This paper proposes an authentication technique for use in the global mobility network (GLOMONET), which provides a personal communication user with global roaming service. This technique is based on new distributed security management, where authentication management in roaming-service provision is conducted only by the roamed network (the visited network). The original security manager (OSM) administrates the original authentication key (OAK) acquired when a user makes contracts with the home network, while the temporary security manager (TSM) is generated for a roamer in the visited network in order to provide roaming services. The TSM generates and administrates the temporary authentication key (TAK) for a roamer, which key is confidential to the OSM, releases the TAK administration when a roamer moves to other networks, and then disappears. The proposed authentication technique consists of two phases. In the roaming-service-setup phase, triggered by the user's location registration request, authentication control to set up the roaming-service environment is negotiated by the TSM in the visited network, the OSM, and the roamer. In the roaming-service-provision phase, triggered by the user's service request, authentication control to provide the roaming service is negotiated (using the TAK acquired by the roamer in the first phase) only by the visited network and the roamer. This authentication control using the TAK provides a unified authentication procedure with a single logic to both subscribers and roamers. In addition, the security management of the whole GLOMONET is reinforced and the security responsibility is made clear by allocating the subscriber's/roamer's security administration to only the TSM.

The network for supporting the global personal communication is called the global mobility network (GLOMONET), where global mobility is guaranteed by coordination between intelligent networks (INs). This paper describes the implementation of a roaming signaling protocol for the personal handy-phone system (PHS) GLOMONET, clarifying the concepts of the PHS architecture regarding the GLOMONET. The PHS is a more economical personal communication system than existing cellular systems, by introducing the concept that the PHS service is provided by the most effective use of the existing ISDN and IN functions, where the majority of network functions to provide ISDN services are commonly used for functions for PHS service provision. The PHS mobility function realized by the IN guarantees flexible and effective roaming service provision for the globalization of future personal communication. The proposed PHS signaling protocol architecture is based on the intelligent network capability set 2 (IN CS2) defined by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) Study Group 11 and a visitor location register (VLR) database scheme with efficient signal transfer in the GLOMONET. The PHS specific roaming signaling protocol is defined by the service-independent IN application protocol (INAP). The proposed PHS concepts and roaming signaling protocol were reflected to the national telecommunications standards in the Telecommunication Technical Committee (TTC) and standards in the PHS-memorandum of understanding (MoU).

An analysis is presented of the traffic performance of a variable-channel-per-burst (VCPB) satellite-switched time-division multiple access (SS-TDMA) that dynamically reconfigures traffic bursts. An SS-TDMA system with an onboard baseband switch is used as the VCPB application system. Bursts are assigned to each earth station one-by-one. Idle channels of other bursts are transferred to a burst having an insufficient number of idle channels by reconfiguration on a call-by-call basis. The VCPB is suited to SS-TDMA systems with relatively few earth stations. VCPB traffic performance depends on the reconfiguration strategy. The effects on traffic performance caused by reallotting idle channels to all bursts in every reconfiguration are described. An approximate formula for the reconfiguration probability from the loss probability of fixed-channel-per-burst TDMA weighted by the binomial distribution for the number of channels in each burst is derived.>