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International Conference on Information Science and Technology (ICIST)

作者： Boya Liu Feng Liu Wenhui Lin Qin Wang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China School of electronic engineering Beijing University of Posts and Telecommunications Beijing China

We present a novel correlation model for measuring web quality based on user perception. In contrast to previous methods, our approach is based on correlation analysis of web quality metrics at user-perceived level. Our model has three significant characteristics. First, we extract several web quality metrics which are closely related to user's subjective feelings. Second, by means of Pearson correlation analysis, we acquire five key metrics best reflecting web quality. Third, based on selected web quality metrics, we propose a novel comprehensive assessment model of web quality. We demonstrate the effectiveness of our approach by evaluating comprehensive assessment scores. A series of real-world experiments are conducted to qualitatively evaluate the effectiveness of our model. Results show that our model can be more intuitive to reflect user's quality of experience (QoE).

关键词： Correlation Delays Correlation coefficient Quality of service Monitoring Standards

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A QoS-Aware Adaptive Access Point Sleeping in Relay Cellular networks for Energy Efficiency

A QoS-Aware Adaptive Access Point Sleeping in Relay Cellular...

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IEEE Conference on Vehicular Technology (VTC)

作者： Yutao Zhu Zhimin Zeng Tiankui Zhang Dantong Liu Beijing University of Posts and Telecommunications Beijing China Beijing Key Laboratory of Network System Architecture and Convergence Beijing China Queen Mary University of London London United Kingdom

ISBN: (纸本)9781479944811

The access point sleeping scheme is an efficiency method for power saving in the cellular networks. This paper proposes a QoS-aware adaptive access point sleeping scheme designed for energy efficiency in the relay cellular networks. To achieve the best tradeoff between QoS guarantee of users and the power saving of the network, the optimization problem of the access point selection for each user is given, and a dynamic energy control (DEC) algorithm is presented, in which, a best access point (base station or relay station) is allocated to each user and the access point without user association will be switched off for energy saving. We evaluated the network performance of power consumption, system throughput and energy efficiency by simulation, which show that, compared other schemes, the proposed access point sleeping scheme with DEC algorithm can improve the energy efficiency with the QoS guarantee for relay cellular networks, especially in low traffic condition.

关键词： Relays Quality of service Energy efficiency Heuristic algorithms Switches Algorithm design and analysis Energy consumption

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SWAN: An SDN based campus WLAN framework

SWAN: An SDN based campus WLAN framework

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International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace and Electronic systems Technology (Wireless VITAE)

作者： Tao Lei Zhaoming Lu Xiangming Wen Xing Zhao Luhan Wang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing P.R. China Beijing University of Posts and Telecommunications Beijing Beijing CN

In order to provide quality of service (QoS) guarantees to the campus WLAN users, typical campus WLAN systems need to provide a variety of services in a scalable manager. However, the existing campus WLAN solutions are proprietary, closed-source and expensive, which limits the network's flexibility and expansibility. In this paper, a Software Defined networking (SDN) based campus WLAN framework SWAN is proposed. The key conceptual contribution of SWAN is a principled refactoring of campus WLAN into control and data planes. The control plane has a centralized global view of the network and bundle operations into Application Programming Interface (API) for upper applications. Besides, we construct software access point (SAP) to abstract the connection between the user equipment (HE) and access point (AP). network operators can utilize these APIs and the SAP abstraction to design programs to manage and configure the network. Hence, SWAN makes campus WLAN more flexible and expansible.

关键词： Wireless LAN IEEE 802.11 Standards Load management Computer architecture Protocols Handover

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Symbol error rate comparisons of star MQAM schemes based on equal cubic metric

Symbol error rate comparisons of star MQAM schemes based on ...

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International Conference on Telecommunications (ICT)

作者： Lu Yu Tiankui Zhang Chunyan Feng Yao Lu Xiao Han Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Research Department Institute Co. Ltd. Beijing China

In this paper, we present several schemes of N rings star M-ary quadrature amplitude modulation (NR-MQAM) with independent bit mapping. The theoretical expression of symbol error rate (SER) for NR-MQAM is derived and compared with that of cross or square MQAM. For NR-MQAM, the ring ratio is selected based on the principle that its cubic metric (CM) value is equal to that of cross or square MQAM. The theoretical SER curves and numerical simulation results show that 4R-32QAM, 8R-64QAM and 8R-256QAM have a lower SER and stronger ability to resist the phase errors than other 32QAMs, 64QAMs and 256QAMs. The validity of simulated results is demonstrated by the minimum Euclidean distance.

关键词： Quadrature amplitude modulation Euclidean distance Phase modulation Telecommunications Error probability Error analysis

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Decentralized Nonlinear Precoding Algorithm for Multi-cell Coordinated systems

Decentralized Nonlinear Precoding Algorithm for Multi-cell C...

