Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks

A new core-based shared tree algorithm, viz core-cluster combination-based shared tree （CCST） algorithm and the weighted version （i.e. w-CCST algorithm） are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit （LEO） satellite IP networks. The CCST algorithm includes the dynamic approximate center （DAC） core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation, the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization. Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay ofw-CCST algorithm is lower than that of the CCST algorithm.

Novel optimized routing algorithm for LEO satellite IP networks

A lot of routing algorithms have been proposed for low earth orbit（LEO） satellite IP networks in recent years,but most of them cannot achieve global optimization.The dynamic characters of LEO satellite networks are reflected in two aspects：topology and traffic change.The algorithms mentioned above are ＂hard routing＂ which only realize local optimization.A distributed soft routing algorithm combined with multi-agent system（MASSR） is proposed.In MASSR,mobile agents are used to gather routing information actively,and blackboard is introduced to achieve direct information exchange between agents.MASSR provides traffic adaptive routing and tracks the change of LEO satellite network topology.The performance of ant colony optimization（ACO） and MASSR are compared in Iridium constellation,and MASSR presents better end-to-end delay as well as enhanced robustness.

Design and verification of a satellite-terrestrial integrated IP network model for the Global Energy Interconnection

In order to meet the pressing demand for wide-area communication required by the Global Energy Interconnection(GEI),accelerating the construction of satellite-terrestrial Integra怕d networks that can achieve network extension and seamless global coverage has become the focus of power communication tech no logy development.In this study,we propose a satellite-terrestrial integrated network model that can support interconnection and interoperation on the IP layer between the satellite system and the怕rrestrial segment of the existing power communication system.First,the composition and function of the satellite-terrestrial collaborative network are explained.Then,the IP-based protocol stack is described,and a typical applicati on experime nt is con ducted to illustrate the particular process of this protocol stack.Fin ally,a use case of IP interconn ection that depends on GEO satellite communication is detailed.The experime ntal study has showed that the satellite-terrestrial collaborative network can efficiently support various IP applications for the GEI.

A WIRELESS MULTIMEDIA TRANSMISSION CONTROL AlGORITHM OVER HETEROGENEOUS IP NETWORKS

In this paper,an algorithm Wireless Multimedia Transmission Control(WMTC) is proposed for multimedia transmission control over wired-wireless networks.The relationship between packet length and packet loss rate in the Gilbert wireless error model is investigated.Furthermore,the algorithm can detect the nature of packet losses by sending large and small packets alternately,and control the sending rate of nodes.In addition,by means of updating factor K,this algorithm can adapt to the changes of network states quickly.Compared with previous algorithms,simulation results show that WMTC can both improve the networks throughput of multimedia transmissions and reduce the congestion loss rate in various situations.

Research on the Method of Implementing Named Data Network Interconnection Based on IP Network

In order to extend the application scope of NDN and realize the transmission of different NDNs across IP networks,a method for interconnecting NDN networks distributed in different areas with IP networks is proposed.Firstly,the NDN data resource is located by means of the DNS mechanism,and the gateway IP address of the NDN network where the data resource is located is found.Then,the transmission between different NDNs across the IP network is implemented based on the tunnel technology.In addition,in order to achieve efficient and fast NDN data forwarding,we have added a small number of NDN service nodes in the IP network,and proposed an adaptive probabilistic forwarding strategy and a link cost function-based forwarding strategy to make NDN data obtaining the cache service provided by the NDN service node as much as possible.The results of analysis and simulation experiments show that,the interconnectionmethod of NDN across IP network proposed is generally effective and feasible,and the link cost function forwarding strategy is better than the adaptive probability forwarding strategy.

A FUZZY-LOGIC CONTROL ALGORITHM FOR ACTIVE QUEUE MANAGEMENT IN IP NETWORKS

Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.

