An Efficient HAPS Cross-Layer Design to Mitigate COVID-19 Consequences (original) (raw)
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Wireless Personal Communications, 2007
This paper looks into the relatively new field of high altitude platform stations. HAPS is seen as a 'middle ground' between the terrestrial and satellite cases, and aims to exploit of the advantages of both types of system. Since HAPS is such a new field, this paper focuses on the technology behind a HAPS communications system, how this has developed, and compares it to the terrestrial and satellite equivalents. One important area that is being investigated is the applications for which HAPS should be used. This is a critical issue if a significant business case is to be made for HAPS. Worldwide HAPS projects and research issues are also highlighted. Finally, the review concludes with the remarks on the future of HAPS for wireless communications systems.
A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future
2020
A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an altitude around 20 km and is instrumental for providing communication services. Triggered by the technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels and the battery energy density, and fueled by the flourishing industry ecosystems, the HAPS exerts itself as an indispensable component of the 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 survey. We highlight the undiscovered 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 fo...
Performance of Multiple High Altitude Platforms using Directive HAP and User Antennas
Wireless Personal Communications, 2005
This paper examines the behaviour of system capacity in High Altitude Platform (HAP) communications systems as a function of antenna directivity and HAP positioning. Antenna models for the user and the HAP are discussed, and it is shown that a flat sidelobe antenna pattern is suitable for modelling multiple HAP constellations when HAPs are located outside the coverage area. Using a single HAP scenario it is shown how narrowing the HAP antenna beamwidth may give better downlink Carrier-to-Noise Ratio (CNR) over the most of the coverage area. The roles of the HAP antenna beamwidth, HAP antenna pointing and HAP spacing radius are investigated. An equation is derived to determine the location of the peak CNR combined with these three parameters. A more complex multiple HAP scenario where all HAP's operate on the same channel and interfere with each other is also assessed in terms of the Carrier to Interference plus Noise Ratio (CINR) and spectral efficiency. It is shown that locating HAPs at a specific spacing radius that is outside the coverage area can improve performance. Using these techniques the combined bandwidth efficiency is shown to increase almost pro-rata when the number of HAPs is increased up to 16.
Improving the system capacity of broadband services using multiple high-altitude platforms
IEEE Transactions on Wireless Communications, 2000
A method of significantly improving the capacity of high-altitude platform (HAP) communications networks operating in the millimeter-wave bands is presented. It is shown how constellations of HAPs can share a common frequency allocation by exploiting the directionality of the user antenna. The system capacity of such constellations is critically affected by the minimum angular separation of the HAPs and the sidelobe level of the user antenna. For typical antenna beamwidths of approximately 5 an inter-HAP spacing of 4 km is sufficient to deliver optimium performance. The aggregate bandwidth efficiency is evaluated, both theoretically using the Shannon equation, and using practical modulation and coding schemes, for multiple HAP configurations delivering either single or multiple cells. For the user antenna beamwidths used, it is shown that capacity increases are commensurate with the increase in the number of platforms, up to 10 HAPs. For increases beyond this the choice of constellation strategy becomes increasingly important.
Optimizing an array of antennas for cellular coverage from a high altitude platform
IEEE Transactions on Wireless Communications, 2003
In a wireless communications network served by a high altitude platform (HAP) the cochannel interference is a function of the antenna beamwidth, angular separation and sidelobe level. At the millimeter wave frequencies proposed for HAPs, an array of aperture type antennas on the platform is a practicable solution for serving the cells. We present a method for predicting cochannel interference based on curve-fit approximations for radiation patterns of elliptic beams which illuminate cell edges with optimum power, and a means of estimating optimum beamwidths for each cell of a regular hexagonal layout. The method is then applied to a 121 cell architecture. Where sidelobes are modeled as a flat floor at 40-dB below peak directivity, a cell cluster size of four yields carrier-to-interference ratios (CIRs), which vary from 15 dB at cell edges to 27 dB at cell centers. On adopting a cluster size of seven, these figures increase, respectively, to 19 and 30 dB. On reducing the sidelobe level, the improvement in CIR can be quantified. The method also readily allows for regions of overlapping channel coverage to be shown.
HAP antenna radiation pattern for providing coverage and service characteristics
2014 International Conference on Advances in Computing, Communications and Informatics (ICACCI), 2014
the purpose of this paper is to show the most important technique in wireless communication networks that is an antenna radiation pattern. The antenna radiation pattern represents features of the antenna radiation shape in the space. The antenna radiation patterns used for determine the shape of cell size so that the difference cell sizes have difference antenna radiation patterns. The quality of coverage is depending on the cell size and QoS is depending on the coverage area which can provide via HAPs. Therefore, the antenna radiation pattern plays the most important role for HAPs coverage. The study focuses on the manner of cells or tier provided via HAP and the probability of services. If the distance between cells decreases, the number of cells increases that means the large number of tiers are used as well as the network performance will be affected by decreasing the distance between cells. Using steerable antenna is able to vary for providing constant coverage and improve the QoS. Since a steerable antenna is used on the HAP for allowance HAPs to be deployed in the different parts of the sky while the antennas boresight are still pointing at the desired coverage area. For each antenna pattern result is shown when Single HAP is considered in this study.
