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1.
The use of communication satellites as a possible way of offering broadband island interconnectivity appears to be a very attractive option, as it will enable the provision of an all-digital, transparent service to a number of ATM islands spanning a wide area, accommodating efficiently a variety of traffic demands. The CATALYST Project (RACE II/R2074) is an attempt to demonstrate the applicability and compatibility of satellite technology with the terrestrial BISDN. In this paper we present an overview of the project and focus on an initial study of the expected user performance through the CATALYST network. Our analysis is based upon mathematical and simulation models and describes the end-system to end-system transfer delay for given message lengths. The protocol profiles assume a mix of Novell NetWare and Network File System client/server architectures, which are supported by either the IEEE 802.3/Ethernet or fibre distributed data interface LANs, which are themselves linked via LAN/ATM/satellite interface units. Areas of further investigation, and the implication of our analysis on the actual network architecture, are discussed.  相似文献   

2.
A set of asynchronous transfer mode (ATM) bearer service categories, differentiated in terms of quality of service (QOS), that will support the large spectrum of applications expected in broadband integrated services digital networks (B-ISDN) is defined. The evolution of applications and the traffic requirements in B-ISDN/ATM networks are described, and the evolution of network services to address these requirements is discussed. The definition of ATM bearer service categories necessary for the economical support of initial applications and evolution to future B-ISDN services is proposed. The elements of the ATM traffic management strategy to support these service categories are presented  相似文献   

3.
Future broadband satellite networks for multimedia will be seamlessly integrated into terrestrial broadband networks which often use asynchronous transfer mode (ATM) and recently also the less complex multi protocol label switching (MPLS) technique as transmission and switching protocol. In light of this, future broadband satellite networks may adopt the ATM transmission scheme and implement ATM or ATM‐like switches on board the satellites. However, as compared to communication in fixed networks, satellite communication is characterized by special constraints (e.g. signal delay, channel quality, dynamic network topology) that require novel ATM‐based communication technology for satellite systems. This paper presents results from the ATM‐Sat project that aims to complete this technically challenging and important R&D task in the cooperation between DLR, Fraunhofer Gesellschaft and Tesat‐Spacecom. In brief the following aspects have been addressed in the ATM‐Sat project:
  • development of the concept and communication technology for a multimedia satellite system with,
    • non‐geostationary orbit (NGSO) satellites;
    • inter satellite links (ISLs);
    • on‐board ATM switching;
    • fixed and mobile terminals;
  • verification of the developed communication technology with a demonstrator.
In particular the ATM‐Sat R&D tasks cover the system and protocol architecture, on‐board processing, ISL routing, up/downlink and on board ATM resource management (including medium access control), error control, IP over satellite‐ATM, and active intelligent antennas. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

4.
Next-generation broadband satellite networks are being developed to carry bursty Internet and multimedia traffic in addition to the traditional circuit-switched traffic (mainly voice) on a global basis. These satellites provide direct network access for personal applications as well as interconnectivity to the terrestrial remote network segments. The main requirement in success of these networks is that they should be able to transmit high data rate traffic with prescribed quality of service (QoS). Thus, the broadband satellite network has no choice other than the rise of ATM technology and to be optimized for Internet-based traffic. ATM is the promising technology for supporting high-speed data transfer potentially suitable for all varieties of private and public telecommunications networks. IP, on the other hand is the fast-growing Internet layer protocol that is applicable over any data link layer Internet-based applications are the emerging source of traffic in the future wireless networks and broadband satellite networks should consider Internet as the primary service. In this paper, we discuss the traditional ATM and wireless ATM networks and explain the characteristics of the wireless IP networks. The paper then uses those concepts in defining the criteria for the broadband satellite networks such as the QoS and traffic management. Application of the broadband satellite networks is also proposed  相似文献   

5.
本文介绍了通信发展的状况和 B-ISDN 的特性,重点提出现有局域网、N-ISDN 网络与B-ISDN 网络互连的策略,以及面向21世纪宽带通信网的网络结构。最后简述了通信业务的发展趋势及利用 ATM/B-ISDN技术改造中国现有通信网的设想。  相似文献   

6.
Management architectures as well as protocols for accessing managed entities and exchanging management information are well developed in standards. On the other hand developments in open distributed processing (ODP) are of recognized importance for network and service management. Their generic features fit well into the geographically extended, multiple vendor and heterogeneous environment of communication networks. As a third ongoing development asynchronous transfer mode (ATM) broadband integrated services digital networks (B-ISDN) offer challenging problems for resource allocation, network performance and quality of service (QoS) evaluation in real time. The paper shows how performance monitoring and evaluation for ATM networks can greatly profit from the features of a distributed system environment (DSE). The extreme flexibility offered by the ATM principle requires a rich and reusable set of servers accomplishing coordinated performance evaluation tests. DSE transparencies are an excellent match to corresponding management applications (MA) requirements, so that tests can be performed in a distributed, flexible and adaptable way under a conceptually simple architecture. The paper draws extensively from a non-distributed counterpart, i.e. an existing sophisticated ATM test and analysis tool developed under the “Research for Advanced Communications in Europe” (RACE) program, R1083 PARASOL project  相似文献   

