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arXiv 2023年

作者： Li, Zheng Guo, Caili Wang, Xin Feng, Zerun Wang, Yanjun The Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China The Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China China Telecom Digital Intelligence Technology Co. Ltd. Beijing100035 China

Image-Text Retrieval (ITR) is essentially a ranking problem. Given a query caption, the goal is to rank candidate images by relevance, from large to small. The current ITR datasets are constructed in a pairwise manner. Image-text pairs are annotated as positive or negative. Correspondingly, ITR models mainly use pairwise losses, such as triplet loss, to learn to rank. Pairwise-based ITR increases positive pair similarity while decreasing negative pair similarity indiscriminately. However, the relevance between dissimilar negative pairs is different. Pairwise annotations cannot reflect this difference in relevance. In the current datasets, pairwise annotations miss many correlations. There are many potential positive pairs among the pairs labeled as negative. Pairwise-based ITR can only rank positive samples before negative samples, but cannot rank negative samples by relevance. In this paper, we integrate listwise ranking into conventional pairwise-based ITR. Listwise ranking optimizes the entire ranking list based on relevance scores. Specifically, we first propose a Relevance Score Calculation (RSC) module to calculate the relevance score of the entire ranked list. Then we choose the ranking metric, Normalised Discounted Cumulative Gain (NDCG), as the optimization objective. We transform the non-differentiable NDCG into a differentiable listwise loss, named Smooth-NDCG (S-NDCG). Our listwise ranking approach can be plug-and-play integrated into current pairwise-based ITR models. Experiments on ITR benchmarks show that integrating listwise ranking can improve the performance of current ITR models and provide more user-friendly retrieval results. The code is available at https://***/AAA-Zheng/Listwise_ITR. Copyright © 2023, The Authors. All rights reserved.

关键词： Benchmarking

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A Data Center Load Balancing Algorithm Based on Artificial Bee Colony Algorithm 6

A Data Center Load Balancing Algorithm Based on Artificial B...

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6th IEEE International Conference on Computer and Communications, ICCC 2020

作者： Yao, Guohao Wu, Muqing Yang, Xu Beijing University of Posts and Telecommunications Institute of Information and Communication Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing China

ISBN: (数字)9781728186351

ISBN: (纸本)9781728186351

Aiming at the link congestion and unbalanced load for data center network when scheduling the elephant flow by traditional methods, a load balancing algorithm based on artificial bee colony algorithm IALB (improved artificial bee colony load balancing) is proposed. In the paper we introduce the concept of stability is devoted to selecting the best transmission path for the elephant flow under the multiple constraints of path length, link load, and link stability. In order to find the best path, the algorithm redefines the fitness function according to the number of large flows on the link, the real-time load of the link, and the link stability. Experimental results show that, compared with the traditional ECMP algorithm and Hedera algorithm, the IALB algorithm can perform better in terms of link utilization and network throughput. © 2020 IEEE.

关键词： Scheduling

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FC-BET: A Fast Consecutive Beam Tracking Scheme for MmWave Vehicular Communications

FC-BET: A Fast Consecutive Beam Tracking Scheme for MmWave V...

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IEEE Conference on Wireless Communications and networking

作者： Chen Wang Yawen Chen Zhaoming Lu Xiangming Wen Zifan Wang Luhan Wang Beijing Key Laboratory of Network System Architecture and Convergence Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781728195056;9781728195063

Millimeter wave (mmWave) communication is a promising technique to meet the demands of data-rate hungry applications in vehicular networks. Multiple-input multiple-output (MIMO) and beamforming technique are usually adopted in mmWave communications to overcome the high path and penetration losses. However, the high mobility of vehicles would result in significant beam training overhead in the mmWave vehicular communications. Hence, in this paper, a fast consecutive beam tracking (FC-BET) scheme based on long short-term memory (LSTM) is proposed. By predicting beam angles through the LSTM network consecutively, the overhead caused by frequent beam training in mmWave vehicular communications can be reduced. To evaluate the proposed scheme, a time series channel dataset is built by using sequential vehicle information generated from road traffic simulation software named “Simulation of Urban MObility (SUMO)”. Simulation results show that the FCBET scheme can significantly reduce overhead with an acceptable loss in spectral efficiency compared with conventional beam training schemes.

关键词： Training Spectral efficiency Simulation Roads Time series analysis Traffic control Loss measurement

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An SDN Oriented Loop Detection Mechanism Based on TTL Statistics

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China Communications 2020年第6期17卷 1-12页

作者： Tao Yu Longfei Yu Diyue Chen Hongyan Cui Jilong Wang Institute of Network Science and Cyberspace Tsinghua UniversityBeijing 100084China Beijing Advanced Information Network Key Laboratory School of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China Network System Architecture and Integration Beijing Key Laboratory Beijing 100876China

The rise of the network has injected new impetus into the development of traditional *** to the complexity of the network itself and its network programmability,there is a risk of routing loops occurring in the SDN *** paper proposes a loop detection *** to the Time To Live(TTL)value of the loop packet,there is approximately periodicity in the same *** use sFlow to count the number of packets corresponding to each TTL value of a switch in the loop over a period of time,and perform discrete Fourier transform on the obtained finite-length sequence to observe its frequency domain performance and determine whether there are periodic *** doing so,it is determined whether there is a routing loop,and the purpose of passively detecting the routing loop is *** to existing algorithms,it has advantages in real-time,scalability and false positive *** experimental results show that the routing loop detection algorithm based on TTL statistics in this paper still maintains high judgment accuracy under the scenarios of lower stream sampling rate and smaller detection period.

