检索结果-内蒙古大学图书馆

IEEE Conference on Wireless communications and Networking

作者： Haiyang Ding Daniel B. da Costa Xiaodong Wang Ugo S. Dias Rafael T. de Sousa Jianhua Ge State Key Laboratory of Integrated Service Networks Xi' an Communication Institute Xi'an China Department of Computer Engineering Federal University of Ceará (UFC) Sobral CE Brazil Department of Electrical Engineering Columbia University NY USA Department of Electrical Engineering University of Brasília DF Brazil

In this paper, considering a mixed Rician and Rayleigh fading environment, we investigate the impact of line-of-sight (LOS) path component on the outage performance of dual-hop energy harvesting (EH) amplify-and-forward (AF) relay systems. To this end, a tight asymptotic outage lower bound expression is derived, which reveals that the system diversity order is limited to one and the outage behavior decays as log(SNR)/SNR, with SNR denoting the transmit signal-to-noise ratio (SNR) at the source. In contrast, when the LOS path component in the first-hop link becomes very strong (i.e., a large Rician K factor), our analytical results show that the easing-off factor log(SNR) can be effectively eliminated, becoming the decaying rate of outage curves steeper in this case and, consequently, improving the end-to-end transmission robustness since the outage curves scale as 1/SNR at high SNR regions.

关键词： Relays Signal to noise ratio Rician channels Wireless communication Energy harvesting Rayleigh channels

来源：评论

学校读者我要写书评

暂无评论

Modelling cyber security for software-defined networks those grow strong when exposed to threats: Analysis and propositions

引用

Journal of Reliable Intelligent Environments 2015年第2-4期1卷 123-146页

作者： Ahmed, Usama Raza, Imran Hussain, Syed Asad Ali, Amjad Iqbal, Muddesar Wang, Xinheng Department of Computer Science Communication and Networks Research Centre COMSATS Institute of Information Technology Lahore Pakistan Department of Software Engineering Government College University Faisalabad Pakistan Pak-UK Institute of Innovative Technologies for Disaster Management University of Gujrat Gujrat Pakistan

With each passing day, the information and communication technologies are evolving with more and more information shared across the globe using the internet superhighway. The threats to information, while connected to the cyber world are getting more targeted, voluminous, and sophisticated requiring new antifragile and resilient network security mechanisms. Whether the information is being processed in the application, in transit within the network or residing in the storage, it is equally susceptible to attack at every level of abstraction and cannot be handled in isolation as the case has been with conventional security mechanisms. The advent of Software-Defined networks (SDN) has given a new outlook to information protection, where the network can aid in the design of a system that is secure and dependable in case of cyber threats. The nature of SDN, mainly its programmability and centrality of network information and control has led us to think of security in an antifragile perspective. Our networks can now thrive and grow stronger when they are exposed to volatility by overwhelming cyber threats. However, SDN infrastructure itself is susceptible to severe threats that may mutilate the provision of its usability as security provider. Both these perspectives of "Security with SDN" and "Security for SDN" have invited research and innovations, yet both these approaches remain disintegrated, failing to support each other. The contribution of this paper is threefold, with first reviewing the current state of the art work for both perspectives of SDN security. Second, it advocates the necessity and introduces a novel approach of antifragile cyber security within SDN paradigm and finally it proposes a unified model for integrating both approaches of "Security with SDN" and "Security for SDN" to achieve the overall objective of protecting our information from cyber threats in this globally connected internetwork. © 2015, Springer International Publishing Switzerland.

关键词： Cybersecurity

来源：评论

学校读者我要写书评

暂无评论

YouQoS – Combining quality of service with network neutrality

YouQoS – Combining quality of service with network neutrali...

