基于IrDA OBEX协议的移动设备数据传输

随着移动设备的日益普及，红外数据通讯已经进入了黄金发展时期。OBEX对象交换协议具有简单、紧凑、灵活的优点，特别适用于资源受限的移动设备进行快速数据交换。文章在介绍红外通信协议层结构的基础上，分析了OBEX协议的对象模型和会话模型，讨论了OBEX对象交换的传输过程，最后提出了在移动设备上OBEX对象交换的设计与实现。     

一种基于SIP和MSRP协议实现文件断点续传的方法

在文件传输过程中发生中断后,下次为了减少重复传输断点前的文件内容,提高传输效率,提升用户体验,需要文件传输服务具备断点续传功能。对会话初始协议(SIP)和消息会话中继协议(MSRP)进行了研究,介绍了这2种协议在即时消息子系统中的具体应用;提出一种基于SIP和MSRP协议实现断点续传的文件传输流程,并分别从协议字段扩展、信令流程和断点续传3个方面进行了详细阐述;对文件传输软件架构进行了设计。在统一通信系统中应用表明,该方法达到了无缝断点续传的效果。     

大规模RapidIO协议交换的FPGA实现

RapidIO交换模块是RapidIO系统的核心模块,决定了整个RapidIO系统的数据带宽.文中介绍了一种大规模RapidIO协议交换的FPGA实现方式,并且在基于VPX总线的RapidIO交换模块中得到实际应用.该交换模块除具有RapidIO协议交换功能,还具有RapidIO系统主控功能以及以太网交换功能.经过使用实际的RapidIO端点模块进行测试,该交换模块实现了RapidIO交换功能以及RapidIO系统主控功能.     

简单文件传送协议（TFTP）的C语言实现

TFTP（简单文件传送协议）是TCP／TP协议族中用来在客户机与服务器之间进行简单文件传输的协议。文中给出了在visual C＋＋6．0开发平台上,用C语言按照TFTP协议在服务器跟多客户端之间进行文件传输的实现方法,该方法可以传输超过32MB的文件。     

近程激光保密通信系统设计应用

相比于传统使用常规波段的电磁波作为载波传输信息的通信终端,激光通信系统使用红外波段的不可见光作为其传输信息的载波,在抗干扰性、保密性、可靠性等方面具有明显的优势。因此,设计一套双向近程激光保密通信系统,基于脉位调制、数据帧结构设计与光路对准等关键技术进行设计与工程应用,并通过收发协议与检验纠错编码,实现视距范围内的保密语音通信和信息传递。系统不仅可以快速实现通信链路的建立,完成保密语音通信,而且能够支持点对点的高速文件传输,以接近5Mb/s的速度实现本地设备中SD卡上的文件传输,且具有断点续传功能。     

基于TFTP协议的简单文件传输系统的研究

文章通过研究TFTP协议,实现了基于TFTP协议的简单文件传输系统。TFTP服务器端通过采取创建新socket和分配新端口等措施实现了多客户端与服务器的文件传输功能。该系统采用超时重传、socket信息保存、上一条消息暂存等方法解决了丢包、多任务执行等问题,具有一定的容错能力。     

一种高效的具有用户匿名性的无线认证协议

提出了一种高效的具有用户匿名性的无线认证协议。利用Hash函数和Smart卡实现了协议的用户匿名性。协议充分考虑了无线网络自身的限制和移动设备存储资源及计算资源的局限性，在认证过程中移动用户只需要进行一次对称加密和解密运算，用户与访问网络、本地网络与访问网络都只进行一次信息交换，而且所有对称加密都使用一次性密钥。本协议具有实用、安全、高效的特点。     

一种用于更新触摸屏遥控器红外协议的方法

为解决触摸屏遥控器红外协议更新的问题,设计了一种数据下载方法,并对自定义数据格式的内容进行了详细描述.该方法包括红外协议数据处理、红外协议数据下载、存储和红外协议下载网页操作3个部分.通过实验测试,设计的数据下载方法能够将红外协议数据准确地下载到触摸屏遥控器中,并且触摸屏遥控器能够正确地控制红外设备.因为不同的红外协议均可按照自定义的数据格式来处理,并存储在触摸屏遥控器中,故可以实现触摸屏遥控器控制多种家电的功能.     

移动多媒体广播中的FLUTE协议及其客户端实现

介绍和分析了移动多媒体广播中的一种文件传输协议--FLUTE协议,给出了一种FLUTE协议客户端系统的软件设计和实现方案,并给出了实现结果.     

基于SSL的安全文件传输系统在linux环境下的研究与实现

文章在linux环境下对安全文件传输系统进行了研究与设计,使数据在linux设备间的访问与传输具有更高的安全性。通过网络编程建立套接字,并结合基于SSL(Secure Socket Layer)的传输协议,对服务器与客户端软件进行需求分析与设计;用加入线程池的设计方法,实现服务器同多个客户端间安全高效的文件传输。     

OBEX Over IrDA: Performance Analysis and Optimization by Considering Multiple Applications

OBEX (Object Exchange Protocol) is a session protocol designed to exchange all kind of objects between portable devices using different ad hoc wireless links including IrDA and Bluetooth. This paper develops a mathematical model for OBEX over the IrDA protocol stack by considering multiple applications and presence of bit errors. The model is also verified by simulation results. We derive throughput equations and carry out an optimization study focusing on four major parameters: OBEX packet size, TinyTP (IrDA transport layer) buffer size, IrLAP (IrDA link layer) frame and window size. Equations are derived for the optimum IrLAP window and frame sizes. Numerical results show significant improvement on OBEX performance using the optimized parameters. The major contribution of this work is the modelling of OBEX including the low layer protocols and optimization of the overall throughput by appropriate parameter selection     

