SDN in the Stratosphere: Loon's Aerospace Mesh Network
Abstract
The Loon project orchestrated a moving mesh network of high-altitude balloons interconnected using point-to-point radio links. Each balloon carried 4G LTE base stations that provided coverage to cellular devices in emergency response and commercial mobile contexts. This paper presents insights from 3 years of operational experience above 3 continents.
The challenging environment, comparable to many emerging non-terrestrial networks (NTNs), highlighted the design continuum between predictive optimization and reactive recovery. By forecasting the physical environment as a part of network planning, our novel Temporospatial SDN (TS-SDN) successfully moved from reactive to predictive recovery in many cases. We present insights on the following NTN concerns: connecting meshes of moving nodes using long distance, directional point-to-point links; employing a hybrid network control plane to balance performance and reliability; and understanding the behavior of a complex system that spanned physical and logical domains in an inaccessible environment. The paper validates TS-SDN as a compelling architecture for orchestrating networks of moving platforms and steerable beams, and it provides insights for those building similar networks in the future.
The challenging environment, comparable to many emerging non-terrestrial networks (NTNs), highlighted the design continuum between predictive optimization and reactive recovery. By forecasting the physical environment as a part of network planning, our novel Temporospatial SDN (TS-SDN) successfully moved from reactive to predictive recovery in many cases. We present insights on the following NTN concerns: connecting meshes of moving nodes using long distance, directional point-to-point links; employing a hybrid network control plane to balance performance and reliability; and understanding the behavior of a complex system that spanned physical and logical domains in an inaccessible environment. The paper validates TS-SDN as a compelling architecture for orchestrating networks of moving platforms and steerable beams, and it provides insights for those building similar networks in the future.
Research Areas