High-Altitude Platforms Cellular System for Sparsely Populated Areas
International Journal of Computer Network and Information Security, 2014
In this paper, the cellular communications using high altitude platform (HAP) will be discussed including the coverage analysis and design. The cells are analyzed showing the main parameters affecting its shape, layout and area which are important in the cellular design stage. This HAP cellular system is very important to cross the gap of difficult extension of ground infrastructure especially for sparsely populated areas needing communications services. The system design is explained where the footprint of the HAP cell is demonstrated and the overall cellular layout is established. As a case study, the coverage of the HAP cellular system is proved to cover some areas in the Kingdom of Saudi Arabia (KSA) using several scenarios such as populated as well as long highways passing through desert areas. The HAP cells are generated using spot-beam antennas which are practically candidate. The simulation results show that a single HAP can provide hundreds of microcells for urban areas while covering very long highways that can extend to several hundreds of kilometers which is very useful in covering the long highways linking sparsely separated cities in KSA.
High Altitude Platform Stations (HAPS): Architecture and System Performance
2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), 2021
High Altitude Platform Station (HAPS) has the potential to provide global wireless connectivity and data services such as high-speed wireless backhaul, industrial Internet of things (IoT), and public safety for large areas not served by terrestrial networks. A unified HAPS design is desired to support various use cases and a wide range of requirements. In this paper, we present two architecture designs of the HAPS system: i) repeater based HAPS, and ii) base station based HAPS, which are both viable technical solutions. The energy efficiency is analyzed and compared between the two architectures using consumption factor theory. The system performance of these two architectures is evaluated through Monte Carlo simulations and is characterized in metrics of spectral efficiency using LTE band 1 for both single-cell and multi-cell cases. Both designs can provide good downlink spectral efficiency and coverage, while the uplink coverage is significantly limited by UE transmit power and an...
IEEE Transactions on Aerospace and Electronic Systems, 2010
An investigation into the impact of antenna radiation patterns on the performance of a 3G mobile communication system provided a single high-altitude platform (HAP) is presented. Use of elliptical and circular beam antennas is examined for a 91-cell system. Crucial performance parameters are shown to be the mainlobe power roll-off and sidelobe level. It is presented that the optimum power roll-off from cell center to the cell edge ranges between 10-35 dB, which is dependent on the types of antennas used, sidelobe level, and antenna gain strategy employed. Elliptical beam antennas are proven to provide the best solution, but circular beam antennas with their gain adjusted to reduce the degree of cell overlap and compensate for increasing path loss are shown to provide similar performance, with the advantage that they are practically more realizable. It is shown that poorer overlap performance can be partially compensated for by an increased power roll-off at the cell edge, a strategy that is employed in the case of the gain adjusted circular beam antennas. The impact of cell radius and elevation angles is also assessed. I. INTRODUCTION Third generation (3G) mobile systems, e.g., UMTS (universal mobile telecommunications system), especially when supplemented with high-speed downlink packet access (HSDPA), should fulfill the increasing requirements for high-speed mobile data communications [1, 2]. The rapid deployment of UMTS networks is limited by many factors. In many instances, particularly in suburban and rural areas, coverage is the dominant consideration. High-altitude platforms (HAPs) will be situated in the stratosphere at an altitude from 17 to 22 km [3-6] and could be used as an alternative to a terrestrial component for UMTS 3G mobile networks or as a complementary element of terrestrial networks in providing telecommunication and data services in sparsely populated areas such as in Africa during disasters, terrorist attacks, etc. The frequency spectrum
Multi-Mode High Altitude Platform Stations (HAPS) for Next Generation Wireless Networks
The high altitude platform station (HAPS) concept has recently received notable attention from both industry and academia to support future wireless networks. A HAPS can be equipped with 5thgeneration (5G) and beyond technologies such as massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surface (RIS). Hence, it is expected that HAPS will support numerous applications in both rural and urban areas. However, this comes at the expense of high energy consumption and thus shorter loitering time. To tackle this issue, we envision the use of a multi-mode HAPS that can adaptively switch between different modes so as to reduce energy consumption and extend the HAPS loitering time. These modes comprise a HAPS super macro base station (HAPS-SMBS) mode for enhanced computing, caching, and communication services, a HAPS relay station (HAPS-RS) mode for active communication, and a HAPS-RIS mode for passive communication. This multi-mode HAPS ensures that operations rely...