A Timed Verification of the IEEE 1394 Leader Election Protocol

The IEEE 1394 architecture standard defines a high performance serial multimedia bus that allows several components in a network to communicate with each other at high speed. In the physical layer of the architecture, a leader election protocol is used to find a spanning tree with a unique root in the network topology. If there is a cycle in the network, the protocol treats this as an error situation. This paper presents a formal model of the leader election protocol in the language IOA and a correctness proof. Hereby, it is shown that under certain timing restrictions the protocol behaves correctly. The timing parameters in the IEEE 1394 standard documentation obey the restrictions found in this proof.     

IEEE 1394: status and growth path

In December 1995, the final public review of the High Performance Serial Bus draft standard concluded, and the IEEE ratified it as IEEE Std 1394-1995. As 1394 working-group chair, I extend my appreciation to all those who took the time to review vote, and comment upon the draft standard. It is also gratifying to the entire working group to observe the various computer and digital audiovisual (AV) products now incorporating support for the 1394 interface. This column's purpose is to review technical issues raised by the IEEE study group exploring the development of a second-generation standard based on 1394. This second-generation activity is likely to consist of several 1394-related working groups. Each expanding a different attribute or capability of the standard. To set a proper foundation for the discussion of 1394's future. I first summarize the concepts and facilities of the present standard and review its current status in the computer and digital AV industries     

一种基于IEEE1394总线的高速数据传输设备的设计

为了满足姿轨控/推进仿真中心计算机与通用仿真接口箱之间的高速实时数据传输,设计了一套基于IEEE1394串行总线的通用数据传输设备,同时介绍了IEEE1394协议的传输类型以及物理层、链路层、事务层和总线管理层的功能,并详细描述了基于高性能的1394控制器TSB12LV01B和TSB41AB1的传输系统的硬件设计、软件设计和工作过程.经测试方案实验验证,该设备可以实现最高400 Mb/s的高速数据实时传输,证明了这种系统的可行性和可靠性,对其他通信系统的设计具有参考价值.     

多媒体应用接口——IEEE1394

本文在分析和比较了现有I／O系统各类接口的分类和应用的同时，介绍了多媒体接口IEEE1394及其原理，并得出结论：IEEE1394是目前最适宜的多媒体应用接口．     

VxWorks下1394b总线系统驱动软件设计

结合IEEE 1394b协议规范,设计了某通信系统单节点1394b模块的驱动接口程序,并对各接口的设计做了详细的分析,实现了在VxWorks操作系统下对PCI接口的访问以及1394b总线网络的通信测试及性能测试,在以单节点1394b模块组成的通信系统中的运行结果表明该驱动程序运行稳定、可靠。     

False Loop Detection in the IEEE 1394 Tree Identify Phase

The physical layer of the IEEE 1394 (FireWire, i-Link) architecture contains a protocol for spanning a tree in the network topology, which fails if the topology contains a loop. We show that the timing requirements for both the 1394-1995 and 1394a-2000 standards are too lenient: these allow for scenarios in which there is no loop in the topology, but the tree-spanning protocol does detect one. The scenarios are found by the model checker UPPAAL. Received August 2001/Accepted in revised form August 2001 Correspondence and offprint requests to: J. M. T. Romijn, Computing Science Department, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands. Email: J.M.T.Romijn@tue.nl     

Verification of a Leader Election Protocol: Formal Methods Applied to IEEE 1394

The IEEE 1394 high performance serial multimedia bus protocol allows several components to communicate with each other at high speed. In this paper we present a formal model and verification of a leader election algorithm that forms the core of the tree identify phase of the physical layer of the 1394 protocol.We describe the algorithm formally in the I/O automata model of Lynch and Tuttle, and verify that for an arbitrary tree topology exactly one leader is elected. A large part of our verification has been checked mechanically with PVS, a verification system for higher-order logic.     