7.
This paper deals with the interworking of a satellite system for mobile multimedia applications with the terrestrial environment. The concept of an “overlying network” is introduced with the aim of giving a common approach for the interworking of the considered satellite system with the various terrestrial networks (B-ISDN, N-ISDN, TCP/IP). The paper particularizes the introduced concept to the case in which the considered satellite system is interfaced with the broadband ISDN (B-ISDN)  相似文献   

8.
Asynchronous transfer mode (ATM) has emerged as a possible contender for the next generation switching system and fundamental transport basis for the broadband integrated services digital network (B-ISDN) and telecommunications in the future. It is widely thought of as the network to accommodate the uncertain requirements of future public communications because of its high degree of flexibility and service independency. The Orwell protocol developed by British Telecom can provide a communication base to meet the requirements of such a network. Orwell is used as a slotted ring protocol designed to carry a mixture of services which form the basis of an ATM network. The authors describe the realisation of a 155.52 Mbit/s fibre-optic physical layer from the Orwell protocol based on an ATM technology, and also discuss how the Orwell protocol can offer broadband transport capabilities and can provide access to and interwork with existing networks, such as telephone networks and 64 kbit/s based ISDNs  相似文献   

9.
The evolution of public telecommunication networks toward broadband integrated services digital networks (B-ISDNs) is presented. The asynchronous transfer mode (ATM), which supports B-ISDNs, and the B-ISDN protocol reference model are discussed. It is shown that the service offered by the ATM layer in the B-ISDN protocol reference model is equivalent to the service offered by the OSI physical layer. It is also shown that the service offered by the ATM adaptation layer (AAL) type 3/4 is similar to an OSI data link service. The emergence of the metropolitan area network (MAN) standard as an intermediate support for broadband services and the similarities between the DQDB MAC and the AAL type 3/4 in its connectionless mode are discussed  相似文献   

10.
One of the aims of the SatNEx (Satellite Network of Excellence, http://www.satnex.de ) European project is to provide the scientific community that operates on satellite communications with measurement campaign results and evaluation tools, in order to support research activities that investigate problems in satellite communications at different levels of the OSI stack. In fact, the research activities developed in SatNEx address the most relevant aspects of satellite communications, such as channel modulation and coding schemes, access strategies, advanced networking, end‐to‐end quality of service, transport performance, delay tolerant networks, and new applications. Even if SatNEx is mainly devoted to satellite communications, integration of satellite and terrestrial wireless segments has also been taken into account. This paper presents the results obtained in the specific research activity devoted to trials and testbeds developed during the SatNEx project. The high number of authors of this paper is an indication of the strong collaborative work sustained, the numerous measurement campaigns, and the complexity in developing integrated testbeds. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

11.
A granulated broadband network (GBN) is proposed as an intermediate asynchronous transfer mode (ATM) based platform to be part of an evolution scenario toward B-ISDN. The GBN enables various types of services to be provided including 64-kb/s-based services and broadband services. In the GBN, information is transformed into ATM cells at subscriber line terminals or at customer premises and is transferred through ATM networks; consequently, the cost feasibility of a single-channel cell assembly/deassembly device is a significant factor in economically providing ATM-based conventional services and interworking between STM and ATM networks. Various virtual path capacities with a fine degree of granularity can be provided in a mesh structure between transit modes in the GBN. Economic feasibility studies of the GBN, by simulating on certain large-size real networks in the greater Tokyo area, indicate the possibility of a more than 50% cost reduction in transit networks  相似文献   

12.
The key features of the synchronous optical network (SONET) and asynchronous transfer mode (ATM) standards for the broadband integrated services digital network (B-ISDN) public network, which is expected to provide a powerful and ubiquitous infrastructure to support the emerging gigabit-per-second data and multimedia applications, are reviewed. The advantages of ATM, the ATM cell format, the B-ISDN protocol reference model and the ATM layer, the ATM adaptation layer, and ATM traffic management and signaling are discussed. An experimental high-performance parallel interface (HIPPI)-ATM-SONET interface is presented as an example to illustrate how the SONET and ATM techniques can be used to provide end-to-end transport for applications requiring a bandwidth of 800 Mb/s and possibly 1600 Mb/s  相似文献   

