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。     

QOS测试方法初探

网络发展日新月异,随着网络上新应用的不断出现,IP网络已经从当初的单一数据网络向集成数据、语音、视频、图像的多业务网络转变。网络的服务质量(QoS)也日益成为人们关注的重点。     

探析公司NGN通讯网络改造技术

近年来,IETF（Internet工程任务组）、ITU（国际电信联盟电信标准部）、ETSI（欧洲电信标准协会）、ISC（美国工业安全委员会）和Parlay（由65家通信和IT领域的公司共同参与的非盈利性组织）等标准组织共同致力研究的下一代网络NGN或NGI（下一代互联网）,国际通信标准组织（3GPP、3GPP2、ETSI）提出的IMS网络,其网络的日的都在于提供多种新业务的同时,尽量能够在业务层（业务平台）实现新业务的添加,而不是在网络层面追加新的投资,即把语音、数据、视频等逐步统一到一个安全、稳定、有业务保障的新型IP平台。     

下一代基于策略的网络管理中Ponder语言的性能分析和改进

根据TMF描述的下一代基于策略的网络管理的特点,提出了对高层策略语言的要求：（1）具备一定的分组机制;（2）能够描述流程;（3）支持有限状态机模型,并根据这些要求对目前最有影响力的高层策略语言Ponder的性能特点进行了分析,且针对其缺陷做了改进。最后,通过基于策略的下一代IP计费原型系统的设计和实现,验证了对高层策略语言提出的三项要求的正确性和有效性。     

IP QoS的体系结构及其发展

随着互联网的飞速发展，IP网上的VOIP受到了越来越多的关注。而QoS一直是VOIP在网络内大规模部署的关键性问题，所以有效的QoS体系结构对于VOIP来说是必不可少的。本文首先介绍了DiffServ和IntServ两种IP QoS协议的体系结构，然后分别分析它们的不足，最后补充了一种可能的实现机制。     

基于VoIP的SIP-Qos扩展机制的研究

通信网的演进和发展,要求在下一代网络中提供具有QOS保证的电信级业务.在对基于SIP的VoIP系统的QoS控制技术进行研究的基础上,深入研究SIP协议支持QoS控制功能的扩展机制,分析利用SIP/SDP进行QoS预置条件设置和协商的模型,给出基于状态表的生成规则和实现机制.     

通用以太音响设备的应用（六）音响管理器软件的运用

以太音响网络中常用的音响管理器（音响管理程序器）软件可以管理多区域（按英文字母顺序A—Z编排）音响装置。对于利用传统铺设的缆线或以太网络所构建的音响系统,安排播放列表,管理音频数据（库）,处理信号流程;并借助其遥控功能,通过传输控制／网际协议（TCP／IP）实现每个地方的音频管理,完成各项监控任务。     

IP电视中的视频转码技术探析

随着我国科学信息技术的不断发展,我国电信网络、计算机网络以及电视网络这三大网络不管是在业务上、应用上还是在业务上不断地融合与渗透,出现了很多新的应用技术,其中IP电视就是其应用之一。IP电视的应用就是为了让宽带不同的这些用户能够利用互联网来观看相应的数字电视节目,通过卫星数字技术进行电视网络的直播。本文笔者就IP电视中的视频转码技术进行研究和分析。     

固网运营商使用NGN软交换技术

随着互联网技术的发展,特别是基于互联网Voip技术不断的实践,各大运营商出于网络成本及新业务提供等各种不同目的,将NGN技术应用于电信级网络.NGN是基于IP分组技术,业务与呼叫完全分离,呼叫控制和承裁完全分离,融合语音、数据、多媒体和移动业务的网络.本文结合营口网通软交换建设实践,主要对NGN架构进行了详细论述,并对固网运营商实现软交换后,业务能力的提升进行了阐述.     

IMS网络中业务触发数据的研究

分析了现有IP多媒体子系统(IMS)业务触发数据存在的问题,给出了一种业务键的实现方式,业务键的存在可以使多个应用服务器(AS)之间的初始过滤准则(iFC)互不干扰,从而不会因为新业务的部署而引发新旧业务之间的冲突.接着对第三代合作伙伴计划(3GPP)业务触发和基于业务键的业务触发进行了性能建模,理论分析和仿真结果表明,通过增加业务键数据,可提高服务呼叫会话控制功能(S-CSCF)和AS的匹配效率,使S-CSCF在一次业务触发中可以触发多个业务,从而简化业务触发流程.基于业务键的业务触发方式可以有效地提高业务触发效率,增加系统的吞吐量,降低会话建立时延,提高IMS网络的服务质量(QoS).     

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.     

BPEL组合服务流程动态性能的定量预测方法

针对服务质量研究在流程模型相关性和流程性能动态性方面存在的不足,将吞吐量和响应时间引入到组合服务流程性能评估的流程级指标中,借助排队网络系统的相关结论,研究了组合服务流程动态性能的定量预测方法,给出了针对组合服务流程执行语言(BPEL)的动态性能临界值计算方法,并通过一个示例介绍了该方法在BPEL组合服务流程的动态性能定量预测和组合方案优化中的应用。     

Cloud manufacturing service composition based on QoS with geo-perspective transportation using an improved Artificial Bee Colony optimisation algorithm

Cloud Manufacturing (CMfg) ambitions to create dedicated manufacturing clouds (i.e. virtual enterprises) for complex manufacturing demands through the association of various service providers’ resources and capabilities. In order to insure a dedicated manufacturing cloud to match the level of customer’s requirements, the cloud service selection and composition appear to be a decisive process. This study takes common aspects of cloud services into consideration such as quality of service (QoS) parameters but extend the scope to the physical location of the manufacturing resources. Unlike the classic service composition, manufacturing brings additional constraints. Consequently, we propose a method based on QoS evaluation along with the geo-perspective correlation from one cloud service to another for transportation impact analysis. We also insure the veracity of the manufacturing time evaluation by resource availability overtime. Since the composition is an exhaustive process in terms of computational time consumption, the proposed method is optimised through an adapted Artificial Bee Colony (ABC) algorithm based on initialisation enhancement. Finally, the efficiency and precision of our method are discussed furthermore in the experiments chapter.     

