Evolution of ISDN towards broadband ISDN

Worldwide activities to evolve integrated services digital network (ISDN) into an optical-fiber-based universal broadband network have resulted in the first baseline documents, such as CCITT Recommendation I.121. The asynchronous transfer mode has been established as a key element of broadband ISDN (BISDN). The adoption of the G.707-709 recommendations on the new digital transmission hierarchy will also strongly influence further BISDN development. The author presents the current state of the BISDN discussion, especially within CCITT, briefly addressing broadband services and then concentrating on the user-network interface, as its definition is of utmost importance with respect to the introduction of a worldwide unique BISDN. Network scenarios and evolution and interworking aspects of the arising broadband realizations are also addressed     

Narrowband ISDN and broadband ISDN service and network interworking

For a significant period of time, B-ISDN will coexist with the 64-kb/s-based (narrowband) ISDN. The specification of a concept and the mapping functions employed for interworking between the two networks, in particular for voice services, is a major factor for the success of B-ISDN     

Technologies towards broadband ISDN

It is argued that it is vital to form a sound strategy for developing broadband integrated services digital network (BISDN) technology and services and deploying them in the field, so that smooth migration from the existing network is accelerated. Three major steps in this context are to expand fiber networks into the subscriber loop area to provide broadband capabilities everywhere, to construct a universal digital network that facilitates smooth evolution from the existing network to the broadband network of the future through deployment of (SDH) synchronous digital hierarchy transmission systems, and to integrate both services and network components through introduction of asynchronous transfer mode (ATM) technologies. Development efforts now being carried out at Fujitsu and Fujitsu Laboratories along this line are described, and the impact on network construction and service offerings is indicated     

Migration to broadband ISDN

The current state of telecommunications in Japan is briefly discussed, with particular reference to broadband services. Experience with the migration from the analog telephone network to the present narrowband integrated services digital networks (ISDN) is described. Three strategies for the transition from narrowband ISDN to broadband ISDN are examined. The market-driven strategy is to replace existing metallic subscriber loops with optical media, wherever possible, even if only narrowband services are required, with the expectation that these subscribers will eventually use broadband services. The service-oriented strategy entails putting into place a flexible and multipurpose platform that would also allow HDTV distribution and bidirectional communications. Early installation of such a platform would allow for the early announcement of broadband services, which would in turn stimulate demand. The benefits and drawbacks of each of these strategies are discussed. The advance-investment strategy is to press ahead with the introduction of optical subscriber loops to accelerate technological innovation, even if the cost is somewhat high. Other issues that are important to the migration of broadband ISDN are noted     

Broadband ISDN technology and architecture

Broadband integrated services digital network (BISDN) network architecture for local public serving areas is described. It is designed to offer end-users access to bandwidths up to 155 Mb/s. The BISDN protocols described support the simultaneous delivery of voice, data, image, and video services to business and residential customers. The objective of the broadband architecture described is to suggest designs that can evolve from today's base of narrowband equipment toward BISDN. It supports the use of fiber for narrowband services, in order to ensure that a broadband infrastructure is in place to serve as a platform from which broadband services can be offered. It also uses optional broadband modules on existing narrowband systems to facilitate evolutionary growth of broadband services and recognizes the metropolitan area network (MAN) protocol defined by IEEE 802.6 as a possible early implementation of BISDN     

Narrowband and broadband ISDN CPE directions

Noting that ISDN customer premises equipment (CPE) is critical to the successful deployment of ISDN whatever the bandwidth, the author examines the market for narrowband and wideband integrated services digital network (NISDN and BISDN) CPE. He establishes the basic requirements for NISDN terminals and discusses terminal adaptors, digital telephone sets, screen-based telephony, workstations, customer premises networks, and CPE maintenance and upgrades. He examines the BISDN market and discusses the features and architecture of the terminals     

Satellite ATM for broadband ISDN

This paper presents the development of satellite ATM for broadband ISDN based on the Research in Advanced Communications in Europe (RACE) CATALYST project. The purpose of the project is to develop an experimental ATM satellite link for the future B-ISDN services, particularly for the interconnections of the ATM testbeds which are in the form of broadband islands developed in Europe. Then initial ATM based B-ISDN can be introduced by interconnections of these broadband islands. An evolutionary approach has been adopted in the development of the ATM networks that the CATALYST project has developed the equipment to be able to interconnect the newly developed ATM testbeds as well as the existing networks such as DQDB, FDDI and Ethernet networks. In March 1994, the project carried out an experiment on the second demonstratoras the Laboratories of Alcatel Telespace in Nanteere near Paris to demonstrate the capability of the satellite ATM connections supporting data, voice, video and multimedia applications. This experiment provided a real system demonstration of satellite ATM for B-ISDN. In the light of the experiment, this paper presents the model and architecture of the ATM satellite equipment, studies the relevant issues and the impact of ATM-via-satellite on the applications and the protocols, and evaluates of satellite ATM based on some measured and simulated results.     

