The Internet of Drones: Why the Sky Is Not the Limit

Recently, our seminal work “The Sky Is Not the Limit: LTE for Unmanned Aerial Vehicles” received the 2021 IEEE Communications Society Fred W. Ellersick Award, a prestigious annual award for best article published in any IEEE Communications Society journal in the previous three calendar years. We appreciate the IEEE Communications Association for awarding us the award, which recognizes the contributions of Ericsson employees who advance communications technology.

Dr. Ismael Guvenk, Professor in the Department of Electrical and Computer Engineering at North Carolina State University, has nominated the paper “The Sky Is Not the Limit” for the 2021 IEEE Fred W. Elric Prize. She was a pioneer in studying cell-connected drones, identifying key challenges, and developing innovative solutions.”

Guvenc continued: “In addition to their efforts to standardize 3GPP, Ericsson engineers have published several influential academic papers in the literature on mobility and interference management for cell-connected UAVs. These work have influenced academic research in the field.”

In this blog post, we give a retrospective of our “Sky is Not the Limit” flight and an overview of the next few years on connected drones.

Figure 1: Overview of our “sky is not the limit” trip.

Drones operate on a mobile phone

Commercial drone applications are becoming increasingly popular. Drones are already widely used in news gathering (photography and video, for example), and for inspection and mapping in industrial applications. They are also being tested in agricultural and logistics deployments.

The potential of drone technology will only be unleashed when both technological capabilities and regulations allow for autonomous operation outside the visual line of sight. A secure wireless network connection is required at scale to safely expand drone operations and unlock the potential of drone technology for commercial applications.

At Ericsson, we believe that mobile networks are well suited to provide the necessary connectivity for drones. To ensure that airborne communications are reliable, we studied the communication performance that terrestrial mobile networks can provide, as well as the additional capabilities that mobile networks can provide for drone operations and management.

An example of a use case for drones for agriculture: Monitoring distant crops.

Figure 2: Example of a UAV use case for agriculture: Monitoring remote crops.

The journey began with the 3GPP Rel-15 consolidation

In early 2016, we identified that a key area to study in 3GPP 15 is enabling mobile network-connected drones, based on our research work (some of which were announced later in the “Sky is Not the Limit” background paper).

In December 2016, we submitted a new proposal for a Study Item on LTE Enhanced Support for Air Vehicles to the 74th Plenary Meeting of the 3GPP RAN. The proposal attracted much interest, which led to the approval of the study item at the 75th Plenary Meeting of the 3GPP RAN in March 2017. The study item was supported by 35 3GPP members, and Ericsson and NTT DOCOMO worked together as rapporteurs of the study items.

The 3GPP study evaluated the performance of LTE networks supporting aerial vehicles up to 3GPP version 14 functionality. The study was completed in December 2017 and the results are documented in 3GPP TR 36.777 including comprehensive analysis, evaluation and field measurement results. 3GPP TR 36.777 has become a definitive guide to mobile network-connected UAVs, and has been widely cited by academia, industry, and regulatory organizations.

The 3GPP study concluded that it is possible to use existing LTE networks to provide connectivity to drones, but that there may be challenges with interference as well as mobility. The challenges become more apparent when the density of drones is high. Both implementation and specification-based improvements were identified during the 3GPP study to address these issues.

Following the completion of the study item, the follow-up work item was approved at the 3GPP RAN #78 General Meeting in December 2017. Ericsson served as rapporteur for the work item. The goal of the action item was to identify features that could improve the efficiency and robustness of the LTE terrestrial network to deliver more efficient UAV connectivity solutions. This 3GPP work item was completed in June 2018.

In addition to 3GPP version 15 work on LTE Aerials in the RAN, 3GPP SA has studied remote identification of unmanned aerial systems (UAS) in version 16, and continues to investigate further aspects including communication, identification, tracking, and application layer support. , and security in version 17.

Trip beyond 3GPP

After completing work on 3GPP Version 15 on Connected UAVs, we have seen an increase in field trials of Connected UAVs worldwide by major operators and suppliers. Various industry organizations such as the GSMA and CTIA have created drone interest groups to develop new use cases and help create an open and trusted regulatory environment. Besides, GSMA and GUTMA collaborate to align the mobile and aviation industries.

The world has also seen increased efforts by governments to safely integrate civilian and public drone operations into airspace systems. One typical effort is the Unmanned Aircraft Systems Integration Pilot Program (IPP) in the United States. The IPP was completed in October 2020, after which the FAA launched a new program called BEYOND to continue work on remaining challenges to UAS integration.

At Ericsson, we contribute to relevant forums to align mobile network capabilities with the requirements of drone communications and traffic management. Ericsson is a full member of the Open Gen consortium, which initially focuses on use cases related to operating 5G-enabled drones over the United States.

We have also seen a growing momentum in academic research in this area, which has led to the creation of the IEEE Emerging Technologies Initiative on Air Communications and the IEEE Association for Vehicle Technology Ad Hoc Committee on UAVs. We have been contributing to both initiatives since their inception.

Recently, under the NSF PAWR Industry Consortium program, Ericsson contributed state-of-the-art equipment to the Advanced Wireless Air Test and Experiment Platform (AERPAW) for testing 5G applications. The AERPAW platform is designed to conduct experiments with UAV communications. This work will accelerate the research and commercialization of connected drones.

Guvenc, Project Manager for NSF AERPAW, said: “Our NSF AERPAW project team is working closely with Ericsson engineers to deploy a 4G/5G NSA wireless network in Raleigh. Ericsson’s network will be used by the broader wireless community in the United States to conduct advanced wireless trials with drones. Pilot. The AERPAW team is grateful to Ericsson for their help and support for academic research.”

Towards the Internet of Drones and 6G

Extensive network coverage is needed to safely extend drone operations beyond visible line-of-sight missions. Mobile networks can provide secure wireless communication at scale, using proven technology based on licensed mobile spectrum and global standards.

Today, LTE networks can support the initial deployment of drones at low altitudes. The greatly improved capabilities of 5G networks will provide more efficient and effective mobile connectivity for large-scale drone deployments with more diverse applications. As the 5G launch continues to gain momentum around the world, network complexity and location numbers will increase. Connected drones in turn can help speed up site deployment and launch while reducing health and safety risks, as shown for example in the blog post Afraid of heights? Drones, artificial intelligence and digitization to the rescue!

Video surveillance of rural network infrastructure by drones

Figure 3: Video surveillance of rural network infrastructure by drones

To further improve the capabilities of 5G networks for serving drones, we are leading the introduction of drone-related improvements to version 18 of the 5G NR standard. Our vision is that NR networks will be more capable of serving drones than LTE networks.

The future of the drone-connected sky is exciting, despite the challenges we need to overcome on our way to sixth generation. To mention a recent inspiring example, NASA’s Persevering Helicopter-carrying rover touched down on Mars on February 18, 2021. Perhaps now is the time for researchers to look at interplanetary communications and networking.

As we continue our “Sky is not the Limit” journey towards 6G, we will remain committed to working actively in relevant forums to align mobile network capabilities with the requirements of drone communications and traffic management.

Our research team

Fred W Ellersick Prize Winners Pictures 2021

Want to know more?

Check out our award-winning article (the 2021 Fred W. Elric Award for the IEEE Communications Association): The Sky Is Not the Limit: LTE for Unmanned Aerial Vehicles.

Read our white paper Drones and Networking: Ensuring Safe and Secure Operations to learn more about drones and networks.

What will the sky connected to 6G look like? Read our recent article On 6G with Connected Sky: Drones and Beyond to find out.

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