A Cross-layer Quality-oriented Energy-efficient Scheme for Multimedia Delivery in Wireless Local Area Networks PDF Download

Author: Yang Song
Publisher:
ISBN:
Category :
Languages : en
Pages : 273

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Author: Shengyang Chen
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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The wireless communication technology has been developed focusing on fulfilling the demand in various parts of human life. In many real-life cases, this demand directs to most types of commonly-used rich-media applications which - with diverse traffic patterns - often require high quality levels on the devices of wireless network users. Deliveries of applications with different patterns are accomplished using heterogeneous wireless networks using multiple types of wireless network structure simultaneously. Meanwhile, content deliveries with assuring quality involve increased energy consumption on wireless network devices and highly challenge their limited power resources. As a result, many efforts have been invested aiming at high-quality and energy-efficient rich-media content deliveries in the past years. The research work presented in the thesis focuses on developing energy-aware content delivery schemes in heterogeneous wireless networks. This thesis has four major contributions outlined below: 1. An energy-aware mesh router duty cycle management scheme (AOC-MAC) for high-quality video deliveries over wireless mesh networks. AOC-MAC manages the sleep-periods of mesh devices based on link-state communication condition, reducing their energy consumption by extending their sleep-periods. 2. An energy efficient routing algorithm (E-Mesh) for high-quality video deliveries over wireless mesh networks. E-Mesh evolves an innovative energy-aware OLSR-based routing algorithm by taking energy consumption, router position and network load into consideration. 3. An energy-aware multi-flow-based traffic load balancing scheme (eMTCP) for multi-path content delivery over heterogeneous wireless networks. The scheme makes use of the MPTCP protocol at the upper transport layer of network, allowing data streams to be delivered across multiple consequent paths. Meanwhile, this benefit of MPTCP is also balanced with energy consumption awareness by partially off-loading traffic from the paths with higher energy cost to others. 4. A MPTCP-based traffic-characteristic-aware load balancing mechanism (eMTCP-BT) for heterogeneous wireless networks. In eMTCP-BT, mobile applications are categorized according to burstiness level. eMTCP-BT increases the energy efficiency of the application content deliveries by performing a MDP-based distribution of traffic delivery via the available wireless network interfaces and paths based on the traffic burstiness level.

Author:
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Category : Electronic books
Languages : en
Pages : 33

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Although computing and battery technology has improved for mobile devices, the advancement in battery technology is falling behind that of computing technology. Also, as more and more people are using mobile devices throughout everyday and for more applications, such as uploading or downloading multimedia directly on mobile devices, improving energy efficiency for this is necessary to prolong battery usage and life. This thesis presents a cross-layer scheduling approach for Quality of Experience (QoE) oriented energy efficiency in multimedia uplink communications for mobile device networks. We study the energy-quality tradeoffs and apply our strategy to the network communication model of a transmitter device to an access-point via a relay device. The strategy also incorporates some simple game theory concepts to determine the best compromise of the energy-quality tradeoff between the transmitter and relay. We investigate the different communication data rates of the standard IEEE 802.11b network protocol and various frame level dependency to examine their effects on energy efficiency and QoE.

Author: Guowang Miao
Publisher:
ISBN:
Category : Ad hoc networks (Computer networks)
Languages : en
Pages :

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The future success of communication networks hinges on the ability to overcome the mismatch between requested quality of service (QoS) and limited network resources. Spectrum is a natural resource that cannot be replenished and therefore must be used efficiently. On the other hand, energy efficiency (EE) is also becoming increasingly important as battery technology has not kept up with the growing requirements stemming from ubiquitous multimedia applications. The qualities of wireless channels vary with both time and user. We use channel state information (CSI) to dynamically assign wireless resources to users to improve spectral and energy efficiency. We first investigate a series of general treatments of exploiting CSI in a distributed way to control the medium access to maximize spectral efficiency for networks with arbitrary topologies and traffic distributions. As the first step, we propose decentralized optimization for multichannel random access (DOMRA), which uses local CSI and two-hop static neighborhood information to achieve performance comparable with the global optimal channel-aware Aloha. The generic framework developed in DOMRA proved to be very useful in improving cellular networks as well. We develop cochannel interference avoidance (CIA) medium access control (MAC), which is optimized by DOMRA, to mitigate the downlink severe cochannel interference that is usually experienced by cell-edge users. Aloha-based schemes have low channel utilization efficiency because of the collision of entire data frames. We further develop channel-aware distributed MAC (CAD-MAC), which avoids collision through signaling negotiation ahead of data transmission. CAD-MAC completely resolves the contention of networks with arbitrary topologies, achieves throughput close to centralized schedulers, and is robust to any channel uncertainty. Then we address energy-efficient wireless communications while emphasizing orthogonal frequency multiple access (OFDMA) systems. We first discover the global optimal energy-efficient link adaptation in frequency-selective channels using the strict quasiconcavity of energy efficiency functions. This link adaptation optimally balances the power consumption of electronic circuits and that of data transmission on each subchannel. The global optimal energy-efficient transmission can be obtained using iterative operations, which may be complex to be implemented in a practical system. Besides, running iterative algorithms consumes additional energy. Hence, we further develop a closed-form link adaptation scheme, which performs close to the global optimum. Besides, since subchannel allocation in OFDMA systems determines the energy efficiency of all users, we develop closed-form resource allocation approaches that achieve near-optimal performance too. In an interference-free environment, a tradeoff between EE and spectral efficiency (SE) exists, as increasing transmit power always improves SE but not necessarily EE. We continue the investigation in interference-limited scenarios and show that since increased transmit power also brings higher interference to the network, SE is not necessarily higher and the tradeoff is improved. Especially, in interference-dominated regimes, e.g., local area networks, both spectral- and energy-efficient communications desire optimized time-division protocols and the proposed DOMRA, CIA-MAC, and CAD-MAC can be used to improve both spectral and energy efficiency.