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IEEE Global Communications Conference

作者： Zhirui Hu Chunyan Feng Tiankui Zhang Qiubin Gao Shaohui Sun Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China State Key Laboratory of Wireless Mobile Communications (CATT) Beijing China State Key Laboratory of Wireless Mobile Communications (CATT) Beijing China

Multi-cell coordinated system is an attractive way of improving data rate, by serving one user through several base stations (BSs). BSs might share both data and their channel state information (CSI), but the demand on backhaul capacity makes it inflexible. In this paper, we consider the case with BSs sharing data dedicated to users but having only local CSI, and propose a decentralized nonlinear precoding algorithm for multi-cell coordinated system with multi-stream multi-antenna users. The proposed algorithm is designed to eliminate the inter-user interference and the inter-stream interference, and meanwhile to achieve equal performance for streams of each user. In the proposed algorithm, Tomlinson-Harashima precoding is applied to eliminate partial interference, and transmit space matrix is designed to eliminate the other interference. After the interference elimination, closed-form expression of the transmit and receive processing matrix are derived to maximize the minimum signal to interference plus noise ratio for streams of each user. Simulation results show that, compared with the decentralized linear precoding, the proposed algorithm achieves better performance.

关键词： Interference Signal processing algorithms Algorithm design and analysis Complexity theory Signal to noise ratio

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Correlation Model for User Perceived Web Quality

Correlation Model for User Perceived Web Quality

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2014 4th IEEE International Conference on Information Science and Technology

作者： Boya Liu Feng liu Wenhui Lin Qin Wang Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications School of electronic engineering Beijing University of Posts and Telecommunications

关键词： Pearson Correlation Model for User Perceived Web Quality Web Model

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2.35 GHz near ground wideband channel measurement and characterization

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Journal of Information and Computational Science 2013年第2期10卷 335-343页

作者： Zhao, Min Wu, Muqing Yu, Deshui Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing 100876 China

The increasing interest that has been drawn to wireless sensor network technology is therefore required measurement and analysis of wideband mobile channel with near ground antennas. Using slippage correlation algorithm, a typical suburban environment was analyzed to compare the system performance in 2.33-2.37 GHz, with antenna elevation and sensor's velocity as only variables. Large and small-scale characteristics are both investigated. Results such as channel impulse response, power delay profile, paths number, delay spread, Doppler spectrum, path loss exponent and shadowing parameter are extracted, evaluated and reported.

关键词： Wireless sensor networks

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EM wave propagation in non-uniform soil

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Information Technology Journal 2013年第19期12卷 5011-5016页

作者： Li, Li Dong, Na Chen, Jianya Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications 100876 Beijing China

As an emerging research field, Wireless Underground Sensor network (WUSN) is getting more and more focused these years because of its tremendous application benefit in agriculture, industry, military and so on. As the determinant of the performance of WUSN, the propagation characteristics of electromagnetic (EM) wave in the soil must be deeply investigated. Usually the soil is assumed ideal and uniform in existing works which results in a non-ignorable discrepancy to the reality of underground propagation. In this study, the propagation of EM wave in non-uniform soil is theoretically analyzed. Moreover, a novel simulation method for it based on Kriging interpolation and ADI-FDTD is proposed, based on which the propagation of 300 MHz EM wave in non-uniform soil is simulated and analyzed. The results expose the striking impact of non-homogeneity of the soil to the underground EM wave propagation performance which must be seriously taken into account when design and construct WUSNs. © 2013 Asian network for Scientific Information.

关键词： Electromagnetic waves

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A DYNAMIC BANDWIDTH PLANNING ALGORITHM BASED ON ODUFLEX

A DYNAMIC BANDWIDTH PLANNING ALGORITHM BASED ON ODUFLEX

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The 13th International Conference on Optical Communications and networks, ICOCN 2014(2014第13届光通信与网络国际会议)

作者： Yang Su Hui Li Yuefeng Ji Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications No.10 Xi Tu Cheng Road100876BeijingP.R.China

Under the situation that the existing ODU rates were not efficient to meet the new requirement,this paper provides an optical network planning based on ODUflex to decrease the waste of bandwidth to solve this problem.

关键词： optical network planning ODU ODUflex

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Multi-Cell Coordinated Scheduling and Power Allocation in Downlink LTE-A systems

Multi-Cell Coordinated Scheduling and Power Allocation in Do...

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IEEE Vehicular Technology Conference

作者： Jian Yu Geoffrey Ye Li Changchuan Yin Suwen Tang Xiaolong Zhu Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications School of Electrical and Computer Engineering Georgia Institute of Technology Huawei Shanghai Research Institute

ISBN: (纸本)9781479944484

In this paper, we investigate multi-cell coordinated scheduling and power allocation in downlink long term evolution advanced (LTE-A) systems, where orthogonal frequency division multiple-access (OFDMA) is used. The proposed scheme performs joint scheduling, power allocation, and modulation and coding scheme (MCS) selection to maximize the overall weighted throughput with proportional fairness. Our scheme considers the practical constraints in LTE-A systems. Since the optimization problem is a combinatorial and non-convex one and is with high complexity, low-complexity and suboptimal algorithms are proposed, which separate the scheduling and power allocation into two subproblems. Simulation results show that the proposed scheme can improve the average system throughput by 10% and the 10th percentile throughput by 15% compared with the existing scheme.

关键词： Resource management Throughput Interference Signal to noise ratio Indexes Optimization Scheduling

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