Download or read book Effective Data Dissemination Over Multi hop Gigabit Wireless Networks written by and published by . This book was released on 2015 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimal Data Dissemination in Stochastic and Arbitrary Wireless Networks written by Hongxing Li and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Optimal Data Dissemination in Stochastic and Arbitrary Wireless Networks" by Hongxing, Li, 李宏兴, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Data dissemination among wireless devices is an essential application in wireless networks. In contrast to its wired counterparts which have more stable network settings, wireless networks are subject to network dynamics, such as variable network topology, channel availability and capacity, which are due to user mobility, signal collision, random channel fading and scattering, etc. Network dynamics complicate the protocol design for optimal data disseminations. Although the topic has been intensively discussed for many years, existing solutions are still not completely satisfactory, especially for stochastic or arbitrary networks. In this thesis, we address optimal data dissemination in both stochastic and arbitrary wireless networks, using techniques of Lyapunov optimization, graph theory, network coding, multi-resolution coding and successive interference cancellation. We first discuss the maximization of time-averaged throughput utility over a long run for unicast and multirate multicast, respectively, in stochastic wireless networks without probing into the future. For multi-session unicast communications, a utility-maximizing cross-layer design, composed of joint end-to-end rate control, routing, and channel allocation, is proposed for cognitive radio networks with stochastic primary user occupations. Then, we study optimal multirate multicast to receivers with non-uniform receiving rates, also making dynamic cross-layer decisions, in a general wireless network with both a timevarying topology and random channel capacities, by utilizing random linear network coding and multi-resolution coding. In both solutions, we assume users are selfish and prefer only to relay data for others with strong social ties. Such social selfishness of users is a new constraint in network protocol design. Its impact on efficient data dissemination in wireless networks is largely unstudied, especially under stochastic settings. Lyapunov optimization is applied in our protocol design achieving close-to-optimal utilities. Next, we turn to latency-minimizing data aggregation in wireless sensor networks having arbitrary network topologies under the physical interference model. Different from our effort for stochastic networks where we target at time-averaged optimality over a long run, the objective here is to minimize the time-span to accomplish one round of aggregation scheduling for all sensors in an arbitrary topology. This problem is NP-hard, involving both aggregation tree construction and collision-free link scheduling. The current literature mostly considers the protocol interference model, which has been shown to be less practical than the physical interference model in characterizing the interference relations in the real world. A distributed solution under the physical interference model is challenging since cumulative interferences from all concurrently transmitting devices need to be well measured. In this thesis, we present a distributed aggregation protocol with an improved approximation ratio as compared with previous work. We then discuss the tradeoff between aggregation latency and energy consumption for arbitrary topologies when the successive interference cancellation technique is in force. Another distributed algorithm is introduced with asymptotic optimality in both aggregation latency and latency-energy tradeoff. Through theoretical analysis and

Download or read book Effective Data Transport for Reliable End to end Communication in Multihop Wireless Networks written by Sherif Moustafa Elrakabawy and published by . This book was released on 2009 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multihop Wireless Networks written by Kai Zeng and published by John Wiley & Sons. This book was released on 2011-07-13 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to opportunistic routing an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks This book presents a comprehensive background to the technological challenges lying behind opportunistic routing. The authors cover many fundamental research issues for this new concept, including the basic principles, performance limit and performance improvement of opportunistic routing compared to traditional routing, energy efficiency and distributed opportunistic routing protocol design, geographic opportunistic routing, opportunistic broadcasting, and security issues associated with opportunistic routing, etc. Furthermore, the authors discuss technologies such as multi-rate, multi-channel, multi-radio wireless communications, energy detection, channel measurement, etc. The book brings together all the new results on this topic in a systematic, coherent and unified presentation and provides a much needed comprehensive introduction to this topic. Key Features: Addresses opportunistic routing, an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks Discusses the technological challenges lying behind this new technology, and covers a wide range of practical implementation issues Explores many fundamental research issues for this new concept, including the basic principles of opportunistic routing, performance limits and performance improvement, and compares them to traditional routing (e.g. energy efficiency and distributed opportunistic routing protocol design, broadcasting, and security issues) Covers technologies such as multi-rate, multi-channel, multi-radio wireless communications, energy detection, channel measurement, etc. This book provides an invaluable reference for researchers working in the field of wireless networks and wireless communications, and Wireless professionals. Graduate students will also find this book of interest.

