PHS roaming signaling protocol architecture toward global mobility network

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).