PTN技术及在铁路通信中的应用探讨

新时期铁路通信传送网将实现基于IP的融合承载,统一承载铁路沿线的各种业务。所承载的业务占用带宽将更高,对QoS、安全性、可靠性等的要求将更严格。为此,铁路通信传送网引入PTN(Packet Transport Network)为最佳选择。本文阐述了PTN技术及其在铁路通信中的应用。     

基于综合业务接入的IP RAN网络规划探讨

IP RAN（IP Radio Access Network）IP化无线接入网是一种基于IP技术的移动网回传网络。IPRAN拥有相比起MSTP网络更高效的网络资源利用率,IPRAN采用三层交换组网方式。完善的QoS规划部署,成熟的技术标准使得IPRAN的网络应用有着良好的保障。本文首先介绍了IPRAN的特点,然后分析了现有MSTP网络承载的业务和增长的趋势,最后本文探讨了建设IPRAN传送网的方案。     

基于高保真颜色再现的色域拓展方法研究

针对高保真颜色再现的需要,研究了多种拓展目标色域方法。这些方法包括基于新显示技术的色域映射方法、改善纸张表面性能和采用多种数字印刷纸张、采用超过四色的高保真印刷方式等。并将这些拓展目标色域的方法分为软件方法和硬件方法两类。详细分析了上述方法实现色域拓展的特点,并比较了其色域拓展的效果。试验结果表明,采用软件方法和硬件方法拓展色域,所得色域范围和效果明显不同。该结果有助于进一步研究实现高保真颜色再现的方法,使颜色在传递过程中达到最佳的视觉效果。     

IP网络服务质量管理体系研究

在对IP网络QoS管理现状进行客观分析的基础上,提出了新一代IP网络的QoS管理体系结构。新体系加强了业务管理,并将QoS部署、测量和管理有效地融合为一体。进一步讨论了QoS管理体系的设计原则和体系的逻辑结构。该体系结构已在863项目中得到应用。     

宽带IP网络的QoS路由:框架和问题

宽带IP网络中 ,对于IP电话和视频会议等有QoS要求的应用 ,网络和用户要达成某种QoS合约 ,网络要依据合约按着一定的路由策略选择可行路径、建立连接并预留相应资源。针对此问题 ,主要从QoS路由策略、QoS合约的优化与约束条件出发 ,概述了IP网络QoS路由的框架体系 ,并指出需要迫切解决的一些问题。     

从IP分组转发到IP分组标记交换

对“交换”的本质和IP与交换的关系进行了反思,提出了直接基于带标坊的IP分组的交换机制（称为IP分组标记交换）。它将IP路由和交换、QoS统一起来,为未来的多媒体因特网提供了全新的技术平台。     

异种类型显示器间的色域映射技术研究

为解决不同媒体间色外貌不一致的现象,结合现今流行的"图像主导型色域映射算法"和"三次元色域压缩技术"的优势,设计了"三次元图像主导型色域映射技术"方式,并以4种典型的色域映射方式来实现CRT荧幕到LCD荧幕的色域压缩,从而让大色域荧幕较好的模拟小色域荧幕的色彩再现.经心理物理实验评估,"以最小彩度差为依据法"是最佳的色域映射方式,这为设计更加合理的跨媒体色域映射方式提供了又一崭新思路.     

IP网络QOS研究

本文首先讨论了IP QoS的基本概念和主要机制,然后详细分析了目前正在研究和实施的几种QoS模型的原理及其相互关系。并且基于这几种模型各自的优势和不足,探讨了将它们互相结合以更好实现IP QoS的可能方案。     

支持QoS管理的下一代互联网网络管理流程

根据下一代互联网IP业务的灵活、动态管理和新业务扩展的需求,深入剖析了支持QoS管理的下一代互联网网络管理流程,给出了一个描述业务管理、网络管理与实际物理网络之间关系的分层透视模型,在此基础上提出了一套可行的IP业务QoS管理流程,并以IP-VPN业务的客户投诉应用场景为例分析了网络管理流程的实现.分析结果表明,该分层的QoS管理流程能够实现下一代互联网IP业务的业务流程自动化、业务管理灵活性和动态性,能够适应新业务的可扩展性和对业务的有效管理.     

