Inter-network roaming based on personal digital cellular standards

The paper describes inter-network roaming based on the standards of Japan´s digital cellular system called personal digital cellular (PDC). The gateway location register (GLR) is defined for mobile users roaming from the home network to the visited network. The numbering plan includes the mobile subscriber ISDN number, international mobile station identity, location area identity and roaming number. The roaming number is used by the visited network for recognizing the roaming user as a home user, The signaling protocol for the air interface is based on the I interface defined by CCITT; that for the inter-office interface is defined as the mobile application part (MAP), one of three regional MAPs recognized by CCITT. The call connection functions for the roaming user, such as location registration, terminating call connection and originating call connection are described, PDC can be upgraded to an intelligent mobile network (IMN) that can offer universal personal telecommunications (UPT) by applying the concept of terminal mobility management scheme to the personal mobility management scheme and intelligent network (IN) model. The paper also describes the IMN functional model