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Author :
Release : 2005
Genre :
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Resource Allocation Techniques for High Altitude Platforms by :
Download or read book Resource Allocation Techniques for High Altitude Platforms written by . This book was released on 2005. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Ahmed Ibrahim
Release : 2022-09-01
Genre : Technology & Engineering
Kind : eBook
Book Rating : 900/5 ( reviews)
Book Synopsis Optimization Methods for User Admissions and Radio Resource Allocation for Multicasting over High Altitude Platforms by : Ahmed Ibrahim
Download or read book Optimization Methods for User Admissions and Radio Resource Allocation for Multicasting over High Altitude Platforms written by Ahmed Ibrahim. This book was released on 2022-09-01. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the issue of optimizing radio resource allocation (RRA) and user admission control (AC) for multiple multicasting sessions on a single high altitude platform (HAP) with multiple antennas on-board. HAPs are quasi-stationary aerial platforms that carry a wireless communications payload to provide wireless communications and broadband services. They are meant to be located in the stratosphere layer of the atmosphere at altitudes in the range 17-22 km and have the ability to fly on demand to temporarily or permanently serve regions with unavailable telecommunications infrastructure. An important requirement that the book focusses on is the development of an efficient and effective method for resource allocation and user admissions for HAPs, especially when it comes to multicasting. Power, frequency, space (antennas selection) and time (scheduling) are the resources considered in the problem over an orthogonal frequency division multiple access (OFDMA) HAP system.Due to the strong dependence of the total number of users that could join different multicast groups, on the possible ways we may allocate resources to these groups, it is of significant importance to consider a joint user to session assignments and RRA across the groups. From the service provider's point of view, it would be in its best interest to be able to admit as many higher priority users as possible, while satisfying their quality of service requirements. High priority users could be users subscribed in and paying higher for a service plan that gives them preference of admittance to receive more multicast transmissions, compared to those paying for a lower service plan. Also, the user who tries to join multiple multicast groups (i.e. receive more than one multicast transmission), would have preferences for which one he would favor to receive if resources are not enough to satisfy the QoS requirements.Technical topics discussed in the book include: • Overview on High Altitude Platforms, their different types and the recent works in this area Radio Resource Allocation and User Admission Control in HAPs Multicasting in a Single HAP System: System Model and Mathematical Formulation Optimization schemes that are designed to enhance the performance of a branch and bound technique by taking into account special mathematical structure in the problem formulation
Author : Ahmed Ibrahim
Release : 2016
Genre :
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Admission Control and Radio Resource Allocation for Multicasting Over High Altitude Platforms by : Ahmed Ibrahim
Download or read book Admission Control and Radio Resource Allocation for Multicasting Over High Altitude Platforms written by Ahmed Ibrahim. This book was released on 2016. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, optimization techniques for a joint admission control and radio resource allocation are developed for multicasting over high altitude platforms. First, a primary system model in a multicellular high altitude platform system is considered, in which each user can receive any requested multicast session in its cell from no more than only one HAP antenna simultaneously. All the users have equal priority for admission. The users are selected to join the respective multicast groups and the power, subchannels and time slots are allocated such that the spectrum utilization is maximized while satisfying the quality of service requirements. Lagrangian relaxation and the subgradient algorithm are used to obtain solution bounds for the primary system model problem formulation. These bounds were then used in the branch and bound algorithm for pruning of nodes. The numerical results illustrate the goodness of the bounds for different constraint set dualizations and for different subgradient step size rules. The system model is then extended to allow the multicast group users to receive a session's transmission from more than one antenna simultaneously at different frequencies. This also allows the user to receive multicast sessions transmitted in neighboring cells too, not just those transmitted in the cell which the user resides in. The users have different priority levels of admission and the objective is to maximize the admission of highest priority users to the system. A much efficient formulation is obtained for the extended model in terms of size, as compared to the primary model. Linear outer approximation using McCormick underestimators are used for the relaxation of the mixed binary quadratically constrained problem. The solution method is based on branch and cut scheme in which cutting planes, domain propagation and heuristics are integrated. Various branching schemes are considered and a presolving reformulation linearization scheme for a specific set of quadratic constraints is considered. The numerical experiments compare the performances in terms of the duality gap, number of nodes, number of iterations, the number of iterations per node, the time needed to obtain the first feasible solution and the percentage of instances a feasible solution was found.
Author : David Grace
Release : 2011-06-20
Genre : Technology & Engineering
Kind : eBook
Book Rating : 559/5 ( reviews)
Book Synopsis Broadband Communications via High Altitude Platforms by : David Grace
Download or read book Broadband Communications via High Altitude Platforms written by David Grace. This book was released on 2011-06-20. Available in PDF, EPUB and Kindle. Book excerpt: A unique book with systematic and thorough coverage of HAP related issues, problems and solutions. Handbook of Broadband Communications from High Altitude Platforms provides a thorough overview and state of the art of the HAP enabling technologies, as well as describing recent research activities with most promising results. It outlines the roadmap for future development of HAPs. Focuses on placing HAPs in the perspective of current and future broadband wireless communication systems, providing the readers with an overview of the constraints affecting HAP-based broadband communications Provides a thorough overview of HAP enabling technologies, describes recent research activities with most promising results, and outlines the roadmap for future development of HAPs Covers enabling technologies and economics of HAP-based communication system including issues related to aeronautics, energetics, operating scenarios, applications and business modeling Examines the operating environment, advanced communication techniques for efficient radio link resource management, and suitable antennas Addresses multiplatform constellations, presenting the multiple HAP constellation planning procedure and discussing the networking implications of using multiple HAPs
Author : Alejandro Aragón-Zavala
Release : 2008-09-15
Genre : Technology & Engineering
Kind : eBook
Book Rating : 427/5 ( reviews)
Book Synopsis High-Altitude Platforms for Wireless Communications by : Alejandro Aragón-Zavala
Download or read book High-Altitude Platforms for Wireless Communications written by Alejandro Aragón-Zavala. This book was released on 2008-09-15. Available in PDF, EPUB and Kindle. Book excerpt: Provides an introduction to High-Altitude Platform Stations (HAPS) technology and its applications for wireless communications High-altitude platform stations offer a promising new technology that combines the benefits of terrestrial and satellite communication systems for delivering broadband communications to users at a low cost. They are easily deployable and easy to maintain, which is why they offer a good alternative for network operators who need to find ways to get more coverage to satisfy the increasing demand for more capacity. HAPS are usually balloons, airships or unmanned aerial systems (UAS) located in the stratosphere. An enormous interest has grown worldwide to examine their use not only for broadband communications, but also for emergency services, navigation, traffic monitoring, cellular, etc. Key features include: Unique book focusing on emerging HAPS technology and its applications Provides a thorough overview of the technology including HAPS-based communications systems, antennas for HAPS, radio propagation and channel modelling issues and HAPS networking aspects Presents various HAPS-related projects and initiatives developed throughout the world (North America, Europe and Asia-Pacific) Features a comprehensive overview on both aeronautical and telecommunications regulatory aspects, which will affect the deployment and future developments in the field of HAPS High-Altitude Platform Systems for Wireless Communications will prove essential reading for postgraduate students in the field of HAPS, engineers, developers and designers involved in the design and maintenance of HAPS, aerospace engineers, and communications system planners and researchers.