Sprint's evolution to broadband ISDN

One telecommunications company's-Sprint's-transformation of their infrastructure architecture away from dedicated transmission facilities and toward high-bandwidth virtual facilities which will enable customers to construct transmission networks that can be reconfigured almost instantaneously is described. Sprint's current X.25, frame-relay, switched circuit, and private line services are reviewed. The evolving architecture that will, on a moment's notice, enable a customer to redirect his traffic among the networks as well as to dynamically expand and contract transmission bandwidth to any of the networks is discussed. The architecture will be based on frame-relay permanent logical links at the end of 1992 and move to ATM cell-based access in 1994 to 1995     

World-wide standardization of broadband ISDN

A growing market demand for high-performance voice, data, image and video networks, coupled with advances in high-speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high-bandwidth, high-performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high-speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.     

A new direction for broadband ISDN

The industry strategy to introduce broadband ISDN is addressed. This strategy is placed within a marketing context, and possible ramifications are considered. It is suggested that the current vision of a complex, multifeatured network rolling out in 1994 may be overly ambitious and still not meet end-user needs. An alternate strategy based on a minimal technical solution is derived and discussed     

Two years of experience with broadband ISDN field trial

The BERKOM project, which represents the largest broadband ISDN (BISDN) field trial in the world, is discussed. The objectives of the field trial are outlined. Three aspects of the test network are then addressed: system concept, system extension, and system experience. Tests demonstrated that the overall system performance met all requirements for telecommunication applications     

城域网与B－ISDN

本文首先阐述了应用需求是如何促进宽带高速网络发展的，然后在说明现有通信网技术的缺点和比较两种过渡技术的基础上，指出利用城域网过渡到Ｂ－ＩＳＤＮ的优点，最后提出现有通信网通过城域网技术逐步演变成Ｂ－ＩＳＤＮ的基本设想。     

Management of capacity and control in broadband ISDN

The trend towards integration of services onto a single network and the addition of accompanying control features has led to an increase in the complexity of functional signalling protocols. A continuing dramatic reduction in the cost of traffic-carrying capacity has meant that call control costs are becoming an increasingly significant component of the total network cost. In BISDN, the support of many diverse services may result in an excessive control cost. To avoid this potential problem, virtual paths may be used. Capacity may be reserved on virtual paths to simplify the set-up procedure for individual calls. One benefit of this approach is that the cost of establishing a virtual path is shared among all individual connections which subsequently use it. However, this reduced control cost comes at the expense of installing additional traffic carrying capacity. This paper describes techniques for the management of traffic carrying capacity and control mechanisms in BISDN and presents a cost-benefit analysis to determine policies for reserving capacity on virtual paths. Significant savings in the total BISDN cost can result from the use of virtual paths.     

Research on Advanced Switching Techniques for the Evolution to ISDN and Broadband ISDN

Switching techniques for packetized data and for video communications are a key element in the evolution of the central office from IDN, to ISDN, and to broadband ISDN. An evolutionary scenario, based both on a short-term and on a longterm reference architecture for the switching system, is proposed, and two advanced switching techniques for labeled switching and for diffusive video switching, respectively, are analyzed which match the above scenario well. Plans and preliminary results are also reported on experimental research through laboratory demonstrators of the two switching techniques.     

New directions in signaling for broadband ISDN

User networks signaling is considered. The evolution of signaling protocols is outlined, analyzing the forces producing changes in the past. Emerging broadband switching technologies and services are discussed, emphasizing capabilities that might be required. A conceptual model for representing integrated-services digital network (ISDN) calls is presented as the basis for structuring a more flexible signaling protocol to meet the needs for a broadband environment     

无线宽带通信系统及其应用分析

移动多媒体在提供服务的过程中,主要是要将文本、图形、语音等信息经过任意整合提供给用户.在这一过程中为了确保移动多媒体能够为用户提供优质的服务必须努力构建覆盖面广、质量高的无线宽带建设.从整体上看,我国无线宽带通信网在2002年之后建造速度不断加快,在进行研究的过程中,文中主要以TD-LTE技术为例进行了研究.     

Analysis of bandwidth allocation strategies with accessrestrictions in broadband ISDN

Bandwidth allocation strategies with access restrictions for the integration of wideband (WB) and narrowband (NB) traffic in a broadband integrated services digital network (BISDN) are studied. Access restrictions are placed on both types of traffic to meet the grade of service required for each. The WB traffic is assumed nonqueuable, whereas the NB traffic may be queued. As an improved strategy, an access strategy which allows each type of traffic to use its bandwidth in the access-restricted region with the risk of being preempted by an arriving call for which the overflowed region is reserved is considered. Under this strategy, the preempted NB calls are queued at the head of a waiting room, and preempted WB calls are queued in another finite waiting room. The performance of these strategies is analyzed in terms of access delay for NB traffic and blocking probability for WB traffic by the matrix-geometric solution method. It is shown numerically that these strategies can easily be adapted to varying traffic loads by changing the restriction levels     

Technology Aspects for System 12 Broadband ISDN

Although the enhancement of System 12, SEL's digital switching system, for ISDN services is virtually complete, further development work is being carried out to allow broadband switching for videophone services, videoconferencing, and the distribution of radio and television programs. This paper describes an appropriate approach to the evolution Of System 12 toward the broadband ISDN (B-ISDN), emphasizing the crosspoint and technology aspects of the broadband switch. Test results on a broadband switch VLSI circuit for 140 Mbit/s in a 2μm CMOS technology are presented.