This paper describes the implementation types of private networks from the viewpoint of equipment and users, and utilization trends from low to high-speed services. Technology trends of private networks from the viewpoint of high-speed and broadband communication, multimedia communication, media access methods and intelligent communication are also examined. A concept for implementing future private networks in the Broadband ISDN (B-ISDN) age, and the major technology and the future efforts to achieve this implementation are discussed. Asynchronous Transfer Mode (ATM) is shown to be the key technology for integrating both various and heavy traffic media communication.

This paper describes a future private network service and the system configurations for providing it. Technologies and service trends in local area and wide area networks are shown. As network services become more diversified and integrated, it becomes more difficult for users to use the networks effectively. This paper shows how this problem can be solved by using virtual network technology to attain seamless networking. It also presents the concept of group networking among many parties, which can be used as the basis for a virtual private network.