检索结果-内蒙古大学图书馆

Lowering the energy consumption in silicon photonic devices and systems [Invited]

Photonics Research 2015年第5期3卷 28-46页

作者： Zhiping Zhou Bing Yin Qingzhong Deng Xinbai Li Jishi Cui State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University

We review current silicon photonic devices and their performance in connection with energy *** critical issues are identified to lower energy consumption in devices and systems: reducing the influence of the thermo-optic effect, increasing the wall-plug efficiency of lasers on silicon, optimizing energy performance of modulators, and enhancing the sensitivity of photodetectors. Major conclusions are(1) Mach–Zehnder interferometer-based devices can achieve athermal performance without any extra energy consumption while microrings do not have an efficient passive athermal solution;(2) while direct bonded III–V-based Si lasers can meet system power requirement for now, hetero-epitaxial grown III–V quantum dot lasers are competitive and may be a better option for the future;(3) resonant modulators, especially coupling modulators, are promising for low-energy consumption operation even when the power to stabilize their operation is included;(4) benefiting from high sensitivity and low cost, Ge/Si avalanche photodiode is the most promising photodetector and can be used to effectively reduce the optical link power budget. These analyses and solutions will contribute to further lowering energy consumption to meet aggressive energy demands in future systems.

关键词： Invited Lowering the energy consumption in silicon photonic devices and systems MZI

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

Performance evaluation of network header compression schemes for UDP, RTP and TCP

Periodica polytechnica Electrical engineering and computer s...

引用

Periodica polytechnica Electrical engineering and computer science 2016年第3期60卷 151-162页

作者： Tömösközi, Máté Seeling, Patrick Ekler, Péter Fitzek, Frank H. P. Acticom GmbH Berlin Germany Department of Electronic Systems Aalborg University Denmark Communication Networks Group Technische Universität Dresden Germany Department of Computer Science Central Michigan University Mount PleasantMI48859 United States Department of Automation and Applied Informatics Faculty of Electrical Engineering and Informatics Budapest University of Technology and Economics Hungary

Modern cellular networks utilising the Long-Term Evolution (LTE) set of standards face an ever-increasing demand for mobile data from connected devices. Header compression is employed to minimise the overhead for IP-based cellular network traffic. In this paper, we evaluate the three header compression implementations used by such networks with respect to their potential throughput increase and complexity for different mobile service scenarios. We compare RTP, UDP and TCP profile compressions regarding their compression gain and complexity. Specifically, we consider header compression as defined by (i) IP Header Compression (RFC 2507), (ii) Robust Header Compression version 1 (RFC 3095), and (iii) the recently updated Robust Header Compression version 2 (RFC 5225) with TCP/IP profile (RFC 6846).This paper presents the performance evaluation of these header compression schemes for UDP, RTP and TCP, for both IPv4 and IPv6 streams in error-free and error-prone scenarios. A comparison between the Robust Header Compression methods and IP Header Compression is also provided. Our results show that all implementations have great potential for saving bandwidth in IP-based wireless networks, even under varying channel conditions. We also present for the first time an analysis of certain RTP header fields which, depending on the transmission characteristics, could have high impact on the overall compression gain. © 2016, Technical University of Budapest. All rights reserved.

关键词： Bandwidth

来源：评论

学校读者我要写书评

暂无评论

A Simulator Concept for Cloud Computing Infrastructure

引用

6th International Image Processing and communications Conference, IPandC 2014

作者： Hanczewski, Slawomir Kedzierska, Marta Piechowiak, Maciej Chair of Communication and Computer Networks Poznan University of Technology Polanka 3 60-965 Poznan Poland Institute of Mechanics and Applied Computer Science Kazimierz Wielki University Kopernika 1 85-074 Bydgoszcz Poland

ISBN: (纸本)9783319106618

This paper presents a concept for a simulator for cloud computing environment. According to the assumptions, and in intention, the simulator will make studies on cloud efficiency (from the cloud operator's perspective) possible. One of its possible applications will be then the evaluation of cloud effectiveness in a situation where, for example, new services have been introduced or existing service parameters have been changed. Results obtained by this simulator can be also used in validation and verification of analytical models proposed for a cloud environment. © Springer International Publishing Switzerland 2015.

