Asynchronous Transfer Mode (ATM) is considered to bo the key technology for realizing B-ISDN. This paper discusses current research on ATM switching nodes for high-speed communication networks. Although some ATM switching nodes have been deployed, much work continues for resolving problems as regards operations and maintainability, such as ATM layer performance evaluation including layered management scheme upon detection of line failure, function test methods regarding channel connectivity for multicasting, and real-time ATM traffic-monitoring mechanism with QoS control. To achieve sufficient ATM node maintainability, the ATM cell transfer quality on the VP and VC levels should be ensured both within the ATM nodes and between adjacent ATM nodes. Since ATM switching nods handle many kinds of virtual paths and virtual channels, each channel's connectivity must be confirmed. This paper proposes ATM layer performance evaluation concept, layered management scheme upon detection of line failure, function test methods for a multicast switch using test cells that periodically pass through pre-determined switching path routes. It also proposes the concept of test cell generation for simulating multiplexed ATM test cells taking ATM truffic characteristics into account. Furthermore, this paper describes a fault diagnosis scheme using test cells that can continually observe the entire ATM connection length in the system. A real-time traffic monitoring hardware configuration and an interface with software control are also discussed and it is clarified that the required functions can be realized by using commercially available DSPs.

The Asynchronous Transfer Mode (ATM) is considered to be a key technology for B-ISDN. This paper discusses VLSI trends and how VLSI's can be applied to realize ATM switching node systems for B-ISDN. Implementing a practical ATM node system will require the development of technologies such as high-throughput ATM switch LSI's with up to 10 Gb/s capacity and SDH termination technology based on optical fiber transmission. An ATM traffic-handling mechanism with Quality of Service (QoS) controls such as ATM layer performance monitoring, virtual channel handling, usage parameter control, and VP shaping requires several hundred thousand logic gates and several megabytes of high-speed static RAM; VLSI's must be introduced if such mechanisms are to be implemented. ATM node system architecture is based on design principles of a building-block-type structure and hierarchical multiplexing. The basic ATM call handling module, the AHM, is composed mainly of a line termination block and a self-routing switch block; we analyzed this module from the viewpoint of the amount of hardware it requires. Finally, future ATM node systems are discussed on the basis of 0.2-µm VLSI development trends and hardware requirements such as the need for ultrahigh integration of logic gate with memory, multichip modules, and low power dissipation technology.

A mechanism of an integrated switching system architecture where PS, CS, and ATM switching functions are integrated based on a hierarchical memory system concept is discussed. A packet buffering control mechanism, and practical random time-slot assignment mechanism for CS traffic, which are composed of multiple bearer rate data traffic are then described. The feasibility of the random time-slot assignment mechanism is also confirmed by a practical experimental system using VLSI technology, particularly, content addressable memory (CAM) technology. The required queuing delay between the nodes for the corresponding call set up procedure is also shown and its application is clarified. For practical digital networks that provide various types of data communications including voice, data, and video services, it is highly desirable to evaluate the transmission efficiency of integrating packet switching (PS) type non-real time traffic and circuit switching (CS) type real time traffic. Transmission line utilization improvement is expected when the random time-slot assignment and the movable boundary scheme on a TDM (Time Division Multiplexing) data frame are adopted. The corresponding control procedure by signaling between switching nodes is also examined.

Visible light communication (VLC) will play a wide variety of important roles in future communication services. This paper deals with color shift keying (CSK) for the modulation of visible light communications. There are some previous studies about psychological and physiological effects of colors. These studies implied that color offset CSKs have psychological and physiological effects, which normal CSK doesn't have. This paper evaluates the psychological and physiological effects of color offset CSKs compared with normal CSK based on interviews and electroencephalogram (alpha wave, beta wave, and P300) measurements. This study evaluates the feasibility of visible light communication providing added value by measuring arousal, rest, visual attraction, task performance, capacity of working memory, and response for the CSK codes. The results showed that red-, green- and blue-offset CSK have specific features. Red-offset CSK induces excitement and increasing wakefulness levels, attracts attention, enlarges capacity of working memory, raises task performance, and induces fast responses. Green-offset CSK maintains rest levels, elevates relaxation levels, reduces stress, raises task performance, and induces fast responses. Blue-offset CSK maintains rest levels and induces fast responses. It is thought that we can use color offset CSK appropriately and provide added value to their application by considering the results of psychological and physiological investigations. Red-offset CSK is thought to be suitable for commercial advertisements. Green- and blue-offset CSK are thought to be suitable for wireless communication environments in hospitals. Red- and green-offset CSK are thought to be suitable for wireless communication environments in business. Red-, green- and blue-offset CSK are thought to be suitable for use in intelligent transportation systems (ITS).