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Energy-Aware Cooperative Wireless networks with Multiple Cognitive Users

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Energy-Aware Cooperative Wireless Networks with Multiple Cog...

作者： Ashour, Mahmoud Butt, Muhammad Majid Mohamed, Amr ElBatt, Tamer Krunz, Marwan Computer Science and Engineering Department Qatar University Doha2713 Qatar Department of Electrical Engineering and Computer Science Pennsylvania State University State CollegePA16801 United States Center for Future Networks Trinity College University of Dublin Dublin 2 Ireland Electronics and Communication Engineering Department Faculty of Engineering Cairo University Cairo12613 Egypt Wireless Intelligent Networks Center Nile University Cairo12677 Egypt Department of Electrical and Computer Engineering University of Arizona TucsonAZ85721 United States

In this paper, we study and analyze cooperative cognitive radio networks with arbitrary number of secondary users (SUs). Each SU is considered a prospective relay for the primary user (PU) besides having its own data transmission demand. We consider a multi-packet transmission framework that allows multiple SUs to transmit simultaneously because of dirty-paper coding. We propose power allocation and scheduling policies that optimize the throughput for both PU and SU with minimum energy expenditure. The performance of the system is evaluated in terms of throughput and delay under different opportunistic relay selection policies. Toward this objective, we present a mathematical framework for deriving stability conditions for all queues in the system. Consequently, the throughput of both primary and secondary links is quantified. Furthermore, a moment generating function approach is employed to derive a closed-form expression for the average delay encountered by the PU packets. Results reveal that we achieve better performance in terms of throughput and delay at lower energy cost as compared with equal power allocation schemes proposed earlier in the literature. Extensive simulations are conducted to validate our theoretical findings. © 2016 IEEE.

关键词： Throughput

UCDC: Unlimited Content-Defined Chunking, A File-Differing Method Apply to File-Synchronization among Multiple Hosts

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UCDC: Unlimited Content-Defined Chunking, A File-Differing M...

International Conference on Semantics, Knowledge and Grid (SKG)

作者： Jihong Ma Chongguang Bi Yuebin Bai Lijun Zhang Science and Technology on Information Transmission Dissemination in Communication Networks Lahoratory Shijiazhuang China School of Computer Science and Engineering Beihang University Beijing China

ISBN: (纸本)9781509047963

Nowadays, the data centric system has been playing an increasingly important role in blogs sharing, content delivery and news broadcasting, file-synchronization, and so on. Due to generated amount of data within the system, data backup and archiving has become a main challenging task. A main methods to solve the problem is Chunking based deduplication by eliminating redundant data and reducing the total storage space. In this paper, we summarized several ways of file-differing, and then designs a new Unlimited Content-Defined Chunking (UCDC) algorithm, which contains file-chunking, file-comparing and file-merging. We evaluate the effectiveness of the UCDC by simulation example that produces the description of file.

关键词： Algorithm design and analysis computers Blogs Broadcasting Semantics computer science Information processing

Taxonomy and issues for antifragile-based multimedia cloud computing

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Journal of Reliable Intelligent Environments 2016年第1期2卷 37-49页

作者： Haider, Syed Fawad Abbas, Laraib Ali, Amjad Iqbal, Muddesar Raza, Imran Hussain, Syed Asad Suh, Doug Young Faculty of Computing and Information Technology University of Gujrat Gujrat Pakistan Department of Computer Science Communication and Networks Research Centre COMSATS Institute of Information Technology Lahore Pakistan Pak-UK Institute of Innovative Technologies for Disaster Management University of Gujrat Gujrat Pakistan Department of Electronics and Radio Engineering College of Electronics and Information Kyung Hee University Yongin446-701 Korea Republic of

Cloud computing has become one of the most dynamic and adoptable computing paradigms. Multimedia Cloud Computing (MCC) is one of today’s hot research topic. MCC is proven to be a most dynamic and efficient platform for managing a large amount of multimedia contents with maximum deployment of computing and processing resources at the service provider instead of users. Resilience and dependability are two key constituents to assure the reliability and availability of any service in the presence of errors and system failures. The heterogeneous environment of MCC has given rise to various challenges related to resource allocation and task management. Antifragility is a key to such environments, to let the disorder drive the strength of these systems. This paper is mainly divided into three parts. The first part discusses in detail the available state-of-the-art related to resource management under MCC. Similarly, the second part presents the comprehensive literature review on the task management in MCC. The third part presents the critical analysis and open research issues in MCC which help the researcher to define their research objectives in the field of MCC. © 2016, Springer International Publishing Switzerland.

关键词： Quality of service

Negative exponential behavior of image mutual information for pseudo-thermal light ghost imaging: Observation, modeling, and verification

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arXiv 2017年

作者： Li, Junhui Luo, Bin Yang, Dongyue Yin, Longfei Wu, Guohua Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China

When use the image mutual information to assess the quality of reconstructed image in pseudo-thermal light ghost imaging, a negative exponential behavior with respect to the measurement number is observed. Based on information theory and a few simple and verifiable assumptions, semi-quantitative model of image mutual information under varying measurement numbers is established. It is the Gaussian characteristics of the bucket detector output probability distribution that leads to this negative exponential behavior. Designed experiments verify the model. Copyright © 2017, The Authors. All rights reserved.