IP承载网络技术演进方向研究

互联网业务的快速发展对IP承载网络提出了确定性、高可靠性、大带宽、弹性连接等新要求,而运营商业务本身的发展对IP承载网络提出了降本增效、差异化承载、安全可信的需求。基于业务演进对网络的需求、IP新技术的发展,对IP承载网络演进方向开展讨论,旨在打造高质量、差异化承载底座,满足多样化业务需求,提升网络价值,降低网络运营成本,筑牢网络安全底座,保障网络安全。

宽带卫星IP通信网络中数字调制解调技术研究

针对宽带卫星网络之间互连的协议(Internet Protocol,IP)通信网络解调过程中受到非线性通信信道影响,出现信道失真,导致通信信道误码率高的问题,提出宽带卫星IP通信网络中数字调制解调技术。利用I/Q偏压进行数字式调制,避免正交型时引起的信道间干扰。通过星座图调制信号,使其满足恒包络特性,获取星座图向量。求解调制码元中各位元的对数似然比,利用基于通道特征的解调方法,解调振幅畸变和相位畸变的星座图。根据获取的星座图星座点坐标,构建通信信道参数估计模型。使用最小二乘法估计信道参数向量修正的星座图并进行解调,使用四相移相键控解调差分检测方式修正信号幅频,达到更平稳的通信效果。由解调性能实验分析结果可知,该技术能够使解调曲线趋于一条直线,达到频域均衡的目的,且误码率最小为10-5 B,可实现通信网络的高效准确解调。

深度学习在恶意IP识别中的应用

为了加强网络安全防御能力,可以应用深度学习技术来提高对恶意IP的识别准确率。本文介绍了如何应用深度学习中的前馈神经网络来构建恶意IP识别模型。实证分析的结果显示,基于深度学习技术的恶意IP识别模型表现出了更高的准确率和实时性,为网络安全领域提供了一种有效的恶意IP识别解决方案。

全产业链结构对网络文学IP价值开发的影响机制与路径优化研究

IP全产业链开发是催化IP价值,实现文化商品收益规模化的主要手段,也是探索文化科技融合、推动文化产业高质量发展的重要途经。近年来,网络文学IP经历了资本大规模导入的快速扩张期和资本转移后的平台发展期,目前进入产业增长方式的深度转型期。网络文学IP开发是典型的内容生产环节,剖析网络文学IP全产业链的演化机制对于提高数字化时代文化产业全要素生产率具有重要的理论与实践意义。本研究立足数字化时代文化消费者与内容生产的关系逻辑特征,在系统回顾近十年来网络文学IP全产业链发展历程的基础上,提出网络文学IP价值开发的全产业链结构图,构建网络文学IP阶段性泡沫化与空心化现象的解释框架,提出相关优化路径。

公网卡IP管理工具的设计与开发

公网卡已被广泛应用于电力行业,每张公网卡都需要唯一的IP。采用人工方式管理IP,工作量大且容易出错。针对公网卡IP管理中的难点问题,设计研发了对应的公网卡IP管理工具,并在实际应用中取得了良好的管理成效。

一种基于KVM OVER IP的通信专业智能化集中运维方式

随着运营线路的增多,郑州地铁已进入网络化运营的新阶段,对设备的日常维护也提出了更高的要求,通信专业设备众多,更需要通过智能运维来满足网络化运营的新要求。本文基于车站、控制中心的通信设备的维护现状,通过研究通信专业智能化集中运维方式,优化日常运维场景、故障处理场景、抢险抢修场景下人员分工和生产方式,提出新的基于KVM OVER IP的设备管理架构和运维模式,在不影响现网正常稳定运行、投资成本不高的情况下,实现地铁通信专业设备的集中化、智能化维护,进一步提升设备管理维护水平,同时为下一步建设网管网奠定基石,最终可轻松实现业务、管理2张网运行,结合大数据技术亦可实现地铁通信设备的智能监测、智能分析、智能维护,最大化的增加经济效益。

IP化技术在电视制播融合中的网络架构与信号传输应用

网际互连协议(Internet Protocol,IP)化网络作为一种新兴的传输技术,正在改变传统的电视制作和播出模式。基于此,概述了IP化技术的相关概念,分析了IP化技术的数字编码和分组传输机制,阐述了IP化技术在推动电视制播融合方面的作用,提出了电视制播IP化网络的分层架构,解析了IP化核心网和接入网的组成,以及软件定义网络(Software Defined Network,SDN)在IP化网络中的控制作用。