引用

9. ITG-Fachkonferenz Breitbandversorgung in Deutschland - 9th ITG Conference on Broadband Coverage in Germany

作者： Liss, Christian Fendler, Tamas Gajic, Danica Vensmer, Alexander InnoRoute GmbH Marsstr. 14a Munich80335 Germany Institute of Communication Networks and Computer Engineering University of Stuttgart Stuttgart70569 Germany

ISBN: (纸本)9783800739257

Broadband Internet connectivity is often limited by the last mile, which’s average achievable data rate is rising only slowly. Quality of Service (QoS) measures to improve on existing lines may easily violate regulatory rules for privacy and network neutrality. YouQoS is a concept for user-controlled traffic management, which preserves privacy and network neutrality, while offering supreme Quality of Service especially in downstream direction. The idea is that users provide information on general preferences and situation-specific needs that an arbiter in the network uses to send flow configuration commands to the respective access network equipment. The arbiter, called the YouQoS Server, is a broker that on the one hand prevents user-provided private information from leaking, and on the other hand prevents the creation of malicious commands towards network operator equipment. In future Software-Defined Access networks (SDAN) the only remaining physical devices will be simplified Software-Defined Network (SDN) Datapaths. To investigate options for YouQoS usage together with those SDN Datapaths, the YouQoS Box was defined. It implements all necessary YouQoS functionalities, like packet inspection, QoS marking, and shaping, in order to identify the most efficient function splits. With this device, it will be possible to add advanced functionality and full visibility to QoS experimentation. The YouQoS Box might even be added to current access networks between Broadband Remote Access Server (BRAS) and DSL Access Multiplexer (DSLAM) to provide the YouQoS service. © VDE VERLAG GMBH ∙ Berlin ∙ Offenbach

关键词： Quality of service

来源：评论

学校读者我要写书评

暂无评论

Performance and energy efficiency of parallel processing in data center environments

Lecture Notes in Computer Science (including subseries Lectu...

引用

Lecture Notes in computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2015年 8945卷 17-33页

作者： Kuehn, Paul J. Institute of Communication Networks and Computer Engineering University of Stuttgart Stuttgart Germany

ISBN: (纸本)9783319157856

A novel approach is presented for the analysis of parallel processing of stochastic workload by multi-processor/multi-core processing resources in data center environments. The method is based on job workload descriptions by task graphs with generally-distributed task execution times and task scheduling under consideration of prescribed precedence and synchronization constraints. For the analytic performance evaluation, task graphs are restricted to the analysis of directed acyclic graphs which are reduced by stepwise aggregations of tasks. The reduction allows to aggregate the whole task graph under a given number n of processing elements to a single virtual job processing time with average value hv and coefficient of variation cv. By this way, the whole multi-processor system can be modeled by a queuing system of type GI/G/1 from which the response time TR and the speedup factor S(n) is derived. Finally, the influence of the stochastic properties of the workload on the performance and on energy efficiency of parallel computing will be studied and compared with serial computing on a multi-processor system modeled by a queuing system of the type M/G/n. © Springer International Publishing Switzerland 2015.

关键词： Energy efficiency

来源：评论

学校读者我要写书评

暂无评论

Approaches to Adaptively Reduce Processing Effort for LTE Cloud-RAN Systems

Approaches to Adaptively Reduce Processing Effort for LTE Cl...

引用

International Conference on communication Workshop

作者： Thomas Werthmann Institute of Communication Networks and Computer Engineering University of Stuttgart Germany

Cloud-RAN is a novel architecture for LTE networks, where antennas with only limited processing capabilities are deployed in the field and all baseband and higher layer processing of the base stations is pooled in a central office. It has been shown that the centralization leads to multiplexing gains for signal processing hardware. When a system is able to efficiently cope with overload of the compute resources, significant savings are possible. This allows to install less resources (saving Capital Expenditure, CAPEX) and to switch off more resources during low-load periods (saving Operational Expenditure, OPEX). In this publication, the resource allocation of a system of LTE base stations is formulated as an optimization problem. The formulation includes the reduction of interference by not using radio resources for transmission and the flexibility of using different MIMO modes. The results of optimization runs are evaluated. They show that about 50 % of the compute resources can be saved without impacting the system performance. In overload situations, only 20 % of the resources are sufficient to deliver 87 % of the system performance. The most efficient approach to reduce processing effort is to adapt the MIMO mode and to reduce the number of virtual transmit antennas.

