Guest Editorial: Flexible Reconfigurable Intelligent Surfaces for Integrated Air-to-ground Internet of Things: Architecture, Recent Advances, and Future Applications

Abstract

In 6th generation (6G), a plethora of novel services is unfolding to cater to a myriad of Internet of Things (IoT) devices, surpassing the conventional offerings of mobile phones and internet connectivity. Instances of these services encompass extended reality gadgets, sensors, as well as ground and aerial robots. Nonetheless, the implementation of these sophisticated services presents hurdles for the wireless network, specifically in its capacity to uphold pervasive connections while adhering to varied quality-of-service (QoS) specifications. To sustain capacity growth at an economical cost and low energy consumption while meeting diverse QoS requirements, the advent of innovative technologies is imperative. Recent considerations include millimeter-wave, TeraHertz, and optical frequencies, holographic multiple-input multiple-output (MIMO), ultramassive MIMO, reconfigurable intelligent surfaces (RIS), and ultra-dense networks for various applications. Additionally, the overall system performance is further enhanced through various techniques like beamforming-enabled antennas, cognitive spectrum utilization, and advancements in modulation and coding.