基于JAIN SIP的用户代理软件设计

会话初始化协议(SIP)是下一代网络中应用层的信令控制协议。JAIN SIP是用于实现SIP应用而提供的一套标准Java接口。提出了一个基于JAIN SIP的用户代理软件框架,包括图形用户界面(GUI)、SIP消息处理模块、媒体处理模块和SIP协议栈,并对各个功能模块进行了详细分析。用JAIN SIP来开发基于SIP协议的应用不仅可以提高开发效率,而且将使应用程序获得较高的可靠性和较好的移植性。     

A PC cluster system employing IEEE 1394

In this paper, we describe the design and evaluation of a PC cluster system in which IEEE 1394 is applied. Networks for parallel cluster computing require low latency and high bandwidth. It is also important that the networks be commercially available at low cost. Few network devices satisfy all of the above requirements. However, the IEEE 1394 standard provides a good compromise for fulfilling these requirements. We have used IEEE 1394 devices, which support a 400 Mbps data transfer rate, to connect the nodes of a PC cluster system which we have designed and implemented. We have implemented two communication libraries. One is a fast communication library called CF for IEEE 1394. The other is a MPI layer library on the CF library. Experimental results show that CF achieves a 17.2 microsecond round‐trip time. On application benchmarks, the system was considerably faster than TCP/IP over Fast Ethernet. Even though the system was constructed at very low cost, it provides good performance. Using the IEEE 1394 standard is thus a good solution for low‐cost cluster systems. Copyright © 2004 John Wiley & Sons, Ltd.     

100_1000兆位以太网物理层通信的研究分析

目前很多单位网络设备处于百兆千兆设备共存的情况,存在着百兆、千兆设备互联时的一些通信问题。为了理解网络通信的基本原理,从OSI的7层结构和IEEE802协议入手,研究分析百兆、千兆以太网的数据链路层和物理层的结构体系,重点对百兆、千兆以太网的MAC层和物理层通信规则作了对比和详细分析介绍,并在遇到网络通信障碍时,提出应该如何解决问题的方向。     

IEEE1394传输原理

IEEE1394作为多媒体应用的接口，前途无量，本文对其传输标准、数据标准和传输机制矛以介绍和分析．     

IEEE1394/UPnP软件桥分析及应用

本文介绍了可以连接IEEE1394设备和UPnP设备之间的IEEE1394/UPnP软件桥的结构功能与作用过程。此软件桥可以使UPnP控制点将IEEE1394设备等同于UPnP设备,并能实现IEEE1394传统设备或新型设备与UPnP设备间的数据格式转换和功能转换,并可解决IEEE1394与UPnP设备之间几种不匹配的问题。此文还介绍了一种利用此软件桥连接硬件设备的应用实例。     

Channel time allocation scheme based on feedback information in IEEE 802.11e wireless LANs

The IEEE 802.11e standard defines a set of quality of service (QoS) enhancements for wireless local area network (WLAN) applications such as voice and streaming multimedia traffic. In the standard, a new medium access control (MAC) protocol is called the hybrid coordinator function (HCF), and also a channel access scheme to transmit multimedia traffic is called the HCF controlled channel access (HCCA). In the IEEE 802.11e WLANs, to satisfy the stringent real-time constraints of multimedia services it is very important to provide an efficient method of allocating network resources. In this regard, we propose a feedback-assisted dynamic channel time allocation scheme considering the application layer information in order to achieve better performance of multimedia traffic over IEEE 802.11e HCCA under the constrained QoS requirements. Performance of the proposed scheme is investigated by simulation. Our results show that under typical channel error conditions, the proposed scheme is very effective regardless of the variation of station numbers and service intervals. Also, it yields high performances while guaranteeing the delay bound.     

