Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Cross-layer Optimization"”.
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Cross-Layer Optimization: System Design and Simulation Methodologies
… protocol stack is inflexible as various protocol layers communicate in a strict manner. In such a case the layers are designed to operate under the worst conditions as opposed to adapting to changing conditions. This leads to inefficient use of spectrum and energy. Adaptation represents the …
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Cross-Layer Optimization and Distributed Algorithm Design for Frequency-Agile Radio Networks
… simple joint channel scheduling and flow routing optimization algorithm that maximizes network throughput. The model quantifies the impact of fundamental network settings, such as node density and traffic load, on the performance of partially overlapped channel based networks. We then propose a …
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Analysis and Cross -Layer Design of Medium Access and Scheduling in Wireless Mesh Networks
Due to the characteristics of wireless PHY/MAC, cross-layer design is needed to achieve good performance in multihop wireless mesh networks. We propose a cross-layer scheme to coordinate the operations of different layers in IEEE 802.16 backhaul mesh networks where the nodes are equipped with …
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Maximizing Resource Utilization In Video Streaming Systems
… efficiently. In this research, we develop two cross-layer optimization frameworks that maximize the bandwidth optimization of 802.11 wireless network. We develop a distortion-based cross-layer optimization framework that manages bandwidth in the wire-less network in such a way that minimizes …
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Design and Implementation of An Emulation Testbed for Video Communications in Ad Hoc Networks
… traditional video codec, either single steam or layered video, requires at least one relatively stable path between source and destination nodes. Recent advances in multiple description (MD) video coding have opened up new possibilities to offer video communications over ad hoc networks. In this …
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Cross-Layer Capacity Optimization In OFDMA Systems: WiMAX And LTE
… and subscriber's satisfaction is proposed. A cross-layer optimization design for subchannel, for Wimax, and physical resource block (prb), for lte, and power allocations with the objective of maximizing the capacity (in bits/symbol/hz) subject to fairness parameters and qos requirements as …
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Analysis and Optimization of Cooperative Wireless Networks
… and time. However, in previous research, each optimization problem has been investigated separately, and the optimal solution for one problem is usually not optimal for the other problems.</p> <p>This dissertation focuses on joint optimization or cross-layer optimization in wireless cooperative …
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Autonomous Link-Adaptive Schemes for Heterogeneous Networks with Congestion Feedback
… nodes adapt greedily following traditional link layer optimization objectives. Given the growing data rate demand, increasing system complexity and the difficulty of implementing centralized cross-layer optimization frameworks, our work simplifies resource allocation in heterogeneous cellular …
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Service-Oriented Sensor-Actuator Networks
… reliable path to the sink. We also propose query optimization techniques that contribute to the efficient execution of queries in SOSANETs. To evaluate the proposed service-oriented architecture, we implemented TinySOA, a prototype SOSANET built on top of TinyOS with uRACER as its routing …
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Multiple Description Video Communications in Wireless Ad Hoc Networks
… video problem, we follow an applicationcentric cross-layer approach and formulate an optimal routing problem that minimizes the application layer video distortion. We show that the optimization problem has a highly complex objective function and an exact analytic solution is not obtainable. …
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MIMO Wireless Networks: Modeling and Optimization
… nowadays, network design and performance optimization for MIMO-based wireless networks is considerably more challenging. Many fundamental problems remain unsolved. Due to the complex characteristics of MIMO physical layer technology, it is not only desirable but also necessary to consider …
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Design and Implementation of An Emulation Testbed for Optimal Spectrum Sharing in Multi-hop Cognitive Radio Networks
… for such multi-hop CR network from multiple layers, including modeling of spectrum sharing and sub-band division, scheduling and interference constraints, and flow routing. We give a formal mathematical formulation with the objective of maximizing the network throughput for a set of user …
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Directional Communications to Improve Multicast Lifetime in Ad Hoc Networks
Wireless ad-hoc networks are easily deployed, untethered to infrastructure, and have virtually an unlimited number of applications. However, this flexibility comes at the cost of finite and often unreplenishable power supplies. Once a node has consumed all of its power, it can no longer receive, …
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From Energy Efficient to Energy Neutral Wireless Sensor Networks
… stack design, all the way from the application layer to underlying hardware. At the application layer, the relaxed requirements make it possible to propose techniques to reduce the data exchanges among the nodes, the most power hungry operation in WSNs. For example, we propose a simple yet …
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Cognitive Networks
… difference between it and other cognitive and cross-layer technologies. From this definition, we develop a general, three-layer cognitive network framework, based loosely on the framework used for cognitive radio. In this framework, we consider the possibility of a cognitive process consisting …
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Cross-layer Control for Adaptive Video Streaming over Wireless Access Networks
… our tool, researchers can implement new network layers, protocols, and algorithms, and redesign the interconnections between the protocols. It offers logging and monitoring capabilities as well as dynamic reconfigurability of the modules' attributes and interconnections during runtime. We present …
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Distributed Scheduling and Delay-Throughput Optimization in Wireless Networks under the Physical Interference Model
… and non-linear.<br />The system performance optimization and tradeoffs with respect to throughput and delay require a ``global\'\' view across<br />transport, network, media access control (MAC), physical layers (referred to as cross-layer optimization)<br />to take advantage of the control …
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Efficient Resource Allocation Schemes for Wireless Networks with with Diverse Quality-of-Service Requirements
… for diverse wireless paradigms. We first study cross-layer dynamic spectrum allocation in a LTE macro-cellular network with fractional frequency reuse to improve the spectral efficiency for cell-edge users. We show that the resultant optimization problem is NP-hard and propose a low-complexity …
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Game-Theoretic Analysis of Topology Control
Ad hoc networks are emerging as a cost-effective, yet, powerful tool for communication. These systems, where networks can emerge and converge on-the-fly, are guided by the forward-looking goals of providing ubiquitous connectivity and constant access to information. Due to power and bandwidth …
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Video Communications over Dynamic Ad Hoc Networks
… typically optimize one or more network layer metrics, but they are usually agnostic to any kind of application layer performance. Consequently, new methodologies must be explored to improve the performance of video applications in multihop wireless networks. This dissertation directly …
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