13.
The capabilities of the emerging broadband integrated services digital network (B-ISDN) are examined. Fundamental differences between broadband and narrowband ISDN are identified. The basics of asynchronous transfer mode (ATM), the switching technique used by BISDN networks, are discussed. Channel identification, generic flow control, using ATM, and connectionless service are considered. The first services expected to make use of ATM are briefly described  相似文献   

14.
The authors discuss the architecture and protocol for broadband ISDN (B-ISDN) based on the CCITT standards. The discussion attempts to address the general concept of B-ISDN architecture and protocol and, whenever possible, present alternatives and the rationale for decisions in the selection of the protocol. B-ISDN is presented as a network evolution, and the impact of the asynchronous transfer mode (ATM) on the network is described. The role of virtual channel and virtual path in B-ISDN is discussed. The B-ISDN protocol structure and lower layer functions comprising the physical, ATM, and adaptation layers are presented, and the tentative trends of signaling and traffic control for the B-ISDN are delineated  相似文献   

15.
郑云章 《数字通信》1996,23(3):7-10,50
本文首先通过对宽带业务发展情况,ATM标准,ATM适配层的分析引出了ATM对B-ISDN发展的作用及向B-ISDN过渡的步骤,并指出工发具SMDS和FR业务接口的ATM交换机,对实现N-ISDN向B-ISDN过渡具有积极现实意义,其次介绍和分析了ITU-T,日本NTT及欧洲各国关于ATM和B-ISDN的标准化活动,应用试验等情况。  相似文献   

16.
Unlike traditional best-effort packet networks, ATM networks support a wide range of services by providing a specified QoS on each ATM connection. Currently, QoS can be measured with specialized high-speed testing equipment but their complexity and cost prevent them from wide field use. This article describes the INQIRE project approach based on software for enabling common personal computers (with an ATM network interface card) to function as QoS monitoring stations at the edges of an ATM network. The main objective is to develop a low-cost, off-the-shelf alternative to broadband testing equipment. An INQIRE station, consisting of a PC running the INQIRE application, can actively probe any selected connection and collect sample measurements of the QoS. The monitoring approach is intended to be non-intrusive and work with any ATM network without requiring any modifications to existing ATM switch equipment or interruptions to active services  相似文献   

17.
Voice packetization and compression in broadband ATM networks   总被引:2,自引:0,他引:2  
Some methods of supporting voice in broadband ISDN, (B-ISDN) asynchronous transfer mode (ATM), including voice compression, are examined. Techniques for voice compression with variable-length packet format at DS1 transmission rate, e.g., wideband packet technology (WPT), have been successfully implemented utilizing embedded adaptive differential pulse code modulation (ADPCM) coding, digital speech interpolation (DSI), and block-dropping schemes. For supporting voice in B-ISDN, voice compression techniques are considered that are similar to those used in WPT but with different packetization and congestion control methods designed for the fixed-length ATM protocol at high speeds. Possible approaches for packetization and implementation of variable-bit-rate voice coding schemes are described. ADPCM and DSI for voice coding and compression and cell discarding (CD) for congestion control are considered. The advantages of voice compression and CD in broadband ATM networks are demonstrated in terms of transmission bandwidth savings and resiliency of the network during congestion  相似文献   

18.
刘斌 《电信科学》1996,12(6):53-59
本文分析了宽带业务的应用,讨论了ATM网络与现有各种网络的互通问题,并概述了B-ISDN网络的发展策略。  相似文献   

19.
Practical experiments in a satellite network environment assist in the design and understanding of future global networks. This article describes the practical experiences gained from TCP/IP on ATM networks over a high-speed satellite link and presents performance comparison studies of such networks with the same host/traffic configurations over local area and wide area networks. These comparison studies on the LAN, WAN, and satellite environments increase our understanding of the behavior of high-bandwidth networks. NASA's Advanced Communications Technology Satellite (ACTS), with its special characteristics and high data rate satellite channels, and the ACTS ATM Internetwork (AAI) were used in these experiments to deliver broadband traffic. Network performance tests were carried out using application-level software (Netspec) on SONET OC-3 (155.52 Mb/s) satellite links. Finally, we experimentally study the performance, efficiency, fairness, and aggressiveness of TCP Reno, TCP New Reno, and TCP SACK end hosts on ATM networks over high BDP networks  相似文献   

20.
The paper models and evaluates key design issues for the adaptation layer in ATM networks. The role and efficient design of the adaptation layer is crucial for future B-ISDN based on ATM. We concentrate on packet-mode adaptation services analyzing and simulating relevant protocols employed for narrowband ISDN signaling and packet data. Processing and transmission resources are modeled. In particular we investigate the performance of software based solution resident in microprocessors and interfaces to the ATM world via a generic interface component. This set-up which is currently under development is found adequate to handle narrowband ISDN signaling and data traffic. It offers a cost effective and readily-available solution for the transition phase towards fully customized broadband components  相似文献   

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