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National Doctoral Academic Forum on Information and Communications Technology 2013

作者： Qiao, Yuan-Yuan Yang, Jie Lei, Zhen-Ming Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunication Beijing 100876 China

ISBN: (纸本)9781849198196

Mobile Internet is one of the most popular networks in the world. Constructing the physical structure of mobile Internet is the key to modeling the network. The existing studies of fixed Internet are not suitable for mobile Internet and a deep understanding of traffic graph in mobile Internet is required. In this paper, we construct a user-server network graphs from the complete flow records of mobile Internet collected from our self-developed equipment deployed in southern China. We investigate the characteristics of the properties of Web, IM and overall traffic as the complex network point of view. Different types of traffic have different characteristics. In addition, node degree and node strength distribution of servers show that mobile network follow the power law, however, node degree and node strength distribution of users do not possess the power law property. We further study the distributions of average strength for each edge of node which follow the power law, and find the regular pattern of exponents for different applications. These discoveries could be used by the ISPs and researchers to optimize the deployment of network resources and enhance the security of the network and the Quality of Services(QoS).

关键词： Complex networks

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Resource allocation scheme based on weighted power control in cognitive radio systems

Resource allocation scheme based on weighted power control i...

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2013 International Conference on Communications, Circuits and systems, ICCCAS 2013

作者： Li, Jingye Luo, Tao Yue, Guangxin Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China State Key Laboratory of Integrated Services Networks Xidian University Xi'an China

ISBN: (纸本)9781479930517

Opportunistic spectrum access (OSA) is a promising method to improve the spectrum utilization. In this paper, we propose a weighted power control approach to further exploit the flexibility of OSA. We first give the definition and basic idea of confidence level of sub-channel idle (CLSI), then two schemes are raised to enhance the system performance considering the time-variance of channels, the accuracy of spectrum sensing and mutual interference (MI) in power-constrained cognitive radio systems. The first scheme is to maximize the system capacity, and the second one is a multi-objective optimization model for maximizing both the system capacity and the user satisfaction. Both theoretical analysis and simulation results demonstrate that scheme 1 can achieve optimal system capacity, and scheme 2 can obtain sub-optimal system capacity with optimal user satisfaction compared to the conventional algorithm. © 2013 IEEE.

关键词： Optimal systems

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A novel blocking probability balance scheme to improve network performance for SLICE network

A novel blocking probability balance scheme to improve netwo...

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Asia Communications and Photonics Conference, ACP 2013

作者： Wang, Jinyu Guo, Junhu Cao, Bei Li, Hui Ji, Yuefeng Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications No.10 Xi Tu Cheng Road 100876 Beijing China

We proposed a novel blocking probability (BP) balance scheme called BPB to improve SLICE network performance under dynamic traffic, by not only considering network's average BP value but also balancing each node&#... 详细信息

ISBN: (纸本)9781557529893

关键词： Blocking probability

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Large-Scale Traffic Characterization of Chinese Multimedia Messaging Service Using Hadoop

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China Communications 2013年第9期10卷 143-154页

作者：董超彭栋黄博伦雷振明杨洁 Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Texas A&M University

Recently, there have been many mo- bile value-added services in the Chinese mo- bile telecommunication market nowadays. Am- ong them, the characteristics of Multimedia Mes- saging Service （MMS） have not yet been fully understood. In this paper, with the help of a cloud computing platform, we investigated the flow-level charactefistcs of Chinese MMS. All of the experimental data were collected by the TMS equipment deployed in a major node in Sou- them China. The collection time spanned six mo- nths. We performed high-level analysis to show the basic distributions of MMS characteristics. Then, by analysing the detailed MMS features, we determined the distribution of personal MMS, and made a comprehensive comparison between 2G and 3G MMS. Finally, we tried to build a model on the personal MMS inter-arrival time, and we found that the Weibull distribution was optimum.

关键词： traffic monitoring MMS cloud co-mputing mobile telecommunication network

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Neighbour Peer Selection Scheme Based on Effective Capacity for Mobile Peer-to-Peer Streaming

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China Communications 2013年第5期10卷 89-98页

作者：夏海轮王宁曾志民 Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications

For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This paper proposes a novel Effective Capacity Peer Selection (ECPS) scheme based on effective capacity. In the ECPS scheme, the neighbour peer selection problem was modeled using the Multiple Attribute Decision Making (MADM) theory, which considered multiple factors of candidate peers, including Signal to Interference and Noise Ratio (SINR), residency time, power level, security, moving speed, and effective capacity. This model could increase the suitability of ECPS for wireless mobile environments. Then, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to solve the MADM problem and identify the preferred neighbour peers. Simulation results show that the ECPS scheme can improve the network throughput, reduce packet delay by about 82%, and almost double the packet delivery ratio of the mobile P2P streaming service.

关键词： P2P mobile P2P streaming peer selection effective capacity MADM QoS

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Improved RETE algorithm in context reasoning for web of things environments

Improved RETE algorithm in context reasoning for web of thin...

