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Dynamic hybrid multimedia distribution scheme based on network reconfiguration

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Science China(Information Sciences) 2014年第10期57卷 107-116页

作者： DONG Fang hu yuxiang LAN JuLong National Digital Switching System Engineering and Technological Research Center

This paper addresses a key challenge in the design and implementation of multimedia distribution systems so that users can experience good performance with minimal operational costs. In current structures,the conflict between network architectures and service provision causes a decline in users’ expectations of quality. Network reconfiguration provides a feasible solution for dynamic distribution as a primitive for both quality and efficiency. In this paper, we first present a scheme for a layer-based hybrid multimedia distribution system LHMDS, and then introduce a dynamic sliding push-delivery mechanism based on reconfiguration of the distribution of hotspot files. The LHMDS adopts a unique structure with hybrid channels, including broadcast and unicast ones, and adjusts its distribution topology according to the congestion status, thereby pushing hotspot files dynamically. The mechanism dynamically pushes files to upper or lower network layers depending on the network status while distributing hotspot files by broadcast channels and other files by unicast *** guarantees service quality as well as improving resource utilization. Finally, we validate the feasibility and performance of the scheme through a simulation.

关键词： network reconfiguration hybrid distribution dynamic sliding push-delivery

A Reconfigurable Hardware Architecture for Packet Processing

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Chinese Journal of Electronics 2018年第2期27卷 428-432页

作者： DUAN Tong LAN Julong hu yuxiang LIU Shiran National Digital Switching System & Engineering Technological Research Center

In this paper, we propose a reconfigurable packet processing hardware architecture for future switch,in which several protocol-independent action units are introduced to remove the protocol dependence of conventional packet processors. With the proposed architecture,any specified header fields can be mapped into the right action unit, so that the processor can meet any packet processing demands. To reduce the hardware resource cost,the processor cost model and optimization algorithm are proposed. The Net FPGA-based implementation shows a throughput of 94 Gb/s with 64-B packets. The programmability cost is approximately 1.5 times of conventional design, which consumes only 8% of the total FPGA resources.

关键词： Packet processing Hardware architecture Reconfigurable Protocol-independent

Providing Customized Security Based on Network Function Composition and Reconfiguration

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China Communications 2016年第S1期13卷 177-189页

作者： hu yuxiang LI Yufeng XING Chiqiang LIAO Jianxin National Digital Switching System Engineering & Technological Research Center State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Real-time multimedia sharing in Consumer-centric Multimedia Network(CMN) requires usability anywhere, anytime and from any device. However, CMNs are usually located or implemented on application layer, which makes CMNs subjected to their fixed substrate security framework. A fundamental diversifying attribute for the customized security experiences of CMNs is pressing. This paper proposes a programmable network structure which is named Service Processing Chain(SPC) based on network function combination. The SPC is established by the ordinal combination of network functions in substrate switches dynamically, and therefore constructs a special channel for each CMN with required security. The construction and reconfiguration algorithms of SPC are also discussed in this paper. Evaluations and implementation show that above approaches are effective in providing multilevel security with flexibility and expansibility. It is believed that the SPC could provide customized security service and drive participative real-time multimedia sharing for CMNs.

关键词： consumer-centric multimedia network customized security network function combination service processing chain

Using the Cooperative Game for Service Placement of Virtual Network Functions

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China Communications 2016年第S1期13卷 146-157页

作者： XIONG Gang hu yuxiang WANG Weiming WANG Lingqiang National Digital Switching System Engineering and Technological R&D Center School of Information and Electronic Engineering Zhejiang Gongshang University Zhongxing Telecommunication Equipment Corporation

To address the issues that middleboxes as a fundamental part of today's networks are facing, Network Function Virtualization(NFV)has been recently proposed, which in essence asserts to migrate hardware-based middleboxes into software-based virtualized function *** to the demands of virtual services placement in NFV network environment, this paper models the service amount placement problem involving with the resources allocation as a cooperative game and proposes the placement policy by Nash Bargaining Solution(NBS). Specifically,we first introduce the system overview and apply the rigorous cooperative game-theoretic guide to build the mathematical model, which can give consideration to both the responding efficiency of service requirements and the allocation *** a distributed algorithm corresponding to NBS is designed to achieve predictable network performance for virtual instances ***, with simulations under various scenarios,the results show that our placement approach can achieve high utilization of network through the analysis of evaluation metrics namely the satisfaction degree and fairness index. With the suitable demand amount of services, the average values of two metrics can reach above 90%. And by tuning the base placement, our solution can enable operators to flexibly balance the tradeoff between satisfaction and fairness of resourcessharing in service platforms.

关键词： Middlebox game theory network function virtualization software defined networking

ESMD-Flow: An Intelligent Flow Forwarding Scheme with Endogenous Security Based on Mimic Defense in Space-Air-Ground Integrated Network

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China Communications 2022年第1期19卷 40-51页

作者： Ziyong Li yuxiang hu Di Zhu JiangxingWu Yunjie Gu PLA Strategic Support Force Information Engineering University Zhengzhou 450002China 61660 Unit of PLA Beijing 100089China

The Space-Air-Ground Integrated Network(SAGIN) realizes the integration of space, air,and ground networks, obtaining the global communication ***-Defined Networking(SDN) architecture in SAGIN has become a promising solution to guarantee the Quality of Service(QoS).However, the current routing algorithms mainly focus on the QoS of the service, rarely considering the security requirement of flow. To realize the secure transmission of flows in SAGIN, we propose an intelligent flow forwarding scheme with endogenous security based on Mimic Defense(ESMD-Flow). In this scheme, SDN controller will evaluate the reliability of nodes and links, isolate malicious nodes based on the reliability evaluation value, and adapt multipath routing strategy to ensure that flows are always forwarded along the most reliable multiple paths. In addition, in order to meet the security requirement of flows, we introduce the programming data plane to design a multiprotocol forwarding strategy for realizing the multiprotocol dynamic forwarding of flows. ESMD-Flow can reduce the network attack surface and improve the secure transmission capability of flows by implementing multipath routing and multi-protocol hybrid forwarding mechanism. The extensive simulations demonstrate that ESMD-Flow can significantly improve the average path reliability for routing and increase the difficulty of network eavesdropping while improving the network throughput and reducing the average packet delay.

