Download or read book Network Coding based Survivability Techniques for Multi hop Wireless Networks written by Osameh Al-Kofahi and published by . This book was released on 2009 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Network Coding for Quality of Service in Wireless Multi hop Networks written by Youghourta Benfattoum and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis we deal with the application of Network Coding to guarantee the Quality of Service (QoS) for wireless multi-hop networks. Since the medium is shared, wireless networks suffer from the negative interference impact on the bandwidth. It is thus interesting to propose a Network Coding based approach that takes into account this interference during the routing process. In this context, we first propose an algorithm minimizing the interference impact for unicast flows while respecting their required bandwidth. Then, we combine it with Network Coding to increase the number of admitted flows and with Topology Control to still improve the interference management. We show by simulation the benefit of combining the three fields: Network Coding, interference consideration and Topology Control. We also deal with delay management for multicast flows and use the Generation-Based Network Coding (GBNC) that combines the packets per blocks. Most of the works on GBNC consider a fixed generation size. Because of the network state variations, the delay of decoding and recovering a block of packets can vary accordingly degrading the QoS. To solve this problem, we propose a network-and content-aware method that adjusts the generation size dynamically to respect a certain decoding delay. We also enhance it to overcome the issue of acknowledgement loss. We then propose to apply our approach in a Home Area Network for Live TV and video streaming. Our solution provides QoS and Quality of Experience for the end user with no additional equipment. Finally, we focus on a more theoretical work in which we present a new Butterfly-based network for multi-source multi-destination flows. We characterize the source node buffer size using the queuing theory and show that it matches the simulation results.
Download or read book Network Coding for Multihop Wireless Networks written by Misfa Susanto and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Network Coding written by Somayeh Kafaie and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Network coding is an innovative idea to boost the capacity of wireless networks. However, there are not enough analytical studies on throughput and end-to-end delay of network coding in multi-hop wireless mesh network that incorporates the specifications of IEEE 802.11 Distributed Coordination Function. In this dissertation, we utilize queuing theory to propose an analytical framework for bidirectional unicast flows in multi-hop wireless mesh networks. We study the throughput and end-to-end delay of inter-flow network coding under the IEEE 802.11 standard with CSMA/CA random access and exponential back-o↵ time considering clock freezing and virtual carrier sensing, and formulate several parameters such as the probability of successful transmission in terms of bit error rate and collision probability, waiting time of packets at nodes, and retransmission mechanism. Our model uses a multi-class queuing network with stable queues, where coded packets have a non-preemptive higher priority over native packets, and forwarding of native packets is not delayed if no coding opportunities are available. The accuracy of our analytical model is verified using computer simulations. Furthermore, while inter-flow network coding is proposed to help wireless networks approach the maximum capacity, the majority of research conducted in this area is yet to fully utilize the broadcast nature of wireless networks, and to perform e↵ectively under poor channel quality. This vulnerability is mostly caused by assuming fixed route between the source and destination that every packet should travel through. This assumption not only limits coding opportunities, but can also cause bu↵er overflow at some specific intermediate nodes. Although some studies considered scattering of the flows dynamically in the network, they still face some limitations. This dissertation explains pros and cons of some prominent research in network coding and proposes a Flexible and Opportunistic Network Coding scheme (FlexONC) as a solution to such issues. Moreover, this research discovers that the conditions used in previous studies to combine packets of di↵erent flows are overly optimistic and would a↵ect the network performance adversarially. Therefore, we provide a more accurate set of rules for packet encoding. The experimental results show that FlexONC outperforms previous methods especially in networks with high bit error rates, by better utilizing redundant packets permeating the network, and benefiting from precise coding conditions.
Download or read book Partial Network Coding with Cooperation written by Panupat Poocharoen and published by . This book was released on 2011 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The imperfections of the propagation channel due to channel fading and the self-generated noise from the RF front-end of the receiver cause errors in the received signal in electronic communication systems. When network coding is applied, more errors occur because of error propagation due to the inexact decoding process. In this dissertation we present a system called Partial Network Coding with Cooperation (PNC-COOP) for wireless ad hoc networks. It is a system which combines opportunistic network coding with decode-and-forward cooperative diversity, in order to reduce this error propagation by trading off some transmission degrees of freedom. PNC-COOP is a decentralized, energy efficient strategy which provides a substantial benefit over opportunistic network coding when transmission power is a concern. The proposed scheme is compared with both opportunistic network coding and conventional multi-hop transmission analytically and through simulation. Using a 3-hop communication scenario, in a 16-node wireless ad hoc network, it is shown that PNC-COOP improves the BER performance by 5 dB compared to opportunistic network coding. On average, it reduces the energy used by each sender node around 10% and reduces the overall transmitted energy of the network by 3.5%. When retransmission is applied, it is shown analytically that PNC-COOP performs well at relatively low to medium SNR while the throughput is comparable to that of opportunistic network coding. The effectiveness of both opportunistic network coding and PNC-COOP depends not only on the amount of network coding but also on other factors that are analyzed and discussed in this dissertation.