Download or read book Reliable Data Dissemination in Dense Wireless Networks written by Weiyao Xiao and published by . This book was released on 2010 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Commercial providers are increasingly permitting third-parties to develop and implement their own applications on wireless devices, ranging from sensors to 3G cellular phones. Accordingly, reliable data dissemination is quickly emerging as a key enabling technology, providing fundamental services such as over-the-air programming and security patching. The commonly high density of wireless devices hampers efficient accomplishment of this task, however. In this dissertation, we address the scalability of reliable data dissemination in two ways: (i) we develop and analyze policies harnessing the multi-channel transceiving capabilities of single radio wireless devices, and (ii) we rigorously address the problem of quantifying forward error correction (FEC) redundancy to eliminate control traffic (e.g., Acknowledgments) with high probability. We first analyze the performance limits of data dissemination in multi-channel, single radio networks. For arbitrary topology networks, we model this problem as a stochastic shortest path optimization and provide approaches to compute the optimal control policy achieving minimum average delay, in a finite number of steps. Due to the prohibitive computational complexity of the optimal solution, we develop asymptotically optimal polices for practical networks with high node density. Our analysis and simulations reveal that a single radio in each receiver suffices to achieve performance gain directly proportional to the number of channels available. Next, pairing rateless coding with extreme value theory, we quantify FEC redundancy by analyzing the cumulative distribution function (CDF) of the data dissemination completion time. We precisely characterize this CDF and demonstrate the existence of a phase transition associated with it. Further, we analyze heterogeneous packet loss models, by establishing a connection to the multi-set coupon collector problem. Finally, we address the problem of performing online FEC estimation under unknown channel statistics. Leveraging properties of extreme value estimators, we design novel techniques that extrapolate over limited information. We demonstrate the benefit of accurately quantifying FEC redundancy through real experiments, which reveal drastic reduction in control traffic, energy consumption and overall delay. In summary, this work contributes to the design and analysis of rapid and energy-efficient data dissemination protocols for large scale wireless networks, thereby facilitating their deployment.

Download or read book Efficient Data Transport in Cellular Multi hop Networks written by Hans-Martin Zimmermann and published by . This book was released on 2009 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Internetworking and Computing Over Satellite Networks written by Yongguang Zhang and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emphasis of this text is on data networking, internetworking and distributed computing issues. The material surveys recent work in the area of satellite networks, introduces certain state-of-the-art technologies, and presents recent research results in these areas.

Download or read book Protocol Design in Wireless Networks written by Mohammad Asadul Hoque and published by . This book was released on 2012 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless Networks provide a very cost efficient solution for data connectivity over wide areas enabling ubiquitous computing environment through multi-hop relay. The scope of this dissertation encompasses two correlated domains of Wireless Network area, one is the Multi-Radio Multi-Channel Wireless Mesh Network (MRMC-WMN) and the other is Vehicular Ad hoc Network (VANET). The research issues studied here are related to IEEE 802.11 based, multi-hop ad hoc wireless network. In the first part, we deal with some of the fundamental issues of Wireless Networks, with particular emphasis given on approaches and techniques for channel assignment and delay analysis in multi-radio multi-channel wireless mesh network. A novel channel assignment scheme has been proposed utilizing Partially Overlapped Channel (POC). We also introduced the notion of I-Matrix as a new interference model which takes into account one additional type of channel interference ignored by most researchers. Specifically, our interference model considers the effect of Self-Interference for multi-radio environment in addition to Adjacent Channel Interference(ACI) and Co-Channel Interference. We evaluate the performance of our POC based channel assignment algorithm in terms of capacity by comparing with the one using only orthogonal channels. Our results show capacity improvement as the increased link assignments at an average of more than 15 percent. The second part presents a spatio-temporal analysis of multi-hop V2V connectivity and network partitioning along with the statistical behavior of urban taxi mobility pattern. We developed two new approaches in analyzing the connectivity. One is the bitwise matrix manipulation for determining multi-hop connectivity and transitive closure. The other is the detection of saturated connectivity based on the k-hop reachability. The proposed algorithm of generating multi-hop reachability and network partition, though not optimal in performance, is better than traditional BFS approach in terms of space and time complexity. We then apply our algorithm for spatio-temporal analysis of urban taxi mobility pattern. Using the presented empirical analyses, wireless researchers can estimate the capabilities and constraints of vehicular communication from connectivity and mobility patterns as well as government can plan and work on issues related to implementing proper DSRC infrastructure for optimal data connectivity in urban area. We also propose an innovative application of V2X communication for Intelligent Transportation System (ITS). The application relates to DSRC based taxi hailing system in urban metropolitan area. The proposed system can work in both presence and absence of ITS infrastructure. Our evaluation results show that the system can not only reduce the passenger's waiting time and driver's empty cruise time, but also increase the overall taxi availability using multi-hop communication.

