Unmanned aerial vehicle assisted communications and networking

Abstract

In 5G and beyond networks, the explosive data and the massive connections are some of the key challenges. To alleviate the pressure on the ground networks and reduce the cost of densely deployed small cells, unmanned aerial vehicle (UAV) can be exploited as a promising technology in future communications networks. The UAV technology is becoming more and more mature, which owns advantages on high reliability, flexible deployment, cooperative operation and low cost. In particular, the air-to-air and air-to-ground channels are much better than the ground-to-ground channels. In many cases, they have line-of-sight (LoS) links. For these channels, mmWave transmission becomes practicable for UAV communications, which provides much higher data rate. Furthermore, UAVs can be combined with massive MIMO technology to meet ever-increasing data demand. Considering the device miniaturization and cost reduction of UAVs, it is more feasible than ever before to deploy UAV as relay to realize range extension in wireless communication systems. Meanwhile, in order to reduce the transmission latency as well as the load of backhaul links, UAVs are equipped with the ability of caching popular contents. In addition, UAVs can also be utilized in other important applications, such as emergency networks, traffic monitoring and military attacks, etc. However, there still exist many challenges in this emerging technology of UAV communications and networking, such as interference management, security and safety, beam tracking and alignment, trajectory and placement optimization, and so on. Furthermore, UAV enabled networking also requires great effort to reshape the current ground systems for satisfactory performances. Therefore, it is imperative to conduct thorough investigation and research on the UAV enabled communications and networking. Motivated by this, a collection of papers are included in this special issue, which mainly focus on the analysis and optimization of UAV-enabled networks and cache-aided UAV relay networks. Moreover, the analysis of energy efficiency, the design of secure transmission, and the optimization of outage probability and UAV-aided localization are investigated as well.