基于ADSL和G.Lite的PPP 0ver ATM

主要讨论了基于ADSL和G.Lite技术的PPP over ATM的应用。ADSL和G.Lite作为新型的宽带接入技术,将给目前基于模拟Modem的网络接入服务带来意义深远的变革。因此在介绍ADSL和G.Lite的基本原理、功能及对高层协议（PPP over ATM)影响的基础上,讨论了ADSL系统在应用中的有关PPP起点和业务会聚的问题。     

HDSL2与G.Lite及其他

文章介绍了数字用户线技术的新成员——HDSL2和简化的无分离器ADSL——G.LiteADSL的原理、特点与应用场合,并对几种不同的xDSL作了解释.     

EWSD中的ADSL.lite和xDSL

在简单介绍了ADSL技术的基础上,具体介绍了如何在EWSDU交换机中创速和设置ADSL用户功能和xDSL功能.     

Voice over ATM: an evaluation of network architecture alternatives

This article describes eight application scenarios in which there is a business case for voice over ATM. It then evaluates alternative network architectures for implementing the required network functionality. The article incorporates much of the ongoing work of the ATM Forum and the ITU, but does not restrict itself to standards and implementation agreements. In addition, it evaluates nonstandardized alternatives for ATM transport of voice traffic. There are two main areas: N×64 kb/s structured data transfer, also known as composite cell transport-a network operator may aggregate individual voice calls into N×64 kb/s blocks for transport to an intermediate point in the network. At that point the individual calls need to be remapped into new M×64 kb/s blocks for the next stage of their transport. Architectural alternatives and advantages of remapping are investigated. Interworking of signalling is of two types: network interworking, in which the end users are connected to non-ATM networks and an ATM network is used for backbone transport; and service interworking, in which an ATM user is connected to a non-ATM user. Functionality and architectural alternatives for network and service interworking are evaluated     

Wormhole IP over (connectionless) ATM

High-speed switches and routers internally operate using fixed-size cells or segments; variable-size packets are segmented and later reassembled. Connectionless ATM was proposed to quickly carry IP packets segmented into cells (AAL5) using a number of hardware-managed ATM VCs. We show that this is analogous to wormhole routing. We modify this architecture to make it applicable to existing ATM equipment: we propose a low-cost, single-input, single-output wormhole IP router that functions as a VP/VC translation filter between ATM subnetworks. When compared to IP routers, the proposed architecture features simpler hardware and lower latency. When compared to software-based IP-over-ATM techniques, the new architecture avoids the overheads of a large number of labels, or the delays of establishing new flows in software after the first few packets have suffered considerable latencies. We simulated a wormhole IP routing filter, showing that a few tens of hardware-managed VCs per outgoing VP usually suffice. We built and successfully tested a prototype, operating at 2×155 Mb/s, using one field programmable gate array (FPGA) and DRAM. Simple analysis shows that operation at 10 Gb/s and beyond is feasible today     

A growable packet (ATM) switch architecture: design principles andapplication

The problem of designing a large high-performance, broadband packet of ATM (asynchronous transfer mode) switch is discussed. Ways to construct arbitrarily large switches out of modest-size packet switches without sacrificing overall delay/throughput performance are presented. A growable switch architecture is presented that is based on three key principles: a generalized knockout principle exploits the statistical behaviour of packet arrivals and thereby reduces the interconnect complexity, output queuing yields the best possible delay/throughput performance, and distributed intelligence in routing packets through the interconnect fabric eliminates internal path conflicts. Features of the architecture include the guarantee of first-in-first-out packet sequence, broadcast and multicast capabilities, and compatibility with variable-length packets, which avoids the need for packet-size standardization. As a broadband ISDN example, a 2048×2048 configuration with building blocks of 42×16 packet switch modules and 128×128 interconnect modules, both of which fall within existing hardware capabilities, is presented     

MPOA（Multiprotocol over ATM）规范研究与分析

ＭＰＯＡ规范是继局域网仿真（ＬＡＮＥ）、ＩＰｏｖｅｒＡＴＭ技术规范之间提出的又一个针对ＡＴＭ民传统网络协议间互操作问题的解决方案。ＭＰＯＡ规范综合了上述两种技术方案的优点并加以了完善了发展。本文对ＭＰＯＡ规范进行了较为详尽的阐述和分析，并对比说明了ＭＰＯＡ技术规范与其它技术规范的异同点。     

