Paving the path to 5G: Optimizing commercial LTE networks for drone communication
Officially called Unmanned Aerial Vehicles (UAVs), drones and drone technology are serving as a launchpad for new services. For instance, they give farmers the opportunity to more cost effectively survey their fields and track livestock; they allow real estate agents to show clients entire neighborhoods and the proximity of important stores and services; they enable first responders to manage emergencies and disasters more efficiently, they provide wireless broadband services in remote regions or areas hit by natural disasters… the list goes on.
Presently, these new use cases can be deployed on a relatively small scale. Wide-scale deployments of UAVs are expected to reshape countless industries, including agriculture, construction, delivery, entertainment, insurance, mapping, newsgathering, public safety, public utilities, railroads, real estate, and wildlife conservation. A study commissioned by the trade group representing the unmanned systems and robotics industry forecasts that Unmanned Aerial Systems (UAS) will generate $13.6 billion (USD) in economic impact for the U.S. in the first three years after they are cleared to operate in the U.S. National Airspace System and will grow — cumulating to more than $82.1 billion by 2025.
The role of cellular technologies
As these new drone applications take shape, it’s important to keep the safety concerns associated with advanced drone research and development top of mind. Similar to air traffic management and control today, wide-scale deployments of drones require coordination and traffic management. This will be needed, especially for large fleets of autonomous drones and/or when flying in close proximity of Controlled Air Space (e.g., an airport or military air base).
What few people realize however, is that cellular technology can bring a new dimension of high reliability, robust security, ubiquitous coverage and seamless mobility to wide-scale drone operation. Cellular networks enable the operation and control of drones beyond a pilot’s visual line of sight, which will be key to safe, wide-scale drone operation and the many new services to which drones open the door. Furthermore, cellular connectivitycan enhance autonomous drone operation safety by enabling and expediting the delivery of optimal flight plans and transmission of flight clearances, tracking drone location and adjusting flight routes in near real time. Cellular connectivity can also be used to share real-time video feeds from a surveillance drone or the vaccine’s temperature form a medical delivery drone.
The use of cellular technology for autonomous drone flight appears to be very reasonable and practical, but it has its critics, who still question the safety of doing so.
Evaluating LTE in challenging and real-world testing environments
As a leader in 4G LTE technology, Qualcomm and its engineers did not hesitate to jump at the opportunity to test LTE-controlled drones in real-world scenarios. We were eager to analyze how, and if drones could operate safely and securely on today’s commercial 4G LTE networks.
Today’s cellular networks are designed to serve smartphones and other ground mobile devices, so the first thing we wanted to find was how cellular networks can serve drones which operate at higher altitudes. Conventional wisdom says that current cellular deployments can’t provide coverage for drones at higher altitudes because antennas on cell towers point down to serve mobile devices on the ground.
We also wanted to study how to support safe drone operation in real-world environments without impacting terrestrial network operation. Our findings from this research would not only help us optimize LTE networks for safe drone operation, but also inform positive developments in drone regulations and 5G specifications as they relate to wide-scale deployment of numerous drone use cases.
To begin, Qualcomm Technologies worked with the U.S. Federal Aviation Administration (FAA) on a certification of authorizationallowing for drone testing below 400 feet around the company’s San Diego headquarters. Our FAA-authorized Unmanned Aerial Systems (UAS) Flight Center not only provided ideal proximity to extensive Qualcomm R&D facilities, but it also allowed for testing inside Class B Controlled airspace because of its location near Marine Corps Air Station (MCAS) Miramar — a very active military air station. In addition, our flight center is surrounded by the very real-world conditions autonomous drones must one day navigate, including commercial zones, populated residential areas and large swaths of uninhabited areas. Combined, these areas make our flight center’s location one of the most challenging real-world testing environments possible.
After getting FAA authorization, we joined forces with AT&T to trial drone operation on AT&T’s commercial networks — testing key performance indicators (KPI’s) such as coverage, signal strength, throughput, latency and mobility under various scenarios on commercial LTE networks. Our early findings showed that current cellular networks can provide coverage to drones at higher altitudes. We also found out that our test drones are capable of demonstrating seamless handovers between different base stations during flights with zero link failures. Good news, but are we done? No.
We’ve found multiple opportunities to further optimize commercial LTE networks, including:
- Interference management: Despite the fact that drones can be well served by multiple base stations up to 400 feet above ground level (AGL), we found that increased interference at higher altitudes impact link quality. We are working on ways to manage interference received by the drone from a high number of “neighbor” base stations radiating effectively up to 400 feet AGL.
- Handover optimization: We also observed different handover characteristics for drones compared to ground mobile devices. Impact and optimization opportunity is under study.
- LTE-enabled drone-specific requirements: In order for the network to optimize service for drones, the network may need to be able to distinguish a drone from a ground mobile device. The network may also want to reject drones that are impacting KPI’s and are harmful to the network.
Paving the path to 5G
Besides optimizing current 4G LTE networks for safe drone operations, our findings are helping us accelerate 5G technology development. 5G will bring the required ultra-high reliability, ultra-high availability, incredibly-low latency and strong end-to-end security for mission-critical drone use cases, when connectivity absolutely cannot fail or be compromised (such as with emergency services).
When the capabilities of 5G come into the picture, we envision fleets of drones flying autonomously, communicating, and adjusting behavior through real-time data inputs and sharing. Imagine a team of drones collaborating with each other to conduct search and rescue mission – first searching for and finding a lost hiker, then manipulating and lowering a net, and ultimately bringing the victim to the nearest medical facility. On a lighter note, imagine a drone equipped with a 360-degree camera capturing and broadcasting in real time what its seeing as it flies through the Grand Canyon. Meanwhile, a tour group with head-mounted VR viewers is experiencing that footage, live, as a virtual reality tour at an amusement park in Florida. Wherever there are cellular networks that can provide the capacity and reliability to operate air traffic control for autonomous drones, the use cases and possibilities are endless.
Modern commercial drones are far and above (pun intended) the toys we see flown by children in parks. They’re faster, bigger, more powerful and more technologically advanced than ever. So much so that they truly offer opportunities and capabilities once reserved for sci-fi stories. Cellular connectivity will only allow the autonomous drone market to grow those opportunities and capabilities exponentially. With our work in computer vision, machine learning, sensor processing, precise GNSS localization, obstacle avoidance, autonomous visual navigation, and 4K videography, as well as with Qualcomm Snapdragon Flight drone platform development, you can be sure that Qualcomm is at the forefront of bringing new levels of on-board intelligence, wireless connectivity and safety to the autonomous drones of the future.