An adaptive congestion control mechanism for intelligent broadband networks

The provision of novel multimedia services in broadband networks through intelligent network (IN) technology is a promising solution that guarantees fast deployment of new services and minimum changes to already operating networks. In this architecture, the broadband service control point (B-SCP) is the main actor in the processing of complex IN service requests. This centralized approach which is reflected in the multiplicity of tasks undertaken by the B-SCP in a broadband IN architecture, can easily lead to network performance degradation. Therefore, the presence of a congestion control mechanism operating at the level of calls is considered essential in order to protect the network nodes from overload conditions and to attain high levels of network performance. In this paper, we propose an adaptive congestion control mechanism (ACCM) which is able to guarantee the desirable quality of service under overload conditions. The proposed mechanism gradually reduces the message transmission rate from the source node to the destination node when overflow conditions have been detected, taking as feedback the buffer capacity state of the destination. Results, obtained by simulation show that the proposed ACCM improves the network performance by maximising the number of established calls and reducing the number of rejected calls.     

一种支持SOA系统开发的服务注册库

为了支持SOA系统开发,需要对各种形式的服务进行有效地管理.在前期工作的基础上,提出了一个语义增强服务库,用于基于语义的服务注册、搜索和组装.重点介绍其中的服务注册库部分,包括服务注册库的功能、所用的服务描述规范,并用一个实例说明了服务注册、发布的整个过程.该服务库通过支持多种形式的服务,可以有效地管理企业现有的各种软件资源,并为基于SOA的系统开发提供支持.     

An autonomic architecture for optimizing QoE in multimedia access networks

The recent emergence of multimedia services, such as Broadcast TV and Video on Demand over traditional twisted pair access networks, has complicated the network management in order to guarantee a decent Quality of Experience (QoE) for each user. The huge amount of services and the wide variety of service specifics require a QoE management on a per-user and per-service basis. This complexity can be tackled through the design of an autonomic QoE management architecture. In this article, the Knowledge Plane is presented as an autonomic layer that optimizes the QoE in multimedia access networks from the service originator to the user. It autonomously detects network problems, e.g. a congested link, bit errors on a link, etc. and determines an appropriate corrective action, e.g. switching to a lower bit rate video, adding an appropriate number of FEC packets, etc. The generic Knowledge Plane architecture is discussed, incorporating the triple design goal of an autonomic, generic and scalable architecture. The viability of an implementation using neural networks is investigated, by comparing it with a reasoner based on analytical equations. Performance results are presented of both reasoners in terms of both QoS and QoE metrics.     

一个安全的CORBA音/视频流服务模型:SecStream

通过对传统CORBA(common object request broker architecture)体系结构的扩展,OMG(Object Management Group)提出的CORBA音/视频流服务规范使得多媒体应用可以获得分布式对象计算在开放性、标准化等方面的优势.但该规范在安全方面有所欠缺,没有提供解决分布多媒体应用所面临的安全问题的完整方案.通过引入CORBA安全服务,并定义数据安全服务的概念,对原有流服务体系结构进行了安全扩展,提出了一个完善的安全流服务模型SecStream,对其进行设计和实现,并加以实践应用,验证了该模型可以灵活地提供多种安全保证,并具有较大的可扩展性.     

智能网业务的提供与软件重用

智能同业务是由智能网系统中一串SIB构成的SLP软件实体来实现的．为了易于智能网业务快速、经济地提供．在CIN－01智能网系统中，本文提出了一套软件重用的方法．在该系统中．为各个SLP提出了可重用的软件设计，SLP由可重用的软件—SIB，CCB和可重用的模式—SLR·SIBSSD和CCBAPPEND构成.     

下一代网络处理器及应用综述

网络处理器作为能够完成路由查找、高速分组处理以及QoS保障等主流业务的网络设备核心计算芯片,可以结合自身可编程性完成多样化分组处理需求,适配不同网络应用场景.面向超高带宽及智能化终端带来的网络环境转变,高性能可演进的下一代网络处理器设计是网络通信领域的热点问题,受到学者们的广泛关注.融合不同芯片架构优势、高速服务特定业...     

