Optimal distributed scheduling algorithm for cooperative communication networks

There has been an enormous interest towards cooperative communication in recent years. Cooperative communication plays a signi cant role in providing a reliable communication in wireless networks. Cooperative communication helps overcome fading and attenuation in wireless networks. Its main purpose is to increase the communication rates across the network and to increase reliability of time-varying links. It is known that wireless communication from a source to a destination can bene t from the cooperation of nodes that overhear the transmission. In this thesis we consider problem of resource allocation in cooperative network consisting of Primary User (PU) and (N - 1) Secondary Users (SUs), operating in a shared wireless medium. In our network scenario, PU's dedicated channel su ers from fading. PU, in order to overcome fading and attenuation, grants access of its dedicated channel to other SUs conditioned on their cooperation. Whenever PU's dedicated channel is OFF, its packet can be relayed through SU's. Our ultimate goal is to design a distributed algorithm to achieve optimal throughput properties. Maximum Weight Scheduling can achieve throughput optimality by exploiting opportunistic gain in general network topology with fading channels. Despite the advantage of opportunistic scheduling, this mechanism requires that the existing central scheduler is aware of network conditions such as channel state and queue length information of users. We break this assumption by considering that only individual information is available at each user. We design a Carrier Sense Multiple Access (CSMA) based algorithm which only uses individual queue length information. We derive exact capacity region of the cooperative network for two user scenario thus establishing superiority of the cooperative network over non cooperative network. Then we prove throughput optimality of our proposed algorithm for two scenarios; rst being a cooperative network consisting of N users with only PU having fading channel and second a two user scenario where all existing links su er from fading

Parallel and Distributed Computing

The 14 chapters presented in this book cover a wide variety of representative works ranging from hardware design to application development. Particularly, the topics that are addressed are programmable and reconfigurable devices and systems, dependability of GPUs (General Purpose Units), network topologies, cache coherence protocols, resource allocation, scheduling algorithms, peertopeer networks, largescale network simulation, and parallel routines and algorithms. In this way, the articles included in this book constitute an excellent reference for engineers and researchers who have particular interests in each of these topics in parallel and distributed computing

Ant Colony Optimization

Ant Colony Optimization (ACO) is the best example of how studies aimed at understanding and modeling the behavior of ants and other social insects can provide inspiration for the development of computational algorithms for the solution of difficult mathematical problems. Introduced by Marco Dorigo in his PhD thesis (1992) and initially applied to the travelling salesman problem, the ACO field has experienced a tremendous growth, standing today as an important nature-inspired stochastic metaheuristic for hard optimization problems. This book presents state-of-the-art ACO methods and is divided into two parts: (I) Techniques, which includes parallel implementations, and (II) Applications, where recent contributions of ACO to diverse fields, such as traffic congestion and control, structural optimization, manufacturing, and genomics are presented

Queueing models for cable access networks

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Operational Research: Methods and Applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes

Telecommunications Networks

This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

Throughput Characterizations of Wireless Networks via Stochastic Geometry and Random Graph Theory

The shared medium of wireless communication networks presents many technical challenges that offer a rich modeling and design space across both physical and scheduling protocol layers. This dissertation is organized into tasks that characterize the throughput performance in such networks, with a secondary focus on the interference models employed therein. We examine the throughput ratio of greedy maximal scheduling (GMS) in wireless communication networks modeled as random graphs. A throughput ratio is a single-parameter characterization of the largest achievable fraction of the network capacity region. The throughput ratio of GMS is generally very difficult to obtain; however, it may be evaluated or bounded based on specific topology structures. We analyze the GMS throughput ratio in previously unexplored random graph families under the assumption of primary interference. Critical edge densities are shown to yield bounds on the range and expected GMS throughput ratio as the network grows large. We next focus on the increasing interest in the use of directional antennas to improve throughput in wireless networks. We propose a model for capturing the effects of antenna misdirection on coverage and throughput in large-scale directional networks within a stochastic geometry framework. We provide explicit expressions for communication outage as a function of network density and antenna beamwidth for idealized sector antenna patterns. These expressions are then employed in optimizations to maximize the spatial density of successful transmissions under ideal sector antennas. We supplement our analytical findings with numerical trends across more realistic antenna patterns. Finally, we characterize trade-offs between the protocol and physical interference models, each used in the prior tasks. A transmission is successful under the protocol model if the receiver is free of any single, significant interferer, while physical model feasibility accounts for multiple interference sources. The protocol model, parameterized by a guard zone radius, naturally forms a decision rule for estimating physical model feasibility. We combine binary hypothesis testing with stochastic geometry and characterize the guard zone achieving minimum protocol model prediction error. We conclude with guidelines for identifying environmental parameter regimes for which the protocol model is well suited as a proxy for the physical model.Ph.D., Electrical Engineering -- Drexel University, 201