Download or read book Network Coding written by Mohammad Matin and published by BoD – Books on Demand. This book was released on 2018-08-22 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Network coding is an elegant and novel technique that allows nodes in the network to perform coding operations at the packet level. In particular, network coding represents a powerful approach to protect data from losses due to link disconnections and can also exploit the combination of multiple links to deliver data to users with the possibility of recoding at intermediate nodes. This phenomenon will reduce information congestion at some nodes or links, which will improve the network information flow such as to increase network throughput and robustness. This book is intended to provide the current R
Download or read book Network Coding for Multi user Wireless Networks written by Dong Van Nguyen and published by . This book was released on 2010 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until a few years ago, wireless-capable laptops were considered novelties by many. It is now hard to find a laptop or a hand-held computing device that is not wireless-ready. As wireless devices are becoming commodities, they have also become an indispensable part of the modern society. Not surprisingly, research in wireless communication has also been significantly advanced in the past decade, to accommodate the growing demand for these wireless devices and applications. Yet, many challenges remain in transmitting information reliably, timely, and efficiently over wireless channels. Unlike wired transmissions, wireless transmissions are subjected to limited bandwidth, and are much more susceptible to environmental noises such as fading and interferences. As a result, it is difficult to transmit information reliably at high data rates. The problem is further compounded by the strict requirements on maximum delay and minimum throughput imposed by current and future multimedia applications. That said, recent advances in coding techniques, communication protocols and architectures provide an optimistic view of future wireless networks that help proliferate high quality wireless multimedia applications. One significant advance in coding theory in the past decade is em Network Coding (NC). NC refers to the notion of mixing information from different flows at intermediate nodes in the network, and it has been shown to achieve throughput capacity. In this dissertation, we investigate NC theories and practical techniques for improving throughput and reducing delay of wireless networking applications. Specifically, the dissertation will focus on theoretical analysis of NC benefits and limitations as well as design of NC-based practical protocols for improving performance in a wireless access network such as Wi-Fi or WiMax. There are three main contributions of the dissertation. First, we propose a NC-based retransmission protocol for broadcasting information from a wireless base station to multiple users in a wireless access network. The proposed NC protocol exploits the special property of wireless transmissions that users in proximity, can listen to each other's transmissions to code the packets in such a way to increase every user throughputs. Both theoretical analysis and simulation results show a significant throughput gain when using the proposed NC protocol over the standard ARQ protocol. Second, we propose a NC-based packet scheduler at a wireless base station for delivering multimedia streams, particularly scalable video streams to multiple users in a wireless access network. We formulate the NC-based packet scheduler problem in the framework of Markov Decision Process (MDP) in which, packet delay, inter-dependency of packets, and different visual contributions of packet types are taken into account, to optimize for the overall visual qualities. We describe an optimal scheduler for transmitting scalable video streams to a small number of users. For a large number of users, we propose a heuristic, simulation-based algorithm for finding the near-optimal transmission policy. Third, we introduce Random Network Coding (RNC) techniques. More specifically, we present a prioritized RNC scheme for multimedia transmissions for multi-user in a wireless access network. We then study a real-world implementation of RNC. We describe the step-by-step design of encoding and decoding modules of RNC and measure their computational rates.
Download or read book BATS Codes written by Shenghao Yang and published by Springer. This book was released on 2017-09-19 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses an efficient random linear network coding scheme, called BATched Sparse code, or BATS code, which is proposed for communication through multi-hop networks with packet loss. Multi-hop wireless networks have applications in the Internet of Things (IoT), space, and under-water network communications, where the packet loss rate per network link is high, and feedbacks have long delays and are unreliable. Traditional schemes like retransmission and fountain codes are not sufficient to resolve the packet loss so that the existing communication solutions for multi-hop wireless networks have either long delay or low throughput when the network length is longer than a few hops. These issues can be resolved by employing network coding in the network, but the high computational and storage costs of such schemes prohibit their implementation in many devices, in particular, IoT devices that typically have low computational power and very limited storage. A BATS code consists of an outer code and an inner code. As a matrix generalization of a fountain code, the outer code generates a potentially unlimited number of batches, each of which consists of a certain number (called the batch size) of coded packets. The inner code comprises (random) linear network coding at the intermediate network nodes, which is applied on packets belonging to the same batch. When the batch size is 1, the outer code reduces to an LT code (or Raptor code if precode is applied), and network coding of the batches reduces to packet forwarding. BATS codes preserve the salient features of fountain codes, in particular, their rateless property and low encoding/decoding complexity. BATS codes also achieve the throughput gain of random linear network coding. This book focuses on the fundamental features and performance analysis of BATS codes, and includes some guidelines and examples on how to design a network protocol using BATS codes.