OFDMA系统中支持混合业务的跨层调度算法

针对正交频分多址接入(OFDMA)系统下行链路的混合业务调度问题,提出了一种基于队列等待时间的跨层调度算法.该算法联合利用了MAC层的队列等待时间与物理层的信道状态信息作为调度参数,通过队列等待时间反映用户的服务质量要求,并利用多用户分集增益提高系统性能;针对实时和非实时用户的不同服务质量要求,在队列等待时间的计算上采取了不同的策略;在子载波的分配过程中根据分配状态及时更新队列等待时间,使资源的利用更为有效.仿真结果表明,提出的算法可显著降低实时用户的平均时延和最大延时违反概率,同时保证了非实时用户的吞吐量需求,能够有效地支持下一代网络中混合业务的多种服务质量要求.     

一种QoS感知的语义Web服务组合群决策算法

针对QoS信息不确定和存在多个决策者的语义Web服务组合问题,基于多属性群决策理论给出了一个自治的语义Web服务组合群决策算法(AGSC).该算法能够对以实数型、区间型和语言型数据描述的复杂的QoS信息进行综合评估,从而为多客户提供正确、高效的决策支持,为其优选出最佳的组合服务执行计划.利用真实Web服务的质量对该算法进行了实验验证,结果表明该算法具有优秀的决策灵敏性和稳定性,并能有效地反映决策群中个体角色的变化.     

Genetic algorithm quality of service design in resilient dense wavelength division multiplexing optical networks

The important role of quality of service (QoS) in deployment of a resilient dense wavelength division multiplexing (DWDM) backbone for global networks requires critical design-phase planning optimisation. The design issues of resilient DWDM networks for bandwidth and delay sensitive applications of dedicated path protection are addressed. A genetic algorithm (GA) model has been developed to solve the routing and wavelength assignment problem using binary variable-length chromosome encoding under two different schemes of bandwidth optimisation (BOS) and delay optimisation (DOS).The performance of the new GA-based resiliency model has been evaluated for four benchmark networks: PAN EUROPEAN, COST239, NSFNETand ARPA2. Simulation results show a superior capability and efficiency for the model to solve this complex, multi-constraint and nondeterministic polynomial-hard problem for BOS and DOS. The nonlinear nature of this process reveals a significant sensitivity for optical layer network topology on the optimum-design QoS. The results also demonstrate that the PAN EUROPEAN network shows the highest flexibility for primary path design, NSFNET for the secondary path and ARPA2 comes with the lowest design flexibility for both primary and secondary paths.     

Mobile agent based approach for QoS routing

A mobile agent based on-demand quality of service (QoS) unicast routing scheme for supporting multimedia applications is proposed that considers bandwidth, delay and packet loss as QoS metrics for feasible path computation. A mobile agent is employed to find multiple QoS paths and select a best path among them to preserve resources so as to increase call success ratio and network bandwidth utilisation as well as adapt to network dynamics. The scheme is simulated in various network scenarios (sparse and dense networks) to verify performance and operation effectiveness, and compared with RSVP-based QoS routing by using an internet routing protocol. The results demonstrate significant improvements in call success ratio and network bandwidth utilisation compared with RSVP-based QoS routing, both in case of sparse and dense networks. Benefits of the agent-based scheme are adaptability, flexibility, and support for component-based software engineering features such as software reuse, customisation and maintainability     

Cooperative wireless networks for better green services

During the last two decades, mobile communication systems (such as GSM, GPRS and 3G networks), wireless broadcasting networks, wireless local area networks (WLAN or WiFi), and wireless sensor networks have been successfully developed and widely deployed through different technological routes for providing a variety of communication services in different application scenarios. While making tremendous contributions to social progress and economic growth, these heterogeneous wireless networks consume a lot of energy in achieving overlapped service coverage, and at the same time, generate strong electromagnetic interference (EMI) and radiation pollution, especially in big cities with high building density and user population. In order to guarantee the overall return on investment (ROI), improve user experience and quality of service (QoS), save energy, reduce EMI and radiation pollution, and enable the sustainable deployment of new profitable applications and services, this paper proposes a cross-network cooperation mechanism to effectively share network resources and infrastructures, and then adaptively control and match multi-network energy distribution characteristics according to actual user/service requirements in different geographic areas. Some idle or lightly-loaded Base Stations (BS or BSs) will be temporally turned off for saving energy and reducing EMI. Initial simulation results show the proposed approach can significantly improve the overall energy efficiency and QoS performance across multiple cooperative wireless networks.     

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。     

Adaptive bandwidth sharing mechanism for quality of service administration in infrastructure wireless networks

In infrastructure wireless networks, the wireless hop can be considered as another hop of the transmission path. With the rapid growth of wireless traffics, the future wireless network is expected to provide services for heterogeneous data traffics with different quality of service (QoS) requirements. Most proposed schemes do not have adaptive mechanisms to deal with the environment changes. In real situation, bandwidths, error rates and loss rates of wireless links vary frequently. We will base on the differentiated service model and propose a wireless differentiation (WD) scheme for user datagram protocol (UDP) flows and a wireless differentiation with prioritised ACK scheme for connections with transmission control protocol (TCP) flows. Both schemes provide QoS support for IEEE 802.11b and do not change the basic access mechanism of IEEE 802.11b.