Performance Analysis of the Advanced Infrared (AIr) CSMA/CA MAC Protocol for Wireless LANs

Advanced Infrared (AIr) is a proposed standard of the Infrared Data Association (IrDA) for indoor infrared LANs. AIr Medium Access Control (MAC) employs Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) techniques with Request To Send/Clear To Send (RTS/CTS) frame exchange to address the hidden station problem. A long Collision Avoidance Slot (CAS) duration, that includes the beginning of the CTS frame, is defined to cope with collisions caused from hidden stations. AIr MAC employs linear adjustment of the Contention Window (CW) size to minimize delays emerging from the long CAS duration. This paper provides a simple and accurate analytical model for the linear CW adjustment that calculates AIr throughput assuming a finite number of stations and error free channel transmissions. Validity of the model is verified by comparing analysis with simulation results. By examining the first derivative of the throughput equation, we derive the optimum CW size that maximizes throughput as a function of the network size. In the case of the AIr protocol, where a collision lasts exactly one CAS, different conclusions result for maximum throughput as compared with the corresponding conclusions for the similar IEEE 802.11 protocol. Using the proposed model, we present an extensive AIr throughput performance evaluation. The effectiveness of physical and link layer parameters on throughput performance is explored. The proposed long CAS duration combined with CW linear adjustment are proven quite effective. Linear CW adjustment combined with the long CAS duration offer an efficient collision avoidance scheme that does not suffer from collisions caused from hidden stations.     

IrBurst Modelling and Performance Analysis in the Presence of Transmission Errors

IrBurst is a session/presentation layer protocol dedicated for high speed large volume information transfer over IrDA links. The protocol is developed by IrDA in order to complement the existing protocol OBEX which is best suited for small files. This paper presents a mathematical model for IrBurst over the IrDA protocol stacks taking into account the presence of bit errors and multiple simultaneously applications. The performance of IrBurst is examined considering TinyTP buffer sizes and the number of IrBurst application connections as parameters. The contribution of this work is to develop a mathematical model for IrBurst, investigate the compatibility of IrBurst to low layer protocols, as well as providing suitable design guidelines for IrDA devices for high performance of IrBurst. Pi Huang received the B.Sc. degree in Electrical and Electronic Engineering from University of Central Lancashire, U.K., in 2001, the M.Sc. degree in Telecommunications from University College London, U.K., in 2002 and the Ph.D degree in the Personal Wireless Networks and Outdoor Optical Links from Bournemouth University, U.K., in 2006. He is currently working in wireless solution division of British Telecom. His research focuses on performance modelling and analysis as well as discrete-event simulation of wireless communication protocols and wireless communication networks. He has published over 20 papers in the areas of wireless communications. Anthony C. Boucouvalas has worked at GEC Hirst Research Centre, and became Group Leader and Divisional Chief Scientist until 1987, when he joined Hewlett Packard (HP) Laboratories as Project Manager. He joined Bournemouth University in 1994 and became a Professor in Multimedia Communications in 1996, and in 1999 became Director of the Microelectronics and Multimedia Research Centre. His current research interests span the fields of wireless communications, optical fibre communications and components, multimedia communications, and human-computer interfaces, where he has published over 200 papers. He has contributed to the formation of IrDA as an industry standard and he is now a Member of the IrDA Architectures Council. He is a Fellow of Fellow of the Royal Society for the encouragement of Arts, Manufacturers and Commerce, (FRSA) and a Fellow of IEE, (FIEE). In 2002 he became a Fellow of the Institute of Electrical and Electronic Engineers (FIEEE), for contributions to optical fibre components and optical wireless communications. He is an Editor of numerous Journals and in the Organising committee of many conferences.     

红外无线数字通信

本文介绍了计算机领域正在兴起的一种通信技术－－红外无线数字通信，介绍了其工作原理及组成结构，目前已有的两个标准：ＩｒＤＡ及ＩＥＥＥ８０２．１１。对国外已有的产品及专用ＩＣ进行了总结，并就国外的一些研究成果作了简要综述。     

红外通信IrDA标准与应用

红外光是有许多优势的通信媒介,红外通信IrDA标准是目前IT和通讯业普遍支持的近距离无线数据传输规范。本文介绍了红外通信IrDA标准的内容以及它的物理层协议,脉冲调制的必要性,不同传输速率下不同的脉冲调制方式,连接建立协议层的帧结构。给出了符合IrDA标准的芯片TOIM32325和TFDS4500在高电压环境下调试实验设备的应用。     

基于低速率的短距离无线通信网络新技术--ZigBee

介绍了ZigBee的技术特点及应用前景。并把它与Bluetooth、IrDA进行了对比,最后分析了ZigBee所面临的挑战。     

漫射红外技术的智能家居无线局域网设计

分析了红外技术在短距离无线通信中的优势,并将其应用在智能家居局域网中;结合安华高科技公司的HSDL-3020红外收发模块搭建了硬件电路,构成网络的主从节点;介绍了网络组建的过程,包括IrDA协议栈结构、数据编码格式、链路连接、网络管理机制等。本设计实现了对家居设备的统一管理,具有较高的应用价值。     

常用无线数据通讯技术比较

随着计算机技术与无线通信技术的发展,人们已经不再满足于国家的网络通信,用户对移动计算的需求也日益增长,为了满足用户的需求,出现了多种无线传输协议。本文重点分析了蓝牙技术与IrDA技术的异同点,并指出了两种技术的不同使用场合。在本文的结尾,指出了两种技术进一步融合的可行性。     

基于嵌入式Linux的RF手持设备红外通讯的设计

本文从硬件及软件两个方面介绍了TagmasterAB公司的RF手持设备的红外通讯的实现。硬件方面,结合AT91RM9200对红外接口的支持以及HSDL3602的硬件特性,给出了一个设计方案;软件方面,结合硬件特性,从驱动出发,分别讨论了上位机和下位机应用程序的实现过程。最后给出了该方案的设计结果。     

红外无线与BACnet网络的接入研究

提出了一种红外无线接入BACnet网络的解决方案,并从硬件和软件两方面对此解决方案展开了探讨。此方案采用MCS-51作为网关的处理器,并在此基础上开发了IrDA/BACnet协议栈,实现IrDA协议与BACnet协议之间的转换。     

Windows CE的红外通信及其应用

本文描述了基于Windows CE设备的IrDA通信功能,介绍了几种进行红外通信的方法,并给出了用IrSock方法实现IrDA数据传输的程序代码。