Download or read book Applied Network Coding in Wireless Networks written by Johannes Hund and published by GRIN Verlag. This book was released on 2010-04-14 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masterarbeit aus dem Jahr 2007 im Fachbereich Informatik - Internet, neue Technologien, Note: 1,3, Fachhochschule Heidelberg, Sprache: Deutsch, Abstract: Network coding describes a technique to perform coding operations on packet contents throughout the network, increasing the information density of a single transmission and therefore increasing network throughput. This book describes the portation of an application of network coding onto an embedded linux. It therefore describes the software COPE, which is a network coding implementation based on the modular software router CLICK. This router is also introduced. Then the book explains the embedded Linux system OpenWRT and the portation of a software onto that system as well as the compilation and deployment of a new firmware image. Then the experiment and its results are explained. The work then introduces novel schemes of network coding based on the idea behind COPE. These schemes are based on the improvement of resience rather than throughput.
Download or read book Priority Based Data Transmission in Wireless Networks Using Network Coding written by Pouya Ostovari and published by . This book was released on 2015 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapid development of mobile devices technology, they are becoming very popular and a part of our everyday lives. These devices, which are equipped with wireless radios, such as cellular and WiFi radios, affect almost every aspect of our lives. People use smartphone and tablets to access the Internet, watch videos, chat with their friends, and etc. The wireless connections that these devices provide is more convenient than the wired connections. However, there are two main challenges in wireless networks: error-prone wireless links and network resources limitation. Network coding is widely used to provide reliable data transmission and to use the network resources efficiently. Network coding is a technique in which the original packets are mixed together using algebraic operations. In this dissertation, we study the applications of network coding in making the wireless transmissions robust against transmission errors and in efficient resource management. In many types of data, the importance of different parts of the data are different. For instance, in the case of numeric data, the importance of the data decreases from the most significant to the least significant bit. Also, in multi-layer videos, the importance of the packets in different layers of the videos are not the same. We propose novel data transmission methods in wireless networks that considers the unequal importance of the different parts of the data. In order to provide robust data transmissions and use the limited resources efficiently, we use random linear network coding technique, which is a type of network coding. In the first part of this dissertation, we study the application of network coding in resource management. In order to use the the limited storage of cache nodes efficiently, we propose to use triangular network coding for content distribution. We also design a scalable video-on-demand system, which uses helper nodes and network coding to provide users with their desired video quality. In the second part, we investigate the application of network coding in providing robust wireless transmissions. We propose symbol-level network coding, in which each packet is partitioned to symbols with different importance. We also propose a method that uses network coding to make multi-layer videos robust against transmission errors.
Download or read book Efficient Operation of Coded Packet Networks written by Desmond Siu Men Lun and published by . This book was released on 2006 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Our main contribution for the network coding problem is to give a scheme that achieves the maximum rate of a multicast connection under the given injection rates. As a consequence, the separation of network coding and subgraph selection results in no loss of optimality provided that we are constrained to only coding packets within a single connection. Our main contribution for the subgraph selection problem is to give distributed algorithms that optimally solve the single-connection problem under certain assumptions. Since the scheme we propose for network coding can easily be implemented in a distributed manner, we obtain, by combining the solutions for each of the smaller problems, a distributed approach to the efficient operation problem. We assess the performance of our solution for three problems: minimum-transmission wireless unicast, minimum-weight wireline multicast, and minimum-energy wireless multicast. We find that our solution has the potential to offer significant efficiency improvements over existing techniques in routed packet networks, particularly for multi-hop wireless networks.
Download or read book Recent Developments in Smart Healthcare written by Wenbing Zhao and published by MDPI. This book was released on 2018-03-23 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Smart Healthcare" that was published in Applied Sciences
Download or read book Spatial Audio written by Woon Seng Gan and published by MDPI. This book was released on 2018-03-23 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Spatial Audio" that was published in Applied Sciences
Download or read book Network Coding For Star and Mesh Networks written by Juma Ben Saleh and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Network Coding Based Reliable Communication in Wireless Networks written by 代仕芳 and published by . This book was released on 2012 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Network Coding in Relay Networks written by Eduardo Alban and published by VDM Publishing. This book was released on 2008 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission over wireless networks presents multiple technical challenges due to noise, interference, fading, power constraints and bandwidth limitation. Different solutions have been propposed to overcome these issues and some of them are treated here. Cooperative diversity has been proposed as an implementation for networks where terminals are restricted to using physical arrays; this technique implements space diversity by creating virtual antennas arrays with cooperating nodes in order to combat multipath fading. Network Coding recently has been presented as a technique to increase the throughput in multicast networks. Most of the work done on the topic considers an error free transmission and few works have taken into account the errors due to the nature of the wireless channel. This thesis proposes the use of network coding over some scenarios in relay networks, in order to obtain diversity. It also addresses some cooperative protocols and their performance in terms of bit error rate. Reliability criteria based on channel information are established for a practical network implementation. In short, we propose a scheme for a wireless network using ideas based on network coding.
Download or read book Research Highlights written by Iowa State University. Department of Electrical and Computer Engineering and published by . This book was released on 2010 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
