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13th International Symposium on Wireless Communication systems, ISWCS 2016

作者： Liu, Tang Xia, Hailun Chunyan, Feng 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)9781509020614

Wireless multimedia traffic has increased considerably in recent years, which puts forward higher demand on the capacity of existing network. Multicast, as a transmission strategy with high spectral efficiency, has not been widely studied in heterogeneous cellular network (HetNet). In this paper, we propose a QoS-based multi-rate multicast scheme over HetNet to effectively improve the system throughput while guaranteeing the quality of service (QoS) of the whole system. We formulate an expression of system throughput of the proposed multicast scheme and decouple it into three subproblems for its computational complexity, namely, user association (UA), subgroup formation (SF) and resource allocation (RA). In UA, we present a traffic-oriented access method based on reference signal receiving power (RSRP). In SF, the associated users are divided into several subgroups according to their channel state information (CSI) and the users in one subgroup are served with the same rate determinated by the CSI level of the subgroup. In RA, fractional frequency reuse (FFR) mechanism is used to eliminate the co-channel cross-tier interference between macro base station (MBS) and small base stations (SBS). And QoS is considered both in subcarrier allocation and power allocation processes. Simulation results show that the system throughput is significantly improved while QoS is guaranteed by using our scheme. © 2016 IEEE.

关键词： Quality of service

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Diffraction Loss of Mobile Communications Electromagnetic Wave in L-corridor

Diffraction Loss of Mobile Communications Electromagnetic Wa...

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The 5th International Symposium on Electromagnetic Compatibility

作者： ZHOU Feng MA Zhen ZHANG Hai-man GAO Feng YUAN Xiu-hua ZHANG Xiang-yang China Academy of Information and Communication Technology China Mobile Communications Group Shan-xi Co.Ltd.Network Optimization Center School of Electronic Engineering Beijing University of Posts and Telecommunication Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunication

Diffraction loss exists in the corner of L-corridor in *** measurement and simulation show that conventional diffraction propagation model does not fit *** diffraction loss increases linearly with frequency on 0.831 G... 详细信息

关键词： L-corridor diffraction loss mobile communication

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An effective visual saliency detection method based on maximum entropy random walk

An effective visual saliency detection method based on maxim...

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2016 IEEE International Conference on Multimedia and Expo Workshop, ICMEW 2016

作者： Lu, Jingyu Wen, Xiangming Hua, Shao Lu, Zhaoming Chen, Yawen Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications 100876 China

ISBN: (纸本)9781509015528

Visual saliency detection (VSD) has been attracting increasing attention due to its wide applications in computer visions. In this paper, a visual saliency detection method based on maximum entropy random walk (MEVSD) is proposed. Gaze wandering over images is modeled as a random walk process on a graph, in which the super-pixels and their similarities are regarded as nodes and edges respectively. The visual salient region is detected based on the stationary distribution of the stochastic process. Compared with the stat-of-the-art methods, MEVSD focuses on globally maximizing the entropy of walking trajectories. A two-tier neighbor scheme of super-pixels is proposed to reduce the computational complexity. Besides, a belief diffusion algorithm on weight matrix is proposed to improve precision rate. Extensive experiments with diverse content of pictures indicate that MEVSD performs well compared with 11 state-of-the-art methods. © 2016 IEEE.

关键词： Random processes

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An autonomous system collaboration caching strategy based on content popularity in CCN 27

An autonomous system collaboration caching strategy based on...

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

作者： Kaili, Wang Muqing, Wu Min, Zhao Yanqing, Cheng Beijing Key Laboratory of Network System Architechture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509032549

The Content-Centric network (CCN) is a very important structure in the future network, in which every node has caching ability. Caching strategy has a decisive influence on the performance of the CCN. In this paper, an Autonomous system Collaboration Caching Strategy (ASCCS) is proposed to achieve the explicit collaboration, reduce the cache redundancy, improve the cache utilization rate and increase the cache hit rate. Firstly, the network is divided into several Autonomous systems (AS) before carrying out the centralized control. Then we select the control nodes according to the betweenness and the cache replacement rate of the nodes. Each AS is centralized controlled by the control node. At the same time, the selected control node computes the popularity statistics of different contents to determine the suitable cache policy for them. Under this strategy, nodes in the same AS cooperate with each other, which improves the transparency of the network cache, and thereby achieve the cache performance gain of the CCN. It makes the optimal performance of the cache become possible. © 2016 IEEE.

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Echo State Transfer Learning for Data Correlation Aware Resource Allocation in Wireless Virtual Reality

Echo State Transfer Learning for Data Correlation Aware Reso...

