Developing a way to control drones that will share airspace with airplanes full of people and fly over towns and cities is a complex and vital task. Qualcomm this week released results of testing of how drones behave when they are controlled by LTE. The company said that the testing, which focused on drones as high as 400 feet above ground, “supports the viability” for LTE as the mechanism for use beyond visual line of sight (BVLOS) operations.
The wording of the press release suggests that the results overall validate LTE as a way to control drones. The company said that about 1,000 test flights were performed. In addition, simulations were run to assess rapid feature changes and performance in environments crowded with LTE devices and drones.
The results, the company maintains, reveal “very strong” signals at high altitudes, successful handover and good prospects for improvements as LTE evolves. The testing also suggests lower signal quality as drones rise but similar outage probability to devices on the ground, lower drone-to-network uplink power at higher altitudes, effective power control optimization and different cell selection characteristics compared to devices on the ground.
Qualcomm is not the only company testing the approach. Verizon last month conducted tests to determine how big an area can serve as a “flying cell site” under the control of LTE. The testing was done by a long endurance drone piloted by American Aerospace Technologies at Woodbine Municipal Airport in New Jersey. The brief note at the Verizon site doesn’t include results of the tests.
LTE is not the only option for controlling drones. uAvionix offers a good tutorial on the four approaches. Not surprisingly, the topic is complex. The pros and cons of the candidates are presented in order of their readiness for use: Automatic Dependent Surveillance-Broadcast ADS-B), LTE, Vehicle to Vehicle (V2V) and Remote Identification (RID).
uAvionix President Christian Ramsey wrote that the candidates have subtly different goals. ADS-B is a safety technology for shared airspace, LTE/5G is a tracking and payload communications technology, V2V is focused on semi-autonomous systems that depend heavily on unmanned aircraft systems traffic management (UTM), and RID is a security system that identifies itself to law enforcement.
Ramsey suggests that only one system is ready for prime time, and that this is the key:
We are in a situation where we cannot afford 5 years or more of the traditional standards development and R&D timelines that will be associated with maturing LTE, V2V, and RID to what will likely become global standards (maybe make that 10 years). There is only one clear choice when it comes to what can be done today to make the skies safer, to prevent near misses or worse. It simply has to be ADS-B – at least as a stop-gap technology until something more tailored comes along.
Hopefully, regulators will take their time to make decisions on how to control drones. It is especially important is ensuring that approaches that were not initially developed for this purpose can do the job.
Carl Weinschenk covers telecom for IT Business Edge. He writes about wireless technology, disaster recovery/business continuity, cellular services, the Internet of Things, machine-to-machine communications and other emerging technologies and platforms. He also covers net neutrality and related regulatory issues. Weinschenk has written about the phone companies, cable operators and related companies for decades and is senior editor of Broadband Technology Report. He can be reached at [email protected] and via twitter at @DailyMusicBrk.