Download or read book Quantization and Transmission in Wireless Multi hop Networks written by Behzad Mohammadi Dogahe and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Many applications like streaming audio/video, gaming, distributed or remote computing transmit data over communication networks. The quality-of-service (QoS) of these applications depends on parameters like rate, reliability, delay, power level, etc. Furthermore, these applications need to share network resources and co-exist with other applications which run on the same network. Since these communication networks are digital communication systems, the transmitter captures the real time data, quantizes and transmits to the receiver. At the receiver not only a reconstruction of the original signal is performed but also there may be a need to classify the signal into several classes. Therefore, reconstruction fidelity and classification are also QoS requirements that many applications may demand. We are interested in the problem of transmitting data in a layered multi-hop wireless network. The QoS in our system is a function of rates and end-to-end delay from transmitters to the receivers. We are considering wireless multi-hop networks, therefore the capacity of the communication links is a function of power of transmitters and the interference from other links transmitters. Furthermore, we are not only interested in reconstructing the received quantized data but also we would like to perform signal classification on the signals based only on the characteristics of the received quantized data. We break down this problem into two separate problems to be solved at different layers of communication network as follows Problem 1 which solves a network optimization problem where QoS depends on the rate, end-to-end delay, and power of transmitters. The solution to this problem essentially entails the rate control (congestion control) in the transport later, and the power control in the physical layer to achieve bounded average queuing delay for the end-to-end transmission of the data. Problem 2 which focuses on designing a quantizer that guarantees reproduction fidelity of the signals and good classification results based on the information preserved in the reconstructed signal. Linkage and Inter-connection between Problem 1 and Problem 2 Problem 1 determines the data rate of the sessions. The data rate can be translated into bits/vector rate which is fed into the quantizer that is designed by solving Problem 2. Therefore a communication system is devised that takes advantage of the solutions of Problem 1 and 2 in order to achieve the bigger objective of this dissertation. Let us now consider the solution to Problem 1. Allocating limited resources such as bandwidth and power in a multi-hop wireless network can be formulated as a Network Utility Maximization (NUM) problem. Researchers have been using NUM in order to develop new network resource allocation algorithms by augmenting the earlier NUM problems. In the NUM framework, sources in the network measure their performance by a utility function. We augment the basic NUM problem with a constraint based on the average queueing delay requirements of the sources. Furthermore, the capacity of the links in the case of wireless networks depend on the power of transmitters. This augmented NUM formulation turns out to be a non-convex problem. We convert this non-convex problem with high-SIR assumption and a change of variable to a convex problem. We furthermore propose methods to solve this problem in an iterative distributed manner. Simulation results demonstrate the efficacy of the distributed algorithm developed. To solve Problem 2, we adopt high-rate analysis to design a quantizer that is optimized in the task of reconstruction fidelity as well as classification at the decoder. We deploy symmetric Kullback-Leibler (KL) divergence measure between the conditional probabilities of class given the signal before and after quantization as our distortion measure. We derive the optimum point density of the quantizer for minimizing the symmetric KL divergence. We study tradeoff between classification accuracy and reproduction fidelity. We also derive the effects of a mismatched distortion measure and show that for reduced complexity the original distortion measure can be replaced by a weighted mean square error (WMSE) distortion measure. We examine the performance of these methods on synthetically generated data as well as real data set and observe that our methods are superior in the task of classification of signals at the decoder. The tradeoff is the lower performance in distortion. The linkage and interrelationship of Problem 1 and 2 is shown at the end. Problem 1 determines the data rate of the sessions. The data rate can be translated into bits/vector rate which is fed into the quantizer that is designed by solving Problem 2. Therefore a communication system is devised that takes advantage of the solutions of Problem 1 and 2 in order to achieve the bigger objective of this dissertation.

