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27th IEEE Annual International Symposium on Personal, Indoor, and Mobile Radio Communications, PIMRC 2016

作者： Xiaoqiang, Zhou Min, Zhao Muqing, Wu Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509032549

Content-centric networking (CCN) is considered as a promising architecture to achieve reliable content distribution at large scale. One of the key research items of CCN is cache strategy, and most of the existing approaches consider little of the dynamicity of user interests. In this paper, we present a new cache policy, named as the betweenness and content popularity prediction (BEACON). Betweenness measures the importance of nodes in the whole network, and content popularity represents the user preference for service contents. By taking into account both network topology characteristics and flow distribution, the load of network and server is optimized. Moreover, we use the gray model to predict the content popularity, tracking the trend of user interest. The simulation results demonstrate that the BEACON scheme can effectively improve the cache hit rate, shorten access distance and reduce the delay of transmission. © 2016 IEEE.

关键词： network topology

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Fog computing for vehicular Ad-hoc networks: paradigms, scenarios, and issues

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The Journal of China Universities of Posts and Telecommunications 2016年第2期23卷 56-65,96页

作者： Kang Kai Wang Cong Luo Tao School of Software Engineering Beijing University of Posts and Telecommunications Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts Telecommunications School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts Telecommunications

Vehicular Ad-hoc networks（VANETs） are kinds of mobile Ad-hoc networks（MANETs）, which consist of mobile vehicles with on-board units（OBUs） and roadside units（RSUs）. With the rapid development of computation and communication technologies, peripheral or incremental changes in VANETs evolve into a revolution in process. Cloud computing as a solution has been deployed to satisfy vehicles in VANETs which are expected to require resources（such as computing, storage and networking）. Recently, with special requirements of mobility, location awareness, and low latency, there has been growing interest in research into the role of fog computing in VANETs. The merging of fog computing with VANETs opens an area of possibilities for applications and services on the edge of the cloud computing. Fog computing deploys highly virtualized computing and communication facilities at the proximity of mobile vehicles in VANET. Mobile vehicles in VANET can also demand services of low-latency and short-distance local connections via fog computing. This paper presents the current state of the research and future perspectives of fog computing in VANETs. Moreover, we discuss the characteristics of fog computing and services based on fog computing platform provided for VANETs. In this paper, some opportunities for challenges and issues are mentioned, related techniques that need to be considered have been discussed in the context of fog computing in VANETs. Finally, we discuss about research directions of potential future work for fog computing in VANETs. Within this article, readers can have a more thorough understanding of fog computing for VANETs and the trends in this domain.

关键词： VANET fog computing cloud computing application vehicular cloud computing

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A Study on The Multi-Antenna Geometrical Depolarization Channel Modeling

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China Communications 2016年第3期13卷 105-114页

作者： SUN Xuehong YANG Xiaoli ZENG Zhimin ZHANG Cheng BAI Bing Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Intelligent Sensing for Desert Information School of Physics Electrical EngineeringNingxia UniversityYinchuan750021China

The traditional geometrical depolarization model that single transmitter to single receiver provides a simple method of polarization channel modeling. It can obtain the geometrical depolarization effect of each path if known the antenna configuration, the polarization field radiation pattern and the spatial distribution of scatters. With the development of communication technology, information transmission spectrum is more and more scarce. The original model provides only a single channel polarization state, so the information will be limited that the polarization state carries in the polarization modulation. The research is so significance that how to carries polarization modulation information by using multi-antenna polarization state. However, the present study shows that have no depolarization effect model for multi-antenna systems. In this paper, we propose a multi-antenna geometrical depolarization model. On the basis of a single antenna to calculate the depolarization effect of the model, and through simulation to analysis the main factors that influence the depolarization effect. This article provides a multi-antenna geometrical depolarization channel modeling that can applied to large-scale array antenna, and to some extent increase the speed of information transmission.

关键词： large-scale array antenna multi-antenna channel modeling depolarization effect cross polarization discrimination

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COFFEE-CUP: A cost-efficient routing strategy for delay tolerant networks using time-varying community partitioning 13

COFFEE-CUP: A cost-efficient routing strategy for delay tole...

