一种用于信令寻径高速光纤交换网的信令降频方法

针对高速光纤交换网络高质量的交换服务需求,提出了一种适用于信令寻径式高速光纤通道交换机的信令降频方法.该方法采用一套特殊的序列码对信令帧内容进行编码后传输,以达到信令帧信号频率成倍降低的目的,使交换机无需借助串并转换器对高频信令帧进行降频,就能够直接识别信令帧内容.试验结果显示,采用信令降频方法后,交换机的结构显著简化,可靠性得到很大提高,并且硬件成本大大降低.     

基于信令降频码方法的信令寻径式光纤交换机的研究

信令寻径式高速光纤交换机需要使用大量"串/并"转换器件提取信令来实现对信道的控制,这使得交换机的底板面积十分庞大,无法检测BGA封装焊接质量;针对以上问题,提出了一种使用特殊的降频码对信令进行编码,成倍地降低信令的频率,采用普通的FPGA器件即可提取信令,取代了大量占线的"串/并"转换器件,减少了PCB面积和降低了成本;并在此基础上给出了高速光纤交换机的解决方案;目前,基于信令降频码方法的信令寻径式光纤交换机已经调试成功,性能稳定,运行状态良好。     

面向机群系统的高速光纤传输网络接口卡设计

针对机群系统的通信瓶颈问题,研究一种新型的以“信令寻径式交换技术”为核心的高速光纤传输交换网络。本文分析了信令寻径式交换网络通信协议,在此基础上设计并实现了基于光纤通道技术的高速网络接口卡。该网卡针对大小数据包的特点,分别对各种类型的帧进行专门设计,具有较高的通信效率。测试结果表明,由该网络接口卡组成点对点网络,其单向传输延时为4.22µs,通信带宽高达993.8Mbps,最大链路利用率为93.53％。目前,该网络接口卡性能稳定,运行状况良好,能满足机群系统通信需要。     

面向航电系统的千兆光纤传输交换网 FC-AS通信协议的研究

文章采用了一种信令寻经式交换网TR-Net,实现“端-端”的Class1类服务,硬件结构简单;设计了FC-AS通信协议,其帧格式精简,信令帧长为3个字,数据帧长度比ANSIFC标准短24～152Bytes。FC-AS有效地对短消息数据包通信进行优化,传输效率高。信令中嵌入了优先级控制,交换机可进行实时调度。     

光纤通道交换网络接口卡的零拷贝技术研究与实现

介绍了信令寻径式光纤通道交换网的特点,为了提高光纤通道交换网络接口卡的通信性能,通过地址管理表的内存映射实现在用户空间实现虚实地址转换,实现用户数据从用户空间到网络接口卡(NIC)的零拷贝,因此大大提高了NIC的通信速度,优化了其体系结构;并将其成功应用于中尺度数值天气预报的MM5模式中,为各级气象部门提供准确、高效的数值预报服务;测试结果表明,零拷贝技术能够使网络接口卡性能有较大提高,达到了设计目的。     

SIP和DSS1协议互通的研究与实现

会话初始协议(SIP)是IETF定义的基于IP的应用层信令控制协议,是VoIP技术的核心协议;ISDN网络-用户接口协议DSS1,是传统电路交换网的主要信令控制协议.文章介绍并深入分析了SIP和DSS1协议,从互通的角度对二者进行了分析,给出了二者之间一种互通的结构、消息的映射方法以及会话建立的过程,设计并实现了一个可行的解决方案,为设计以SIP为核心的软交换设备提供一些理论上依据,同时为实现传统电路交换技术向IP软交换技术的平滑过渡提供了一种可行的解决方案.     

一种高效的串行通信协议的制定及实现

探讨了一种基于串行通信的简单、高效的通信协议制定方法.实验结果证明,该协议有效提高了串行通信的通信效率.     

信令寻径式高速光纤传输交换机研究与设计

针对未来航电系统需求,研究一种新型的以“信令寻径式交换技术”为核心的高速光纤传输交换网络。该文设计了信令寻径式交换网络通信协议,并在此基础上详细论述了高速光纤传输交换机设计方案。目前,16端口的信令寻径式高速光纤传输交换机已初步调试成功,性能稳定,运行状况良好,可应用于航电和中尺度天气预报等高速网络通信系统中。     

单片机的高效串行通信研究

随着数据交互需求的进一步提高,对串行通信的通信效率、通信性能提出了越来越高的要求。本文探讨一种基于串行通信,简单、高效的通信协议的制定方法,并通过实例代码实现了串行通信数据的高效传输。实验结果证明,该协议有效提高了串行通信的通信效率。     

IP网同七号信令网的互通

该文介绍了IP网与七号信令网互通的组网方法,信令网关的组成,以及实现信令网关的主要协议.     

