Dynamic Aerial Base Station Placement for Minimum-Delay Communications
Dynamic Aerial Base Station Placement for Minimum-Delay Communications
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DOI：
10.1109/jiot.2020.3013752
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发表时间：
2020-08
影响因子：
10.6
通讯作者：
Tong Bai;Cunhua Pan;Jingjing Wang;Yansha Deng;M. Elkashlan;A. Nallanathan;L. Hanzo
中科院分区：
文献类型：
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作者：
Tong Bai;Cunhua Pan;Jingjing Wang;Yansha Deng;M. Elkashlan;A. Nallanathan;L. Hanzo
在设备缓冲区大小有限的物联网场景中，排队延迟至关重要。现有的跨层研究成果以最小化排队延迟为目标，通常依赖于发射功率控制或动态频谱分配。考虑到传输吞吐量取决于发射器和接收器之间的距离，在这种情况下，我们利用无人机（UAV）安装的基站（BSs）的灵活性，根据无线通信动态主动调整空中BS （ABS）的位置。具体来说，我们为无人机支持的网络制定了一个最小延迟ABS放置问题，该问题受到ABS电池寿命和速度的现实限制。其解决方案在技术上是在关于无线通信动态的三种不同假设下实现的。在掌握无线通信动态的全部知识的情况下，以及仅掌握其统计知识的情况下，都可以调用反向归纳技术。相反，当到达数据包的确切数量和他们的统计知识都不可用时，会调用强化学习辅助方法。数值结果表明，与基准方案相比，我们提出的算法在平均延迟和缓冲区溢出概率方面都能够提高系统的性能。
Queuing delay is of essential importance in the Internet-of-Things scenarios where the buffer sizes of devices are limited. The existing cross-layer research contributions aiming at minimizing the queuing delay usually rely on either transmit power control or dynamic spectrum allocation. Bearing in mind that the transmission throughput is dependent on the distance between the transmitter and the receiver, in this context we exploit the agility of the unmanned-aerial-vehicle (UAV)-mounted base stations (BSs) for proactively adjusting the aerial BS (ABS)’s placement in accordance with wireless teletraffic dynamics. Specifically, we formulate a minimum-delay ABS placement problem for UAV-enabled networks, subject to realistic constraints on the ABS’s battery life and velocity. Its solutions are technically realized under three different assumptions in regard to the wireless teletraffic dynamics. The backward induction technique is invoked for both the scenario where the full knowledge of the wireless teletraffic dynamics is available, and for the case where only their statistical knowledge is available. In contrast, a reinforcement learning aided approach is invoked for the case when neither the exact number of arriving packets nor that of their statistical knowledge is available. The numerical results demonstrate that our proposed algorithms are capable of improving the system’s performance compared to the benchmark schemes in terms of both the average delay and of the buffer overflow probability.