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13th International Symposium on Wireless Communication systems, ISWCS 2016

作者： Lin, Guoping Liao, Qing Can, Deng Tianyi, Wang Zhao, Jingling Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781509020614

Delay Tolerant networks are a special kind of ad hoc networks that consist of a number of mobile devices. In DTNs, network topology frequently changes and source-to-destination communication paths can hardly be sustained. However, some social features have been observed in DTNs by analyzing the real mobile trajectories of DTNs. To utilize these social features to facilitate data routing, we present a community-based routing protocol that efficiently detects the community structure by using proposed time-varying community partitioning algorithm. For intracommunity routing, according to the remaining time-to-live of the message, the minimum number of message copies necessary to achieve a given delivery probability is calculated, which is the number of message copies utilized to spray in the current community. To facilitate intercommunity routing, we choose the gateway node that connects the next community frequently as relay. The evaluation of our strategy is conducted by extensive traced-driven simulations. The results of simulations confirm the effectiveness of our routing strategy. © 2016 IEEE.

关键词： Delay tolerant networks

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Indoor Visible Light Localization Algorithm Based on Received Signal Strength Ratio with Multi-Directional LED Array

Indoor Visible Light Localization Algorithm Based on Receive...

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International Conference on Communications Workshops

作者： Lixuan Wang Caili Guo Pengfei Luo Qiang Li Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications China Research Department of HiSilicon Huawei Technologies Co. Ltd Beijing China

ISBN: (纸本)9781509015269

Visible light communication (VLC) based localization is a potential candidate for indoor localization. However, since the field of view (FOV) of the photodiode (PD) is normally narrow, the PD might not be capable to detect enough LEDs to perform the triangulation algorithm. Furthermore, high directionality is a significant character in VLC, and in practice, the direction of LED is commonly fixed and able to be known for once, but the direction of the PD is commonly random. In this paper, we exploit the direction of the LED in the lamp structure design and manage to mitigate the influence of the direction of the PD in the algorithm design. A localization algorithm based on received signal strength ratio (RSSR) with multi-directional LED array (MDLA) is proposed. In addition, we introduce the coverage ratio (CR) and the average angle acceptance ratio (AAAR) to evaluate the localization scheme's coverage in location and acceptance in direction, respectively. Simulation results show that when the tilt angle of LEDs is 15°, the proposed scheme can attain the root-mean-square error (RMSE) of 0.04 m and 0.06 m in 2-D and 3-D localization, respectively, and it is more probably for it to obtain enough lamps compared to the conventional scheme using the triangulation algorithm with the lamp structure of a single LED.

关键词： candidate indoor localization

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Asymmetrical And Direct Current Biased Optical OFDM for Visible Light Communication With Dimming Control

Asymmetrical And Direct Current Biased Optical OFDM for Visi...

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International Conference on Communications Workshops

作者： Namei Yin Caili Guo Yang Yang Pengfei Luo Chunyan Feng Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications China Research Department of HiSilicon Huawei Technologies Co. Ltd Beijing China

ISBN: (纸本)9781509015269

In visible light communication (VLC) systems, optical orthogonal frequency division multiplexing (O-OFDM) is an appealing modulation. Among many proposed O-OFDM schemes, both direct current biased O-OFDM (DCO-OFDM) and asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) are widely used. Since VLC needs to take the dual requirements of illumination and communication into account, different dimming levels are often required. For high and low dimming level scenarios, system with ACO-OFDM normally has a better spectral efficiency performance than system with DCO-OFDM due to the smaller clipping noise. However, regarding the middle dimming level scenarios, the DCO-OFDM generally outperforms the ACO-OFDM. In order to improve system spectral efficiency within the wide dimming range, an asymmetrical and direct current biased optical orthogonal frequency division multiplexing (AAD-OFDM) is proposed in this paper. In AAD-OFDM based system, the modulation scheme is switched between ACO-OFDM and DCO-OFDM according to the required dimming level. Therefore, by adopting the proposed AAD-OFDM, the VLC system can fully utilize the dynamic range of LED at any dimming levels thus improving the performance. Simulation results show that the proposed scheme has high spectral efficiency within a wide dimming range.