构造未来的宽带IP网

在分析了3成选的未来IP网络解决方案的基础上,对IP网的关键技术－分帖技术和IPdirectly over WDM的方法进行了深入研究。     

IP家庭网络的服务质量架构研究

经过对IP网络和家庭网络服务体系的客观分析,提出了基于策略的IP家庭网络QoS保证架构.它融合了数据平面、控制平面和管理平面,可以与现有的IPQoS体系无缝连接,支持高质量的语音和视频服务.该结构对其他设备的依赖程度低,适应异构、复杂的家庭网络环境.通过在863项目中的应用,验证了该系统架构对IPTV、VoD及VoIP等多媒体业务的支持.     

Hybrid Swarm Intelligence Based QoS Aware Clustering with Routing Protocol for WSN

Wireless Sensor Networks (WSN) started gaining attention due to its wide application in the fields of data collection and information processing. The recent advancements in multimedia sensors demand the Quality of Service (QoS) be maintained up to certain standards. The restrictions and requirements in QoS management completely depend upon the nature of target application. Some of the major QoS parameters in WSN are energy efficiency, network lifetime, delay and throughput. In this scenario, clustering and routing are considered as the most effective techniques to meet the demands of QoS. Since they are treated as NP (Non-deterministic Polynomial-time) hard problem, Swarm Intelligence (SI) techniques can be implemented. The current research work introduces a new QoS aware Clustering and Routing-based technique using Swarm Intelligence (QoSCRSI) algorithm. The proposed QoSCRSI technique performs two-level clustering and proficient routing. Initially, the fuzzy is hybridized with Glowworm Swarm Optimization (GSO)-based clustering (HFGSOC) technique for optimal selection of Cluster Heads (CHs). Here, Quantum Salp Swarm optimization Algorithm (QSSA)-based routing technique (QSSAR) is utilized to select the possible routes in the network. In order to evaluate the performance of the proposed QoSCRSI technique, the authors conducted extensive simulation analysis with varying node counts. The experimental outcomes, obtained from the proposed QoSCRSI technique, apparently proved that the technique is better compared to other state-of-the-art techniques in terms of energy efficiency, network lifetime, overhead, throughput, and delay.     

一种多业务IP网络中的服务等级规范(SLS)监测系统

在对IP网络服务质量管理需求及现有监测系统进行客观分析的基础上,提出了一种多业务IP网络中的SLS监测系统。该系统采取徽流和汇聚流监测相结合,主动测量和被动测量相结合的策略,有效地降低了监测系统的负荷。适配子层的提出,很好地屏蔽了网络上不同厂家的网元设备差异和技术差异。同时,基于CORBA的分布式计算环境的实现,使得该系统易于部署。该监测系统已在863项目中得到应用。     

基于区分服务的因特网电话服务质量保障

因特网电话是IP网上一种非常重要的实时数据业务．如何在网络流量背景复杂的情况下保证因特网电话的服务质量是当前的一个研究热点．本文提出了一种完全基于区分服务架构的方案，保证因特网电话对服务质量的要求，同时照顾其他流量的公平性．     

HELP-WSN-A Novel Adaptive Multi-Tier Hybrid Intelligent Framework for QoS Aware WSN-IoT Networks

Wireless Sensor Network is considered as the intermediate layer in the paradigm of Internet of things (IoT) and its effectiveness depends on the mode of deployment without sacrificing the performance and energy efficiency. WSN provides ubiquitous access to location, the status of different entities of the environment and data acquisition for long term IoT monitoring. Achieving the high performance of the WSN-IoT network remains to be a real challenge since the deployment of these networks in the large area consumes more power which in turn degrades the performance of the networks. So, developing the robust and QoS (quality of services) aware energy-efficient routing protocol for WSN assisted IoT devices needs its brighter light of research to enhance the network lifetime. This paper proposed a Hybrid Energy Efficient Learning Protocol (HELP). The proposed protocol leverages the multi-tier adaptive framework to minimize energy consumption. HELP works in a two-tier mechanism in which it integrates the powerful Extreme Learning Machines for clustering framework and employs the zonal based optimization technique which works on hybrid Whale-dragonfly algorithms to achieve high QoS parameters. The proposed framework uses the sub-area division algorithm to divide the network area into different zones. Extreme learning machines (ELM) which are employed in this framework categories the Zone's Cluster Head (ZCH) based on distance and energy. After categorizing the zone's cluster head, the optimal routing path for an energy-efficient data transfer will be selected based on the new hybrid whale-swarm algorithms. The extensive simulations were carried out using OMNET++-Python user-defined plugins by injecting the dynamic mobility models in networks to make it a more realistic environment. Furthermore, the effectiveness of the proposed HELP is examined against the existing protocols such as LEACH, M-LEACH, SEP, EACRP and SEEP and results show the proposed framework has outperformed other techniques in terms of QoS parameters such as network lifetime, energy, latency.     

