Starlink constellations are currently the largest LEO WAN and have seen considerable interest from the research community. In this paper, we use high-frequency and high-fidelity measurements to uncover evidence of hierarchical traffic controllers in Starlink -- a global controller which allocates satellites to terminals and an on-satellite controller that schedules transmission of user flows. We then devise a novel approach for identifying how satellites are allocated to user terminals. Using data gathered with this approach, we measure the characteristics of the global controller and identify the factors that influence the allocation of satellites to terminals. Finally, we use this data to build a model which approximates Starlink's global scheduler. Our model is able to predict the characteristics of the satellite allocated to a terminal at a specific location and time with reasonably high accuracy and at a rate significantly higher than baseline.

翻译：星链星座目前是最大的低轨广域网，并已引起研究界的广泛关注。本文通过高频高保真度测量，揭示了Starlink中存在层次化流量控制器的证据：一个全局控制器负责为终端分配卫星，以及一个星载控制器负责调度用户流的传输。随后，我们设计了一种创新方法来识别卫星如何分配给用户终端。利用该方法收集的数据，我们对全局控制器的特性进行了测量，并确定了影响卫星分配给终端的因素。最后，我们基于这些数据构建了一个近似Starlink全局调度器的模型。该模型能够以相当高的准确率（显著高于基线水平）预测特定位置和时间点分配给终端的卫星特性。