关键词： Visible Light Communication

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UNDERSTANDING ONLINE SHOPPING AND OFFLINE MOBILITY BEHAVIOR IN URBAN AREA FROM THE VIEW OF MULTILAYER networkS 5

UNDERSTANDING ONLINE SHOPPING AND OFFLINE MOBILITY BEHAVIOR ...

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2016 5th IEEE International Conference on network Infrastructure and Digital Content(IC-NIDC 2016)

作者： Yuanyuan Qiao Yanting Zhang Anders Lindgren Jie Yang Beijing Key Laboratory of Network System Architecture and Convergence BUPT Center for Data Science BUPT SICS Swedish ICT Lulea University of Technology

ISBN: (纸本)9781509012473

The interactive nature of the Internet offers many opportunities to increase the efficiency of online shopping by improving availability of product information,enabling direct multi-attribute comparisons,and reducing buyer search costs.A great body of research focuses on how consumers shop online or why and how online shopping impacts urban development,but the understanding of mutual influence between online and offline behavior of consumers remains somewhat *** paper bridges that gap by quantifying the relationship between consumers' online shopping and offline mobility *** results of the study give insights to further understand human behavior from both a cyber and real world point of view,which may help to place location based targeted advertisements,and plan commercial & retail centers in urban areas.

关键词： Online shopping behavior Mobility behavior Multilayer networks Mobile traffic

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Graphene reflectarray that steers vortex THz waves

Graphene reflectarray that steers vortex THz waves

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International Symposium on Antennas and Propagation (ISAP)

作者： Mengyu Wang Xing Xu Botao Feng Li Deng College of Optoelectronic Engineering Shenzhen University Shenzhen China College of Electronic Science and Technology Shenzhen University Shenzhen China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Post and Telecommunications Beijing China

A graphene reflectarray is designed to realize two functions simultaneously at terahertz frequency: generating vortex waves, and steering the waves. Four parts of graphene patches with different values of reflection phase are used to generate vortex waves. On the other hand, generalized Snell's Law is applied to introduce additional reflection phase. Anomalous reflection is realized to steer the Vortex wave by 30 degrees.

关键词： Graphene Chemicals Surface waves Electric potential Telecommunications Plasmons

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LBT with adaptive threshold for coexistence of cellular and WLAN in unlicensed spectrum 8

LBT with adaptive threshold for coexistence of cellular and ...

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8th International Conference on Wireless Communications and Signal Processing, WCSP 2016

作者： Li, Bin Zhang, Tiankui Zeng, Zhimin Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509028603

Coexistence of cellular networks and wireless local area network (WLAN) in unlicensed spectrum will be a vital application scenario in the future 5G network. Listen-before-talk (LBT) is one of the mechanisms to ensure a fair coexistence among various radio access networks. In this paper, we present a LBT algorithm with an adaptive threshold jointly considering the diverse traffic load conditions of cellular networks and the quality of service (QoS) metrics of user equipment (UE). The transmission procedure of a cellular base station (BS) is modeled utilizing M/GI/1 queuing system via queuing theory. Then the BS control the clear channel assessment (CCA) threshold according to the queue length to adapt to the diverse traffic loads under the condition of QoS guarantee. Simulation results show that the proposed algorithm achieves significant performance gain of the cellular network under the coexistence scenario on the premise of tolerable sacrifices on WLAN performance. © 2016 IEEE.

关键词： Wireless local area networks (WLAN)

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An Error Compensation Method of Time Synchronization for Cross-domain Interconnection in SD-TSN

An Error Compensation Method of Time Synchronization for Cro...

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Optical Fiber Communication Conference, OFC 2016

作者： Zhang, Xiaodong Shou, Guochu Xue, Junli Li, Hongxing Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

We propose a time synchronization modeling and error compensation method for Software-Defined TSN. Experiments verify that the combination method of POE and NNPID can effectively improve time synchronization performan...

ISBN: (纸本)9781943580071

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