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Asilomar Conference on Signals, systems, and Computers

作者： Mingzhe Chen Walid Saad Changchuan Yin Merouane Debbah Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China Wireless@VT Virginia Tech Blacksburg VA USA Huawei France R&D Mathematical and Algorithmic Sciences Lab Paris France

In this paper, the problem of data correlation-aware resource management is studied for a network of wireless virtual reality (VR) users communicating over cloud-based small cell networks (SCNs). In the studied model, small base stations (SBSs) with limited computational resources act as VR control centers that collect the tracking information from VR users over the cellular uplink and send them to the VR users over the downlink. In such a setting, VR users may send or request correlated or similar data (panoramic images and tracking data). This potential spatial data correlation can be factored into the resource allocation problem to reduce the traffic load in both uplink and downlink. This VR resource allocation problem is formulated as a noncooperative game that allows jointly optimizing the computational and spectrum resources, while being cognizant of the data correlation. To solve this game, a transfer learning algorithm based on the machine learning framework of echo state networks (ESNs) is proposed. Unlike conventional reinforcement learning algorithms that must be executed each time the environment changes, the proposed algorithm can intelligently transfer information on the learned utility, across time, to rapidly adapt to environmental dynamics due to factors such as changes in the users' content or data correlation. Simulation results show that the proposed algorithm achieves up to 16.7% and 18.2% gains in terms of delay compared to the Q-learning with data correlation and Q-learning without data correlation. The results also show that the proposed algorithm has a faster convergence time than Q-learning and can guarantee low delays.

关键词： Correlation Uplink Delays Wireless communication Downlink Resource management Games

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A tri-band bandpass filter with wide stop band based on quad-mode stub loaded resonator

A tri-band bandpass filter with wide stop band based on quad...

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IEEE International Symposium on Electromagnetic Compatibility (EMC-beijing)

作者： Zhentao Zhao Shufang Li Jianfeng Zhu Meijun Qu Yang Kang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing People's Republic of China Police Key Laboratory of IoT Application of the Ministry of Public Security of P.R.C First Research Institute of the Ministry of Public Security of PRC Beijing People's Republic of China

This paper presents a tri-band bandpass filter with high design flexibility in symmetrical structure and a wide stopband by using quad-mode stub loaded resonator. Stub-to-stub coupling is introduced to split two identical modes and produce two transmission zeros. The harmonic passband can be typically eliminated by regularly embedding open-circuited stubs in the feeding structure without affecting the performance of the three passbands. A filter prototype is simulated to validate the proposed design. The results show a desired wide upper stopband at 8.8 GHz with rejection better than 20 dB and three passbands are centered at 2.45 GHz, 3.68 GHz, and 5.19 GHz respectively, which is applicable to WLAN and WiMAX applications.

关键词： Band-pass filters Resonant frequency Passband Resonator filters Harmonic analysis Power harmonic filters Couplings

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Modelling and Forecasting of Commodity Trading Price

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Journal of Physics: Conference Series 2018年第1期1060卷

作者： Jun Liu Yuan Tian Qing Yan Center for Data Science BUPT Beijing 100876 China. School of Information and Communication Engineering BUPT Beijing 100876 China. Beijing Laboratory of Advanced Information Networks BUPT Beijing 100876 China. Beijing Key Laboratory of Network System Architecture and Convergence BUPT Beijing 100876 China.

This paper proposes and improves a model for China's cotton reserves trading market, generates a more accurate price level table in contrast to the widely used China Cotton Association(CCA)'s table, and predicts the future trading price with this model. Data used is all 29895 trade records of cotton reserves from May, 2016 to Sept, 2016. In this paper, we firstly give a briefly introduction to the data as well as basic knowledge of cotton, especially the CCA's price level table as the target to improve accuracy. We then present a multiple linear regression with dummy variable model, which can reduce the error on predicting the trading price of current month, but still remains some problems such as the result shows a batch of cotton with better quality may get a lower price. So we finally advance the model with multidimensional isotonic regression and more factors taken into consideration. Our last model could be used to predict the trade price of both current month and next month with approximately 4% mean absolute percentage error(MAPE).

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Joint remote radio head activation and beamforming for energy efficient C-RAN 13

Joint remote radio head activation and beamforming for energ...

