By integrating three networks, namely, Public Switched Telephone Network (PSTN), Personal Handy-Phone System (PHS) and Intelligent Network (IN) to work together as a Personal Communication Telephone (PCT) service to be offered in the Bangkok metropolis area, the PCT service enables the advent of three new concepts, first, using the same telephone number as that of the fixed line to become a "Personal Number," second, a cell coverage designed to cover larger areas than that of the PHS (by changing hand-out threshold level from 33 dBµV to 30 dBµV and hand-in threshold level from 30 dBµV to 25 dBµV) in order to reduce the muting time during the handover process and provide higher mobility at up to 60 kilometers per hour, and third, a technique of "2 carriers per area" to reduce "call drop." All these techniques will be described in this paper.

The world of mobile communications has undergone dramatic changes in recent years. Since the Personal Digital Cellular (PDC) system of digital mobile communications became commercially available in Japan in 1993, the number of subscribers has increased to the extent that almost 30% of the Japanese population are subscribed. Furthermore, the increasing sophistication of communications, such as the growing popularity of the Internet and expansion of our spheres of existence, have led to demand for new applications, such as use on a global scale. Many new technologies are also being introduced, such as the IMT-2000 system and the IN system which are slated to be introduced at the end of 2000. Based on the above and in view of the increasing scale and sophistication of mobile communications networks, the time has come to reexamine the configuration within networks of SCPs, which perform subscriber data management and service control. This paper focuses on the functions of subscriber data management and service control, classifies data necessary for mobile networks and using the signal number of common networks as a guide considers the optimum arrangement of data and control nodes. The paper also examines reliability measures for SCPs to ensure the reliability of increasingly large-scale networks.

This article clarifies the requirements of VHE (Virtual Home Environment), issues and resolution for realization of VHE, when the environment will use Intelligent Network (IN) within IMT-2000 networks that is targeted to start in the year 2000. The IN aims the applicability of it's architecture to any kind of network. However, the following subjects need to be considered when IN will be used in the IMT-2000 network; The approach of the service related capabilities' extraction and specification; security management; cooperation between the service switching function within a core network and the IN function(s); cooperation between the mobility management function and the IN function(s); and consideration of mobile and fixed network convergence/integration. This article mainly focuses on these subjects. Some open issues like service/feature interaction and their tentative solutions are identified. Main results are; expandability of current IN to supporting IMT-2000 requirements, identification of key issues in providing VHE in IMT-2000, identification of candidate relationships, and associated issues for VHE. The currently available scenarios for VHE are evaluated from these points, and it is proposed that the specification to be common both for mobile and fixed network.

Development of a large-scale mobile communications network (IMN: Intelligent Mobile communications Network), as an infrastructure integrating multimedia functions, is indispensable for the support of future mobile communication services aiming toward "personalization," "intelligence," and "multimedia services." This paper discusses the aims of mobile communications and the outline of network technology aspects of PDC (Personal Digital Cellular) network which is currently in service. In addition, the future prospect of mobile communication technologies is discussed with special focuses on the support of universal mobility, network architecture including mobile communications platform, and multimedia technologies in the transport and access systems.