Satellite communications is undergoing a significant paradigm shift in the next several years. The advent of the low earth orbiting satellite constellations utilizing inter-satellite links to form advanced mesh networks in orbit requires new technologies which can provide the required high throughput and reliability. Many of these technologies are tightly focused on improvements to individual components of the satellite communications stack, switches, routers, free-space optics, and on-board processors. These components are all vital to the creation of a resilient mesh network, however, without a centralized, intelligent controller overseeing their operation and optimizing configurations, the improved performance promised by mesh networking solutions will never be realized. In this proposal, MTI Systems presents a novel concept, which stems from development with partners at Google Loon, Distributed Software Defined Networking (SDN) for satellite communications. Software Defined Networking (SDN) as a concept has been heavily developed in the past several years for terrestrial communications networks. Utilizing a globally optimized network route and resource management solution has yielded significant benefits when handling the high performance network requirements of large data centers. In this proposal, we propose to adapt these classical SDN techniques to the unique challenges associated with satellite mesh network communications. This presents significant challenges for several reasons. Unlike data center networking hardware, low earth orbit satellites are constantly in motion with respect to users on the ground. Also, the resource requirements for satellite communications hardware are much more stringent than hardware on the ground. These stringent requirements on size, weight and power (SWaP) present challenges, but also demonstrate the power of SDN as these requirements can be better met on a global scale by leveraging the global-view of the network offered to the SDN controller. MTI Systems has worked on similar systems in the past, developing a cloud-based SDN controller for Google Loon which operated their balloon mesh network and was adapted for use in satellite networking. In this paper, we will improve on this concept by compressing the SDN control algorithm and developing a version that can be integrated directly onto a satellite on-board processor. This has the significant advantage of enabling tighter control of the satellite on-board equipment, can enable control redundancy across the satellite constellation, and can offer reduced control latency. This product will manage all components of the advanced satellite mesh network, improving global throughput, reducing interference, and will enable future satellite communications that can better meet the safety critical requirements of the next generation of SDA satellite communications.
