Abstract
As lunar exploration transitions toward sustained human presence and intensive robotic operations, communication infrastructure in cis-lunar space demands unprecedented data throughput and resilient dynamic networking. High-throughput satellite constellations deployed across Near Rectilinear Halo Orbits (NRHO) and Distant Retrograde Orbits (DRO) provide effective spatial coverage, yet rapidly varying orbital geometry and narrow beam widths inherent to Optical Inter-Satellite Links (OISL) complicate continuous data routing. Traditional centralized routing schemes introduce significant latency and single-point-of-failure risks due to long propagation delays to Earth ground stations. To resolve these challenges, this paper presents the Cis-lunar Autonomous Optical Routing (CAOR) protocol, a novel decentralized dynamic routing framework optimized for non-Keplerian orbital regimes. CAOR utilizes localized topological state forecasting combined with link-state quality metrics—incorporating pointing, acquisition, and tracking (PAT) lock stability alongside queue backpressure. Simulation results demonstrate that CAOR achieves a 99.4% packet delivery ratio under highly dynamic link conditions, reducing end-to-end latency by 38% compared to conventional shortest-path routing protocols. Furthermore, the protocol demonstrates exceptional fault tolerance during unexpected node disruptions and transient optical beam outages. By enabling autonomous, distributed topology adaptation without terrestrial intervention, CAOR establishes a foundational routing mechanism for future high-throughput cis-lunar communication architectures supporting human and robotic lunar exploration.