RIS-assisted UAV communications

The rapid adoption of the fifth-generation (5G) networks and its new applications such as Internet of Things (IoT) solutions has created new challenges for existing terrestrial networks related to limited coverage and capacity in additional to the high-deployment cost. As a result of extraordinary growth in world-wide cellular traffic, massive coverage, and massive data rate needs, the industry is moving towards the next generation of wireless networks i.e. the sixth-generation (6G) networks. It is critical to utilize innovative network architecture designs that fulfil the requirements of these applications, such as enabling unmanned aerial vehicle (UAV) communications. Thanks to their low cost, small size, high mobility, and deployment flexibility, UAVs are becoming an attractive solution for various wireless communication applications. UAVs can be utilized as aerial communication nodes for enhancing the coverage, capacity, reliability, and energy efficiency of wireless networks. They can be also used as aerial user equipment (UE) for different applications. However, to effectively use UAVs in wireless networks, various technical challenges and fundamental problems need to be addressed. Reconfigurable intelligent surfaces (RISs) may be integrated into UAV networks to overcome some of the UAV communications key challenges, and at the same time, enhance the overall performance of the network in terms of spectrum and energy efficiency. This is due to the ability of RISs to turn the wireless environment into a software-defined entity through shaping and fully controlling its EM response. RIS will play a key role in upgrading the existing UAV networks by enhancing coverage and robustness towards any environment change.