关键词： LTE Cloud-RAN Systems OPEX

来源：评论

学校读者我要写书评

暂无评论

Flexible performance prediction of data center networks using automatically generated simulation models 8

Flexible performance prediction of data center networks usin...

引用

8th EAI International Conference on Simulation Tools and Techniques, SIMUTOOLS 2015

作者： Rygielski, Piotr Kounev, Samuel Tran-Gia, Phuoc Department of Software Engineering Institute of Computer Science University of Würzburg Am Hubland Würzburg97074 Germany Department of Communication Networks Institute of Computer Science University of Würzburg Am Hubland Würzburg97074 Germany

ISBN: (纸本)9781631900792

Using different modeling and simulation approaches for predicting network performance requires extensive experience and involves a number of time consuming manual steps regarding each of the modeling formalisms. In this paper, we propose a generic approach to modeling the performance of data center networks. The approach offers multiple performance models but requires to use only a single modeling language. We propose a two-step modeling methodology, in which a high-level descriptive model of the network is built in the first step, and in the second step model-to-model transformations are used to automatically transform the descriptive model to different network simulation models. We automatically generate three performance models defined at different levels of abstraction to analyze network throughput. By offering multiple simulation models in parallel, we provide flexibility in trading-off between the modeling accuracy and the simulation overhead. We analyze the simulation models by comparing the prediction accuracy with respect to the simulation duration. We observe, that in the investigated scenarios the solution duration of coarser simulation models is up to 300 times shorter, whereas the average prediction accuracy decreases only by 4 percent. Copyright © 2015 ICST.

关键词： Modeling languages

来源：评论

学校读者我要写书评

暂无评论

5G entering into a new era [Guest Editorial]

引用

China communications 2017年第12期14卷 iv-vi页

作者： Feifei Gao Changle Li Jun Fang Kaizhi Huang Zhi Quan Chengwen Xing Jianhua Zhang Zhongshan Zhang Liqiang Zhao Yulong Zou Department of Automation Tsinghua University Beijing China State Key Laboratory of Integrated Services Networks Xidian University University of Eletronic Science and Technology of China National Digital Switching System Engineering & Technological Research Center Zhengzhou China College of Information Engineering Shenzhen University School of Information and Electronics Beijing Institute of Technology Beijing University of Posts and Telecommunication School of Computer and Communication Engineering in the University of Science and Technology Beijing State Key Lab. of Integrated Service Networks Xidian University Nanjing University of Posts and Telecommunications (NUPT) Nanjing China

The ever increasing wireless data services, such as imaging, video, audio, multimedia, etc., have demands for the very high speed wireless communications and network, which are unfortunately a bottleneck when combining with the wireline core network. Users' are now expecting high quality of experience with low-cost devices, ubiquitous connectivity, energy efficiency, high reliability, or even ultra-low latency if a vehicle terminal is applied.

关键词：

来源：评论

学校读者我要写书评

暂无评论

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 Antwerp, Belgium. 15-20 July 2017 Abstracts

