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IEEE International Conference on Communications (ICC)

作者： Jie Yang Xinyu Zhang Yuanyuan Qiao Zubair Fadlullah Nei Kato 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

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.

关键词： Trajectory Mobile communication Transportation Mobile computing Cities and towns Next generation networking Long Term Evolution

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Characterizing and modeling of large-scale traffic in mobile network

Characterizing and modeling of large-scale traffic in mobile...

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IEEE Conference on Wireless Communications and networking

作者： Jie Yang Weicheng Li Yuanyuan Qiao Zubair Md. Fadlullah Nei Kato 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)9781479984077

Recently, mobile Internet gained a strong momentum of development, which has led to increasing demand on mobile network traffic characterization and modeling. A good model of mobile network traffic can be used to make accurate prediction regarding various performance metrics. Based on the network trace collected from network backbone, our paper studies mobile network traffic characteristics in terms of the flow arrival numbers and flow connection duration. Basically, we employ the Poisson regression from Generalized Linear Model with time window clustering so as to approximate a time-dependent Poisson Process to the flow arrival process. Our analytical results demonstrate the accuracy of the adopted approach. In addition, through approximating the Phase Type distribution to the heavy-tailed distribution, our paper also models the flow connection duration. The obtained results can help us get a comprehensive understanding of the network performance, in accordance with which the resource usage may be optimized, e.g., we can expand network bandwidth or increase the buffer size when the network arrival is high.

关键词： Mobile communication Mobile computing Internet Measurement Conferences Monitoring Distribution functions

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Energy efficient handover algorithm in OFDMA systems

Energy efficient handover algorithm in OFDMA systems

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International Conference on Computer and Communications (ICCC)

作者： Kai Zhang Changchuan Yin Jin Xu 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

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.

关键词： Handover Power demand Base stations Energy efficiency Telecommunication traffic Algorithm design and analysis

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Performance Study of Relay Coordination Schemes for Two-Hop networks: Two-Cell Case

Performance Study of Relay Coordination Schemes for Two-Hop ...

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IEEE International Conference on Communications

作者： Kasun T. Hemachandra Norman C. Beaulieu Department of Electrical and Computer Engineering University of Alberta School of Information and Communication Engineering and the Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

ISBN: (纸本)9781467364300

The outage probability of a two-hop coordinated decode-and-forward relay network is investigated. Relay coordination is performed only with the dominant interferer. Different levels of network coordination are studied and their performances are compared. Exact expressions are derived for the outage probability of a particular mobile user for each coordination scheme. Asymptotic outage probability is derived to identify the diversity and coding gains for each coordination scheme.

关键词： Cochannel interference Decode-and-forward Outage probability Relay coordination Zero-forcing

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Design of in-network caching scheme in CCN based on grey relational analysis

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 1-8页

作者： CUI Xian-dong HUANG Tao LIU Jiang LI Li CHEN Jian-ya LIU Yun-jie State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Future Network Industry Innovation Center of China

In-network caching is one of the most important issues in content centric networking （CCN）, which may extremely influence the performance of the caching system. Although much work has been done for in-network caching scheme design in CCN, most of them have not addressed the multiple network attribute parameters jointly during caching algorithm design. Hence, to fill this gap, a new in-network caching based on grey relational analysis （GRA） is proposed. The authors firstly define two newly metric parameters named request influence degree （RID） and cache replacement rate, respectively. The RID indicates the importance of one node along the content delivery path from the view of the interest packets arriving The cache replacement rate is used to denote the caching load of the node. Then combining hops a request traveling from the users and the node traffic, four network attribute parameters are considered during the in-network caching algorithm design. Based on these four network parameters, a GRA based in-network caching algorithm is proposed, which can significantly improve the performance of CCN. Finally, extensive simulation based on ndnSIM is demonstrated that the GRA-based caching scheme can achieve the lower load in the source server and the less average hops than the existing the betweeness （Betw） scheme and the ALWAYS scheme.

关键词： CCN in-network caching request influence degree cache replacement rate grey relational analysis

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A Unified Framework for Wireless Connectivity Study subject to General Interference Attack

A Unified Framework for Wireless Connectivity Study subject ...