嵌入式网络通信协议的研究与实现

介绍了光纤通道协议的通信原理,并针对基于光纤通道协议的通信过程过于繁琐的现状,提出了一种高速率、低延迟的通信方案。同时依据新的通信协议,提出了其实现模型,为以后开发高速率、低延迟的嵌入式网络通信软件提供了方便。     

Performance investigation of a token passing access protocol for a multichannel optical fibre LAN

An alternative approach to multichannel local area network access is described. The new multichannel access scheme or protocol is based on a token passing arbitration policy. It is specifically intended for use with a starconfigured optical fibre LAN employing wavelength division multiplexing technology in order to provide a multichannel transmission medium. The multichannel network architecture comprises a single reservation channel and several equivalent speed data channels. Delay versus throughput performance characteristics for the network obtained by both analysis and discrete event simulation are shown. The multichannel token passing protocol is found to significantly improve these characteristics in comparison with a conventional single channel token passing approach using the same overall network transmission rate (i.e. the sum of the individual channel bit rates in the multichannel case). Furthermore, when the end-to-end propagation delay for an individual channel on the network becomes large, the multichannel token passing protocol is shown to exhibit an improved delay versus throughput performance over a multichannel protocol employing carrier sense multiple access with collision detection.     

Providing per-session deterministic quality of service guarantees in cross-path packet switch

Recently, a quasi-static routing scheme called path switching was proposed for large-scale packet switch systems. The path-switched Clos network is called a cross-path switch. Cross-path switch is capable of supporting multirate and multicast traffic. In this paper, we develop a general framework for it to handle multimedia traffic. We obtain upper bounds on the delay and backlog at the cross-path switch on a per-session basis, wherein no packet lost or delay bound violation is allowed. Our results show that these bounds much depend on the way of token assignment at the central stage. To understand such dependence, we quantify the effect of the token assignment on the switch performance. From these results, we design an effective token assignment scheme to achieve better performance guarantees in the switch. We show that cross-path switch with such token assignments always provides near-optimal performance guarantees to each data session.     

基于IEEE802．15．4a的无线测控网络协议

为满足工业现场测控任务对网络通信实时性的要求,提出一种基于IEEE80215．4a的无线测控网络协议,其中的令牌控制子层采用令牌机制管理各站点对无线信道的访问,克服了CSMA／CA机制无序竞争的缺陷,保证数据传输的时间确定性,介绍协议栈模型、逻辑令牌环动态建立过程以及令牌故障的自恢复机制,并在硬件平台NanoNET上加以实现。实验结果表明,该协议能够在强电磁干扰环境中稳定运行,具备实时特性。     

An extended token bus protocol for embedded networks

The network environment considered in this paper exists in commercial and military products such as Autonomous Aircraft and Vehicles. In these products sensors and processors are utilized for control, diagnosis, repair and communication. We refer to such networks as embedded networks and present a bus protocol suitable for these networks. Two modes of operation have been defined for the proposed protocol (IMAP). Normal mode is defined as that in which token passing is done in a random order and the token remains within a cluster of active stations. The other mode of operation is called the interrupt mode. In this mode, token bus operation is carried out and the token is passed through every station. Performance in terms of channel utilization and delay characteristics of IMAP is compared to the token bus and CSMA/CD performance. The performance models are developed by obtaining time-distance diagrams of token bus and IMAP. It is observed that IMAP has better performance characteristics than the conventional token bus and CSMA/CD.     

容错型令牌总线局域网建模及性能指标评估

本文对符合ＩＥＥＥ８０２．４标准的容错型令牌总线局域网给出了其Ｐｅｔｒｉ网建模及性能指标评估方法。文中考虑了具有信包重发机制、令牌最大保持时间和信包缓冲区容量有限的令牌网络的性能指标评估问题。克服了以往不能分配具有信包重发机制和令牌最大保持时间等令牌网性能的局域。本文讨论了带计数禁止弧的确定性时延随机Ｐｅｔｒｉ网（ＤＳＰＮ）的特性，并对给出的ＤＳＰＮ模型进行了仿真计算，对影响网络性能的系统指标进行