EPON中点到点和共享LAN仿真解决方案

在EPON中实现点到点和共享局域网(LAN)的仿真解决方案进行了介绍,该仿真方案首先是在RS子层和媒体接入控制(MAC)层上实现点到点LAN仿真,然后,在光线路终端(OLT)的MAC层之上定义了一个上层共享LAN仿真模块(ULSLE)来实现EPON系统的共享LAN功能,且OLT可以与现有的以太路由器、网桥设备兼容。     

解决EPON兼容性的有效方案

文章介绍了一种在以太网无源光网络(EPON)中共享局域网(LAN)仿真的方法,即在光线路终端(OLT)的媒体接入控制(MAC)层中定义一个上层共享LAN仿真模块(ULSLE),既可以最大限度地利用PON的下行SCB能力,又可以为用户提供点到点的通信能力．而且,具有ULSLE的OLT可以与任何一个现有的以太网设备互通．     

EPON协议参考模型

本文结合G．983规范的建议，介绍了EPON协议参考模型，并重点描述了协议参考模型中的基于帧的仿真子层，以及点到点仿真子层和共享仿真子层的工作过程。     

EPON＋LAN/EOC灵活实现宽带接入

随着信息化社会的发展,广电企业通过推进双向网改造来实现用户宽带上网已成为新的增值业务点。首先介绍了EPON＋LAN与EPON＋EOC两种双向网改造接入技术,然后结合本公司针对不同用户选择不同接入方式的具体案例,探讨两种方式的应用及展望。     

千兆以太网无源光网络(EPON)的物理层研究

EPON是基于以太网技术的宽带接入系统，采用以太网的帧结构，在传统以太网的点到点和共享（多点到多点）媒体访问机制基础上，增加了一种点到多点的媒体访问机制，即无源光网络媒体，因而EPON在物理媒质参数、编／解码和串行／解串，上行突发通信等方面引出了较为复杂的问题，文章在详细阐述了千兆以太网物理层结构的基础上，深入探讨了上述EOON系统中的物理层问题，并给出了相应的解决方法。     

EPON+LAN与EPON+EoC接入方式的选择

介绍了EPON系统与EoC的组成及原理,以此引申出EPON+LAN、EPON+EoC的技术模型,通过EPON+LAN与EPON+EoC的技术对比,根据其优缺点,结合双向网络建设的实际情况,分析双向网络改造中对EPON+LAN与EPON+EoC接入方式的选择。     

FTTH网络结构分析

文章描述了光纤到户（FTTH）在通信网中的位置及作用,FTTH系统的网络结构及功能要求。在FTTH的网络结构方面,通过对各种方案进行比较,建议在不同的应用环境中采取不同的网络方案。这些方案包括光纤到大楼（FTTB）的光网络,基于点到点的纤分方式,基于点到点结构的有源光网络,基于IEEE的以太网无源光网络（EPON）系统和基于ITU—T的吉比特无源光网络（GPON）的系统。     

EPON与HFC网络的融合及网络接入方式的探讨

介绍了淮南有线电视网络的实际状况，概述了HFC网和EPON网的网络结构。对两者进行简单对比，并着重介绍了EPON网络的优点，肯定了EPON技术在双向网络改造中的应用。提出EPON＋LAN和EPON＋EOC种接入方式。介绍在使用EPON技术进行网络改造初期时，如何将HFC网络同EPON网络进行融合，采用新技术的同时使原有网络设备仍可发挥作用。通过新老技术的结合，达到了拓展有线网络发展途径的目的。     

EPON系统上行接入技术的研究

文章介绍了一种新的基于以太网的无源光网络（EPON）。由于其点到多点的特殊共享结构，EPON系统需要不同于传统以太网（CSMA/CD）的新接入机制（Request/Grant）。文章提出了这种机制的初步数学模型，并进行了理论分析，最后给出了一些有益的结论。     

EPON上行带宽动态分配算法的研究

讨论和分析了实现EPON系统的关键技术之一上行信道的复用技术,并针对EPON多点到点的拓扑结构特点介绍了一种动态的带宽分配方案。     

ATM网上的局域网互联

文章从扩展计算机网络功能的角度探讨了利用 ATM 交换机实现 LAN 互联的可行性及其关键的技术问题。     

Efficient use of protocol stacks for LAN/MAN-ATM interworking

Connectionless (CL) services as already developed in LANs, have to interwork with emerging asynchronous transfer mode (ATM) connection-oriented (CO) networks. MANs are a significant evolutionary step and CO MANs, in particular, constitute a technically appealing method to integrate both environments and provide shared medium access for all services. The functions required for enhancing distributed-queue dual-bus (DQDB) MANs with CO services in a way compatible with ATM are described. Within the integrating framework of B-ISDN, the practically useful scenarios for interworking LANs, CO and CL MANs, and ATM are investigated and classified in order to exploit the advantages of an efficient protocol relay utilizing the resources of the lowest possible layer. This is aimed at assisting interworking unit (IWU) designers and implementors to decide on key options in this versatile and evolving environment. The CO DQDB case emerges as the most advantageous development in terms of interworking simplicity and robustness     