便携式红外收发器的设计与实现

介绍了一种以C8051F310单片机为控制核心,可实现红外数据通信的便携式收发器。对其基本原理和标准规范进行了说明,给出了设计思路和硬件电路。阐述了电源处理各模块的特性和实现过程。同时给出了符合IrDA标准通讯协议的设计方法。     

基于IrDA标准的红外无线数字通信及应用

概述了红外无线通信的概念，介绍了IrDA通信协议，在此基础上设计了一种基于单片机的通用红外通信接口模块，它支持IrDA协议，采用串行输入输出，可以做为附加通信模块方便地集成到各种设备和仪器仪表中。     

一种新的红外焦平面图像信号无线光输出协议

文中提出了一种针对红外焦平面图像信号无线光输出的高速数据链路层协议。该协议以IrDA标准的红外数据链路协议(IrLAP)作为参考，通过红外无线信道来实现点对点、高速、稳定的图像信号输出。协议的设计充分考虑了对多种红外传输速率的支持，以及位错误率(BER)、红外帧长度、应答分组大小等因素对系统传输吞吐量的影响，提出了寻找合适参数有效的计算方法，以及基于FPGA的红外无线视频传输平台的设计方法。实验结果显示，传输平台可以在16Mb／s的红外传输速率下长期稳定工作。这表明本协议适用于VFIR及更高速率的图像无线传输，经过不断地测试与完善，可为制订今后焦平面图像信号光输出规范提供参考。     

Performance modeling of the IrDA protocol for infrared wirelesscommunications

This article presents a performance analysis of the IrDA protocol used for short-range IR data communication using an analytical mathematical model. The IrDA protocol specifies a protocol stack for reliable short-range infrared wireless data communication between devices with the data link layer (IrLAP) being an HDLC derivative. The mathematical model is based on unidirectional data transfer and uses the concept of the virtual transmission time, which provides the average end-to-end transmission time of a packet, incorporating the time for retransmissions if packet errors occur or other enforced delays. Analytical results are produced for throughput against packet size, BER and minimum turnaround time. They indicate certain limitations of the protocol for efficient throughput at high data speeds, and indicate that the maximum frame size and window size should be increased and the minimum turnaround time minimized for improved results     

OBEX研究及.net Compact框架实现红外通信的应用

IrDA是一种利用红外线进行通信的点对点通信的技术.设备间的红外线通信具有方便快捷、无需额外硬件支持等特点.基于对OBEX协议的研究,本文在Visual Studio.net Compact框架下,设计并实现了两个独立设备利用红外接口进行信息传输的功能.     

Optimization of IrDA IrLAP link access protocol

The widespread installation of millions of Infrared Data Association (IrDA) infrared (IR) ports in mobile devices for wireless communication applications necessitates for throughput performance optimization of the IR links at the IrDA link access protocol (IrLAP) link layer. For IrDA connectivity, link-layer throughput optimization is important for any line bit-error rate (BER). The paper provides a mathematical model with which we derive a simple equation linking IrLAP throughput with physical and link-layer parameters. Simple equations for optimum values of window size and frame length for maximum link-layer throughput as a function of BER are derived. A study of the importance of parameters such as link minimum turnaround time and F-timer time out period is presented. Finally, a protocol improvement that utilizes special supervisory frames (S frames) to pass transmission control is proposed to deal with delays introduced by F-timer expiration. Results indicate that employing the special S frame highly improves throughput performance when optimum window and frame-size values are implemented.     

Wireless infrared communication system based on edge position modulation

Driven by the Infrared Data Association (IrDA) wireless infrared communication has become a very popular and widely used method for short range data transmission between mobile devices like laptops, PDAs and mobile phones. Quality and speed of infrared communications are mainly limited by the bandwidth of the infrared transceivers. Therefore it is important to use a modulation technique with a high bandwidth efficiency, while simultaneously maintaining a low bit error rate and high power efficiency. Consequently, IrDA has continuously improved the modulation techniques of its standards (IrDA, 2001) by introducing Return to Zero inverted (RZI), 4 Pulse Position Modulation (4-PPM) and HHH(1, 13), whereby the latest is basically a 2/3-rate Run-Length-Limited (RLL) code (Hirt, Hassner, Heise, 2001). Recently the authors have published a novel modulation scheme called Edge Position Modulation (EPM) with Run-Length-Limited (RLL) coding (Lüftner et al., 2003). This article will continue this work by presenting a completely new RLL(5, 12) code that is optimized for EPM.     

Future personal "e-payment": IrFM

There is widespread distribution of millions of mobile devices such as mobile phones and PDAs with infrared data association (IrDA) ports to consumers worldwide. Rapid advancements in both device technology and users' capabilities are the foundations for a new digital payment system, which promises to change the traditional method of payments. By utilizing standard IrDA indoor infrared technology, infrared financial messaging (IrFM) is a financial messaging specification with great prospects for future digital payment systems. In this article, we carry out a comprehensive analysis of IrFM, clarify the benefits of using such a system, and develop a model which allows us to identify the significance of major performance factors of digital payment systems. Issues concerning connection speed, security, reliability, simplicity, and interoperability of IrFM are investigated.