关键词： SDN Loop Detection TTL sFlow

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Research of Epidemic Dynamics Model Considering Individual Movements and Urban Areas

Research of Epidemic Dynamics Model Considering Individual M...

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IEEE International Conference on network Infrastructure and Digital Content (IC-NIDC)

作者： Boxu Pan Jie Yang Yu Wang Zehao Wang Yuangeng Zhu Zhiqi Zhang Beijing Laboratory of Advanced Information Networks & Beijing Key Laboratory of Network System Architecture and Convergence Beijing China Aisino Corporation Beijing China

ISBN: (纸本)9781665405836

With the rapid spread of COVID-19, hundreds of millions of people worldwide have been infected. In order to cope with the epidemic, experts from various countries have carried out a lot of research works. Most of these works chose to use the traditional SEIR model, but the traditional model doesn't consider the individual's movement in the city. Based on the transmission characteristics of COVID-19, this paper optimized the traditional SEIR model by combining the in-depth mining and processed multiple data, such as the real epidemic data published by some official organizations, as well as data with certain credibility obtained from reference papers, journals or newspapers. Compared with the traditional SEIR model, the proposed model takes into account the impact of individuals' movement and the division of urban functional areas. The outcomes can play a certain role in the prediction and analysis of the spread of the epidemic in cities with regular individuals' movements and functions of urban areas.

关键词： COVID-19 Epidemics Analytical models Urban areas Organizations Predictive models Mathematical models

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Demo: a Hybrid Semantic RAN Protocol Stack Design for 6G system and Its Implementation

arXiv

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arXiv 2025年

作者： Wang, Luhan Niu, Haiwen Lu, Zhaoming Wen, Xiangming Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China

Recently, Semantic Communication (SC) has been recognized as a crucial new paradigm in 6G, significantly improving information transmission efficiency. However, the diverse range of service types in 6G networks, such as high-data-volume services like AR/VR/MR and low-data-volume applications requiring high accuracy, such as industrial control and data collection, presents significant challenges to fully replacing the fundamental technologies with SC. Therefore, we design a Hybrid Semantic Communication Ratio Access network (HSC-RAN) protocol stack demo for 6G systems to achieve compatibility and smooth transition between SC and non-SC. Specifically, we take the Physical Downlink Shared Channel (PDSCH) as an example, to efficiently integrate SC with Orthogonal Frequency Division Multiplexing (OFDM). Furthermore, we introduce a novel Downlink Control Information (DCI) format that jointly supports SC and non-SC, enabling real-time video transmission via SC and text transmission through non-SC. Experimental results demonstrate that our approach allows simultaneous transmission of semantic and non-semantic information while maintaining high-quality reconstruction at the receiver. © 2025, CC BY.

关键词： Orthogonal frequency division multiplexing

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Visible Light Positioning Based on a Single Luminaire: A Novel Visual Odometry Assisted Algorithm

Visible Light Positioning Based on a Single Luminaire: A Nov...

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IEEE International Conference on Communications (ICC)

作者： Zhiyu Zhu Yang Yang Mingzhe Chen Caili Guo Yipeng Bai Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China Department of Electrical and Computer Engineering Institute for Data Science and Computing University of Miami Coral Gables FL USA Beijing Laboratory of Advanced Information Networks School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

Visible light positioning (VLP) is a promising positioning technique, which, however, typically requires multiple luminaires to achieve accurate positioning. This paper proposes a novel visual odometry (VO) assisted visible light positioning algorithm (VO-VLP) in achieving positioning with only a single luminaire. In the considered model, a user equipped with a camera jointly uses geometric features in the captured images and coordinates information obtained via visible light communication (VLC) for positioning. The proposed VLP algorithm does not rely on any extra inertial measurement unit and relaxes the tilted angle limitation at the user. In particular, VO-VLP first uses the circle feature of a luminaire to obtain dual normal vectors of the luminaire. Then, the basic principle of VO is used to eliminate the wrong normal vector by exploiting the geometric features in two consecutive images captured when the user moves. Finally, the pose and location of the user are obtained by using an artificially marked point on the luminaire's contour. VO-VLP can achieve accurate positioning with only a single luminaire and a camera. Simulation results show that the proposed indoor positioning algorithm can achieve a 97th-percentile positioning accuracy of around 10 cm.

关键词：

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Camera assisted received signal strength algorithm for indoor visible light positioning

Camera assisted received signal strength algorithm for indoo...

