Output-buffer switch architecture for asynchronous transfer mode

This paper proposes a new asynchronous transfer mode (ATM) switch architecture for the broadband ISDN. The ATOM switch ATM output-buffer modular switch has a multi-stage network structure, and is highly modular to facilitate capacity expansion. The ATOM switch element is of the output-buffer type with a time-division multiplexed bus and FIFO buffer for each outgoing line. Bit-slice techniques are used to implement the high-speed time-division bus and buffer memories. The output buffer switch has the advantages of no throughput degradation since internal contention is eliminated, and a simple control structure for providing priority and multi-point connections. This paper also deals with switching delay and buffer overflow probabilities for mixed (bursty and non-bursty) traffic.     

点对多点ATM交换网络的实现与性能分析

本文中 ,我们基于Knockout交换结构 ,提出了一种能实现点到多点交换的ATM交换结构 ,并对其性能进行了分析 ,然后通过模拟证明该方法有较好的性能     

异步转移模式（ATM）的研究现状与前景

ＡＴＭ是实现宽带综合业务数字网（Ｂ－ＩＳＤＮ）关键技术之一。本文综述了ＡＴＭ近几年来在网路控制、业务模型、资源分配、允许接入控制、流量控制以及选路控制等诸多方面的研究进展与存在问题，并提出了实现ＡＴＭ综合多种业务与有效利用网路资源这一目标的途径。     

ATM switches—basic architectures and their performance

The prospect of a broadband ISDN based on the ATM principle has stimulated the development of new, high-performance switching node architectures. In this paper different options for the switching networks used in such a node will be discussed in some detail. First, some generic architectures for the individual switching elements will be presented including the aspects of buffering and collision resolution, followed by a short classification of different types of switching networks and some performance figures for delta networks, a class of multi-stage, single-path interconnection networks. In the last section, the sensitivity of the performance results with respect to the traffic assumptions will be discussed.     

Broadband ISDN and asynchronous transfer mode (ATM)

The transfer mode chosen by the CCITT Study Group XVIII Task Group on ISDN Broadband Aspects as the basis of broadband ISDN is called the asynchronous transfer mode (ATM). ATM is a high-bandwidth, low-delay, packetlike switching and multiplexing technique. It is essentially a connection-oriented technique, although it is envisioned as a basis for supporting all services, connectionless as well as connection-oriented. The basic transfer mode concepts are explained. The limits of synchronous transfer mode (ATM) are discussed and reasons for choosing ATM over STM are given. The main technical issues having an impact on the ATM specifications are discussed     

Traffic studies of a multiplexer in an ATM network and applications to the future broadband ISDN

In the first part of this paper the influence of the arrival process on these three performance parameters is discussed. The values of these three performance parameters depend strongly on the utilization distribution over the input trunks of the multiplexer while the total utilization on the input trunks is fixed. If there is the same utilization on all input trunks, the values of these three performance paramters reach a maximum. This result is also valid for an ATM switching matrix with a separate FIFO buffer at each output trunk. In the second part of this paper some examples are provided of how to apply the results of these studies to the future broadband ISDN which is intended to transmit services with very high bit rates (e.g. 135 Mb/s) as well as services with very low bit rates (e.g. 64 kb/s).     

用卫星ATM技术互连LAN/MAN

介绍了一般的卫星ATM网络互连单元,重点讨论了互连LAN／MAN的ASIU的结构,并指出了设计LAN／MAN互连技术应该考虑的基本问题,最后指出用卫星ATM实现LAN／MAN互连所面临的挑战。     

ATM via satellite: A framework and implementation

This paper describes an ATM‐based satellite network, focusing on the networking (ATM) aspects of the design. The ATM requirements and the basic design of the network are outlined. In particular, a simple MAC layer is proposed in which ATM service classes are mapped onto MF‐TDMA uplink access methods. The uplink access and resource allocation approaches based on this model are described in detail. Also, this paper shows how different qualities‐of‐service can be provided by using a combination of different access schemes. This paper also covers scheduling for the uplink portion of the satellite network. The use of Hierarchical Round Robin is argued on the grounds of performance, flexibility and implementability. This revised version was published online in June 2006 with corrections to the Cover Date.     

基于ATM的宽带多媒体通信卫星系统运维管理技术研究

随着卫星网络以及通信系统的逐渐研发,宽带多媒体通信卫星系统在通信领域中备受关注.宽带多媒体通信卫星系统能够实现全球无缝隙覆盖的网络互连,在通信系统研发中发挥着重要的作用.基于宽带多媒体通信卫星系统运行维护管理是保障通信卫星系统稳定运行的基础.在本文中对基于ATM的宽带多媒体通信卫星系统运维管理技术进行研究.     

