Link Budget Analysis for Reconfigurable Smart Surfaces in Aerial Platforms

Abstract

<div>Non-terrestrial networks, including Unmanned Aerial Vehicles (UAVs), High Altitude Platform Station (HAPS) and Low Earth Orbiting (LEO) satellites, are expected to have a pivotal role in the sixth generation wireless networks. With their inherent features such as flexible placement, wide footprint, and preferred channel conditions, they can tackle several challenges in current terrestrial networks. However, their successful and widespread adoption relies on energy-efficient on-board communication systems. In this context, the integration of Reconfigurable Smart Surfaces (RSS) into aerial platforms is envisioned as a key enabler of energy-efficient and cost-effective deployments of aerial platforms. Indeed, RSS consist of low-cost reflectors capable of smartly directing signals in a nearly passive way. We investigate in this paper the link budget of RSS-assisted communications under the two discussed RSS reflection paradigms in the literature, namely the specular and the scattering reflection paradigm types. Specifically, we analyze the characteristics of RSS-equipped aerial platforms and compare their communication performance with that of RSS-assisted terrestrial networks, using standardized channel models. In addition, we derive the optimal aerial platforms placements under both reflection paradigms. The obtained results provide important insights for the design of RSS-assisted communications. For instance, given that a HAPS has a large RSS surface, it provides superior link budget performance in most studied scenarios. In contrast, the limited RSS area on UAVs and the large propagation loss in LEO satellite communications make them unfavorable candidates for supporting terrestrial users. Finally, the optimal location of the RSS-equipped platform may depend on the platform’s altitude, coverage footprint, and type of environment.</div>

Beyond-Cell Communications via HAPS-RIS

“…Following the standardized 3GPP channel model established for a HAPS and terrestrial nodes in urban environments [13,Sec. 6], and the scattering reflecting paradigm of the RIS as detailed in [8], the effective channel gains from the CS to all UEs in set K 2 through the HAPS-RIS are obtained. For this model, we consider dry air atmospheric attenuation.…”

Taming Aerial Communication with Flight-assisted Smart Surfaces in 6G Era

“…The link budget of an A2G network is directly proportional to the signal wavelength and the number of RIS elements, and inversely proportional to the distance to the user [8]. On the one hand, the increasing demand for higher communication rates and the need to support a massive number of users is pushing future wireless networks towards higher frequency bands, such as millimeter-wave (mmWave) or terahertz (THz).…”

RISe of Flight: RIS-Empowered UAV Communications for Robust and Reliable Air-to-Ground Networks

“…Given the position of the RIS with respect to the BS and the target area A and the fact that we assume the drone to be maneuvered by first responder teams, the communication link between the BS and the RIS is assumed to be in line-of-sight (LoS) condition with a very high probability (see, e.g., [14], [25], [28]). Therefore, the channel power gain from the source to the RIS is defined as per…”