Fujitsu Corporation

Takamitsu Toyoda

Kazumasa Ushiki

Mitsunori Fukazawa

The present invention relates to a mobile communication system. Particularly, the present invention provides a mobile communication system that has functions of autonomously relieving and recovering from a station-location-information loss phenomenon which may be caused when the system performs switching between active and standby home location registers in response to an occurrence of a fault. This mobile communication system has home location registers, visitor location registers, mobile switching centers, and mobile stations. In this mobile communication system, each of the home location register comprises a rerouting information acquisition section for performing routing information acquisition processing when receiving in response to a routing information acquisition message, which is sent out to one of the visitor location registers a response message indicating that a corresponding one of the mobile stations is not present.

Mobile communication system

A mobile communication system employs narrow paging areas for calling mobile stations without increasing location registration requests to a location management center. This system reduces useless calls and improves the efficiency of use of radio resources. Each local area ( - ) of the system is divided into narrow paging areas ( - ). A storage unit ( - ) is installed in each base station ( - ) or exchange station ( - ), to register mobile stations ( - ). When a base station receives a location registration request from a mobile station, the base station registers the mobile station in the storage unit, and if necessary, transmits a location registration request to the location management center. Upon receiving an incoming call to a mobile station, the exchange station sends an inquiry about the mobile station to the storage units, receives an answer from the storage units, finds a paging area where the mobile station is present from the answer, and issues a call request to base stations that belong to the found paging area.

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Tokyo, Japan

Takamitsu Toyoda