IDLB: An SDN‐Based Load‐Balancing Routing Protocol for Autonomous Satellite Constellation Networks

Routing in satellite constellation networks with intersatellite links has become an important aspect to enable broadband Internet access and to integrate into terrestrial networks. However, their dynamic characteristics and large physical size require specifically tailored solutions. To address these challenges, we propose and investigate a load‐balanced routing protocol based on distributed software‐defined networking. The approach relies on independent space‐borne clusters with on‐board controllers. Reduced signaling overhead is achieved by geographical intercluster routing algorithms. We evaluate the performance of the protocol in a custom‐built system‐level simulator, considering different architectures, design choices, and scenarios. Comprehensive comparisons with source‐routed schemes and an upper benchmark demonstrate the viability of the solution. Notably, for the given scenario, the protocol can handle network loads of up to 15.0 Gbps before quality of service compliance falls below 95%. Compared with the 7.6 Gbps supported by source‐routing, this represents an increase of 97.4%. This is achieved while maintaining an average routing convergence of 117.338 ms. The work provides valuable in‐depth insights into the design of optimized routing protocols for satellite constellation networks.