Dynamic Spectrum in Aerospace Networks

In September, we hosted our second DSA Webinar, this time on Dynamic Spectrum in Aerospace Networks. Sponsored by Loon, we were honoured to welcome their representatives, Jameson Dempsey and Wesley Eddy, to share their expert insight into the importance of spectrum sharing for the success and expansion of their initiative. Missed the webinar? Don’t worry – watch the recording on demand via Dynamic Spectrum Alliance’s YouTube channel.

Loon’s mission is to help operators extend the reach of their networks by integrating stratospheric balloons with fundamental cell tower technology, including an access and backhaul antenna, and flying them over the desired region – no matter how remote or rural. Flying 20 km in the air, mesh networks of Loon balloons leverage Machine Learning (ML) technology to ride the wind currents at different layers in the stratosphere, with each balloon staying aloft for approximately 5-6 months. When it is time for the balloons to come down, Loon collaborates with local civil aviation authorities to safely land and recover its equipment. Having flown for over 1 million hours and navigated 40 million km since 2013, this has become a robust system which has been tried, tested and improved over years of active production deployments. Although Loon specializes in advancing Stratospheric Internet Platforms, the technology underlying Loon’s network can support other types of networks, including LEO satellite constellations, terrestrial mesh networks and other advanced networks, to facilitate the extension of traditional internet and telecommunications applications.

When developing its system, Loon had to solve unique engineering challenges not faced by traditional ground-based networks. For example, traditional software-defined networking (SDN), designed for static nodes and devices, presents challenges for larger, highly dynamic aerospace networks with many moving nodes. When applied in the aerospace context, traditional SDN and ad-hoc networking systems can make poor decisions or even fail completely. Moreover, traditional SDN was not designed for radio frequency links and may create interference to incumbent networks.

To address these challenges, Loon has developed Temporospatial Software Defined Networking (Loon SDN), an architecture that leverages and analyses environmental data, radio propagation information, and regulatory requirements to continually predict the location of nodes in aerospace networks. This enables efficient radio resource management, the ability to route through dynamic mesh networks, and interference avoidance with other networks (e.g., satellites, fixed point-to-point links). Loon SDN allows operators to track the arrangement of physical platforms within the network; their orientation, predicted paths and radio configuration details; and how these meet user traffic demands. And Loon SDN is not just for Loon: the company has also partnered with Telesat to adapt Loon SDN for Telesat’s LEO satellite constellation.

As outlined in the Webinar, Loon’s TS-SDN technology can enable emerging connectivity solutions, such as stratospheric Internet platforms and non-geostationary satellite constellations, to coexist with each other and with incumbent networks in spectrum bands where those networks are deployed, such as the E-band and similar millimeter wave bands (Loon SDN is spectrum band and service type agnostic). In doing so, Loon SDN can help regulators address critical issues such as the digital divide by incorporating a variety of new and emerging aerospace connectivity solutions, without risking interference to incumbent systems.

In order to ensure that technologies such as Loon can flourish, it is important for regulators to adopt flexible and transparent licensing frameworks – such as database-supported and self-coordinated light-licensing – that can support the rapid deployment and coexistence of traditional ground-based and emerging aerospace networks. The DSA advocates for the harmonization of spectrum to facilitate Loon’s mission and hopes to see more applications served successfully by dynamic spectrum sharing as we work towards a better-connected future.