Telephone wiring: a conduit for networking standards

The author discusses emerging standards for local area networks (LANs) on unshielded copper wires that are expected to make it cheaper and easier for computers to communicate in offices, factories, and laboratories. He describes two twisted-pair standards developed by the IEEE 802.3 working group, one, already approved, designed for data transmission at 1 Mb/s, the other at 10 Mb/s. The official designation of the 1 Mb/s network is 1BASE5, but it is known as StarLAN after the AT&T network from which it is adapted     

100Base-T/IEEE 802.12/packet switching

Three LAN technologies look set to satisfy the ever-increasing demand for LAN bandwidth. Two of these technologies are 100 Mb/s shared-medium LANs: 100Base-T (aka IEEE 802.3 Fast Ethernet) and IEEE 802.12 (aka 100VG-AnyLAN or 100VG). The third technology is packet switching, which is really an extension of existing LAN bridge technology, but offers excellent performance gains at very low cost. The authors describe the three technologies and provide a comparison between the two 100 Mb/s LANs. Also presented are results that compare the measured performance of 100 Mb/s shared-medium LANs with switched LANs     

10Gbit/s以太网的关键技术

2002年6月12日，10Gbit／s以太网(10GbE)标准被IEEE正式通过．文章介绍了10GbE标准的体系结构，着重讨论了其物理层结构，最后给出了它的应用前景。     

100 Gbit/s CFP光收发模块的研究

随着网络流量的持续增长,100 Gbit/s以太网已开始商用,100 Gbit/s以太网的客户侧光模块为100 Gbit/s CFP(小型可插拔式)光收发模块。文章介绍了100 Gbit/s CFP光收发模块的相关标准,并给出了一种模块的设计方案。该模块由速率转换单元、发射单元、接收单元及控制单元组成。依照IEEE 802.3ba标准对模块进行了测试,结果显示该模块单通道发射平均光功率达到了1.47dBm,接收灵敏度达到了-9.5dBm,各项性能完全符合相关标准,能够应用于100 Gbit/s以太网中。     

一种以太网介质访问控制器芯片的设计与实现

完成了10/100(Mb/s)以太网介质访问控制器芯片的设计与实现,介绍了芯片的架构和主要模块的设计方法,给出了仿真结果.芯片采用0.25μm CMOS工艺流片,工作电压为2.5 V/3.3 V.测试表明,芯片性能完全符合IEEE802.3标准,达到了设计要求.     

The Demand Priority MAC protocol

A new technology needs to offer more than just 100 Mb/s. To succeed in the LAN marketplace, a new LAN technology must be very cost competitive with the established LANs, such as Ethernet and Token Ring, while also providing backwards compatibility with existing network software. We describe a new 100-Mb/s LAN technology that has these characteristics This technology is being defined as an open standard within the IEEE Project 802.12 Demand Priority group. Two important objectives were established for this LAN technology: first, it should be able to use the unshielded twisted pair (UTP) wiring found in a large number of installations and, in particular, to use the same wiring as defined for use in 1OBase-T. This objective was later extended to encompass support for the shielded twisted pair (STP) used for IEEE 802.5. This will enable the majority of current LAN users to benefit from their enormous investment in cable plant. The second objective was that the network should support new applications, such as video conferencing and remote training, while also providing backwards compatibility with the massive installed software base. Both objectives have been met. The Demand Priority MAC protocol currently being standardized in IEEE 802.12, offers substantial benefits over the CSMA/CD protocol of IEEE 802.3. By preserving both the current wiring infrastructure and investment in software, and by using the very simple Demand Priority MAC protocol, 100 Mb/s LANs could soon be as low-cost as 10Base-T is today     

Frame bursting: a technique for scaling CSMA/CD to gigabit speeds

Gigabit Ethernet supports the transmission of ordinary Ethernet frames at a data rate of 1000 Mb/s. Both flow-controlled full-duplex point-to-point links and half-duplex shared collision domains are included in the IEEE 802.3z draft standard. The parameters for half-duplex operation were chosen to align with the requirements of current generic building cabling standards, rather than to match the natural way that network size scales inversely with speed, so a star-wired single repeater topology with a maximum diameter of 200 m is permitted. Thus, gigabit Ethernet is the first time that the CSMA/CD medium access control algorithm has been applied to networks in which the round-trip propagation delay can be much greater than the transmission time for a minimum length frame. In this article, we describe the changes made to CSMA/CD that allow it to support large propagation delays without increasing the minimum frame length or changing its existing one-frame-at-a-time service interface. First, carrier extension is used to decouple the slot time from the minimum frame length, so the slot time can be increased without changing the Ethernet frame format. Second, frame bursting is used to reduce the overhead for transmitting small frames by allowing a host to transmit more than one frame without ever releasing control of the channel. Using simulation, we show that CSMA/CD with carrier extension and frame bursting operating on 1000 Mb/s links provides a significant performance increase over 100 Mb/s Fast Ethernet     

