The integration of Non-Terrestrial Networks (NTN) with Terrestrial Networks (TN) is a key enabler for resilient 5G-Advanced and future 6G backhaul infrastructures. However, managing traffic across these highly asymmetric links remains a significant routing challenge, as systems must support heterogeneous network slices with conflicting service-level agreements (SLAs) while selectively utilizing costly NTN resources. This paper presents a computationally lightweight SLA-aware traffic-steering framework for a hybrid TN-NTN backhaul that models the load-balancing problem as an exact potential game. This mathematical foundation inherently enables decentralized coordination between uplink and downlink load-balancing agents without control-message overhead. By formulating traffic steering as a coupled optimization problem, per-slice (or per-user group) traffic fractions are dynamically distributed across terrestrial and satellite paths based on utility functions that capture throughput, latency, packet loss, and SLA penalties. The resulting game admits a pure Nash equilibrium, ensuring stable and predictable traffic adaptation under non-stationary load conditions. The framework is evaluated on a geographically distributed 5G testbed, using bidirectional traffic generated for five representative slices. Experimental results show that the proposed controller significantly outperforms heuristic and conventional baselines, reducing SLA violations to 1.7% for V2X and 0.7% for the emergency slice while completely eliminating them for video, IoT, and best-effort traffic.

翻译：非地面网络与地面网络的融合是构建具有韧性的5G-Advanced及未来6G回传基础设施的关键使能技术。然而，在高度非对称链路上管理流量仍是一项严峻的路由挑战——系统需在选择性利用高成本NTN资源的同时，支持具有冲突服务等级协议（SLA）的异构网络切片。本文提出一种计算轻量级的SLA感知流量引导框架，用于混合TN-NTN回传场景，将负载均衡问题建模为精确势博弈。该数学框架天然支持上下行负载均衡代理间的去中心化协调，无需控制消息开销。通过将流量引导建模为耦合优化问题，基于捕获吞吐量、时延、丢包率及SLA惩罚的效用函数，动态分配每个切片（或用户组）在天地链路间的流量比例。该博弈存在纯纳什均衡，确保非平稳负载条件下流量自适应的稳定性和可预测性。我们在地理分布式的5G测试平台上进行实验，生成五个代表性切片的双向流量。实验结果表明，所提控制器显著优于启发式及传统基线方案：V2X切片的SLA违例率降至1.7%，应急切片降至0.7%，视频、物联网和尽力而为流量的违例率则完全消除。