Engineering and operational leadership from Loon explained how their AI-controlled balloons can establish HAPS connectivity for mobile users in remote areas during a recent ICAO webinar. (Loon)
Alphabet’s Loon is already providing its High Altitude Platform Station (HAPS) commercial internet services to Kenya, and the company’s continued expansion of its autonomous balloon network at 60,000 feet will serve as a blueprint to others already working on similar and related plans for that airspace and concept of operations.
Resembling balloons or sometimes taking the form of solar-powered aircraft, HAPS are designed to fly at the edge of space, or the stratosphere, and beam connectivity to mobile networks for users in areas hard to reach by satellites or ground-based cellular towers. In July, Loon started transmitting service to Kenya, and has future plans to expand globally.
“We’re operating a fleet of floating cell towers,” Zohaib Mian, head of systems engineering for Loon said during the Sept. 2 “Automated Operations in the Stratosphere” webinar, hosted by the International Civil Aviation Organization (ICAO).
While the use of artificial intelligence powered helium filled balloons the size of tennis courts beaming internet connectivity to mobile users on the ground may sound like something out of a science fiction novel, Loon has been flying its proof of concept for several years and has demonstrated that up to 20 of its balloons clustered together connected to a mobile network on the ground can create a “mesh network’ with up to 4,000 square kilometers of regional coverage.
Loon has improved their floating cell tower concept of operations in recent years through a combination of physics, machine learning and deep reinforcement learning as well as experience in discovering optimal wind currents that allow the balloons to ascend safely into upper E class airspace.
Each balloon features a long rod connected to a payload equipped with solar panels, batteries for energy storage, dual GPS systems, an LTE system and a backhaul feeder link. There are also transponders for communications and navigation purposes, and Loon uses ADS-B to communicate its position to air traffic controllers in civilian space when conducting a launch.
Loon has developed machine learning algorithms and uses Google’s cloud computing infrastructure to simulate up to 15 billion balloon flight days everyday. Over time, their flight engineers have embedded those simulations into optimal trajectory paths for the vehicle’s navigation system to use autonomously in probabilistic swaths of airspace rather than point to point flying.
The vehicles are also capable of flying up to 300 days, and testing of the service in Kenya has already shown latency times as low as 19 milliseconds for mobile users. According to a white paper published by Loon, the company’s goal is to help connect the more than 2.3 billion remote users it has identified in regions like remote areas of Kenya that could use its service.
“The basic concept is that we can change wind layers, change our altitude and get to our destination. There are a lot of different technologies being developed and have been developed over time including machine learning and deep reinforcement learning with years and years of simulation time to understand exactly how we utilize different wind layers,” Zohaib said. “Most of the systems are automated, 99 percent give or take are automated, so that leaves our flight engineers the advantage to focus on top level issues rather than try to manually control each vehicle.”
The journey to enabling their first commercial Internet service for Africa this summer was admittedly challenging for Loon, but the experience of actually going through repeated launches and lowering the amount of time required to actually perform a new launch has optimized the economics of their operation in preparation for future expansion beyond Kenya.
“A process that used to take us 20 people and hours and hours if not weeks, is something that we can now do repeatedly in 45 minutes to an hour with a crew of five in multiple wind conditions, which we couldn’t do before,” Nick Kohli, head of operations for Loon said.
Since Loon is not the only HAPS or stratospheric operator and its vehicles need a concentrated region of the stratosphere and airspace to operate over airspace controlled by sovereign nations, their ability to expand and connect the hard to reach communities relies on their ability to continue to form new partnerships and create de-confliction agreements with other stratospheric users. In February, the industry side of those partnerships advanced when Loon joined AeroVironment, Airbus Defense and Space, Bharti Airtel Limited, China Telecom Corporation, Deutsche Telekom, Ericsson, Intelsat, Nokia Corporation, SoftBank Corp., and Telefónica to form the HAPS Alliance.
Wajahat Beg, head of overflights for Loon, explains where their HAPS operates. (Loon)
The alliance aims to promote the standardization of HAPS network interoperability, along with plans to advocate for the adoption of global spectrum standardization for High Altitude IMT Base Stations within the International Telecommunications Union (ITU), and to influence emerging commercial standards, including 3GPP Non-Terrestrial Networks. There are more than 40 HAPS programs at various stages of development currently, both among HAPS Alliance companies and those that are not members, according to an article on the future potential of HAPS to transform broadband connectivity published in the September edition of Via Satellite.
The latest edition of the Northern Sky Research (NSR) agency’s HAPS report predicts that HAPS services from "balloons and pseudo-satellite platforms" will generate about $4 billion in cumulative revenues by 2030, with most of the activity occurring in the Americas.
In the U.S., there currently are no existing provisions or airspace rules for flight operations above 60,000 feet by civilian aircraft, where a limited number of flights have traditionally been operated by military users. The proof of concept by Loon and plans for other operations in the stratosphere led to the FAA’s publishing of its first “Upper Class E Traffic Management (ETM)” concept of operations document in July, claiming the need for a new approach to high altitude airspace management directly naming “Supersonic and hypersonic flights, slow moving (or stationary) unmanned balloons, very slow (or stationary) long endurance fixed wing vehicles, and high speed, long endurance fixed wing vehicles.”
Initially, the agency is mostly following industry’s lead on ETM, after a 2019 concept of operations was published by a group of stratospheric users. Leonard Bouygues, head of aviation strategy for Loon, said that the different capabilities of different vehicles in the stratosphere requires de-confliction to be managed in a shared approach.
Bouygues said that a key focus right now for Loon’s expansion is continued collaboration with civil aviation regulators and other stratospheric operators to establish an ETM system where network providers use application programmable interfaces to communicate deconfliction needs and potential hazards to users through their third party service of choice.
“To support this federated ecosystem you need a service that is very analogous to what is used in ATM for discovery and synchronization services that allows all actors to have a common view of the airspace. Multiple platform service suppliers have to be able to provide their services in the airspace at the same time,” Bouygues said. “Global standards need to be developed to facilitate those exchanges and protocols.”