引用

BMC NEUROSCIENCE 2017年第SUPPL 1期18卷 95-176页

作者： [Anonymous] Department of Neuroscience Yale University New Haven CT 06520 USA Department Physiology & Pharmacology SUNY Downstate Brooklyn NY 11203 USA NYU School of Engineering 6 MetroTech Center Brooklyn NY 11201 USA Departament de Matemàtica Aplicada Universitat Politècnica de Catalunya Barcelona 08028 Spain Institut de Neurobiologie de la Méditerrannée (INMED) INSERM UMR901 Aix-Marseille Univ Marseille France Center of Neural Science New York University New York NY USA Aix-Marseille Univ INSERM INS Inst Neurosci Syst Marseille France Laboratoire de Physique Théorique et Modélisation CNRS UMR 8089 Université de Cergy-Pontoise 95300 Cergy-Pontoise Cedex France Department of Mathematics and Computer Science ENSAT Abdelmalek Essaadi’s University Tangier Morocco Laboratory of Natural Computation Department of Information and Electrical Engineering and Applied Mathematics University of Salerno 84084 Fisciano SA Italy Department of Medicine University of Salerno 84083 Lancusi SA Italy Dipartimento di Fisica Università degli Studi Aldo Moro Bari and INFN Sezione Di Bari Italy Data Analysis Department Ghent University Ghent Belgium Coma Science Group University of Liège Liège Belgium Cruces Hospital and Ikerbasque Research Center Bilbao Spain BIOtech Department of Industrial Engineering University of Trento and IRCS-PAT FBK 38010 Trento Italy Department of Data Analysis Ghent University Ghent 9000 Belgium The Wellcome Trust Centre for Neuroimaging University College London London WC1N 3BG UK Department of Electronic Engineering NED University of Engineering and Technology Karachi Pakistan Blue Brain Project École Polytechnique Fédérale de Lausanne Lausanne Switzerland Departement of Mathematics Swansea University Swansea Wales UK Laboratory for Topology and Neuroscience at the Brain Mind Institute École polytechnique fédérale de Lausanne Lausanne Switzerland Institute of Mathematics University of Aberdeen Aberdeen Scotland UK Department of Integrativ

来源：评论

学校读者我要写书评

暂无评论

Evaluation of data-center architectures for virtualized Network Functions

Evaluation of data-center architectures for virtualized Netw...

引用

IEEE International Conference on communications Workshops, ICC

作者： Sandra Herker Xueli An Wolfgang Kiess Andreas Kirstädter DOCOMO Communications Laboratories Europe GmbH Munich Germany Institute of Communication Networks and Computer Engineering (IKR) University of Stuttgart Germany

Network Functions Virtualization (NFV) is a recent industrial trend which gains a lot of attention from telecom operators and vendors. The NFV concept delivers network services using commercial off-the-shelf hardware and IT virtualization technologies, thus virtualizing entire classes of network node functions. Traditional and recent data-center architectures are mostly built and optimized for data storage or web based applications. However, NFV type applications have different characteristics with respect to network load and needed computing capacity, which may impact the data-center design. Therefore in this paper, we are motivated to model the characteristics of NFV type applications and investigate the suitability of current data-center architectures for such new applications.

关键词： Servers Topology computer architecture Bandwidth Ports (computers) Conferences Cloud computing

来源：评论

学校读者我要写书评

暂无评论

Data-Center Architecture Impacts on Virtualized Network Functions Service Chain Embedding with High Availability Requirements

Data-Center Architecture Impacts on Virtualized Network Func...

引用

IEEE Globecom Workshops

作者： Sandra Herker Xueli An Wolfgang Kiess Sergio Beker Andreas Kirstaedter Institute of Communication Networks and Computer Engineering (IKR) University of Stuttgart Germany DOCOMO Communications Laboratories Europe GmbH Munich Germany

ISBN: (纸本)9781467395274

Network Functions Virtualization (NFV) is a recent networking trend gaining a lot of attention from telecom operators and vendors. It promises to virtualize entire classes of network node functions within a data-center and to deliver network services in the form of Virtualized Network Function (VNF) service chains using commercial off-the-shelf hardware and IT virtualization technologies. However, availability gets an important issue when purpose-built telecom hardware designed for the "fives nines" standard via built-in failure protection and recovery mechanisms is replaced by the off-the shelf hardware. With commercial off-the-shelf data-center hardware, failure probabilities could be higher than in traditional physical network infrastructure. Thus with NFV, infrastructure availability has to be considered all the way from the physical right up to the hypervisor layer and resilience mechanisms need to be built into the software and service provisioning design. In this work, we model different backup strategies for VNF service chains and provide algorithms for their resilient embedding in the data-center. Further, we answer the question which data-center topologies offer the best cost-per-throughput relation for a given resilience/availability for VNF service chains.

关键词： Impacts Virtualized Network

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：