Performance analysis of a growable architecture for broad-bandpacket (ATM) switching

The performance of a growable architecture for broadband asynchronous transfer mode (ATM) switching consisting of a memoryless self-routing interconnect fabric and modest-size packet switch modules is examined. The cell loss probability is the focus because the architecture attains the best possible delay-throughput performance if the packet switch modules use output queuing. There are two sources of cell loss in the switch. First, cells are dropped if too many simultaneous arrivals are destined to a group of output ports. Second, because a simple, distributed path-assignment controller is used for speed and efficiency, cells are dropped when the controller cannot schedule a path through the switch. The authors compute an upper bound on arrivals, possibly including isochronous circuit connections, and show that both sources of cell loss can be made negligibly small     

Network architecture and medium access control for deploying third generation (3G) wireless systems over CATV networks

We propose a novel and cost‐effective approach for the deployment of third generation (3G) wireless systems over hybrid fiber coaxial (HFC) CATV networks. The main goal is to facilitate 3G deployment over the existing CATV plant and reduce the large cost required for building a dedicated last mile infrastructure for 3G access networks. Our proposal reduces the last mile cost by sharing the existing CATV network and using the standard equipment and protocols of data‐over‐cable systems interface specifications (DOCSIS). This allows rapid deployment of 3G wireless systems, facilitates convergence of wireless and wireline networks and paves the way towards all IP wireless networks. Enhancements to the DOCSIS medium access control (MAC) protocol must be implemented in order to support Quality of Service (QoS) guarantees for 3G data and signaling traffic. This paper presents the proposed 3G over CATV network architecture and DOCSIS medium access control (MAC) enhancements for enabling the support of QoS guarantees for 3G data and signaling traffic. The proposed MAC enhancements can reduce the access delay for delay‐sensitive traffic by 30 to 40% over existing DOCSIS MAC without compromising QoS guarantees for other traffic classes, or the DOCSIS channel utilization. Copyright © 2004 John Wiley & Sons, Ltd.     

IP和ATM的融合_MPOA的研究与实现

介绍了IP与ATM的融合技术_ATM多协议技术(MPOA)的基本功能、系统组成及工作原理,在此基础上阐述了LANE、MPOA在ATM交换机上的具体研究与实现,包括MPS、MPC、NHS、路由器以及LECS、LES、LEC的研究与实现。     

Video-on-demand over ATM: constant-rate transmission and transport

We introduce a specific transport and transmission scheme for video-on-demand (VoD) called constant-rate transmission and transport (CRTT). CRTT establishes a constant bit-rate (CBR) virtual channel between the video provider and the viewer's set-top box (STB) and then transmits cells from the provider into this channel at a constant rate. Since we assume that the number of cells in a frame is variable, CRTT requires that some number of cells be built up in an STB buffer before the commencement of playback. The build up, cell transmission rate, and the set-top memory size must be chosen so that there is no starvation or overflow at the STB. We develop fundamental relationships between these parameters for viable CRTT. We then apply the theory to an MPEG encoding of Star Wars and find that the minimal STB memory far CRTT is 23 Mbytes. We also consider varying the constant rate over a small number of intervals. We find, for example, that for Star Wars approximately 2 Mbytes of set-top memory suffices with 32 constant-rate intervals     

Connection architecture and protocols to support efficient handoffs over an ATM/B-ISDN personal communications network

The next generation personal communication network will likely internetwork wireless networks via the ATM/B-ISDN to enable ubiquitous broadband personal communication services. Support of user terminal mobility, particularly the capability for fast and seamless handoffs, over the ATM/B-ISDN is an expected requirement that is not currently met. We propose extensions to the ATM/B-ISDN user transport and signaling network architectures and signaling protocols to meet these requirements. The new architecture employs the Mobile Virtual Circuit (MVC), a dynamic connection tree in which routes are predetermined but not set up for potential handoff connections. During a handoff, associated signaling using source-routing with a new robust adaptation feature is employed for fast resource allocation to establish the handoff connection by distributed control. We also address the new problem of packet ordering synchronization to enable a seamless handoff. The connection tree reconfigures after each handoff to enable continuous support of successive handoffs. The proposed scheme optimizes handoff delay over the ATM/B-ISDN while minimizing unnecessary resource allocation, chances of handoff failure, and call processing load in the intelligent network, and the extensions are backward compatible to current ATM/B-ISDN standards and implementations.This paper was presented in part in PIMRC'95 in Toronto, and Globecom'95 in Singapore. This work was supported by the Canadian Institute of Telecommunications Research (CITR), funded under the Canadian Federal Government's Networks of Centres of Excellence Program.     

