the utmost importance.

“The probability of failure gives an indication of reliability,” explains Dr. Anoop Kumar Krishna, Head of Airbus Unmanned aerial system Traffic Management (UTM) Lab. “In radio network terms, we look at the connection drops due to radio link failures and the duration of these connection drops before being automatically reconnected.”

“Secured and reliable connectivity is crucial in ensuring that the UAS can operate safely and efficiently during all phases of flight,” adds Dr. Anoop. “It is therefore important to measure the 5G signal propagation on airways at different altitudes. The reduced latency5 of 5G is expected to allow for a more interconnected network, supporting UAV connectivity, remote navigation and surveillance, something that traditional mobile data cannot effectively maintain.”

Airbus is testing 5G SA at various altitudes as part of this trial, and after the trial’s conclusion, they will draw conclusions. Dr. Anoop notes that the initial results show improved handover performance, throughput, and latency compared to 4G, and that 5G is a good contender to offer dependable connectivity.

“Being able to use 5G for navigation will be a game changer, because the global navigation satellite system (GNSS), which is the common mode of navigation today, still poses some weaknesses, such as accuracy in urban environment,” explains Dr. Anoop. This issue of accuracy in localisation can be further addressed using the different methods for localisation provided in the 5G standards together with GNSS.

Base stations for the 4G public terrestrial network are currently orienting their antennas towards the land mass. Technically, this renders them less suitable for assisting aerial use cases.

“With the current 4G network we can operate up to 200 feet without any major issues,” Dr. Anoop explains. “However, for many use cases we will have to fly at between 1,000 and 3,000 feet and for that, we are looking at the possibility of leveraging 5G and the capabilities that come with it.”

In this trial, M1 also observed a “ducting” effect at higher altitudes, which increased the 5G signal’s propagation distances in comparison to scenarios based on the ground. This is due to the atmospheric duct trapping radio frequencies, which prevents isotropic dispersion of the signals across the atmosphere.

The problem of heat dissipation needs to be solved with 5G SA aerial modems. Any customer premises equipment (CPE) finds it challenging to run continuously without active cooling due to the high frequency bands employed in 5G and direct exposure to heat radiation. This crucial discovery was used by the team as yet another teaching tool to aid in the creation of similar gadgets in the future. The placement of drone antennae is another aspect that could be improved, as changing the antenna’s angle would change the weight distribution and have an impact on the drone’s design and flight capabilities.

One of the main achievements that has come out of this trial, among the intriguing findings and novel insights that are anticipated, is the certification of the first 5G SA modem for use in aviation and maritime applications.

Together with their business partner Team One Technologies, M1 developed the modem. During the modem’s development, they got the essential specifications from Airbus. The modem is now comparable to military grade modems because it met the DO160 environmental qualifying requirement. It is dependable for use both on land and at sea since it satisfies strict requirements for resistance to shock and vibration, level, and level of resistance. Being the first of its kind, this modem operates flawlessly even in challenging conditions and for extended periods of time when exposed to factors like water, dust, and heat.

“The certification process took us several months as it had to be sent overseas for stringent testing before getting certified. This is a great milestone achievement for the team, however future innovation such as beamforming antenna for the modem is being considered,” says Denis Seek, Chief Technical Officer at M1.

Airbus has previously participated in 5G experiments and currently has global partnerships active. However, they were only given the chance to conduct a complete 5G SA trial in Singapore. Since then, opportunities to explore and create the future of urban air mobility have been available thanks to a memorandum of understanding (MoU) inked by Airbus and M1 to jointly undertake 5G SA trials and tests in urban locations. The outcomes of the field data collecting will aid not only Airbus but also the sector as they advance in creating a trustworthy aviation future.