Policy-based QoS architecture in the IP multimedia subsystem of UMTS

The third-generation mobile system, or Universal Mobile Telecommunication System, will offer IP-based multimedia applications and services with end-to-end QoS guarantee. The key part providing these services is the policy-based QoS control architecture in the IP multimedia subsystem (IMS). In this tutorial we describe the network entities involved in the policy-based QoS architecture, their interactions to realize guaranteed QoS in the UMTS network, and the communication interfaces employed in the interactions.     

基于SIP的多媒体会议分布式管理架构的设计

与会者及设备在地理上多处分布的大规模多媒体会议系统的一个重要设计思想就是要提高会议管理架构的可伸缩性.文章介绍了基于会话初始协议(SIP)的多媒体会议分布式管理架构的设计,并将策略管理技术引入到分布式管理架构中,从而为解决会议系统的缩放性、扩展性问题提供了一种新途径.     

I/O subsystem architecture

The primary concerns of I/O subsystem architecture include the coordination of central processor and I/O subsystem activities, the mapping of external I/O processing requirements into the basic functionality of the I/O subsystem, and the management of concurrent processing activities within the I/O subsystem itself. Architectural developments such as data and command chaining, channel program interfaces, automatic key searching, rotational portion sensing, and block multiplexing are evaluated in terms of these underlying concerns. A number of new arguments are presented to demonstrate the strengths and weaknesses of current designs, and several projections are made concerning the future evolution of this area.     

3GPP多媒体子系统研究

介绍了第三代移动通信系统中Release 5版本IP多媒体子系统的网络构架、QoS和业务,对IM系统中各个网络实体的功能进行了简单的描述,对IM与SIP软交换的结合以及承载在IP网络上所需的QoS进行了探讨,并介绍了可以承载在IM系统上的各种业务,最后,对GGSN如何适应IM系统业务这一关键技术进行了简单介绍。     

A time-efficient architecture for multimedia applications

This paper presents an architecture that enforces time requirements and gives minimal end-to-end delays for multimedia applications. The layers and mechanisms allowing the system to fulfill the selected synchronization, i.e., the logical relationships and timed interval semantics, are presented. The proposed approach relies on the use of a formal model based on extended time Petri nets, i.e., the time stream Petri net model (TStreamPN), that allows the user to completely specify the time requirements of a given application. The architecture implements, in the application layer and on top of asynchronous environments, the requested quality of service (perceived by the user) with respect to time. At the transport layer, the use of a partial order transport service improves the reactive response of the communication transfers. Its principles are presented together with a presynchronization sublayer that makes the partial order transport service match the applicative synchronization requirements. Moreover, measurements on the implementation of a videoconference system show that the requirements of the quality of service are fulfilled     

一种新的IP分组丢弃策略PRDP

该文分析了IP业务在MPLS/DiffServ上运行的特点,从考虑业务量工程性能的角度出发提出了一种新的IP分组优先级的划分方法,并在此基础上给出了一种新的IP分组丢弃算法基于优先级的丢弃策略(PBDP)。考虑到随机早检测策略(RED)的优点,将PBDP与RED相结合,得到一种改进的算法基于优先级的RED策略(PRDP),仿真结果表明这种算法在提高全网性能上有优势,其性能优于传统的尾丢弃策略。     

The CSI multimedia architecture

An instruction set extension designed to accelerate multimedia applications is presented and evaluated. In the proposed complex streamed instruction (CSI) set, a single instruction can process vector data streams of arbitrary length and stride and combines complex memory accesses (with implicit prefetching), program control for vector sectioning, and complex computations on multiple data in a single operation. In this way, CSI eliminates overhead instructions (such as instructions for data sectioning, alignment, reorganization, and packing/unpacking) often needed in applications utilizing MMX-like extensions and accelerates key multimedia kernels. Simulation results demonstrate that a superscalar processor extended with CSI outperforms the same processor enhanced with Sun's VIS extension by a factor of up to 7.77 on key multimedia kernels and by up to 35% on full applications.     