基于服务开放的一体化承载网设计

传统信息网络因面向业务支撑设计而造成体系架构的刚性,无法满足业务发展多样性和网络异构的需求,因此无法适应下一代网络融合、可扩展等特点。基于服务开放的技术体系可以解决这一问题。本文以网络承载服务为核心,以可重构路由交换平台为关键支撑技术,设计出一种面向服务提供的网络体系架构一体化承载网络模型,并对逻辑承载网的构建进行了讨论,为下一代网络的研究和设计提供了新的思路。     

基于下一代Internet的服务管理研究

Internet is best effort network, on the whole, it doesn't provide any quality of service assurance for services. Especially,all kinds of stream media need more network performance and quality of service. Currently, because of existing many heterogeneous networks, such as telecommunication network, IP data network , mobile network and so on ,in order to break off this heterogeneous network isolated complexion ,research and developmentnext generation network must be carried out,only by this way,can these isolated heterogeneous network be merged into an all IP network. This network will provide enormous services for service users,how to manage these services effectively is a topic proposed by next generation internet. [1] gave research status for service management and advance,this paper researches service management requirement for next generation Internet and workflow etc,and based on these technique,a service management architecture model is proposed. It consists of service access layer, service deployment layer, service providing layer, service mapping layer, policy control layer and network element managing layer. These layers coordinate to implement service management.     

网络服务体系结构及其形式化模型的研究

下一代网络的本质是以提供网络服务为核心的,能够支撑各国政治、经济、文化、教育、国防等各个领域全面信息化的信息基础设施,单纯基于通信功能来进行层次划分的传统网络体系结构已不能适应下一代网络发展的需要．提出了一种基于交互的网络服务体系结构(INSA),作为从服务角度研究下一代网络的下一代网络服务体系结构参考模型,并详细论述了INSA参考模型的总体结构和各层功能．用构件来描述网络实体,用连接件来描述构件间交互,建立起了下一代网络服务体系结构的形式化模型,为形式化分析和验证网络服务体系结构的总体性质以及进一步研究网络服务体系结构中与服务相关的各种性质奠定了基础．     

Distributed computing architecture for effective management of multimedia streams on DPE

We study a networking architecture model that is built on a distributed processing environment (DPE) for multimedia services suitable for high speed transport networks such as ATM networks. In this architecture, the applications are deployed as units of software building blocks. Each building block provides a layered view for the effective management and control of the multimedia network resources and services according to the concept of telecommunications management network (TMN) and telecommunications information networking architecture (TINA). For the purpose of flexible service provision to users and effective service introduction by service providers, this architecture proposes the adoption of ad hoc service building blocks such as a video on demand building block and a CSCW building block that have interactions with a general purpose building block. This paper also proposes a naming structure for the management of user profiles and session profiles using a directory service system, and an effective control model for multimedia logical device objects using a stream process approach. The proposed model is implemented on a DPE platform that provides various transparencies, ANSAware.     

A Modular Approach to Mobile QoS Signaling— Motivation,Design & Implementation

In order to support mobile multimedia applications in next generation wireless IP-based networks, it is necessary to deliver seamless voice, video and data at high quality. Therefore, session mobility and Quality of Service (QoS) for mobile end systems are required. Within this article, the authors point out a new way to approach the problem. Instead of tightly coupling a modified QoS signaling mechanism with a certain mobility mechanism, a more generic and long-term solution is proposed and exemplified on the basis of existing IETF protocols. The connection-less IP network layer is enhanced by a lightweight and truly optional connection-oriented mobile network service, which offers the possibility to establish soft state unicast connections at the network layer. Hence, a connection-oriented network service is available within a radio access network (RAN) architecture to all end systems—mobile or fixed—independent of the application. Thereby, it is possible to integrate QoS and connectivity signaling for mobile end systems, as well as other connection-oriented services like explicit routing or load balancing.     

服务组合的代数规约

现有的服务组合描述途径不能有效地验证和测试组合正确性,针对这一问题,提出了一个代数规约方法,引入规约包机制扩展面向服务代数规约语言SOFIA以支持该方法。用代数规约单元描述服务系统中的各种实体,其中基调部分定义实体的语法和结构,公理部分定义其功能和行为特性。与一个服务相关的规约单元封装在一个包中或拆分在几个相互引用的包中,每个包形成一个命名空间。当多个服务组合在一起时,以这些服务的代数规约包为基础,一方面抽象地定义组合服务的交互过程和语义,形成描述服务组合实现方式的实现规约包;另一方面抽象地定义组合服务对外接口及其功能语义,形成描述组合服务需求的抽象规约包。在实现规约和抽象规约的双元结构基础上,进一步定义了实现规约和抽象规约之间必须满足的“实现”关系,证明了满足实现关系可以保证实现的正确性,从而为服务组合的可验证性和可测试性奠定了理论基础。最后结合实例分析阐述了用代数规约描述服务组合的抽象性、可表达性和可验证性。     