DSP Implementation of Antenna Array Algorithms for OFDM-Based Wireless LAN

Motivated by the theoretical results on multi-antenna signal processing techniques promising substantial performance gains, a feasible reconfigurable hardware architecture for OFDM-based Wireless LANs is presented in this paper. The ultimate objective of the platform is to support single-antenna links, as well as antenna arrays at the receiver and/or at the transmitter, taking into account the limitations caused by a real-time implementation. After a brief overview of the implemented multi-antenna algorithms, we present the hardware platform that has been built based on both fixed point and floating point DSPs from Texas Instruments, together with the evaluation of the complexity associated to the operations, and their scheduling. The performance indicates that a multi-antenna architecture supporting up to four antennas at the receiver side might accomplish the real-time requirements.     

EPON＋LAN环路风暴的预防

EPON逐渐成为许多广电运营商迈向全业务运营的理想接入方案,但EPON在实际运营中会遇到许多的问题,针对温岭广电EPON网络在运维中最常遇到的故障——EPON＋LAN环路所引起的广播风暴问题,分析了该类广播风暴的形成机理、原因,并提出了相应的预防措施。     

Wireless ATM LAN with and without infrastructure

We consider wireless ATM concepts for small LANs, especially for SOHO and future consumer applications. We describe a wireless ATM LAN framework architecture that supports wireless ATM communications in environments with and without fixed ATM infrastructure. For the configuration with an ATM infrastructure, a distributed ATM switched backbone is proposed, which enables a smart ATM switching element to be embedded in every wireless and fixed access point. For bandwidth efficiency and ease of operation (place-and-play), we also propose an ad hoc wireless ATM LAN concept based on the same 5 GHz wireless ATM air interface as is currently under standardization in the ETSI/BRAN and ATM Forum. Unlike CSMA-based ad hoc systems such as HIPERLAN and IEEE802.11, our ad hoc wireless ATM system makes QoS management feasible in an infrastructureless environment by using resource reservation and scheduled medium access protocol. Since cost scalability is essential throughout our system design, we consider forwarding between ad hoc subnets and interworking with the fixed network as important but optional features     

A Key Hiding Communication Scheme for Enhancing the Wireless LAN Security

Authentication per frame and symmetric key based encryption is an implicit necessity for security in Wireless Local Area Networks (LANs). We propose a novel symmetric key based secure WLAN communication scheme. The scheme provides authentication per frame, generates new secret key for encryption of each frame and involves less message exchanges for maintaining the freshness of key and initial vector (IV). It enhances wireless security by utilizing key hiding concept for sharing the symmetric secret key and IV. The shared secret encryption key and IV are protected using counters and then mixed with each other before sending. We prove security of the scheme in Canetti–Krawczyk model.     

Performance analysis of a LAN/WAN bridging architecture

The performance of local area networks (LANs) bridged through a virtual-circuit-based wide area network (WAN) is analyzed. The focus is on understanding end-to-end performance issues from an applications point of view. Results that can be used to traffic engineer the network to meet end-user service objectives on interactive response time and bulk data transfer throughput are derived. It is demonstrated that the use of a windowing protocol in the wide area network provides a robust control mechanism for regulating traffic and delivering high performance     

Low-latency handover in a wireless ATM LAN

The micro- and picocellular architectures proposed for wireless ATM LANs lead to wireless terminals frequently changing their point of attachment to the network. Because ATM connections have quality of service (QoS) guarantees which must be maintained, handover must be as seamless as possible. We present a novel architecture and protocol which primarily aims to keep the interruption period due to handover low, rather than seeking to keep the process entirely lossless. We compare the tradeoffs made, with those in other schemes from the literature, and give quantitative results from an implementation of our scheme on a 10 Mbits/s^-1 prototype wireless ATM LAN     

LAN互连系统

美国泰讯公司的LAN互连系统系列采用面向连接的网络结构,实现各类LAN和WAN的互连。本文简要介绍了企业路由器、路由选择桥接器、接入路由器、FDDI集中器和设备管理系统等设备。