Charge-constrained (0,G/I:C) sequences

A (0,G/I) code is a modulation code used in the partial response maximum likelihood (PRML) recording system in which G and I represent the maximum number of zeros between two consecutive ones in the global sequence and the interleaved subsequences, respectively. For some magnetic recording systems such as the one with a helical scanning rotary head, a DC-balanced write waveform is required to meet channel requirements. In this study, charge-constrained (0,G/I:C) sequences which can generate a DC-balanced write waveform are investigated, where C represents the upper bound of charge. Based upon the runlength subgraphs and the transition matrices, capacities and power spectra of (0, G/I; C) sequences are derived and computed     

Wireless Internet over LMDS: architecture and experimentalimplementation

LMDS is currently a promising emerging technology in broadband fixed wireless communications. The cellular structure, high data rates, and flexibility make it perfect for multimedia, digital television, and interactive services. These high-bandwidth multimedia services received most of the research attention until lately. There has been a clear gap when considering UDP/TCP/IP and other data services over LMDS. We examine the ramifications of using standard TCP/IP data communication over a two-layer LMDS system. We argue that the former emphasis only on multimedia and ATM-based communication over LMDS was a mistake. The most exciting prospect for LMDS should be in the role of enabling Internet and data services together with multimedia. We introduce a basic architecture for two-layer IP-LMDS based on a trial network built between 1996 and 2000     

边缘到边缘的伪线仿真(PWE3):4.仿真ATM业务

4.1 仿真ATM业务类型4.1.1 ATM业务包装格式 图4.l(a)所示为在PSN伪线上包装ATM业务的通用格式。其中: ——PSN运送头 用于运送包装的ATM信息从一端PE跨过PSN核心网络到另一端PE。具体的PSN头与下层所使用的PSN类型以及隧道技术有关,例如在MPLSPSN上的PSN头是MPLS标签或外部标签;在IPPSN上的PSN头是IPv4头或IPv6头。     

Terahipas: a modular and expandable terabit/second hierarchicallymultiplexing photonic ATM switch architecture

A terabit/second hierarchically multiplexing photonic asynchronous transfer mode (ATM) switch network architecture, called Terahipas, is proposed. It combines the advantages of photonics (a large bandwidth for transport of cells) and electronics (advanced logical functions for controlling, processing, and routing). It uses a hierarchical photonic multiplexing structure in which several tens of channels with a relatively low bit rate, say 2.4 Gb/s, are first time-multiplexed on an optical highway by shrinking the interval between optical pulses, then a number of optical highways are wavelength-multiplexed (or space-division multiplexed). As a result, the switch capacity can be expanded from the order of 100 Gb/s to the order of 10 Tb/s in a modular fashion. A new implementation scheme for cell buffering is used for eliminating the bottleneck when receiving and storing concurrent optical cells at bit rates as high as 100 Gb/s. This new architecture can serve as the basis of a modular, expandable, high-performance ATM switching system for future broad band integrated service digital networks (B-ISDN's)     

Downlink scheduling for multimedia multicast/broadcast over mobile wimax: connection-oriented multistate adaptation - [Service-oriented broadband wireless network architecture]

With its comprehensive QoS support and ubiquitous coverage, the mobile WiMAX network offers promising opportunities for unwiring the last mile connectivity to Internet. However, stringent QoS demands of multimedia applications entail studies on service-oriented radio resource management. This article systematically examines the design issues and the state of the art of multimedia downlink scheduling in the multicast/broadcast-based WiMAX system. We propose a viable end-to-end framework, connection-oriented multistate adaptation, by considering cross-layer adaptations in source coding, queue prioritization, flow queuing, and scheduling. Its performance is confirmed by simulations on important metrics, showing that the framework can effectively accommodate heterogeneity in link variations, queue fluctuations, and reception diversities.     

Evolving 3G mobile systems: broadband and broadcast services in WCDMA

The third-generation WCDMA standard has been enhanced to offer significantly increased performance for packet data and broadcast services through the introduction of high-speed downlink packet access (HSDPA), enhanced uplink, and multimedia broadcast multicast services (MBMS). This article provides an overview of the key technologies used, the reasons behind their selection, and their integration into WCDMA. Performance results are also included to exemplify the performance possible in an evolved WCDMA network.