Cloud-Enabled High-Altitude Platform Systems: Challenges and Opportunities

Abstract

Augmenting ground-level communications with flying networks, such as the high-altitude platform system (HAPS), is among the major innovative initiatives of the next generation of wireless systems (6G). Given HAPS quasi-static positioning at the stratosphere, HAPS-to-ground and HAPS-to-air connectivity frameworks are expected to be prolific in terms of data acquisition and computing, especially given the mild weather and quasi-constant wind speed characteristics of the stratospheric layer. This paper explores the opportunities stemming from the realization of cloud-enabled HAPS in the context of telecommunications applications and services. The paper first advocates for the potential physical advantages of deploying HAPS as flying data-centers, also known as super-macro base stations. The paper then describes various cloud services that can be offered from the HAPS and the merits that can be achieved by this integration, such as enhancing the quality, speed, and range of the offered services. The proposed services span a wide range of fields, including satellites, Internet of Things (IoT), ad hoc networks (such as sensor; vehicular; and aerial networks), gaming, and social networks. For each service, the paper illustrates the methods that would be used by cloud providers to offload the service data to the HAPS and enable the cloud customers to consume the service. The paper further sheds light on the challenges that need to be addressed for realizing practical cloud-enabled HAPS, mainly, those related to high energy, processing power, quality of service (QoS), and security considerations. Finally, the paper discusses some open issues on the topic, namely, HAPS mobility and message routing, HAPS security via blockchain and machine learning, artificial intelligence-based resource allocation in cloud-enabled HAPS, and integration with vertical heterogeneous networks.

On the Physical Layer Security of a Dual-Hop UAV-based Network in the Presence of per-hop Eavesdropping and Imperfect CSI

“…In particular, flying base stations (e.g., UAVs, highaltitude platforms, etc.) are strongly advocated to be a key actor in space-to-ground integrated communications, whereby the wireless communication community aims at providing connectivity solutions to underserved or unconnected zones [51]. Such mobile networks, often organized in swarms [9], are prone to numerous threats and security challenges, in which potential malign users attempt to independently compromise each hop of the communication network.…”

Latency-Aware Offloading in Integrated Satellite Terrestrial Networks

“…The main energy source for the daytime operation of HAPs is the solar energy harvested through the photovoltaic system implemented on the surface of the inflatable part of the HAP. The harvested energy depends mainly on the latitude of the HAP and the considered day of the year [6], [7], [10]. HAPs also incorporate energy storage components; which are typically Lithium-Sulphur batteries or hydrogen fuel cells.…”

“…Therefore, we believe that the data center-enabled High Altitude Platform (HAP) is a distinguishable green alternative to traditional terrestrial data centers, given the encouraging merits of the HAPs. Indeed, HAP can be a core futuristic airborne network component that will unleash the networking frontier in the stratospheric range at an altitude between 17 km and 20 km [6], [7]. HAP offers several unique advantages, especially from energy and communication perspectives.…”

“…The HAP feeds the servers with the solar energy harvested during the daytime and stored in the Lithium-Sulphur batteries during the nighttime. Hence, the harvested solar energy can cover amply the computational power required by the data center' servers; while the necessary energy conversion and management strategies are efficiently applied [6], [7]. Secondly, the HAP's location at high altitudes offers LoS communication links with several receivers thanks to the the availability of large terrestrial footprint and the absence of obstructions in the horizon.…”

“…Secondly, the HAP's location at high altitudes offers LoS communication links with several receivers thanks to the the availability of large terrestrial footprint and the absence of obstructions in the horizon. Hence, HAPs can establish reliable direct links with a large number of terrestrial base stations [6], [7]. These advantages enable the data center-enabled HAP to offer a rich panoply of computing services that range Fig.…”