B-ISDN multimedia workstation architecture

Technical issues involved in integrating computer and communication technologies in the broadband integrated services digital network (B-ISDN) environment are discussed. The Multimedia Environment for Remote Multiple-Attendee Interactive Decision-making (MERMAID), an ISDN-based multimedia and multiparty desktop conference system, is described. MERMAID involves B-ISDN key technologies related to multimedia and multicast protocols, and workstation architecture for groupware applications. Technical issues based on user experiences and evaluations of MERMAID over three years are presented and discussed in connection with the system's evolution in the B-ISDN environment     

A framework architecture for multimedia information networks

An overview of the INA architecture, which builds on the current advances in broadband communication and distributed computing technologies and specifies an architecture for future information networks that are required to transport multimedia information and to manage multimedia communication, is presented. The key functional separations that have to be met in any INA-consistent network, the major components of an INA-consistent network, and the various levels in the architecture are described. The INA architecture is compared to other networking and distributed-processing architecture     

An architecture for real-time multimedia communication systems

A multimedia communication system includes both the communication protocols used to transport the real-time data and the distributed computing system (DCS) within which any applications using the protocols must execute. The architecture presented attempts to integrate these communications protocols with the DCS in a smooth fashion in order to ease the writing of multimedia applications. Two issues are identified as being essential to the success of this integration: the synchronization of related real-time data streams, and the management of heterogeneous multimedia hardware. The synchronization problem is tackled by defining explicit synchronization properties at the presentation level and by providing control and synchronization operations within the DCS which operate in terms of these properties. The heterogeneity problems are addressed by separating the data transport semantics (protocols themselves) from the control semantics (protocol interfaces)     

Protocol architecture for multimedia applications over ATM networks

At the data-link layer, ATM offers a number of features, such as high-bandwidth and per-session quality-of-service (QoS) guarantees, making it particularly attractive to multimedia applications. Unfortunately, many of these features are not visible to applications because of the inadequacies of existing higher-level protocol architectures. Although there is considerable effort underway to tune these protocols for ATM networks, we believe that a new ATM-specific protocol stack is essential to effectively exploit all the benefits of ATM. We describe the semantics of such a protocol stack, and discuss its advantages over traditional protocol architectures from the perspective of multimedia applications. The performance impact of the new protocol architecture is experimentally demonstrated on a video conferencing testbed built around IBM RS/6000's equipped with prototype hardware for video/audio processing, and connected via ATM links     

Icosahedrons microstrip antenna network architecture proposal for new USS telecommunication subsystem

The paper presents a new antenna network subsystem architecture developed for application on board wireless communication subsystem. Founded research work results demonstrate the success of mathematical modeling and simulation of the proposed Icosahedrons Microstrip Antenna Network Architecture. Antenna elements are simulated, prototyped and tested. The Icosahedrons Microstrip Antenna Network is developed to meet the visibility requirements during inter small USS satellite radio communications.     

Communication architecture design for reconfigurable multimedia SoC platform

Memory and communication architecture have a significant impact on the performance, cost, and power of complex multiprocessor system-on-chip designs. In this paper, we present an automated bus matrix synthesis flow for efficient transaction-level design space exploration of communication architecture in a reconfigurable multimedia system-on-chip platform. Specifically, we consider hardware interface selection problem, which has significant effect on the overall cost of area and power. We propose a method to solve such hardware interface selection problem through static analysis of communication behavior. We experiment with JPEG encoder and H.264 encoder examples and the results show the reduction of area by 56.91% and power by 48.61% of bus matrix with 0.58% performance overhead on average compared to the case of maximum performance. According to our HW interface selection algorithm, we also experiment MPEG4 video decoder example. And the result is evaluated on the FPGA prototyping board.     

基于工作流管理和策略管理的下一代互联网IP业务管理系统体系结构及应用

为了实现下一代互联网IP业务的业务流程自动化、业务管理灵活性和动态性,适应新业务的可扩展性和对业务的有效管理,在WfMC工作流参考模型和IETF策略框架的基础上,提出了基于工作流管理和策略管理的下一代互联网IP业务管理系统的体系结构,详细分析了体系结构中的构成组件和相关功能,并给出了基于该体系结构的NGIIP业务开通管理流程场景的应用实例。     