关键词： Simulators

来源：评论

学校读者我要写书评

暂无评论

Poster: Full-duplex WiFi: Achieving simultaneous sensing and transmission for future wireless networks 15

Poster: Full-duplex WiFi: Achieving simultaneous sensing and...

引用

16th ACM International Symposium on Mobile Ad Hoc Networking and Computing, MobiHoc 2015

作者： Liao, Yun Bian, Kaigui Song, Lingyang Han, Zhu State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electrical Engineering and Computer Science Peking University Beijing China Electrical and Computer Engineering Department University of Houston HoustonTX United States

ISBN: (纸本)9781450334891

With the booming exploitation of WiFi networks based on the conventional CSMA/CA access scheme, the frequent long collision period becomes unbearable. To better utilize the WiFi spectrum, in this poster, we propose a novel WiFi protocol with the assistance of full-duplex (FD) technique that allows users to sense the spectrum while transmitting, and stop transmission once collision is detected. Analytical and simulated results show that the average collision length is sharply reduced and the normalized throughput can be significantly improved by the proposed FD-WiFi protocol compared with the conventional CSMA/CA. Copyright is held by the author/owner(s).

关键词： Wireless local area networks (WLAN)

来源：评论

学校读者我要写书评

暂无评论

73 nJ, 109 fs Yb-doped fiber laser at 19 MHz repetition rate in amplifier similariton regime

引用

Photonics Research 2015年第5期3卷 248-251页

作者： Yizhou Liu Yifan Cui Jian Zhang Aimin Wang Zhigang Zhang State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer Science Peking University

We report femtosecond pulse generation in an amplifier similariton oscillator and a prechirped fiber amplifier system. The final output power is 1.4W, and the fundamental repetition rate is 19.1 MHz after a single sta... 详细信息

关键词： Yb rate fs Yb-doped fiber laser at 19 MHz repetition rate in amplifier similariton regime nJ

来源：评论

学校读者我要写书评

暂无评论

Hyperpolarizability and operational magic wavelength in an optical lattice clock

arXiv

引用

arXiv 2017年

作者： Brown, R.C. Phillips, N.B. Beloy, K. McGrew, W.F. Schioppo, M. Fasano, R.J. Milani, G. Zhang, X. Hinkley, N. Leopardi, H. Yoon, T.H. Nicolodi, D. Fortier, T.M. Ludlow, A.D. National Institute of Standards and Technology 325 Broadway BoulderCO80305 United States University of Colorado Department of Physics BoulderCO80309 United States Georgia Tech Research Institute AtlantaGA30332 United States Stable Laser Systems BoulderCO United States TeddingtonTW11 0LW United Kingdom Istituto Nazionale di Ricerca Metrologica Strada delle Cacce 91 Torino10135 Italy State Key Laboratory of Advanced Optical Communication Systems and Networks Institute of Quantum Electronics School of Electronics Engineering and Computer Science Peking University Beijing100871 China Department of Physics Korea University 145 Anam-ro Seongbuk-gu Seoul02841 Korea Republic of

Optical clocks benefit from tight atomic confinement enabling extended interrogation times as well as Doppler- and recoil-free operation. However, these benefits come at the cost of frequency shifts that, if not properly controlled, may degrade clock accuracy. Numerous theoretical studies have predicted optical lattice clock frequency shifts that scale nonlinearly with trap depth. To experimentally observe and constrain these shifts in an 171Yb optical lattice clock, we construct a lattice enhancement cavity that exaggerates the light shifts. We observe an atomic temperature that is proportional to the optical trap depth, fundamentally altering the scaling of trap-induced light shifts and simplifying their parametrization. We identify an "operational" magic wavelength where frequency shifts are insensitive to changes in trap depth. These measurements and scaling analysis constitute an essential systematic characterization for clock operation at the 10−18 level and beyond. Copyright © 2017, The Authors. All rights reserved.

