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6th IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies, MAPE 2015

作者： Li, Deng Hong, Weijun Li, Shufang Zhu, Jianfeng Biao, Peng Feng, Botao Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Department of Electronics Engineering Shenzhen University Shenzhen China

ISBN: (纸本)9781467374415

Existing discrete electromagnetic cloaks are often limited to circular shape and always based on one dimensional discretization of radius variable in cylindrical coordinates. In this paper, we proposed a two dimensional (2D) discrete square invisible cloak which really does not require any continuous constitutive material parameters. The discrete square cloak consists of several homogeneous blocks, and they are discretized from the original transform medium whose material parameters are often continuous spatial functions of both x and y variables in Cartesian coordinates. With proper design of numbers of blocks, we demonstrated the scattering properties of the proposed cloaking structure through rigorous analysis of the scattered electromagnetic fields. The proposed cloaking structure could be possibly realized, therefore may lead to a practical path to an experimental demonstration of electromagnetic cloaking. © 2015 IEEE.

关键词： Electromagnetic fields

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Global and individual mobility pattern discovery based on hotspots

Global and individual mobility pattern discovery based on ho...

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IEEE International Conference on Communications, ICC 2015

作者： Yang, Jie Zhang, Xinyu Qiao, Yuanyuan Fadlullah, Zubair Kato, Nei Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Graduate School of Information Sciences Tohoku University Sendai Japan

ISBN: (纸本)9781467364324

Data collected from the mobile Internet have the potential knowledge to provide important human mobility patterns. Understanding human mobility patterns is important to many location-based services, and could be used to predict users' behavior. In this paper, we concentrate on the issue of discovering human mobility patterns on both global and individual levels based on hotspots. We study the human mobility trajectories during 22 days for 3474 individuals collected at the core of a metropolitan Long Term Evolution (LTE) network in China. We employ a parameter-free method to detect hotspots, and demonstrate the effectiveness of our mobility pattern discovery algorithm by using the hotspots identified on both global and individual levels. We analyze the occurrence time distribution of these patterns and find that the global mobility patterns have higher occurrence probability in the morning, which indicates that people in a city tend to share the common commuting routes. For individual mobility patterns, there exists a strong spatiotemporal correlation property, implying that the individual mobility patterns have their own typical occurrence time depending on the pattern's context. © 2015 IEEE.

关键词： Hotspot LTE networks Mobility characteristic Mobility pattern discovery

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Energy efficient handover algorithm in OFDMA systems

Energy efficient handover algorithm in OFDMA systems

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IEEE International Conference on Computer and Communications, ICCC 2015

作者： Zhang, Kai Yin, Changchuan Xu, Jin Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781467381253

Traditional handover algorithms are based on received signal strength indicator (RSSI) and traffic load intensity in orthogonal frequency division multiple access (OFDMA) systems, in order to guarantee all UEs' Quality of Service (QoS) and handover success ratio, a transceiver is activated even if there is only one low date rate activated user in its coverage area. In this paper, we propose an energy efficient handover algorithm combined coordinated multiple-points (CoMP) with OFDMA in a cellular systems, energy efficiency is introduced into the handover algorithm as an important parameter. The idea of the design is to enable adjacent cells to shutdown partial transceivers in some timeslots in low traffic conditions by concentrating the activated edge UEs to less cells. All activated UEs are classified into edge users and center users according to their distance to base stations, the analysis indicates that there exist an optimal edge distance corresponding to the maximum energy efficiency under different load for the proposed algorithm. Furthermore, a practical and low-complexity scheme that only considers the edge users is put forward. The edge users are identified by the reference signal received power (RSRP). Simulation results show that it can obtain up to 60% energy reduction at low traffic scenario. © 2015 IEEE.

