4 research outputs found
Joint Beamforming and User Association Design for Integrated HAPS-Terrestrial Networks
Located in the stratospheric layer of Earth's atmosphere, the high altitude
platform station (HAPS) is a promising network infrastructure, which can bring
significant advantages to sixth-generation (6G) and beyond wireless
communications systems by forming vertical heterogeneous networks (vHetNets).
However, if not dealt with properly, integrated networks suffer from several
performance challenges compared to standalone networks. In harmonized
integrated networks, where different tiers share the same frequency spectrum,
interference is an important challenge to be addressed. This work focuses on an
integrated HAPS-terrestrial network, serving users in an overlapped urban
geographic area, and formulates a fairness optimization problem, aiming to
maximize the minimum spectral efficiency (SE) of the network. Due to the highly
nonconvex nature of the formulated problem, we develop a rapid converging
iterative algorithm that designs the massive multiple-input multiple-output
(mMIMO) beamforming weights and the user association scheme such that the
propagated inter- and intra-tier interference is managed. Simulation results
demonstrate the proposed algorithm's superiority over standalone terrestrial
networks and scenario where only the beamforming weights are optimized.Comment: 8 pages singlecolumn, 5 figures, under review in IEEE Communications
Letter
Data Center-Enabled High Altitude Platforms: A Green Computing Alternative
Information technology organizations and companies are seeking greener
alternatives to traditional terrestrial data centers to mitigate global warming
and reduce carbon emissions. Currently, terrestrial data centers consume a
significant amount of energy, estimated at about 1.5% of worldwide electricity
use. Furthermore, the increasing demand for data-intensive applications is
expected to raise energy consumption, making it crucial to consider sustainable
computing paradigms. In this study, we propose a data center-enabled High
Altitude Platform (HAP) system, where a flying data center supports the
operation of terrestrial data centers. We conduct a detailed analytical study
to assess the energy benefits and communication requirements of this approach.
Our findings demonstrate that a data center-enabled HAP is more
energy-efficient than a traditional terrestrial data center, owing to the
naturally low temperature in the stratosphere and the ability to harvest solar
energy. Adopting a data center-HAP can save up to 14% of energy requirements
while overcoming the offloading outage problem and the associated delay
resulting from server distribution. Our study highlights the potential of a
data center-enabled HAP system as a sustainable computing solution to meet the
growing energy demands and reduce carbon footprint
A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future
A High Altitude Platform Station (HAPS) is a network node that operates in
the stratosphere at an of altitude around 20 km and is instrumental for
providing communication services. Precipitated by technological innovations in
the areas of autonomous avionics, array antennas, solar panel efficiency
levels, and battery energy densities, and fueled by flourishing industry
ecosystems, the HAPS has emerged as an indispensable component of
next-generations of wireless networks. In this article, we provide a vision and
framework for the HAPS networks of the future supported by a comprehensive and
state-of-the-art literature review. We highlight the unrealized potential of
HAPS systems and elaborate on their unique ability to serve metropolitan areas.
The latest advancements and promising technologies in the HAPS energy and
payload systems are discussed. The integration of the emerging Reconfigurable
Smart Surface (RSS) technology in the communications payload of HAPS systems
for providing a cost-effective deployment is proposed. A detailed overview of
the radio resource management in HAPS systems is presented along with
synergistic physical layer techniques, including Faster-Than-Nyquist (FTN)
signaling. Numerous aspects of handoff management in HAPS systems are
described. The notable contributions of Artificial Intelligence (AI) in HAPS,
including machine learning in the design, topology management, handoff, and
resource allocation aspects are emphasized. The extensive overview of the
literature we provide is crucial for substantiating our vision that depicts the
expected deployment opportunities and challenges in the next 10 years
(next-generation networks), as well as in the subsequent 10 years
(next-next-generation networks).Comment: To appear in IEEE Communications Surveys & Tutorial