关键词： Optical lattices

来源：评论

学校读者我要写书评

暂无评论

Crosstalk analysis for closed ring-based optical network-on-chip

Crosstalk analysis for closed ring-based optical network-on-...

引用

IEEE International Conference on communication Problem-Solving, ICCP 2015

作者： Qi, Shixiong Wang, Kun Gu, Huaxi Wang, Kang Wang, Xiaolu State Key Laboratory of Integrated Service Networks Xidian University Xi'an China School of Computer Science and Techonolgy Xidian University Xi'an China Sci. and Techonolgy on Info. Transmiss. and Dissemination in Communication Networks Laboratory Shijiazhuang China

This paper proposes a novel crosstalk analysis model applicable to closed ring-based optical network-on-chip. In order to show how this model is used, an example of analyzing crosstalk noise and SNR in a generic close... 详细信息

ISBN: (纸本)9781467365437

关键词： Network-on-chip

来源：评论

学校读者我要写书评

暂无评论

Survey on cooperative communication in wireless sensor networks

引用

Ruan Jian Xue Bao/Journal of Software 2016年 27卷 71-81页

作者： Wen, Bo Huangfu, Wei Zhang, Zhong-Shan School of Computer and Communication Engineering University of Science and Technology Beijing Beijing100083 China Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services Beijng100083 China

In the exploration of wireless sensor networks, there are two major bottlenecks: lifetime prolonging and resource sharing. The reason that the communication energy consumption is difficult to reduce and the communication resources are also difficult to be virtualized mainly lies in the fact that there is lack of cooperation at the radio-frequency signal level. Cooperative communication technology can obtain the similar space diversity gain as the MIMO (multiple-in multiple-out) systems by the collaboration of single- antenna nodes, which share their antenna with others. The cooperative communication technology in sensor networks introduces a novel key method to break through the two aforementioned bottlenecks. This survey on the techniques of cooperative communication in wireless sensor networks includes the construction of node groups for cooperative communication, the end-to-end transmission with cooperative communication and the system-level optimization. The related technology advances and challenges are also discussed. © Copyright 2016, Institute of Software, the Chinese Academy of sciences. All rights reserved.

关键词： Virtualization

来源：评论

学校读者我要写书评

暂无评论

Social Data Offloading in D2D-Enhanced Cellular networks by Network Formation Games

Social Data Offloading in D2D-Enhanced Cellular Networks by ...

引用

作者： Wang, Tianyu Sun, Yue Song, Lingyang Han, Zhu State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing100871 China Department of Electrical and Computer Engineering University of Houston HoustonTX77004-4005 United States Department of Computer Science University of Houston HoustonTX77204-3010 United States

Recently, cellular networks have become severely overloaded by social-based services, such as YouTube, Facebook, and Twitter, in which thousands of clients subscribe to a common content provider (e.g., a popular singer) and download his/her content updates all the time. Offloading such traffic through complementary networks, such as a delay tolerant network formed by device-to-device (D2D) communications between mobile subscribers, is a promising solution to reduce the cellular burdens. In the existing solutions, mobile users are assumed to be volunteers who selflessly deliver the content to every other user in proximity while moving. However, practical users are selfish and they will evaluate their individual payoffs in the D2D sharing process, which may highly influence the network performance compared to the case of selfless users. In this paper, we take user selfishness into consideration and propose a network formation game to capture the dynamic characteristics of selfish behaviors. In the proposed game, we provide the utility function of each user and specify the conditions under which the subscribers are guaranteed to converge to a stable network. Then, we propose a practical network formation algorithm in which the users can decide their D2D sharing strategies based on their historical records. Simulation results show that user selfishness can highly degrade the efficiency of data offloading, compared with ideal volunteer users. Also, the decrease caused by user selfishness can be highly affected by the cost ratio between the cellular transmission and D2D transmission, the access delays, and mobility patterns. © 2015 IEEE.

关键词： Game theory

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：