关键词： Energy efficiency

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Based QoE-perceptive network selection of video applications in WLAN

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Journal of Information and Computational Science 2015年第13期12卷 5109-5117页

作者： Zhang, Hongchun Lu, Zhaoming Hu, Zhiqun Wen, Xiangming Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China

Wireless Local Area networks (WLAN) is becoming increasingly important. But it is difficult for users to select the best target network for connection in WLAN. For multimedia applications, Quality of Experience (QoE) is an essential measurement for network evaluation, and particularly video applications need the guarantee of QoE. However, many proposed schemes do not take QoE into account. Therefore, a novel network selection mechanism for video applications that takes QoE into consideration is proposed. Users detect the states of the channel and the resource utilization and calculate the Peak Signal to Noise Ratio (PSNR), then use the mapping model to obtain QoE. This mechanism uses QoE in candidate networks as an indicator to select the best target Access Point (AP) network. The simulation results illustrate that QoE of video applications satisfies users' requirement, and the network throughput is greatly improved. ©, 2015, Journal of Information and Computational Science. All right reserved.

关键词： Signal to noise ratio

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An efficient and QoS-aware virtual network resource migration algorithm

An efficient and QoS-aware virtual network resource migratio...

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International Conference on Computer and Communications (ICCC)

作者： Lu Ma Zhaoming Lu Bangchao Yu Luhan Wang Xiangming Wen Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing Beijing CN

In this paper, a joint reducing energy consumption and improving quality of service scheme for the migration of virtual network resources is proposed. This migration algorithm reflects the state of the virtual network resources dynamically, and the algorithm consists of two parts: Energy-efficient Module and QoS Module. Each Module is responsible for a specific function. The Energy-efficient Module is responsible for the energy consumption of servers, and the QoS Module is responsible for the quality of network service, and it can optimize the target nodes with the relative cost of migration. The efficient and QoS-Aware migration algorithm take the energy consumption and the quality of service into account. The simulation results show that the proposed algorithm can reduce energy consumption to the servers, improve the quality of experience, reduce the latency and achieve the objectives of managing of virtual network quickly and easily.

关键词： Servers Algorithm design and analysis Quality of service Energy efficiency Energy consumption Heuristic algorithms Resource management

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Improved recommendation system using friend relationship in SNS 19th

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19th International Conference on Transactions on Computational Collective Intelligence, TCCI 2015

作者： Liao, Qing Wang, Bin Ling, Yanxiang Zhao, Jingling Qiu, Xinyue School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Computer Science Beijing University of Posts and Telecommunications Beijing100876 China Beijing Key Laboratory of Network System Architecture and Convergence Beijing100876 China

ISBN: (纸本)9783662490167

With the rapid development of the Internet, SNS services and 3G commercial mobile applications there have been tremendous opportunities although the development of SNS is very short in China, and the social web game is in the early stage of development. Because of massive users, the potential commercial value of Chinese SNS is still a great mining space. However, a relatively large defects is the precipitation and accumulation on content. The dynamic of friends will affect our own decisions largely, it is favorable for the activity of SNS to increase the number of friends. We have improved the existing models, and conduct experiments to validate it and compare it with previous methods. © Springer-Verlag Berlin Heidelberg 2015.

关键词： Social networking (online)

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Broadcast Transmission Capacity of VANETs with Secrecy Outage Constraints under Multiple Frequency Bands

Broadcast Transmission Capacity of VANETs with Secrecy Outag...

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IEEE Vehicular Technology Conference

作者： Xinxin He Weisen Shi Tao Luo Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479980895

We study broadcast transmission capacity with secrecy outage constraints in a one-dimension vehicular ad hoc network model. We develop our model on the basis of a highway scenario and extend both ends of the highway to infinity, and vehicles are assumed to follow a homogeneous Poisson point process. We divide the fixed total bandwidth into a large number of sub-bands. In intuition, the increasing number of sub-bands theoretically can support more parallel communications simultaneously. However, the broadcast transmission capacity is not always increased with the increasing number of sun-bands. Hence, we study the relationship between broadcast transmission capacity and the number of sub-bands, and then deduce the optimum number of sub-bands. After that, we also derive the equation of the broadcast transmission capacity over Nakagami fading channels and the transmission capacity with the secrecy outage constraint, respectively. Finally, numerical results verify that there is an optimal number of sub-bands in different scenarios.