一种IEEE1394总线监控卡的设计与实现

IEEE1394总线具有带宽高、延迟低、实时性强等特点,广泛应用于航空、航天领域。由于其差分总线上传输数据不透明,且协议复杂给设计开发带来极大困难。文中针对1394总线的原理和特点,分析了1394总线的监控需求,提出一种软硬协同实现的1394b总线监控方案。给出了相关的软件和硬件设计,实现网络中实时传输数据的监视和控制,采用软件对数据进行记录、存储、分析以及图形化显示,方便了数据的观测和结果分析。该设备的应用可为1394总线设备的开发与测试提供有效支持。     

宽带媒体家庭网关系统方案研究

宽带媒体家庭网关(BMG)是面向高性能宽带信息网络的用户终端设备,负责着家庭网络和驻地网的连接,是家庭的联网中心和媒体中心,具有许多全新的功能。本文介绍了一款自行设计实现的BMG的软硬件框架,并对设计中的一些关键技术进行了研究探讨。系统采用了具有强大处理能力的网络SOC外加多功能媒体处理芯片的硬件体系架构,该架构能提供可裁减的配置／成本结构和较大的灵活适应性,通过两种芯片的合理选配,可获得最佳的性价比方案。同时在软件上采用了模块化分层的体系结构,每层软件各司其职,并通过接口函数调用来实现各层之间的功能交换,使整个系统软件具有良好的可扩展性和可移植性。     

Design and evaluation of a novel MAC layer handoff protocol for IEEE 802.11 wireless networks

In recent years, the IEEE 802.11 wireless network family has become one of the most important set of standards in the wireless communications industry. IEEE 802.11 compliant devices are inexpensive and easier to configure and deploy than other wireless technologies. In an IEEE 802.11 wireless network, wireless terminals can move freely. As a result, when the wireless terminal moves away from its current access point, it must switch to another access point to maintain the active connection. This is known as the MAC layer handoff process. MAC layer handoff latency should be minimized to support real-time applications and to provide mobile devices with seamless roaming in IEEE 802.11 wireless networks. This paper proposes a novel MAC layer handoff protocol over IEEE 802.11 wireless networks by introducing advertisement messages sent from other mobile nodes and from which wireless terminals are able to receive the information of access points in their neighborhood. A mobile node can try to associate with access points based on the prediction before starting the probe process. The experimental results demonstrate that our solution can reduce MAC layer handoff latency to meet the requirements of real-time applications.     

1394接口在嵌入式系统上的设计和实现

介绍了一种IEEE 1394接口在嵌入式系统上的实现方法，包括硬件设计和在VxWorks操作系统上驱动程序的编写。经过测试，该设计实现了高速数据的实时传输。根据本实现方法，嵌入式设备能大大提高数据传输的速率。     

基于JAIN SIP的多媒体会议用户代理设计

会议初始化（SIP）协议是下一代网络应用层的核心控制协议。JAIN SIP是SUN公司用于实现SIP应用而提供的一套标准Java接口。文章提出了一个基于JAIN SIP的多媒体会议用户代理的框架，对每一层的功能模块进行了详细分析，包括JAIN SIP协议栈的体系结构、用户代理控制部分信令（创建会议、加入会议、删除会议等）、媒体信息处理等。用JAIN SIP开发基于SIP协议的应用不仅可以提高开发效率，而且将使应用程序获得较高的可靠性和较好的移植性。     

基于UPnP的AV体系结构的设计与实现

UPnP是一种实现网络设备智能互连以及对设备服务自动控制的标准规范.介绍一种基于UPnP的AV体系结构,AV体系结构允许设备支持不同格式类型的娱乐内容(例如:MPEG4、JPEG、MP3、Windows Media Architecture(WMA)、bitmaps (BMP)、NTSC等)和多种传输协议(例如:IEC-61883/IEEE-1394、HTTP GET、RTP、HTTP PUT/POST、TCP/IP等).     

The Washington University multimedia system

The Washington University multimedia system (MMS) is a complete multimedia system capable of transmitting and receiving JPEG-compressed video, CD-quality audio, and high-resolution radiological images, in addition to normal network traffic, over the Washington University broadband ATM network. The MMS consists of an ATMizer and three multimedia subsystems. The ATMizer implements the host interface, the interface to the ATM network, and the interface to the three multimedia subsystems. This paper describes the architecture of the MMS, the software used with the system, and the applications which have been developed to demonstrate the capability and applicability of broadband ATM networks for multimedia applications.