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2021 IEEE/CIC International Conference on Communications in China, ICCC 2021

作者： Li, Chengyang Yang, Yang Bai, Lin Yu, Bei Guo, Caili Xia, Hailun School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing100876 China China Shipbuilding Industry Systems Engineering Research Institute Beijing100094 China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing Laboratory of Advanced Information Networks Beijing100876 China

ISBN: (纸本)9781665443852

In this paper, a camera assisted received signal strength (CA-RSS) algorithm is proposed for visible light positioning (VLP) systems. The basic idea of CA-RSS is to simultaneously utilize visual and strength information of visible lights to achieve accurate positioning at low cost. With rectangular LED layout, the irradiance angles of the visible lights can be estimated regardless of the orientations of the LEDs. Based on the estimated irradiance angles, the distances between the LEDs and the receiver are obtained. Then, the two-dimensional (2D) position of the receiver can be calculated at low cost using a linear least square method. Based on the solid geometry theory, we further propose an independent solution method for three-dimensional (3D) positioning, which can avoid error propagation issue of dependent solution method. Moreover, considering the imperfect channel model in practice, we propose a calibration method of Lambertian model for practical uses. Simulation results show that the proposed approach can achieve 80th percentile accuracies of less than 10 cm for 3D positioning regardless of the orientations of the LEDs and the receiver. In addition, experimental results show that the proposed algorithm achieves an average 3D positioning error of 4.48 cm in a 70 cm × 70 cm × 140 cm space. © 2021 IEEE.

关键词： Light emitting diodes

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Reinforcement Learning for Task Offloading in Mobile Edge Computing for SDN based Wireless networks 7

Reinforcement Learning for Task Offloading in Mobile Edge Co...

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7th International Conference on Software Defined systems, SDS 2020

作者： Kiran, Nahida Pan, Chunyu Changchuan, Yin University of Posts and Telecommunications Beijing Key Laboratory of Network Systeiii Architecture and Convergence Beijing Beijing China

ISBN: (纸本)9781728172194

The explosive growth of the distributed computing resources in mobile edge computing (MEC) create a necessity to have a reasonable controller to ensure efficient utilization of distributed computing resources. The software defined networks (SDNs) capabilities can be used in MEC environment to reduce the energy consumption of user device without service disruptions. SDN, which is not proposed specifically for edge computing, can in fact serve as an enabler to let the real potential of edge computing be achieved and to lower the complexity barriers involved. This paper investigates resource allocation problem in wireless MEC by aiming to save the battery power of user device. Learning from experience plays an important role in a SDN based MEC infrastructure where reinforcement learning (RL) takes a long term goal into consideration besides immediate reward, which is very important for a dynamic environment. A novel software defined edge cloudlet (SDEC) based RL optimization framework is proposed in this paper to tackle the energy minimization problem in wireless MEC. Specifically, Q-learning and cooperative Q-learning based RL schemes are proposed for the intractable problem. Simulation results reveal that the proposed scheme achieves superior performance in saving the battery power of a user device compared to other benchmark methods such as Q-learning with a random algorithm and Q-learning with epsilon greedy. © 2020 IEEE.

关键词： Wireless networks

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Mobility-aware seamless handover with MPTCP in software-defined hetnets

arXiv

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arXiv 2021年

作者： Tong, Haonan Wang, Tao Zhu, Yujiao Liu, Xuanlin Wang, Sihua Yin, Changchuan The Beijing Key Laboratory of Network System Architecture and Convergence Beijing100876 China The Beijing Advanced Information Network Laboratory Beijing University of Posts and Telecommunications Beijing100876 China

In this paper, the problem of vertical handover in software-defined network (SDN) based heterogeneous networks (HetNets) is studied. In the studied model, HetNets are required to offer diverse services for mobile users. Using an SDN controller, HetNets have the capability of managing users’ access and mobility issues but still have the problems of ping-pong effect and service interruption during vertical handover. To solve these problems, a mobility-aware seamless handover method based on multipath transmission control protocol (MPTCP) is proposed. The proposed handover method is executed in the controller of the software-defined HetNets (SDHetNets) and consists of three steps: location prediction, network selection, and handover execution. In particular, the method first predicts the user’s location in the next moment with an echo state network (ESN). Given the predicted location, the SDHetNet controller can determine the candidate network set for the handover to preallocate network wireless resources. Second, the target network is selected through fuzzy analytic hierarchical process (FAHP) algorithm, jointly considering user preferences, service requirements, network attributes, and user mobility patterns. Then, seamless handover is realized through the proposed MPTCP-based handover mechanism. Simulations using real-world user trajectory data from Korea Advanced Institute of Science & Technology show that the proposed method can reduce the handover times by 10.85% to 29.12% compared with traditional methods. The proposed method also maintains at least one MPTCP subflow connected during the handover process and achieves a seamless handover. Copyright © 2021, The Authors. All rights reserved.

关键词： Heterogeneous networks

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