Author: Fadi Al-Turjman
Publisher: CRC Press
ISBN: 0429663633
Category : Computers
Languages : en
Pages : 194

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Smart Cities and intelligence are among the most significant topics in IoT. Intelligence in communication and infrastructure implementation is at the heart of this concept, and its development is a key issue in smart cities. This book addresses the challenges in realizing intelligence in smart cities and sensing platforms in the era of cloud computing and IoT, varying from cost and energy efficiency to availability and service quality. It focuses on both the design and implementation aspects of artificial intelligence approaches in smart cities and sensing applications that are enabled and supported by IoT paradigms, and mainly on data delivery approaches and their performability aspects.

Author: Darshana M. Garach
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

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Wireless ad hoc networks have been an important area of research since past decade. They are self-organized, rapidly deployable and require no fixed infrastructure. They are quickly becoming an important part of our modern communication systems with a wide range of applications like personal communications, gaming, military, disaster relief operations, environment monitoring and more. Transmission of data like voice and video has become increasingly popular for such networks. These applications require strict end-to-end delay constraints on data delivery, requiring speedy transmissions by wireless nodes. Various transmission schemes have been proposed to deal with the delay parameter by implementing smart routing techniques, using more power to guarantee delivery, etc. But for battery powered wireless nodes, minimizing energy consumption is of supreme importance. In absence of strategic transmission schemes the energy consumption of such nodes transmitting delay critical data is very high. Minimizing energy consumption without affecting communication activities is crucial to prolong the lifetime and improve robustness of the network. The power-delay trade-off is hence an important factor in designing the transmission schemes for such networks. Most of the techniques proposed to deal with this trade-off follow the layered approach of the OSI model, which was primarily created with a wired architecture in mind. Characteristics such as absence of a central authority, links subject to multiple access, fading, interference and limited power availability exacerbate the variance of network conditions and bring greater challenges for multimedia delivery. This situation causes interdependencies across the network layers, unlike their wire-line counterparts. Recent studies indicate that power management for ad-hoc networks can be significantly improved using a cross-layer design in which different layers of the OSI stack are jointly optimized for performance. Our approach discusses a cross layer collaboration achieved by a synergy between Application, MAC and PHY layers to serve delay critical applications energy efficiently. We propose a data transmission scheme based upon the channel condition, the power constraint of an individual node and the delay constraint of the data that is being transmitted. We formulate an optimization problem and solve it using dynamic programming techniques for calculating the optimal transmission policy. We provide Matlab simulation results along with simulations performed on the Ns2 network simulator to study the energy-delay tradeoffs in a delay constrained ad hoc network environment. Additionally, we compare the benefits of our transmission policy to a scheme without the benefits of cross-layer network parameter information.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 166

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The layered architecture based on OSI model has been widely used in wired networks. Due to the dynamics of wireless medium and the node mobility, many special problems appear in wireless networks, which prevent the conventional layered architecture from functioning optimally in wireless environment. In this thesis, we study the wireless networks from different perspectives. Our objective is to systematically develop network protocols and architecture to address various limitations of wireless systems by assuming a cross-layer approach. Firstly, we develop an energy consumption model for wireless ad hoc networks. In existing work, transmission power is commonly used to represent energy consumption cost. In this study, we analyze possible energy consumptions in physical layer, MAC layer (such as signaling packets), and upper layers (such as end-to-end retransmission), and propose more accurate models to capture the energy consumption cost due to different factors. Secondly, based on the energy consumption model, we design an energy efficient routing protocol. The existing energy efficient routing protocols only focus on the search of the most energy efficient path. However, there are many problems in these protocols, including broadcast storm issue, long setup delay, and poor performance in mobility scenario. In this study, we propose an efficient method for estimating the accurate link cost, a quick path searching scheme to find the energy efficient path, and an efficient maintenance scheme to adjust the path according to the environment. Thirdly, we perform the cross-layer design for multiple-channel multiple-interface network to improve the throughput. Current MAC and routing protocols are mainly developed for only one channel and the existing wireless devices are equipped with only one wireless interface. In this study, we design a unified MAC and routing framework to exploit the benefits enabled by the multiple channels to improve the capacity of ad hoc networks. Our joint channel assignment and routing scheme searches for an efficient transmission path, while taking into account the limited number of channels/interfaces, local topology information, and link rate diversity. Our scheduling scheme at MAC layer coordinates transmissions within the vicinity over a short time scale to maximize channel usage and avoid collision among nodes sharing the same channel. The scheduling scheme complemented with prioritized transmitting will also coordinate interface switching to avoid unnecessary switching delay, support load balancing, reduce the broadcast delay and further improve throughput in a multi-channel multi-interface environment.