Service oriented evolutionary algorithms

This work presents a service oriented architecture for evolutionary algorithms, and an implementation of this architecture using a specific technology (called OSGiLiath). Service oriented architecture is a computational paradigm where users interact using services to increase the integration between systems. The presented abstract architecture is formed by loosely coupled, highly configurable and language-independent services. As an example of an implementation of this architecture, a complete process development using a specific service oriented technology is explained. With this implementation, less effort than classical development in integration, distribution mechanisms and execution time management has been attained. In addition, steps, ideas, advantages and disadvantages, and guidelines to create service oriented evolutionary algorithms are presented. Using existing software, or from scratch, researchers can create services to increase the interoperability in this area.     

Design and evaluation of a multimedia storage server for mixed traffic

The relative simplicity of access to digital communications nowadays and the simultaneous increase in the available bandwidth are leading to the definition of new telematic services, mainly oriented towards multimedia applications and interactivity with the user. In the near future, a decisive role will be played in this scenario by the providers of interactive multimedia services of the on-demand type, which will guarantee the end user a high degree of flexibility, speed and efficiency. In this paper, some of the technical aspects regarding these service providers are dealt with, paying particular attention to the problems of storing information and managing service requests. More specifically, the paper presents and evaluates a new storage technique based on the use of disk array technology, which can manage both typical multimedia connections and traditional requests. The proposed architecture is based on the joint use of the partial dynamic declustering and the information dispersal algorithm, which are employed for the allocation and retrieval of the data stored on the disk array. We also define efficient strategies for request management in such a way as to meet the time constraints imposed by multimedia sessions and guarantee good response times for the rest of the traffic. The system proposed is then analyzed using a simulation approach.     

Effective distributed service architecture for ubiquitous video surveillance

Video surveillance systems are playing an important role to protect lives and assets of individuals, enterprises and governments. Due to the prevalence of wired and wireless access to Internet, it would be a trend to integrate present isolated video surveillance systems by applying distributed computing environment and to further gestate diversified multimedia intelligent surveillance (MIS) applications in ubiquity. In this paper, we propose a distributed and secure architecture for ubiquitous video surveillance (UVS) services over Internet and error-prone wireless networks with scalability, ubiquity and privacy. As cloud computing, users consume UVS related resources as a service and do not need to own the physical infrastructure, platform, or software. To protect the service privacy, preserve the service scalability and provide reliable UVS video streaming for end users, we apply the AES security mechanism, multicast overlay network and forward error correction (FEC), respectively. Different value-added services can be created and added to this architecture without introducing much traffic load and degrading service quality. Besides, we construct an experimental test-bed for UVS system with three kinds of services to detect fire and fall-incident features and record the captured video at the same time. Experimental results showed that the proposed distributed service architecture is effective and numbers of services on different multicast islands were successfully connected without influencing the playback quality. The average sending rate and the receiving rates of these services are quite similar, and the surveillance video is smoothly played.     

Synchronous optical network and broadband ISDN protocols

High-level technical information on Sonet (synchronous optical network) B-ISDN (broadband integrated services digital network) protocols, and interface structures is provided. Since the B-ISDN protocol standards to be used in the Broadband Reference Model are currently being discussed in the CCITT, most of the standards are not yet available. Therefore, some of the protocols described here are not based on agreements reached in national and international standards bodies. The discussion covers B-ISDN architecture and the ISO model. Sonet protocols and architecture, B-ISDN configuration, and the ATM (asynchronous transfer model) architecture     

基于IMS的多媒体彩像业务的设计和实现

多媒体彩像(MRT)业务是一种采用多种媒体作为振铃音的增值业务。该文结合IP多媒体子系统(IMS)网络体系结构和MRT业务属性,提出了一种利用多媒体彩像业务平台(MRTSP)来实现MRT业务的方案,包括系统设计和基于会话发起协议(SIP)的信令流程,分析了相关特点并进行了总结。