Patent ID: 6839561

Claim:
A general packet radio service system (GPRS, hereinafter), in which one or more subscriber switchboard stations are founded, plural mobile radio terminals are connected with said one or more subscriber switchboard stations by radio, and a packet data is transmitted and received between said transmitting and receiving mobile radio terminals via said one or more subscriber switchboard stations, comprising: a number-management server, which is connected with said one or more subscriber switchboard stations, manages a correspondence between user's addresses respectively assigned to said plural mobile radio terminals and mobile radio terminals-discriminators respectively corresponding to said user's addresses, and reads out said mobile radio terminal-discriminator corresponding to said receiving user's address in accordance a requirement presented from said first subscriber switchboard station in a location area of which said transmitting mobile radio terminal exists, wherein said transmitting mobile radio terminal has required said first subscriber switchboard station to start a packet data communication directed to said receiving mobile radio terminal, and notified said first subscriber switchboard station of said receiving user's address, and transmits said mobile radio terminal-discriminator corresponding to said receiving user's address to said first subscriber switchboard station, and a home location register (HLR, hereinafter) which is connected with said one or more subscriber switchboard stations, reads out said second subscriber switchboard station in a location area of which said receiving mobile radio terminal exists on a basis of said mobile radio terminal-discriminator corresponding to said receiving user's address transmitted from said first subscriber switchboard station, transmits information on said second subscriber switchboard station to said first subscriber switchboard station, and thereby enables said first subscriber switchboard station to start a packet data communication directed to said receiving mobile radio terminal via said second subscriber switchboard station.