Akihiko Takase

Datapath architecture and technology for large scale ATM switching systems

Datapath architecture and technologies for large scale switching systems are studied. Two main key-factors, the complexity of the functional blocks such as the switch fabric, and the interconnection between the functional blocks should be considered. This paper mainly focuses on the interconnection, which is the most important issue to be resolved before achieving a practical multi-hundreds-Gbps switching system. The complexity of the switch fabric would not be the constraints considering the progress of very large scale integrated circuit (VLSI) technology, which allows more than one-mega gates on a chip. Many aspects of interconnection technologies have been investigated including switch fabric functional allocation to functional blocks, datapath width expansion between VLSI chips or shelves, and high-speed transmission utilizing CMOS and optical technologies. This paper also shows a single card ATM unit switch with a throughput of 20-Gbps as an example of the feasibility of these technologies.

ATM transport node for flexible and robust access networks

This paper describes an architecture and functions required for integrated access networks for a future multi-service telecommunication environment. A multi-service access network can be configured over a physical ATM/SDH ring-star network applying the virtual path layering as a logical networking technology. Service specific path management and fault tolerant networking technologies, such as the automatic protection switching and the traffic management are described with hardware implementation examples. An ATM add-drop-multiplexer for 2.4-Gbps transmission link and an ATM access multiplexer with 24 156-Mbps interfaces are presented to show the feasibility of the proposed integrated access networks.<<ETX>>

An ATM system architecture for seamless network evolution

The paper discusses the ATM network evolution from various points of view including the evolution of ATM services, service interface, and connection management. The key issues for the ATM network evolution are the assurance of independent progress of the core transport system separated from adaptation functions for existing and future telecommunication services, the integration of user service interface, and the enhancement of connection management from semi-permanent virtual path network to the switched virtual circuit network. The node architecture is proposed based on multiplexer/cross-connect and self-routing switch configuration, which provides the smooth evolution from the cross-connect network to the switched network. The traffic management schemes on the node system are also studied.<<ETX>>

Local loop system evolution toward B-ISDN with an integrated MAN/DLC

A strategy is described for subscriber loop systems and architectures leading to broadband ISDN, from the service and economy viewpoints. Since remote multiplexing is the key function for offering initial broadband services as economically as 64-kb/s services, an integrated metropolitan area network/digital loop carrier (MAN/DLC) architecture and a distributed multiplexing scheme are proposed. This architecture supports the independent evolution of transport core networks and customer premises networks and equipment, at a cost comparable with an ordinary approach. Node architectures with the distributed multiplexing are discussed in terms of bus multiplexing, call processing, and LSI implementation. Feasibility studies of this architecture have been conducted with prototypes that incorporate three basic LSIs for the B-ISDN transmission convergence layer and the ATM (asynchronous transfer mode) layer.<<ETX>>

An experimental B-ISDN system for MAN application study

The authors present an experimental broadband ISDN (B-ISDN) system for developing metropolitan area network (MAN) applications. It includes an asynchronous transfer mode (ATM) switch, ATM transmission systems for STM-1 and STM-4, and network terminations for statistical multiplexing utilizing the IEEE 802.6 MAC protocol. Adaptation functions for the IEEE 802.23 LAN, ISDN BRI, NTSC packet video, and high-definition TV (HDTV) were also investigated using the prototype. Applications such as high-definition image file database inquiries, group teleworking, and HDTV program broadcasting were also studied. The experimental system configuration, the design considerations, and results of the prototype investigation are presented.<<ETX>>

A large scale ATM switching system architecture for multimedia communications

1 . Introduction Multimedia communications are having a great impact on switching system architecture . The Asynchronous Transfer Mode (ATM) is the predominant technique used to obtain a B-ISDN with a universal interface . Next-generation switching using this technique must have a flexible architecture to handl e the heterogeneous traffic and sophisticated services multimedia communications will provide . To adapt to the increase of B-ISDN subscribers, we propose a hyper-distributed switching system architecture composed of a non-intelligent module and independent modules with call processing functions . To multiplex burst traffic , ATM shared buffer memory switches are used as the unit switches in both modules .