10Gbit/s EPON对称OLT光模块的设计

介绍了10Gbit/s EPON(以太网无源光网络)系统中对称OLT(光线路终端)光模块的设计方案和关键技术,重点描述在接收端如何实现双速率突发接收,以及10Gbit/s突发接收部分硬件电路的构成。测试结果表明:该模块在突发接收条件下接收端的接收建立时间和灵敏度均满足10Gbit/s EPON标准IEEE Std.802.3av的要求。     

100BASE-T2: a new standard for 100 Mb/s Ethernet transmission overvoice-grade cables

100BASE-T2 is a new physical-layer specification for IEEE 802.3 LANs operating at 100 Mb/s (“Fast Ethernet”). It enables users of the prevailing 10BASE-T Ethernet LAN technology to upgrade their networks from 10 to 100 Mb/s performance while retaining an existing voice-grade cabling infrastructure. 100BASE-T2 transceivers will operate over two pairs in unshielded twisted-pair cables corresponding to EIA/TIA category 3 (UTP-3), as minimally required for 10BASE-T. In a four-pair UTP-3 cable, simultaneous operation of two 100BASE-T2 links, or one 100BASE-T2 and one 10BASE-T link, is permitted. Since voice-grade cables exhibit more signal attenuation and significantly higher crosstalk coupling between adjacent pairs than data-grade cables, sophisticated digital signal processing techniques are needed to achieve reliable duplex 100 Mb/s transmission over two pairs. The 100BASE-T2 standard defines dual-duplex baseband transmission at a modulation rate of 25 Mbaud. During each modulation interval, a four-bit data nibble or Ethernet-specific control information is encoded into a pair of quinary signals. These signals are transmitted simultaneously on the two wire pairs in both signaling directions. In the receivers, adaptive digital filters are required for echo and NEXT cancellation, equalization, and interference suppression     

10G以太网帧发送速率控制机制分析

IEEE Std 802.3ae-2002中提出了两种不同的10G以太网帧发送速率控制机制：插入空闲比特、维持DIC（Deficit Idle Count）。本文通过建立实验模型,测试两种控制机制下10GE接口的帧发送速率,通过分析测试结果,总结出两种机制的区别及其影响10GE接口帧速率的规律。     

AX88180在嵌入式系统中的应用

AX88180是一款高性能低成本的Non-PCI千兆以太网控制器,适用于多种需要高速接入网络的嵌入式系统,如消费电子和家庭网络等.AX88180内置10/100/1000 Mb/s以太网媒体存取控制器(MAC),符合IEEE 802.3/IEEE 802.3u/IEEE 802.3ab协议,可与一般16/32位微控制器连接,其操作与SRAM相同.介绍了AX88180的原理与特性,并给出了具体的应用电路.     

Recent advances and evolution of WLAN and WMAN standards [guest editorial]

Standardization of wireless technologies is a continuous process, and even established standards are updated and modified in response to changes in the technology and the marketplace. One such example is the successful IEEE 802.11 standard for wireless local area networks (WLANs), which was originally designed for 1 and 2 Mb/s traffic, and is now being upgraded to support 600 Mb/s in 802.11n and being considered as a high-throughput (up to 1 Gb/s) wireless interface for the nomadic scenarios of the next generation of wireless systems. Similarly, enhancements to the IEEE 802.16 standard for wireless metropolitan area networks (WMANs) are being considered to develop a mobile air interface with support for up to 100 Mb/s in high mobility scenarios. This continuous evolution of the IEEE 802.11 WLAN and 802.16 WMAN standards is made possible with new innovation and contribution from both academia and industry. Given the rapid growth of these technologies, it is important to understand what new application scenarios have triggered the recent developments within WLAN and WMAN standards, how they are evolving, the technological challenges they face, and the opportunities for both the industry and research communities. In this issue, from a large number of submissions, we have selected five key articles for inclusion, which provide the reader with ongoing developments in these standards, technology roadmaps, current research challenges, and comprehensive evolution of these technologies, as well as deployment experience and application requirements.     