AoIP+基带架构广播播控技术的应用

网际互连协议(Internet Protocol,IP)化技术凭借高带宽和灵活性等优势,为广播电视传输系统带来了新的可能,特别是在广播电视基带架构层,IP化音频(Audio over IP,AoIP)技术可以发挥重要作用,完成从源信号采集到发射的全过程音视频传输任务。基于此,介绍AoIP的相关概念、标准和应用优势,阐述基带架构的组成层次、采集编码和自动化功能,分析其技术特点。在此基础上,详细探讨AoIP技术在基带系统各层面的应用情况,包括AoIP网络部署、音视频流处理、自动化实现和同步方案等,并说明不同应用的效果。

QoS routing based on mobile agent for LEO satellite IP networks

Current quality of service（QoS） routing schemes for low earth orbit（LEO） satellites IP networks either neglect the varying population density or fail to guarantee end-to-end delay.As a remedy,QoS routing protocol based on mobile agent（QoSRP-MA） is proposed.QoSRP-MA is a source-based routing protocol.Once connection requests arrive,QoS mobile agents are dispatched from ingress satellite to explore routes,which migrate using satellite routing tables.Upon arriving in egress satellite,QoS mobile agents migrate back towards ingress satellite to reserve bandwidth.To construct satellite routing tables,load balancing routing algorithm based on mobile agent（LBRA-MA） is presented.In LBRP-MA,at regular intervals mobile agents launched on all satellites migrate autonomously to evaluate path cost and update routing tables.Moreover,path cost between source and destination is evaluated considering satellite geographical position as well as inter-satellite link（ISL） cost.Furthermore,ISL congestion index is considered to update routing table.Through simulations on a Courier-like constellation,it shows that QoSRP-MA can achieve guaranteed end-to-end delay bound with higher throughput,lower connection failing ratio and signaling overhead compared to high performance satellite routing（HPSR） scheme.

基于模型驱动双向主动测量协议的IP网络遥测系统研究与实现

IP层的OAM技术中,双向主动测量协议(TWAMP)通过主动向网络注入测量报文,并根据对测量报文进行采集分析来实现任意2个具备IP可达性网络节点之间的网络层性能监测。文章首先分析了TWAMP测量方案在实际运营部署时存在的主要问题和挑战,然后针对网络的运维管理日益智能化的网络发展趋势下,需要对网络运行状况进行连续实时主动监测的新需求进行了相关分析。基于此,文章提出了一种面向互联网遥测架构的硬探针TWAMP网络监控系统,以此实现IP传送网的性能监测改进,为实现更实时可靠的智能运营提供有力支撑。

Photonic MPLS Network Technologies to Create Bandwidth-Abundant IP Networks

This paper describes the prototypes of the Photonic MPLS router that can create bandwidth-abundant IP networks in a cost-effective manner. The characteristics of and recent advances in these prototypes are also described.

读者与观众:海外输出背景下受众跨媒介接受路径研究——网络文学与IP改编的序位效应考察

当下,网络文学海外输出欣欣向荣,部分业界和学界人士认为这为IP改编作品走出国门奠定了基础。先成为读者还是先成为观众决定了受众跨媒介接受路径的不同,文章以序位效应为理论依据,循着从国内到海外的研究路径,以传播力提升为目标,探讨受众跨媒介接受的路径构建、心理机制、海外输出背景下的路径选择问题。研究发现,从观众到读者的接受路径有利于最大限度提升海外传播力,即以IP改编作品的海外走红带动网络文学的输出。但现实情况并非如此,建议重新规划海外输出策略。

Integrating QoS Management in TLMM:Three Level Mobility Model for Next Generation Wireless IP-Based Networks

In this paper we have designed an implemented an integrated framework of QoS for Three Level Mobility Model(TLMM),which has been recently proved to be the optimal mobility management solution for next generation wireless IP-based networks.The QoS solution uses a combination of IntServ and DiffServ models incorporated in TLMM architecture.The paper also proposes an effi cient dynamic handover policy that takes care of false handover.Simulation and analytical results have shown that this infrastructure guarantees eff icient QoS handling and scalability among end users.To provide a comparative understanding of the QoS mechanism and signaling load of TLMM we have used TeleMIP(without QoS support) and MIP as alternative mobility management protocols.