High-Speed Time Division Switching Technique for Broadband ISDN

A key point in realizing broadband switching networks is architectual efficiency for switching various types of traffic with speeds ranging from several kbits/s to several Mbits/s. We propose a new switching technique, that is, a high-speed time division switching based on the single slot switching technique. This technique has several switching modules corresponding to standardized bit rates of traffic, and each cell is switched in the switching module corresponding to its speed. With this technique, all types of traffic will be equivalent with respect to the grade of service. This paper outlines its principle, clarifies the performance of traffic capacity,and finally proves its feasibility.     

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.     

Broadband Switching System Architecture

The architecture, the design concept, and the network organization for NTT's broadband switching system field trials are described. The features of this system are: a variety of connection-type services such as reservation-based and asymmetric connections, the installation of small-size remote concentrating switch, and a system integration using various subscriber transmission media such as optical fiber, satellite, and radio. This paper also presents the system architecture along with a study of the broadband switching system through a close look at the results obtained from field trials.     

Broadband ISDN Switching Capabilities from a Services Perspective

Broadband switching and transmission technologies are maturing rapidly, promising to make broadband ISDN (B-ISDN) possible and potentially economical in the near future. The diversity of possible B-ISDN services provides much impetus for the implementation of B-ISDN, but complicates the task of specifying network switching requirements. This paper examines a few representative services in order to generate a set of basis vectors in capability space. New services are then projected onto this basis; if a new service cannot be constructed from the basis vectors, other vectors are added to the basis set. B-ISDN architects can then specify switching requirements by selecting those capability basis vectors that are required for the services most in demand. For full motion entertainment video services, circuit switching capability at about 150 Mbit/s may be required, while selective broadcast and remote switching capabilities may reduce the cost of these services. For subvideo-rate services, new transfer mode (NTM) capability may be required to allow users the flexibility to allocate access channels dynamically on a per-call basis. Multiple connection (e.g., voice and video) and multiple party call capabilities may be required for many B-ISDN services, implying a need to extend the ISDN signaling protocol. The capability for the user to request network code conversion between different coding formats (e.g., NTSC or HDTV), and network compression of signals to reduce the cost of interoffice facilities, may also be required. Finally, fast call setup capability and high calling volume capabilities may be required, implying a need to distribute call processing functions over multiple processors in the central office.     

一种高效的光分组交换网络缓存结构

提出了一种新型的、用于光分组交换网络的光纤缓存结构.该结构针对光分组交换网络中解决输出端口竞争需要大量光纤延迟线,从而导致核心节点造价太高的缺陷,采用光纤分段式共享的机制,充分提高光纤延迟线的利用率.仿真和分析表明这种新型结构能有效降低丢包率,并可以取得令人满意的光分组平均延时参数;随着光纤延迟矩阵规模的增大,该结构仅需增加很少数目的光纤延迟线单元便可实现核心节点的扩展;在使用的总光纤延迟线单元数目上,该结构更能体现其优越性.     

Switching System Software Design for ISDN

The ISDN offers various services through multipurpose digital subscriber lines. The switching program for the ISDN should be so designed as to realize the control of various voice and nonvoice services and provide for developing service enhancement. To attain the goal, the ISDN services are classified hierarchically and each category is allocated to appropriate network nodes for implementation. As a result, the local switching program provides an out-slot subscriber line signaling capability and call connection with appropriate compatibility checking including a check for access capability to communications processing nodes. The switching program modules specific to analog services and those specific to digital services are separated to allow the use of the existing program file and to afford easy program design and maintenance. Remote-controlled switching is a suitable means for an economical introduction of the ISDN services to low traffic density areas. Special routing and reliability arrangements as well as the program structure for a remote-controlled switch are discussed.     

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.     

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     

宽带ISDN与ATM交换技术：第五讲 宽带业务应用与ATM网络的发展策略

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。     

The Knockout Switch: A Simple, Modular Architecture for High-Performance Packet Switching

A new, high-performance packet-switching architecture, called the Knockout Switch, is proposed. The Knockout Switch uses a fully interconnected switch fabric topology (i.e., each input has a direct path to every output) so that no switch blocking occurs where packets destined for one output interfere with (i.e., block or delay) packets going to different Outputs. It is only at each output of the switch that one encounters the unavoidable congestion caused by multiple packets simultaneously arriving on different inputs all destined for the same output. Taking advantage of the inevitability of lost packets in a packet-switching network, the Knockout Switch uses a novel concentrator design at each output to reduce the number of separate buffers needed to receive simultaneously arriving packets. Following the concentrator, a shared buffer architecture provides complete sharing of all buffer memory at each output and ensures that all packets are placed on the output line on a first-in first-out basis. The Knockout Switch architecture has low latency, and is self-routing and nonblocking. Moreover, its Simple interconnection topology allows for easy modular growth along with minimal disruption and easy repair for any fault. Possible applications include interconnects for multiprocessing systems, high-speed local and metropolitan area networks, and local or toll switches for integrated traffic loads.     

Switching in the Broad-Band ISDN

The enhancement of ISDN with broad-band services is investigated from the viewpoint of switching systems. Approaches in system architecture and switching technology are described. The extension of an ISDN switch with broad-band modules is presented as an example.     

多业务宽带交换

网络交换经历着一系列发展演变;从电路交换到分组交换;从软件交换到硬件交换;从单一网络业务交换到多种业务交换。多业务宽带交换需要协议机制的支持,如业务类型划分,网络资源预约和用户业务最监控等。目前主要的宽带交换网技术有千兆比以太网,千兆比路由器网和ＡＴＭ网三种。文章最后论述了多业务宽带分组交换网的原理和结构。     

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。     

光分组交换网

本文介绍了全光分组交换网的国内外研究状况，讨论了光分组交换节点的功能和结构及其实现光分组交换网的关键技术，对光分组交换网的研究具有重要的参考价值。     

Novel Packet Switching for Green IP Networks

A green technology for reducing energy consumption has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. Here, we propose a novel energy‐efficient packet switching method for use in an IP network for reducing unnecessary energy consumption. As a green networking approach, we first classify the network nodes into either header or member nodes. The member nodes then put the routing‐related module at layer 3 to sleep under the assumption that the layer in the OSI model can operate independently. The entire set of network nodes is then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using well‐known real network topologies and achieved a more energy‐ efficient performance than that achieved in previous studies.     

High-Speed Packet Switching Systems for Multimedia Communications

High-speed packet switching (HPS) systems can Provide flexible, economical, high-quaiity services for integrated voice, video, and data communications. To realize such HPS systems, methods have been developed to bring about high-speed protocol processing as well as a system architecture for facilitating high-throughput switching. Adopting the parallel processing algorithm into protocol processing allows us to achieve high-speed packet protocol processing of about 100 times faster than conventional processing. Furthermore, a fully distributed system architecture in addition to hierarchical interconnection networks can achieve high-capacity packet switching systems. The proposed HPS system is thus capable of accommodating lines of up to 10-50 Mbits/s, of providing high-throughput switching capability of 1 000 000 packets/s, and of having an average delay of less than 2 ms. Furthermore, an evaluation of network delay performances of video conferencing and voice communications indicate that HPS systems are quite suitable for handling such multimedia communications.