Multi-Rate SerDes Transceiver for IEEE 1394b Applications

This paper presents the implementation of a multi-rate SerDes transceiver for IEEE 1394b applications. Simple and effective pre-emphasis and equalizer circuits are used in the transmitter and receiver, respectively. A phase interpolator based clock and data recovery circuit with optimized linearity is also described. With an on-chip fully integrated phase locked loop, the transceiver works at data rates of 100 Mb/s, 400 Mb/s, and 800 Mb/s, supporting three different operating modes of S100b, S400b, and S800b for IEEE 1394b. The chip has been fabricated using 0.13 μm technology. The die area of transceiver is 2.9×1.6 mm2 including bonding pads and the total power dissipation is 284 mW with 1.2 V core supply and 3.3 V input/output supply voltages.     

The infrared physical layer of the IEEE 802.11 standard forwireless local area networks

The new IEEE 802.11 standard for wireless local area networks defines a specification for an infrared physical layer. This article gives an overview of infrared technology and describes the IEEE 802.11 specification in detail, presenting a historical perspective of its development. The infrared physical layer was designed for diffuse systems supporting two data rates (1 and 2 Mb/s) and includes provisions for a smooth migration to higher data rates. The specification is suitable for low-cost transceivers but allows interoperability with higher-performance systems. The main application envisaged for IEEE 802.11 infrared wireless local area networks is ad hoc networks     

A fully integrated CMOS receiver front-end for optic GigabitEthernet

A fully integrated fiber-optic receiver chip in a CMOS technology is presented. The design was done in a low-cost mixed-signal analog pure CMOS technology with 0.35-μm gate length. It incorporates every building block needed for standard fiber-optic receiver application, e.g., transimpedance amplifier, postamplifier, signal detect, and several control circuits. The chip works without any external components, such as capacitors usually needed to ensure the broadband operation down to several tens of kilohertz. Three designs were processed for typical data applications between 155 Mb/s and 1.25 Gb/s. The difference in the designs can be created by changing only one metal mask and programming some bandwidth and noise-relevant components on the chip. The results in sensitivity, dynamic range, and other behaviors are fully compliant with the relevant standards, such as SONET or IEEE 802.3 (Gigabit Ethernet) and future IEEE 1394 plastic optical fiber (POF) communication     

400Gbit/s光模块的技术浅析

随着IEEE 802.3ba标准的制定完成,100Gbit/s以太网技术已经得到验证并标准化。400Gbit/s以太网和OTN(光传输网)标准成为了下一步人们关注的焦点。文章基于现行100Gbit/s标准,讨论了双载波偏振复用的16QAM(正交幅度调制)、阵列相干探测等以太网和OTN的400Gbit/s光网络模块相关技术。     

超100Gb／s现状及发展趋势

随着网络视频和移动互联网等应用的发展,骨干网带宽面临巨大的挑战,IEEE日前也专门成立高速以太网研究组,开始与业界一起探讨下一代数据接口速率。本文介绍了目前超100Gb／s技术现状和标准化进展,并探讨了超100G技术发展趋势。     

自适应p-持续CSMA/CD介质访问控制策略

针对IEEE802．3局域网介质随机访问协议l-持续CSMA／CD，在同一个冲突域内，它的性能在重荷载下有明显缺陷的问题，本文分析了p-持续CSMA／CD协议，提出了一种新的关于概率p的自适应算法。该算法基于对网络流量的分析，在OSI物理层通过信道信息量的在线实时检测，根据反馈控制的原理，在数据链路层动态地调整控制输入参数p，从而控制站点发送分组数据帧的行为，使信道处于最佳的传输状态，提高信道的效率。     

Design of a power-reduction Viterbi decoder for WLAN applications

In this paper, a 64-state four-bit soft-decision Viterbi decoder with power saving mechanism for high speed wireless local area network applications is presented. Based on path merging and prediction techniques, a survivor memory unit with hierarchical memory design is proposed to reduce memory access operations. It is found that more than 70% memory access can be reduced by taking advantage of locality. Moreover, a low complexity compare-select-add unit is also presented, leading to save 15% area and 14.3% power dissipation as compared to conventional add-compare-select design. A test chip has been designed and implemented in 0.18-/spl mu/m standard CMOS process. The test results show that 30/spl sim/40% power dissipation can be reduced, and the power efficiency reaches 0.75 mW per Mb/s at 6 Mb/s and 1.26 mW per Mb/s at 54 Mb/s as specified in IEEE 802.11a.     

以太网相关技术标准规范与标准组织简介(二)

中首先介绍电气与电子工程师学会(IEEE)组织概况，然后概括说明了IEEE关于局域网／城域网IEEE802．2标准系列、以太网集成电路标准图标，特别着重讨论了关于以太网的IEEE802．3系列标准、在SDH／WDM网络上传输以太网帧信号的相关规范和10吉比特以太网技术标准。最后指出，10吉比特以太网技术标准的开发和广泛应用将在通信领域展现出更加辉煌的明天。