关键词： space-air-ground integrated network(SAGIN) endogenous security multipath routing multi-protocol forwarding

EARS: Intelligence-Driven Experiential Network Architecture for Automatic Routing in Software-Defined Networking

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China Communications 2020年第2期17卷 149-162页

作者： yuxiang hu Ziyong Li Julong Lan Jiangxing Wu Lan Yao Information Engineering University

Software-Defined Networking(SDN)adapts logically-centralized control by decoupling control plane from data plane and provides the efficient use of network ***,due to the limitation of traditional routing strategies relying on manual configuration,SDN may suffer from link congestion and inefficient bandwidth allocation among flows,which could degrade network performance *** this paper,we propose EARS,an intelligence-driven experiential network architecture for automatic *** adapts deep reinforcement learning(DRL)to simulate the human methods of learning experiential knowledge,employs the closed-loop network control mechanism incorporating with network monitoring technologies to realize the interaction with network *** proposed EARS can learn to make better control decision from its own experience by interacting with network environment and optimize the network intelligently by adjusting services and resources offered based on network requirements and environmental *** the network architecture,we design the network utility function with throughput and delay awareness,differentiate flows based on their size characteristics,and design a DDPGbased automatic routing algorithm as DRL decision brain to find the near-optimal paths for mice and elephant *** validate the network architecture,we implement it on a real network *** simulation results show that EARS significantly improve the network throughput and reduces the average packet delay in comparison with baseline schemes(***,ECMP).

关键词： software-defined networking(SDN) intelligence-driven experiential network deep reinforcement learning(DRL) automatic routing

Modulating charge separation and transfer for high-performance photoelectrodes via built-in electric field

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1126-1146页

作者： Houyan Cheng Peng Liu Yuntao Cui Ru Ya yuxiang hu Jinshu Wang Key Laboratory of Advanced Functional Materials of Education Ministry of China Faculty of Engineering and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Cryogenic Science and Technology and Beijing Key Lab of Cryo-Biomedical Engineering Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Inner Mongolia Academy of Science and Technology Hohhot 010020China

Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical ***,considerable efforts have been devoted to this *** review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and ***,mechanisms and tuning strategies for built-in electric fields are ***,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface ***,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.

关键词： photoelectrochemical water splitting bulk built-in electric field cation intercalation charge separation and transfer

A Safe and Reliable Heterogeneous Controller Deployment Approach in SDN

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China Communications 2021年第8期18卷 47-61页

作者： Peng Yi Tao hu Yanze Qu Liang Wang Hailong Ma yuxiang hu Julong Lan National Digital Switching System Engineering and Technological Research Center Zhengzhou 450002HenanChina Information Engineering University Zhengzhou 450001HenanChina

Software-Defined Networking(SDN)provides flexible and global network management by decoupling control plane from data plane,and multiple controllers are deployed in the network in a logically centralized and physically distributed ***,the existing approaches generally deploy the controllers with the same type in the network,which easily causes homogeneous controller common-mode *** this end,this paper proposes heterogeneous controller deployment in the SDN,considering the different types of controllers and relevant criteria(e.g.,delay,control link interruption rate,and controller fault rate).Then,we introduce a Safe and Reliable Heterogeneous Controller Deployment(SRHCD)approach,consisting of two *** 1 determines the type and the number of heterogeneous controllers required for the SDN network based on the dynamic *** 2 divides the SDN network into multiple subnets by k-means algorithm and improves the genetic algorithm to optimize the heterogeneous controller deployment in these SDN subnets to ensure reliable switch-controller ***,the simulation results show that the proposed approach can effectively reduce the control plane fault rate and increase the attack ***,the switch-controller delay has been lowered by 16.5%averagely.

关键词： software defined networking control plane reliability safety controller deployment

Uniform MnO2 nanostructures supported on hierar- chically porous carbon as efficient electrocatalysts for rechargeable Li-O2 batteries

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Nano Research 2015年第1期8卷 156-164页

作者： Xiaopeng Han Fangyi Cheng Chengcheng Chen yuxiang hu Jun Chen Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) College of Chemistry Collaborative InnovationCenter of Chemical Science and Engineering Nankai University Tianjin 300071 China

Through in situ redox deposition and growth of MnO2 nanostructures on hierarchically porous carbon （HPC）, a MnOR/HPC hybrid has been synthesized and employed as cathode catalyst for non-aqueous Li-O2 batteries. Owing to the mild synthetic conditions, MnO2 was uniformly distributed on the surface of the carbon support, without destroying the hierarchical porous nanostructure. As a result, the as-prepared MnO2/HPC nanocomposite exhibits excellent Li-O2 battery performance, including low charge overpotential, good rate capacity and long cycle stability up to 300 cycles with controlling capacity of 1,000 mAh·g^-1. A combination of the multi-scale porous network of the shell-connected carbon support and the highly dispersed MnO2 nanostructure benefits the transportation of ions, oxygen and electrons and contributes to the excellent electrode performance.

关键词： lithium-oxygen batteries manganese oxide nanocomposite catalyst oxygen electrochemistry