Industrial 5G deployments using Time Division Duplex (TDD) networks face a critical challenge: existing schedulers rely on static configuration of Uplink (UL) to Downlink (DL) resource ratios, failing to adapt to dynamic asymmetric traffic demands. This limitation is particularly problematic in Industry 4.0 scenarios where traffic patterns exhibit significant asymmetry between directions and heterogeneous Quality of Service (QoS) requirements. We present FLEX, a novel QoS-aware scheduler that dynamically adjusts the UL/DL ratio in flexible TDD slots while respecting diverse QoS requirements. FLEX introduces DL buffer state estimation to prevent starvation of high-priority DL traffic, exploiting the deterministic nature of industrial traffic patterns for accurate predictions. Through extensive simulations of industrial scenarios using 5G LENA and ns-3, we demonstrate that FLEX achieves similar throughput compared to established scheduling while correctly enforcing QoS priorities in both traffic directions. For deterministic traffic patterns, FLEX maintains minimal latency overhead (less than 1 slot duration), making it particularly suitable for industrial automation applications.

翻译：采用时分双工（TDD）网络的工业5G部署面临关键挑战：现有调度器依赖上行链路（UL）与下行链路（DL）资源比例的静态配置，无法适应动态非对称流量需求。在工业4.0场景中，流量模式在方向间呈现显著非对称性，并具有异构服务质量（QoS）要求，这一局限性尤为突出。我们提出FLEX这一新型QoS感知调度器，能在灵活TDD时隙中动态调整UL/DL比例，同时满足多样化QoS需求。FLEX引入DL缓冲状态估计机制以防止高优先级DL流量陷入饥饿，利用工业流量模式的确定性特征实现精准预测。通过基于5G LENA和ns-3的工业场景仿真验证，FLEX在保持与现有调度方案相当吞吐量的同时，能正确执行两个流量方向的QoS优先级。面向确定性流量模式，FLEX维持最小延迟开销（小于1个时隙长度），特别适用于工业自动化应用场景。