Emergency Prioritized and Congestion Handling Protocol for Medical Internet of Things

Medical Internet of Things (MIoTs) is a collection of small and energyefficient wireless sensor devices that monitor the patient’s body. The healthcare networks transmit continuous data monitoring for the patients to survive them independently. There are many improvements in MIoTs, but still, there are critical issues that might affect the Quality of Service (QoS) of a network. Congestion handling is one of the critical factors that directly affect the QoS of the network. The congestion in MIoT can cause more energy consumption, delay, and important data loss. If a patient has an emergency, then the life-critical signals must transmit with minimum latency. During emergencies, the MIoTs have to monitor the patients continuously and transmit data (e.g., ECG, BP, heart rate, etc.) with minimum delay. Therefore, there is an efficient technique required that can transmit emergency data of high-risk patients to the medical staff on time with maximum reliability. The main objective of this research is to monitor and transmit the patient’s real-time data efficiently and to prioritize the emergency data. In this paper, Emergency Prioritized and Congestion Handling Protocol for Medical IoTs (EPCP_MIoT) is proposed that efficiently monitors the patients and overcome the congestion by enabling different monitoring modes. Whereas the emergency data transmissions are prioritized and transmit at SIFS time. The proposed technique is implemented and compared with the previous technique, the comparison results show that the proposed technique outperforms the previous techniques in terms of network throughput, end to end delay, energy consumption, and packet loss ratio.     

The multiblock method. A new strategy based on domain decomposition for the solution of wave propagation problems

A novel single‐step domain decomposition technique for the elastic wave propagation problem is introduced in this paper, based on the Huygens principle. The method allows an effective and efficient implementation on parallel computers through coarse‐grain multiprocessor computations. The various tests and numerical examples let infer that it is very competitive in comparison with classic substructuring techniques, specially for implicit discretization schemes. Copyright © 2000 John Wiley & Sons, Ltd.     

基于相对密度的DNS请求数据流源IP异常检测算法

研究了域名系统(DNS)的异常检测.通过对基于相对密度的离群点检测算法的研究,提出了一种基于相对密度的DNS请求数据流源IP异常检测算法.该算法计算每个源IP的相对密度,并将该密度的倒数作为其异常值评分;在计算相对密度时,从查询次数、源端口熵值、所请求非法域名占比等9个维度来表示一个源IP.试验结果表明,这种基于相对密度的源IP异常检测方法,能正确地根据各个源IP不同的异常程度,给出其相应的异常值评分.     

AN ADAPTIVE SUCCESSIVE OVER RELAXATION DOMAIN DECOMPOSITION BY THE BOUNDARY SPECTRAL STRIP METHOD

In the present paper a new adaptive successive over relaxation domain decomposition technique is developed for the boundary spectral strip method. The proposed scheme is based on dividing the overall domain of the problem into several subdomains. First each of the subdomains in the BIEM matrices is analysed independently. These matrices together with an arbitrary initial guess of displacements on the interface of each two neighbouring subdomains, enable an iterative and a very efficient solution of the whole problem. An adaptive procedure, based on comparing two norms along the interface of subregions, is carried out to impose successive over relaxation convergence. Numerical results comparing the present scheme with single domain solutions emphasize the capability of the proposed technique regarding accuracy and computational efforts. © 1997 by John Wiley & Sons, Ltd.