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13th International Symposium on Wireless Communication systems, ISWCS 2016

作者： Yan, Zeng Wen, Xiangming Lu, Zhaoming Chen, Yawen Shao, Hua Beijing Laboratory of Advanced Information Networks Beijing Advanced Innovation Center for Future Internet Technology Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509020614

The cloud radio access network (C-RAN) has emerged as a promising architecture to provide extremely high throughput with fantastic energy efficiency (EE) performance. However, as all the RRHs need to be connected to the baseband unit pool (BBU) through transport links, the transmit power consumption becomes significant, which result in the demands of new researches in energy efficiency optimization. In this paper, we focus on the dynamic remote radio head (RRH) activation and network EE optimization in order to fully reap the benefits brought by Green C-RAN. First, an EE optimization problem that jointly considers RRH activation and group sparse beamforming is formulated, which is hard to solve due to its non-convexity nature. Thus, we utilize the weighted minimal mean square error (WMMSE) method to transfer the non-convex EE problem into a concave-convex fractional program problem. And the Lagrangian theory is exploited to assist the problem analysis and algorithm design. Specifically, the weighted group sparse beamforming algorithm is proposed. In this algorithm, we adopt the mixed l1=lp-norm to induce group sparsity in the beamformers, which corresponds to switching off RRHs. Simulation results will show that the proposed algorithm can significantly improve the EE for C-RAN. © 2016 IEEE.

关键词： Energy efficiency

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A fair listen-before-talk mechanism for LTE-U using a coalition formation approach 13

A fair listen-before-talk mechanism for LTE-U using a coalit...

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13th International Symposium on Wireless Communication systems, ISWCS 2016

作者： Wuqiong, Ding Wen, Xiangming Lu, Zhaoming Wenpeng, Jing Yan, Zeng Beijing Key Laboratory of Network System Architecture and Convergence Beijing Advanced Innovation Center for Future Internet Technology Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781509020614

LTE on unlicensed bands (LTE-U), which is a promising way to meet the increasing mobile data demand, has attracted world-wide interests. However, the fair coexistence of LTE-U and WLAN is a critical issue to be solved. In this paper, we devise a semi-distributed channel access approach for LTE-U in dense deployed scenario to improve its capacity and achieve fair coexistence with WLAN. Specifically, the basic listen-before-talk (LBT) mechanism is employed to guarantee the fairness for WLAN, which is similar with the medium control access (MAC) protocol of WLAN. However, in order to decrease the high collision probability at heavy traffic load, a coalition strategy is introduced, in which the LTE-U base stations (BSs) would form into groups, and each group would contend for accessing the channel as one entity. This will effectively reduce the number of stations contending for accessing the channel and the collision probability as a result. In particular, in order to obtain the coalition solution, the cooperative game theory is introduced, and a low-complexity coalition formation algorithm is proposed based on the concept of recursive core in cooperative game. Simulation results verify the effectiveness of the proposed channel access approach, especially improving the LTE-U capacity and ensuring the fairness between LTE-U and WLAN. © 2016 IEEE.

关键词： Medium access control

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Oscillation resolution for massive cell phone traffic data 1

Oscillation resolution for massive cell phone traffic data

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1st Workshop on Mobile Data, MobiData 2016, co-located with MobiSys 2016

作者： Qi, Ling Qiao, Yuanyuan Abdesslem, Fehmi Ben Ma, Zhanyu Yang, Jie Center for Data Science Beijing Key Laboratory of Network System Architecture and Convergence Beijing Laboratory of Advanced Information Network BUPT Beijing China Decisions Networks and Analytics Laboratory SICS Stockholm Sweden Center for Data Science Pattern Recognition and Intelligent System Lab BUPT Beijing China

ISBN: (纸本)9781450343275

Cellular towers capture logs of mobile subscribers whenever their devices connect to the network. When the logs show data traffic at a cell tower generated by a device, it reveals that this device is close to the tower. The logs can then be used to trace the locations of mobile subscribers for different applications, such as studying customer behaviour, improving location-based services, or helping urban planning. However, the logs often suffer from an oscillation phenomenon. Oscillations may happen when a device, even when not moving, does not only connect to the nearest cell tower, but is instead unpredictably switching between multiple cell towers because of random noise, load balancing, or simply dynamic changes in signal strength. Detecting and removing oscillations are a challenge when analyzing location data collected from the cellular network. In this paper, we propose an algorithm called SOL (Stable, Oscillation, Leap periods) aimed at discovering and reducing oscillations in the collected logs. We apply our algorithm on real datasets which contain about 18.9 TB of traffic logs generated by more than 3 million mobile subscribers covering about 21000 cell towers and collected during 27 days from both GSM and UMTS networks in northern China. Experimental results demonstrate the ability and effectiveness of SOL to reduce oscillations in cellular network logs. © 2016 ACM.

关键词： Location based services

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