基于TMN的ATM虚拟专用网(AVPN)管理

建立在 ATM网络之上的 ATM虚拟专用网 (AVPN)可提供话音、数据和图像等多种业务。为了提高 AVPN的运营效率 ,促进 AVPN的进一步发展 ,迫切需要一个开放的、标准的网络管理系统。文中以 TMN框架结构为背景 ,对基于 ATM网络之上的 AVPN的管理作了一些初步的讨论。     

在综合业务数字卫星通信网（ISDSN）中应用ATM技术

由于卫星信道的特殊性，完全照搬地面ＢＩＳＤＮ中采用的ＡＴＭ技术到卫星通信应用环境是不合适的。本文提出一种不需专用ＡＴＭ交换机而利用卫星通信多点－多点通信能力来实现业务的综合传输和交换（以ＡＴＭ方式）的新思路，并对未来发展趋势进行了展望。     

The split-switching network (SSN): A high-performance multicast ATM switch

This paper proposes a new high-performance multicast ATM switch architecture. The switch, called the split-switching network (SSN), is based on banyan networks. The SSN achieves multicasting in a way that is non-typical for banyan-based switches: copying and routeing of multicast cells are carried out simultaneously and within the same fabric. Thus, cells are copied only when needed as they traverse the switch towards the appropriate output ports. The SSN consists of successive spliting stages, and buffering is provided in front of each stage. The SSN is non-blocking with complexity of order Nlog2/2N for a switch of size N, and is characterized by distributed and parallel control. The throughput-delay performance of the SSN is shown to be similar to that of a non-blocking output-buffering switch under different mixtures of unicast/multicast traffic. In particular, the SSN achieves a maximum throughput of 100 per cent and the cell delay and delay variation remain small for loads just below the maximum throughput.     

全域联网技术─—帧中继SMDS和ATM

在全域联网中，帧中继、交换多兆比特数据业务和异步转移模式正成为一个灵活的宽带通信的重要新技术。本文扼要地叙述全域联网这些新技术的协议、体系结构和潜在的应用。     

The customer premises network for ATM: Architecture and standardization issues

This paper discusses the architecture of ATM-based customer premises networks (CPN), which can easily be tailored to the needs of a broad range of residential and (small) business customers. A first part analyses the functions of the classical CCITT reference model, and regroups them into building blocks for a new model. This model features a high degree of modularity, and interfaces with low-level functionality. The building blocks for this CPN are the network termination, connection subnets and switching subnets. Following this, some issues related to the user-network interface standardization are addressed, as this interface has potential to be a candidate for application in the whole CPN. Owing to publication schedules, the author did not have the opportunity to take into account the recent decisions taken by CCITT concerning ATM standards.     

A Time Reuse Capture Access (TRCA) Protocol for PCS and Wireless ATM Applications

The Time Reuse Capture Access (TRCA) protocol isa medium access control protocol appropriate forpersonal communications and wireless AsynchronousTransfer Mode (ATM) applications. It is based on time reuse rather than frequency reuse. Frequencychannels are reused in every cell (frequency reuse one).Each FDMA channel has a TDMA frame structure. The numberof slots in the frame is equal to the time reuse factor and each slot is assigned to aspecific cell in the reuse cluster. Each mobile usertransmits in its assigned frequency channel and TDMAtime slot which corresponds to the cell it currently belongs. The protocol also exploits the powercapture phenomenon in which simultaneous transmissionsof users in adjacent cells may be successfully received.Two possible applications of the proposed TRCA protocol are considered in this paper. In thefirst application, TRCA is used for random packet accessin wireless personal communication. Users transmit theirpackets using the assigned and non-assigned time slots to take advantage of the effect ofcapture and non-uniform traffic loads. The portion oftransmissions that takes place in each time slot iscontrolled so that the overall throughput is maximized. In the second application, TRCA is used forreliable transmission of ATM cell over a wirelesschannel. The proposed protocol allows the transmissionof continuous bit rate (CBR) ATM cells over a wireless link so that bit error rate (BER) and delayrequirements are met. Transmissions take place in theassigned time slots but the non-assigned time slots canbe used for re-transmission if the previous transmission was unsuccessful.     

