Dynamic spectrum sharing (DSS) among multi-operator low Earth orbit (LEO) mega-constellations is essential for coexistence, yet prevailing policies focus almost exclusively on interference mitigation, leaving geographic equity largely unaddressed. This work investigates whether conventional DSS approaches inadvertently exacerbate the rural digital divide. Incorporating Keplerian orbital dynamics, inter-beam co-channel interference, and three real-world constellation geometries (Starlink, OneWeb, Kuiper), we conduct large-scale, 3GPP-compliant non-terrestrial network (NTN) simulations across 20 orbital snapshots spanning 10~minutes of satellite motion. The results uncover a stark and persistent structural bias: SNR-priority scheduling induces a $1.84\times$ mean urban--rural access disparity, with temporal fluctuations reaching $3.9\times$ during favorable interference conditions. Counter-intuitively, increasing system bandwidth amplifies rather than alleviates this gap. To remedy this, we propose FairShare, a lightweight, quota-based framework that enforces geographic fairness. FairShare not only reverses the bias, achieving an affirmative disparity ratio of $Δ_{\text{geo}} = 0.68\times$ with zero variance across all orbital snapshots and interference conditions, but also reduces scheduler runtime by 3.3\%. This demonstrates that algorithmic fairness can be achieved without trading off efficiency or complexity, and that it remains invariant to physical-layer dynamics. Our work provides regulators with both a diagnostic metric for auditing fairness and a practical, enforceable mechanism for equitable spectrum governance in next-generation satellite networks.

翻译：多运营商低轨巨型星座间的动态频谱共享对于共存至关重要，然而现行政策几乎完全聚焦于干扰抑制，地理公平性问题在很大程度上被忽视。本研究探讨传统动态频谱共享方法是否无意中加剧了农村数字鸿沟。通过结合开普勒轨道动力学、波束间同频干扰以及三种实际星座构型（Starlink、OneWeb、Kuiper），我们在涵盖10分钟卫星运行的20个轨道快照上进行了大规模、符合3GPP标准的非地面网络仿真。结果揭示了一种显著且持续存在的结构性偏差：信噪比优先调度导致城乡接入差距均值达$1.84\times$，在有利干扰条件下瞬时波动可达$3.9\times$。反直觉的是，增加系统带宽反而会扩大而非缓解这一差距。为纠正此问题，我们提出FairShare——一个轻量级的基于配额的框架，用于强制实现地理公平。FairShare不仅逆转了偏差，在所有轨道快照和干扰条件下实现了正向差异比$Δ_{\text{geo}} = 0.68\times$且方差为零，还将调度器运行时间降低了3.3%。这表明算法公平性可以在不牺牲效率或复杂度的前提下实现，并且对物理层动态保持恒定。本研究为监管机构提供了用于审计公平性的诊断指标，以及下一代卫星网络中实现公平频谱治理的实用可执行机制。