This paper clarifies the appropriate traffic domains for combination between two database schemes (i. e. , HLR database scheme and VLR database scheme) and two call routing schemes (i. e. , Redirection Routing scheme and Look-a-head Routing scheme) in the Global Mobility Network (GLOMONET), which is able to provide global roaming service for the personal telecommunication user. The appropriate domains for combination between each scheme are shown to depend on user's mobility (i. e. the frequency of a user's access to a network where the user stays, the length of the period during which the user stays in the same network). Whether the appropriate domains for the HLR database scheme exist depends only on the frequency of the user's access to the network. When there are appropriate domains for the HLR database scheme, increasing the frequency of the user's access to the network, decreasing the length of the period the user stays in the user's home network, or increasing the length of the period the user stays in a network that isn't the user's home network widens the domains where the VLR database scheme is appropriate.

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.