Detection and resolution of feature interactions in IP multimedia subsystem

The IP Multimedia Subsystem (IMS) enables the delivery of multimedia services through different access networks. 3GPP adopted the Session Initiation Protocol (SIP) as the IMS signalling protocol. However, IMS interaction with these services faces the ‘feature interaction’ problem encountered in traditional telephony networks. This problem occurs as features invoked during a session behave correctly when processed separately from each other, but not when running together. Although much research work has explored managing feature interactions, applying these solutions in IMS remains challenging and further investigation is needed. This paper aims to analyze the feature interaction issue in IMS and to propose a new solution. We defined a SIP‐based algorithm and the associated mechanisms to enhance IMS service invocation. This algorithm is the core of the Service Broker, a new functional entity in charge of managing feature interaction. We validated our proposal through a performance evaluation and prototyped the Service Broker on an open source IMS platform. Copyright © 2008 John Wiley & Sons, Ltd.     

New architecture for enforcing multimedia synchronization in videoconferencing applications

This paper presents a formally defined architecture allowing the design and the corresponding implementation of a set of modules that fulfill the quality of service requirements of PNSVS (Petri Net Synchronized Videoconference System), an application designed to run on top of an asynchronous environment. It describes the mechanisms and architecture allowing the system to enforce the temporal synchronization between the audio and video streams, the presentation quality, and the end to end delay. This synchronization method relies on a formal model extending time Petri nets: the Time Stream Petri Net (TSPN) model, that will be used to completely specify the time constraints of the application streams. From this, the communication architecture is improved by introducing a new partial order transport service that maximizes the PNSVS quality of service. The partial order transport principle is presented together with the pre-synchronization sub-layer, which makes the partial order transport service match the applicative synchronization requirements. Moreover, it will be shown that each layer of this synchronization architecture can be formally modeled by a well defined set of TSPN models.     

Roaming and service management in public wireless networks using an innovative policy management architecture

Nowadays, public wireless local area networks (WLANs), commonly called hotspots, are being largely deployed by WISPs (Wireless Internet Service Providers) as a means of offering ubiquitous Internet access to their customers. Although a substantial number of solutions have been proposed to improve security, mobility and quality of service on the wireless area, access network management which is mandatory remains a very significant concern. This paper describes RSM‐WISP, a new management architecture designed for WISPs to facilitate the implementation and management of the services they offer at the access side of the WLAN, and to manage roaming contracts between WISPs. Our architecture is based upon the policy‐based management principles as introduced by the IETF, combined with more intelligence at the network edge. RSM‐WISP adopts an architecture that is composed of two elements: a WISP management center (MC) that deploys policies and monitors all the WLANs, and a programmable access router (CPE) located in each WLAN. The CPE ensures service enforcement, service differentiation (access to different service levels) and guarantee, user access management, and dynamic WLAN adaptation according to the user's SLA (service level agreement). It also permits automatic service updates according to the user's requirements. Concerning roaming management, this is achieved on the CPE through multiple service provider support capabilities. This approach provides WISPs with a simple, flexible and scalable solution that allows easy service deployment and management at the access. This management architecture has been implemented, tested and validated on the 6WINDGate routers. Copyright © 2005 John Wiley & Sons, Ltd.     

EPON网管性能管理子系统的设计和实现

分析了EPON网络管理系统性能管理的特点和需求,提出了一种基于SNMP协议以及c/s软件架构的性能管理子系统的设计方案,并采用Java和MySQL加以实现,完成了EPON系统相关性能参数的配置、采集、统计、存储等功能.     

Wireless personal area networks architecture and protocols for multimedia applications

Wireless Personal Area Networks (WPANs) are an emerging technology for future short-range indoor and outdoor multimedia and data centric applications. Two types of WPANs have been standardized by the IEEE 802.15 working group; namely: High data Rate WPANs (HR-WPANs) and Low data Rate WPANs (LR-WPANs). These standards define the network architecture, the physical layer and the medium access control sublayer for these systems. A tremendous number of performance studies through mathematical analysis and simulation have been published. Also, many products have appeared in the market which indicate a clear sign of a quick acceptance to the published standards. An organized review of the network architecture, the physical layer specifications, the Medium Access Control (MAC) protocols and the general network operation concepts of the WPAN systems deserves time and effort to be presented in a collective manner. In this paper we describe the concept of WPANs and its applications. Then, the communication architecture and the allocated frequency spectrum for WPAN operation are explained. The developed MAC sublayer protocols in the literature are explored.