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IEEE International Conference on Communications

作者： Yang Liu Chengzhi Li Changchuan Yin Huaiyu Dai Beijing Key Laboratory of Network System Architecture Convergence Beijing University of Posts and Telecommunications Beijing China Department of Electrical and Computer Engineering North Carolina State University Raleigh NC

Connectivity is crucial to ensure information availability and survivability for wireless networks. In this paper, we propose a unified framework to study the connectivity of wireless networks under a general type of interference attack, which can address diverse applications including Cognitive Radio, Jamming attack and shadowing effect. By considering the primary users, jammers and deep fading as unified Interferers, we investigate a 3-dimensional connectivity region, defined as the set of key system parameters - the density of users, the density of Interferers and the interference range of Interferers - with which the network is connected. Further we study the impact of the Interferers' settings on node isolation probability, which is a fundamental local connectivity metric. Through percolation theory, the sufficient and necessary conditions for global connectivity are also derived. Our study is supported by simulation results.

关键词： Interference Three-dimensional displays Jamming Wireless networks Security Shadow mapping Information systems

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Performance Analysis of DF Relaying with Optimum Combining in a Poisson Field of Interferers

Performance Analysis of DF Relaying with Optimum Combining i...

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IEEE International Conference on Communications

作者： Navod Suraweera Norman C. Beaulieu Department of Electrical and Computer Engineering University of Alberta School of Information and Communication Engineering and Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecomunications (BUPT)

ISBN: (纸本)9781467364300

The performance of optimum combining (OC) in decode-and forward (DF) relaying in the presence of a Poisson field of interferers is analyzed. An approximation for the outage probability of the OC receiver is derived by considering the temporal correlation of the interference. Despite the randomness of the number and the locations of the interferers, the OC receiver suppresses the interference at the destination node and diversity gains are achieved, provided that the relay nodes are noise limited. For single-antenna relay nodes, the end-to-end performance is vulnerable to interference at the relay nodes which is not canceled, resulting in zero diversity gains.

关键词： DF relaying Interference Optimum combining Outage probability Poisson point processes

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Distributed user association for delay-load tradeoffs in energy harvesting enabled HetNets

Distributed user association for delay-load tradeoffs in ene...

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IEEE Wireless Communications and networking Conference Workshops (WCNCW)

作者： Hongzhang Xu Tiankui Zhang Zhimin Zeng Dantong Liu Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China School of Electronic Engineering and Computer Science Queen Mary University of London London UK

ISBN: (纸本)9781479987610

Energy harvesting is an emerging technology to save on-grid power and reduce carbon emissions in wireless communications. Terminals can utilize renewable energy obtained from environment by energy harvesting facilities. This paper investigates user association problem under a flow-level traffic model in energy harvesting enabled heterogeneous networks. In this paper, all the base stations are equipped with energy harvesting facilities and assumed to be solely powered by renewable energy. The average traffic delay is denoted using queuing theory, and a fairness index is redefined to evaluate the level of load balancing. Then a convex optimization problem is formulated in order to reduce average traffic delay and improve load balancing level. To this end, an iterative algorithm completed by user and base station respectively is proposed. Simulation results show that the user association algorithm improves the load balancing level with limited sacrifice on average traffic delay compared with the existing delay-optimal algorithm, and enables a flexible tradeoff between the average traffic delay and load balancing.

关键词： Load management Delays Indexes Energy harvesting Wireless communication Load modeling Renewable energy sources

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Discretization of an square electromagneic cloak based on transformation optics

Discretization of an square electromagneic cloak based on tr...

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International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)

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

ISBN: (纸本)9781467374422

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.

关键词： Manganese Scattering Lead Indexes Optics Metamaterials

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The Relation of Energy-Consumption and the Population of People

The Relation of Energy-Consumption and the Population of Peo...

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International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery, CyberC

作者： HongLiang Liang HongYan Cui Key Lab of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing P.R. China State Key Lab. Of Networking and Switching Technology MIT SENSEable City Laboratory

ISBN: (纸本)9781467392013

Reducing the energy consumption of cellular wireless access networks is not only beneficial for the global environment but also makes commercial sense for telecommunication operators, our research focus on how to put forward a constructive energy saving method in the precondition of guaranteed service quality for customer. In this paper, we based on the signaling data and location data coming from one of Chinese main operator's customers, trying to analysis the law that with the increase of users in a district, how their demand for energy change. Through the use of the law, operators can make a basis when conducting the construction of the base station at the time of city expansion and the redundancy phenomenon of construction of base station can be effectively reduced and then make contributions to energy saving, the law can also be used to provide a reference for city Planning Bureau when they conducting the urban planning and the construction of Green city and then get the purpose of optimal allocation of resources. In our study, we carry out the statistics of 1558053 users from Chongqing city, finally we found that with the increase of customer' number of each special district, the number of total traffic in the city present a change of power function.

关键词： Base stations Business Mathematical model Cities and towns Correlation Internet Urban planning

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