Stringent line-of-sight demands necessitated by the fast attenuating nature of millimeter waves (mmWaves) through obstacles pose one of the central problems of next generation wireless networks. These mmWave links are easily disrupted due to obstacles, including vehicles and pedestrians, which cause degradation in link quality and even link failure. Dynamic obstacles are usually tracked by dedicated tracking hardware like RGB-D cameras, which usually have small ranges, and hence lead to prohibitively increased deployment costs to achieve complete coverage of the deployment area. In this manuscript, we propose an altogether different approach to track multiple dynamic obstacles in an mmWave network, solely based on short-term historical link failure information, without resorting to any dedicated tracking hardware. After proving that the said problem is NP-complete, we employ a greedy set-cover based approach to solve it. Using the obtained trajectories, we perform proactive handoffs for at-risk links. We compare our approach with an RGB-D camera-based approach and show that our approach provides better tracking and handoff performances when the camera coverage is low to moderate, which is often the case in real deployment scenarios.

翻译：毫米波（mmWaves）在穿透障碍物时快速衰减的特性，对下一代无线网络提出了严格视距传输要求，这成为其核心难题之一。由于车辆和行人等障碍物的存在，毫米波链路容易受到干扰，导致链路质量下降甚至中断。动态障碍物通常由RGB-D相机等专用追踪硬件进行监测，但这些设备覆盖范围有限，为实现部署区域的完整覆盖将导致部署成本显著增加。本文提出一种完全不同的方法，仅基于短期历史链路失效信息，无需任何专用追踪硬件即可在毫米波网络中追踪多个动态障碍物。在证明该问题为NP完全问题后，我们采用基于贪婪集覆盖的方法进行求解。利用获取的运动轨迹，我们为面临风险的链路执行主动切换。与基于RGB-D相机的方法相比，我们的方法在相机覆盖率较低至中等（实际部署场景中常见情况）时，表现出更优的追踪与切换性能。