关键词： VANETs Transmission Capacity Secrecy Outage Multiplefrequency bands

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Nonlinear Joint Transceiver Design for Coordinated Multi-cell systems with Energy Cooperation

Nonlinear Joint Transceiver Design for Coordinated Multi-cel...

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IEEE International Conference on Communications

作者： Zhirui Hu Chunyan Feng Tiankui Zhang Qin Niu Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

ISBN: (纸本)9781467364300

This paper studies the nonlinear transceiver design in downlink coordinated multi-cell system where base stations (BSs) are powered by hybrid sources, including conventional grid and renewable energy. Renewable energy is collected by energy harvesting equipment deployed at BS. However, the harvested energy from different BSs varies in space and time, and the system gain will be limited by the least energy of the coordinated BSs. One of the methods to settle this drawback is energy cooperation among BSs. The nonlinear joint transceiver is formulated as an optimization problem to maximize the minimum signal-to-interference noise ratio of streams under the transmit power constraint. The closed-form solutions are derived by the proposed two-step algorithm. The proposed algorithm guarantees the performance balancing among all users and all streams of each user. Simulation results illustrate the performance improvement of the proposed algorithm.

关键词： Coordinated multi-cell Nonlinear precoding Trancseiver design Energy harvesting Energy cooperation

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An Efficient and QoS-Aware Virtual network Resource Migration Algorithm

An Efficient and QoS-Aware Virtual Network Resource Migratio...

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2015 IEEE International Conference on Computer and Communications(ICCC 2015)

作者： Lu Ma Zhaoming Lu Bangchao Yu Luhan Wang Xiangming Wen Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

In this paper, a joint reducing energy consumption and improving quality of service scheme for the migration of virtual network resources is proposed. This migration algorithm reflects the state of the virtual network resources dynamically, and the algorithm consists of two parts: Energyefficient Module and Qo S Module. Each Module is responsible for a specific function. The Energy-efficient Module is responsible for the energy consumption of servers, and the Qo S Module is responsible for the quality of network service, and it can optimize the target nodes with the relative cost of migration. The efficient and Qo S-Aware migration algorithm take the energy consumption and the quality of service into account. The simulation results show that the proposed algorithm can reduce energy consumption to the servers, improve the quality of experience, reduce the latency and achieve the objectives of managing of virtual network quickly and easily.

关键词： virtualization energy efficient virtual resourece QoS

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Coverage Characterization in Wireless Powered Communication networks with Energy Harvesting

Coverage Characterization in Wireless Powered Communication ...

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IEEE Conference on Vehicular Technology (VTC)

作者： Yuanyuan Yao Changchuan Yin Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479980925

The performance of wireless powered communication networks (WPCNs) with transmitters (TEs) self-sustained by opportunistically harvesting radio-frequency (RF) energy from nearby power beacons (PBs) is investigated. A ``harvest-then-transmit'' protocol is considered, under which a TE first harvest the wireless energy from its nearest PB and then send information to its associated receiver (RE) with the energy stored in the battery. A variable power transmission mode is proposed that the TE is allowed to transmit as long as its harvested energy is larger than a predefined transmission threshold. The transmission probability of the TEs is derived. The coverage probability with the TEs non-fully charged and fully charged, respectively, are characterized. By using numerical analysis, we study the tradeoff between energy harvesting and data transmission for different system parameters, such as energy harvest-ratio, transmission threshold, and PB density. Simulation results are provided to validate our theoretical analysis.

关键词： Energy harvesting Wireless communication Wireless sensor networks Radio frequency Batteries Protocols Data communication

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