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2013 IEEE International Conference on Green Computing and Communications and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing, GreenCom-iThings-CPSCom 2013

作者： Gao, Teng Qiu, Xiaofeng He, Lijuan Mobile Life and New Media Laboratory Beijing University of Posts and Telecommunications Beijing China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9780769550466

RETE is the most efficient forward inference algorithm for the development of context-aware rule-based systems. The performance of context reasoning engines in context-aware systems depends mainly on the efficiency of the pattern matching in "Cognition-Execution Loop". Nowadays many real-world contexts from WoT (Web of Things) environments have data characteristics such as large amount, quick change and lots of constant operation, imposing a trade-off between the cost of time and space of RETE algorithm. Thus, in this paper RETE+ - an improved RETE network is proposed, capable of handling context from WoT environment, which actually includes different types of data for reasoning with new characteristics. RETE+ algorithm applies shortcut memory using LRU (Least-Recently-Used) algorithm to the matching process of alpha network and solves the problems of intensive computation with all the alpha nodes. This approach takes advantage of the LRU algorithm to select alpha nodes with the highest possibility to be executed, which considerably reduces the computation overhead. The proposed approach is applied to context reasoning engine and evaluated through contrast experiments using real-world WoT data. The case study and experimental analysis demonstrate the capability of the proposed algorithm. © 2013 IEEE.

关键词： Internet of things

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Interference mitigation scheme for cognitive femtocell networks

Interference mitigation scheme for cognitive femtocell netwo...

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National Doctoral Academic Forum on Information and Communications Technology 2013

作者： Qing, Haobo Liu, Yuanan Xie, Gang Gao, Jinchun Beijing Key Laboratory of Work Safety Intelligent Monitoring School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781849198196

The interference problem is a bottleneck of femtocell development as more and more femtocells are deployed. This paper considers interference from macro-cell as well as femtocells and puts forward a novel interference avoidance scheme. The proposed scheme employs cognitive radio technology which can sniff the resources usage to obtain the real-time environment information, and then allocates the frequency resources to femtocell network. In this way, interference mitigation is fulfilled. Simulations verify that the proposed scheme is able to achieve higher capacity and lower interference than the classical dedicated channel and co-channel deployment schemes.

关键词： Femtocell

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A novel parametric channel estimation approach for OFDM systems

A novel parametric channel estimation approach for OFDM syst...

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2013 International Conference on Information and network Security, ICINS 2013

作者： Qing, Haobo Liu, Yuanan Xie, Gang Liu, Kaiming Liu, Fang Beijing Key Laboratory of Work Safety Intelligent Monitoring School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunication Beijing China

ISBN: (纸本)9781849197298

This paper proposes a novel parametric channel estimation approach for orthogonal frequency-division multiplexing (OFDM) systems. The method is composed of two parts: estimation of channel parameters and estimation of channel coefficients. The exponentially embedded family (EEF) criterion is exploited to determine the number of channel paths as well as the multipath time delays. Based on these parameters, channel frequency responses are estimated. Additionally, our scheme is computational efficient due to the needless of eigenvalue decomposition (EVD) or the estimation of signal parameters by rotational invariance technique (ESPRIT). Simulations are provided to validate the performance of our algorithm from the perspectives of channel parameter error probability (CPEP) and mean square error (MSE).

关键词： Orthogonal frequency division multiplexing

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A novel metric for cache size allocation scheme in Content Centric networking

A novel metric for cache size allocation scheme in Content C...

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National Doctoral Academic Forum on Information and Communications Technology 2013

作者： Cui, Xiandong Liu, Jiang Huang, Tao Chen, Jianya Liu, Yunjie Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing 100876 China Future Network Industry Innovation Center of China Nanjing 211100 China

ISBN: (纸本)9781849198196

Caching scheme will change the original feature of the network in Content Centric networking (CCN). So it becomes a challenge to describe the caching node importance according to network traffic and user behavior. In this work, a new metric named Request Influence Degree (RID) is defined to reflect the degree of node importance. Then the caching performance of CCN has been addressed with specially focusing on the size of individual CCN router caches. Finally, a newly content store space heterogeneous allocation scheme based on the metric RID across the CCN network has been proposed. Numerical experiments reveal that the new scheme can decrease the routing stretch and the source server load contrasting that of the homogeneous assignment and several graph-related centrality metrics allocations.

关键词： Behavioral research

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Secure cloud storage management method based on time stamp authority

Secure cloud storage management method based on time stamp a...

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National Doctoral Academic Forum on Information and Communications Technology 2013

作者： Lin, Wen-Hui Lei, Zhen-Ming Liu, Jun Yang, Jie Liu, Fang He, Gang Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunication Beijing 100876 China Technology Research Institute Aisino Corporation Beijing 100195 China

ISBN: (纸本)9781849198196

We present a fundamentally different approach to improve the security of cloud storage. In contrast to previous methods, our approach introduces third party trusted timestamp and certificate into Cloud storage framework. And user's request is multiply validated. There are three main aspects. (i) Certificate identifies the user's identity;(ii) Trusted timestamp is added to the user's operation request;(iii) Cloud storage system communicates with TSA and Directory server for user information verification. Furthermore, our approach has two important features. First, we use PKI technology to improve cloud storage system security, and through Directory server to authenticate the user certificate status. Second, Cloud storage vets user's operation requests based on trusted timestamps and stores user's operation records, which can provide security services including safety audit, electronic evidence and other services. Our results show that our mechanism can vet and monitor various types of data operations in cloud storage system under the premise of increasing a very small overhead, and the security of cloud storage has greatly enhanced.

关键词： Cloud storage

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