关键词： Probability distributions

Sidebands suppression of 852 nm Cesium Faraday anomalous dispersion optical filter by argon gas

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arXiv 2017年

作者： Xiong, Junyu Yin, Longfei Luo, Bin Chen, Jingbiao Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China

In this work, sidebands suppression induced by the buffer gas argon (Ar) in 852 nm cesium Faraday anomalous dispersion optical filter (FADOF) is investigated. FADOF performances at different Ar pressures (0 torr, 1 torr, 5 torr and 10 torr) are compared, and a single-peak transmittance spectrum with peak transmittance up to 80% is achieved when the pressure of Ar reaches 5 torr. A detailed analysis shows that, this sidebands suppression comes from the depopulation enhancement by the buffer gas. This result can be generalized to other FADOFs with similar level structures such as the D2 lines of other alkali metal atoms. Copyright © 2017, The Authors. All rights reserved.

关键词： Cesium

Binary sampling ghost imaging: Add random noise to fight quantization caused image quality decline

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arXiv 2017年

作者： Li, Junhui Yang, Dongyue Luo, Bin Wu, Guohua Yin, Longfei Guo, Hong State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China

When the sampling data of ghost imaging is recorded with less bits, i.e., experiencing quantization, decline of image quality is observed. The less bits used, the worse image one gets. Dithering, which adds suitable random noise to the raw data before quantization, is proved to be capable of compensating image quality decline effectively, even for the extreme binary sampling case. A brief explanation and parameter optimization of dithering are given. Copyright © 2017, The Authors. All rights reserved.

关键词： Image enhancement

Split-TCP Based Acceleration Gateway over Packet Lossy networks

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China communications 2015年第5期12卷 100-112页

作者： DONG Pingping WANG Jianxin HUANG Jiawei WANG Haodong School of Information Science and Engineering Central South University Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Department of Computer and Information Science Cleveland State University

The conservative Additive Increase Multiplicative Decrease mechanism of traditional TCP causes the link under-utilization in the Wide Area networks(WANs) due to the WANs' intrinsic nature of high latency and high packet *** alleviate the problem,we present the design and implantation of STAG,an Acceleration Gateway with Split-TCP in the *** is built on embedded network equipment and acts as a transparent *** STAG,a new improved congestion control method named Rapid TCP is adopted,which determines whether or not to decrease the congestion window based on the packet loss *** particular,in the fast recovery phase,it chooses different window adjustment strategies based on the current size of congestion window to achieve higher *** performance validation of STAG is done on both our emulation testbed and the real wide area *** results show that STAG with Rapid TCP effectively adapts to the high loss network environment and significantly speeds up the applications without loss of fairness.

关键词： TCP acceleration gateway loss rate embedded network equipment

Marrying safety with privacy: A holistic solution for location privacy in VANETs

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Marrying safety with privacy: A holistic solution for locati...

IEEE Vehicular Networking Conference (VNC)

作者： David Eckhoff Christoph Sommer Computing and Information Systems Department The University of Melbourne Australia Computer Networks and Communication Systems University of Erlangen Germany Dept. of Computer Science Paderborn University Germany

ISBN: (纸本)9781509051984

Existing privacy measures often conflict with the requirements of future vehicular networks. First and foremost, in attempting to achieve local privacy, they interfere with the primary purpose of vehicular networks: to improve road safety. Other solutions undermine accountability or introduce too high overhead to be of practical use. For this reason, proper privacy protection is disregarded in many field experiments, proposals, and standardization documents. In this paper, we take a structured approach to deriving a holistic solution for location privacy protection in Vehicular Ad-Hoc networks (VANETs): Under reasonable assumptions about an adversary's capability, local privacy is neither required nor can it be achieved without compromising traffic safety. Our approach is therefore based on synchronized time-slotted pseudonym pools and the local announcing of pseudonym changes. By this, we overcome the privacy-safety problem while at the same time increasing privacy for all users. Our system is fully compatible with the requirements of vehicular networks and current standardization efforts.

关键词： Privacy Vehicles Safety Proposals Standards Ad hoc networks

Ultrasensitive, high-dynamic-range and broadband strain sensing by time-of-flight detection with femtosecond-laser frequency combs

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arXiv 2017年

作者： Lu, Xing Zhang, Shuangyou Chen, Xing Kwon, Dohyeon Jeon, Chan-Gi Zhang, Zhigang Kim, Jungwon Shi, Kebin State Key Laboratory for Mesoscopic Physics Collaborative Innovation Center of Quantum Matter School of Physics Peking University Beijing100871 China Daejeon34141 Korea Republic of State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer Science Peking University Beijing100871 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan Shanxi030006 China

Ultrahigh-resolution optical strain sensors provide powerful tools in various scientific and engineering fields, ranging from long-baseline interferometers to civil and aerospace industries. Here we demonstrate an ultrahigh-resolution fibre strain sensing method by directly detecting the time-of-flight (TOF) change of the optical pulse train generated from a free-running passively mode-locked laser (MLL) frequency comb. We achieved a local strain resolution of 18 pΕ/Hz1/2 and 1.9 pΕ/Hz1/2 at 1 Hz and 3 kHz, respectively, with large dynamic range of >154 dB at 3 kHz. For remote-point sensing at 1-km distance, 80 pΕ/Hz1/2 (at 1 Hz) and 2.2 pΕ/Hz1/2 (at 3 kHz) resolution is demonstrated. While attaining both ultrahigh resolution and large dynamic range, the demonstrated method can be readily extended for multiple-point sensing as well by taking advantage of the broad optical comb spectra. These advantages may allow various applications of this sensor in geophysical science, structural health monitoring, and underwater science. Copyright © 2017, The Authors. All rights reserved.

关键词： Femtosecond lasers