A Physically Decoupled Onboard Control Plane for Software Defined LEO Constellation Network

With the exploitation of space technology, low earth orbit (LEO) constellations for global communications are becoming an increasingly attractive research topic. To provide programmability in LEO communications constellations, software defined networking (SDN) is an ideal choice over the traditional distributed IP architecture. In this paper, we addressed an onboard architecture where controllers and switches are both placed on the LEO satellites and supported by two different communication systems, one wide-beam radio frequency (RF) system and one free space optical system, to physically decouple the control plane and the forwarding plane. Simulated annealing algorithm is adopted to further determine the placement of the controllers to optimize the average flow setup time with weighted regional user data traffic rates. The performance of the proposed scheme is verified in an IRIDIUM-alike constellation through computer simulations with failure recovery time and flow setup time compared to other LEO SDN architectures.