An SDN Based Highly Reliable in-Band Control Framework for LEO Mega-Constellations

With the rapid development of the LEO mega-constellations, the control technique of the tremendous constellation network become a mean challenge. The SDN-based centralized control scheme can solve the bottleneck of onboard computational resources in traditional distributed LEO mega-constellations. However, frequent network topology variation caused by constellation movement and communication link failure increases the difficulty of in-band control enormously. Therefore, we propose a novel Dual-Layer SDN (DLSDN) in-band control framework, which sets an Upper-layer control plane exclusively for providing reliable in-band control paths for control traffic generated/received by the Lower-layer control plane. In order to provide reliable control traffic transmission, a redundant path-planning algorithm is further proposed. Simulations show that the DLSDN framework possesses fewer inaccessible satellites when multiple link failures occur in a mega-constellation scenario.