Download or read book Optimal Data Dissemination in Stochastic and Arbitrary Wireless Networks written by Hongxing Li (Ph. D.) and published by . This book was released on 2012 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Efficient Data Dissemination Protocols in Wireless Pervasive Networks written by Elena Fasolo and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimal Data Dissemination in Stochastic and Arbitrary Wireless Networks written by 李宏兴 and published by . This book was released on 2012 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Age of Information written by Yin Sun and published by Morgan & Claypool Publishers. This book was released on 2019-12-12 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information usually has the highest value when it is fresh. For example, real-time knowledge about the location, orientation, and speed of motor vehicles is imperative in autonomous driving, and the access to timely information about stock prices and interest rate movements is essential for developing trading strategies on the stock market. The Age of Information (AoI) concept, together with its recent extensions, provides a means of quantifying the freshness of information and an opportunity to improve the performance of real-time systems and networks. Recent research advances on AoI suggest that many well-known design principles of traditional data networks (for, e.g., providing high throughput and low delay) need to be re-examined for enhancing information freshness in rapidly emerging real-time applications. This book provides a suite of analytical tools and insightful results on the generation of information-update packets at the source nodes and the design of network protocols forwarding the packets to their destinations. The book also points out interesting connections between AoI concept and information theory, signal processing, and control theory, which are worthy of future investigation.

Download or read book Efficient Multi hop Communications for Software defined Wireless Networks written by Yuhui Yao and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real Time Ground Based Flight Data and Cockpit Voice Recorder written by Mustafa M. Matalgah and published by John Wiley & Sons. This book was released on 2023-11-22 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-Time Ground-Based Flight Data and Cockpit Voice Recorder Unique text determining the feasibility for implementation and manufacture of ground-based black box systems Real-Time Ground-Based Flight Data and Cockpit Voice Recorder helps familiarize the reader with the nature of issues surrounding existing black box technology integrated on aircrafts and to understand the benefits and importance of proposed real-time ground-based alternative solutions. These are based on predicting aircraft problems while in flight, including understanding the feasibility of using the already existing space and ground-based wireless technologies infrastructures for this purpose. The authors discuss expense reductions in the crash investigation when implementing the new concepts in this book as compared to existing procedures when aircraft accidents occur. The text also opens new research ideas for future investigations. Simulation codes are included to allow for further independent exploration into the covered concepts and ideas. Topics covered in the book include: Satellite Data Transfer Implementation, including basics of the technology, channel data rate, PSTN-based satellite implementation, and expected availability of spectrum Very High Frequency Digital Link (VDL), including modes, sublayers, data transfer, packet and frame structure, and number of channels needed to support a certain number of airplanes Modern Airplane Communication Technologies (including direct air-to-ground communication using 5G) and terahertz band communications; and their integration into aviation communications Black box final architecture and connectivity, including ground and UAV connectivity, and general black box wireless communications challenges For aviation industrial engineers and technical staff, managers, and aerospace and academic researchers, Real-Time Ground-Based Flight Data and Cockpit Voice Recorder is a valuable guide to existing and future technology to successfully predict aircraft problems during flight.

Download or read book Conference Record written by and published by . This book was released on 2003 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Cross layered Approach for Achieving Fairness in Multihop Wireless Mesh Networks written by Nagesh S. Nandiraju and published by . This book was released on 2007 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ubiquitous broadband internet coverage using WLANs has not been considered a viable option until recently. As WLANs have been originally designed to provide the last mile extension for wired networks, they typically require extensive wired infrastructure to access the backhaul network. Provisioning such extensive infrastructure is expensive and often time consuming. Moreover it may not be feasible to lay infrastructure at all locations. Thus, an ideal ubiquitous broadband coverage is a dream yet to become reality. With the increasing popularity and rising demand for more public Wi-Fi hotspots, network service providers are facing a daunting task due to limited availability of bandwidth and error-prone wireless medium. Wireless Mesh Networks (WMNs) offer an easy and economically viable alternative for providing broadband wireless internet connectivity. They are based on the multihop communication paradigms that dynamically form a connected network. However, its progress is hindered by many limitations of the multihop wireless communication such as restricted throughput, unfairness in forwarding and limited capacity. These limitations are primarily due to lack of efficient media access and routing protocols. Although, the widely deployed IEEE 802.11 standard for medium access supports multihop communication, it leads to myriad problems and its suitability for large scale networks is debatable. Even in a typical WLAN scenario, the 802.11s DCF fails to provide fair services to uplink and downlink flows. We have conducted many experiments to demonstrate that using DCF in multihop networks leads to very unfair throughput distribution among the nodes. In this dissertation, we present novel algorithms to solve some of these problems and find that the proposed solutions are effective in mitigating the unfairness. In particular, we proposed implicit ACK based Bidirectional DCF to solve the unfairness in single hop networks and then designed two buffer management algorithms which effectively maintain fairness in a multihop WMN.