Design and evaluation of an efficient traffic control scheme for integrated voice,video, and data over asynchronous transfer mode networks: Explicit allowed rate algorithm

Asychronous transfer mode (ATM) networks are high‐speed networks with guaranteed quality of service. The main cause of congestion in ATM networks is over utilization of physical bandwidth. Unlike constant bit‐rate (CBR) traffic, the bandwidth reserved by variable bit‐rate (VBR) traffic is not fully utilized at all instances. Hence, this unused bandwidth is allocated to available bit‐rate (ABR) traffic. As the bandwidth used by VBR traffic changes, available bandwidth for ABR traffic varies; i.e., available bandwidth for ABR traffic is inversely proportional to the bandwidth used by the VBR traffic. Based on this fact, a rate‐based congestion control algorithm, Explicit Allowed Rate Algorithm (EARA), is presented in this paper. EARA is compared with Proportional Rate Control Algorithm (PRCA) and Explicit Rate Indication Congestion Avoidance Algorithm (ERICA), in both LAN and WAN environments. Simulations of all three algorithms are conducted under both congestion and fairness configurations with simultaneous generation of CBR, rt‐VBR, nrt‐VBR and ABR traffic. The results show that, with very small over‐head on the switch, EARA significantly decreases the required buffer space and improves the network throughput. Copyright © 1999 John Wiley & Sons, Ltd.     

Performance Analysis of the ATM Adaptation Layer 2 (AAL2)

In this paper, we analyze the performance of AAL2 multiplexer for a continuous time Markovian arrival process. AAL2 CPS (Common Part Sublayer) packets are multiplexed in the AAL2 multiplexing queue and transmitted in the transmission queue. This tandem structure suggests that the statistics of AAL2 CPS requires at least 2 dimensional state space. Furthermore, from a network-level point of view, cell multiplexing and de-multiplexing procedures are repeated at each AAL2 switching node. That requires simple analysis model. To solve this problem, we reduce the state space by showing that the output process of multiplexing queue can be modeled with the Coxian distribution. We propose a single dimension analysis model of the CPS transmission queue. When AAL2 convey both real and non real time short packets, QoS management is a problem. This is because the QoS of real time as well as non-real time packets is measured using different metrics – delay and cell loss ratio respectively. Most previous work is concentrated around delay performance due to the real time applications getting the primary attention. From the direct comparison of delay and CLR performance, we show that delay constraint is the dominant parameter in QoS of AAL2.     

A METHODOLOGY FOR REDUNDANCY ASSIGNMENT IN PRIORITY ENCODING TRANSMISSION (PET) OVER ATM NETWORKS

A novel approach called priority encoding transmission (PET) was recently proposed to guarantee delivery of the highest-priority data and/or the timely recovery of real-time data in the transmission of multimedia information over lossy networks. PET allows different segments of a message to be assigned priority levels, resulting in encoding information with different amounts of redundancy; the receiver is then able to recover the information in priority order, based only on the number of packets received per message. In this paper we propose a methodology to determine the fractions of the packets sent that are needed at the receiver to meet the quality of service (QoS) loss requirements specified by the user. It allows mapping of the required segment loss probabilities on the corresponding parameters of the PET system. As a relevant case study, the proposed methodology has been applied to the transmission of MPEG video signals over an ATM network using PET. The relative numerical results are presented and discussed. © 1997 by John Wiley & Sons, Ltd.     

A Distributed Fair Queueing (DFQ) Architecture for Wireless ATM Local Access Networks

The application of Asynchronous Transfer Mode (ATM) to a Wireless Local Area Network (WLAN) environment is an undertaking that poses many problems not encountered in either wireline ATM or data-only WLAN. Wireline ATM networks do not have to transmit over multiple-access, unreliable transmission media while data-only WLANs do not have to satisfy heterogeneous Quality of Service (QoS) contracts for multimedia services. To address this issue, we propose in this paper a DFQ-based WLAN architecture, designed as a centrally controlled network where a complex base station polls simpler mobile terminals for channel access.DFQ is an implementation of Fair Queueing (FQ) algorithm to schedule the access to the transmission channel among the mobile terminals. The implementation of DFQ introduces new design challenges, mainly in the packet scheduler. A DFQ scheduler is designed to allow fast and efficient processing of scheduling data. The DFQ algorithm is introduced and simulated for delay-sensitive connections, and the hardware implementation of the packet scheduler is discussed.The Centre for Wireless Communications is a national R&D Centre funded by the Singapore National Science and Technology Board     

ATM网络中突发信息处理方法的研究

通过分析突发信息的统计特性，提出了ＡＴＭ网络中发信息的处理方法，设计了突发信元的处理模型，在假设缓存器存储量无限的情况下，根据Ｍ／Ｍ／１数字模型，采用状态依赖的服务方式，对突发信元处理模型进行了分析。