Author: Yang Xiao
Publisher: CRC Press
ISBN: 1420067125
Category : Computers
Languages : en
Pages : 352

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Book Description
A detailed review of underwater channel characteristics, Underwater Acoustic Sensor Networks investigates the fundamental aspects of underwater communication. Prominent researchers from around the world consider contemporary challenges in the development of underwater acoustic sensor networks (UW-ASNs) and introduce a cross-layer approach for effec

Author: Zhengguo Sheng
Publisher: CRC Press
ISBN: 1482238225
Category : Computers
Languages : en
Pages : 216

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Book Description
Compared with conventional communications, cooperative communication allows multiple users in a wireless network to coordinate their packet transmissions and share each other's resources, thus achieving high-performance gain and better service coverage and reliability. Energy Efficient Cooperative Wireless Communication and Networks provides a comp

Author: Mahdi Asefi
Publisher:
ISBN:
Category :
Languages : en
Pages : 167

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The emerging vehicular ad-hoc networks (VANETs) offer a variety of applications and new potential markets related to safety, convenience and entertainment, however, they suffer from a number of challenges not shared so deeply by other types of existing networks, particularly, in terms of mobility of nodes, and end-to-end quality of service (QoS) provision. Although several existing works in the literature have attempted to provide efficient protocols at different layers targeted mostly for safety applications, there remain many barriers to be overcome in order to constrain the widespread use of such networks for non-safety applications, specifically, for video streaming: 1) impact of high speed mobility of nodes on end-to-end QoS provision; 2) cross-layer protocol design while keeping low computational complexity; 3) considering customer-oriented QoS metrics in the design of protocols; and 4) maintaining seamless single-hop and multi-hop connection between the destination vehicle and the road side unit (RSU) while network is moving. This thesis addresses each of the above limitations in design of cross-layer protocols for video streaming application. 1) An adaptive MAC retransmission limit selection scheme is proposed to improve the performance of IEEE 802.11p standard MAC protocol for video streaming applications over VANETs. A multi-objective optimization framework, which jointly minimizes the probability of playback freezes and start-up delay of the streamed video at the destination vehicle by tuning the MAC retransmission limit with respect to channel statistics as well as packet transmission rate, is applied at road side unit (RSU). Two-hop transmission is applied in zones in which the destination vehicle is not within the transmission range of any RSU. In the multi-hop scenario, we discuss the computation of access probability used in the MAC adaptation scheme and propose a cross-layer path selection scheme; 2) We take advantage of similarity between multi-hop urban VANETs in dense traffic conditions and mesh connected networks. First, we investigate an application-centric routing scheme for video streaming over mesh connected overlays. Next, we introduce the challenges of urban VANETs compared to mesh networks and extend the proposed scheme in mesh network into a protocol for urban VANETs. A classfication-based method is proposed to select an optimal path for video streaming over multi-hop mesh networks. The novelty is to translate the path selection over multi-hop networks to a standard classification problem. The classification is based on minimizing average video packet distortion at the receiving nodes. The classifiers are trained offline using a vast collection of video sequences and wireless channel conditions in order to yield optimal performance during real time path selection. Our method substantially reduces the complexity of conventional exhaustive optimization methods and results in high quality (low distortion). Next, we propose an application-centric routing scheme for real-time video transmission over urban multi-hop vehicular ad-hoc network (VANET) scenarios. Queuing based mobility model, spatial traffic distribution and prob- ability of connectivity for sparse and dense VANET scenarios are taken into consideration in designing the routing protocol. Numerical results demonstrate the gain achieved by the proposed routing scheme versus geographic greedy forwarding in terms of video frame distortion and streaming start-up delay in several urban communication scenarios for various vehicle entrance rate and traffic densities; and 3) finally, the proposed quality-driven routing scheme for delivering video streams is combined with a novel IP management scheme. The routing scheme aims to optimize the visual quality of the transmitted video frames by minimizing the distortion, the start-up delay, and the frequency of the streaming freezes. As the destination vehicle is in motion, it is unrealistic to assume that the vehicle will remain connected to the same access router (AR) for the whole trip. Mobile IP management schemes can beneffit from the proposed multi-hop routing protocol in order to adapt proxy mobile IPv6 (PMIPv6) for multi-hop VANET for video streaming applications. The proposed cross-layer protocols can significantly improve the video streaming quality in terms of the number of streaming freezes and start-up delay over VANETs while achieving low computational complexity by using pattern classification methods for optimization.