Private radio system for delivering incoming calls to a mobile subscriber

A private network system, comprising:

• at least a first exchange, a second exchange:
• and a third exchange for exchanging telephone calls, said first, second, and third exchanges being connected through a network;
• a radio telephone, said first exchange being a home exchange of said radio telephone, said radio telephone including position registration request signal transmission means for transmitting a position registration request signal including an identification code of said radio telephone;
• a first radio connection controller connected to said first exchange;
• a second radio connection controller connected to said second exchange, said second radio connection controller transmits said position registration request signal, upon receipt of said position registration request signal from said radio telephone, to said second exchange;
• said second exchange comprises:
• second registration means for recording the identification code of said radio telephone and information indicating that said second exchange is a visitor exchange of said radio telephone, when said radio telephone is a visitor radio telephone of said second exchange, upon receipt of said position registration request signal through said second radio connection controller, and
• terminal movement notification signal transmission means for transmitting a terminal movement notification signal to said network with the identification code of said radio telephone and an identification code of said second exchange when the identification code of said radio telephone is registered in said second registration means;
• said first exchange comprises:
• first registration means for registering the identification code of said radio telephone with information that said first exchange is the home exchange of said radio telephone, and further registering an identification code of said second exchange as a visitor exchange in correspondence with the identification code of said radio telephone upon receipt of said terminal movement notification signal including the identification code of the said radio telephone and the identification of the said second exchange from said second exchange through said network in the case where the identification code of said radio telephone added in said terminal movement notification signal corresponds to the identification code of said radio telephone recorded in said first registration means and the information that said first exchange is the home exchange of said radio telephone has been recorded therein,
• visitor exchange registration determination means for determining whether the identification code of said second exchange has been registered or not as said visitor exchange in said first registration means in correspondence to said radio telephone by referring to said first registration means, upon receipt of an incoming call to said radio telephone,
• transfer means for transferring the incoming call to said second exchange when the identification code of said second exchange has been registered as a visitor exchange in correspondence to said radio telephone as a result of the determination by said visitor exchange registration determination means, and
• first connecting means for connecting the incoming call to said radio telephone through said first radio connection controller when the identification code of said second exchange has not been registered as a visitor exchange in correspondence to said radio telephone as a result of the determination by said visitor exchange registration determination means, and further that the identification code of said radio telephone has been recorded in said first registration means together with information that said first exchange is the home exchange of said radio telephone;
• said second exchange further comprises:
• second connecting means for connecting the incoming call to said radio telephone through said second radio connection controller, referring to said second registration means upon receipt of the incoming call transferred by said transfer means if the identification code of said radio telephone has been registered in said second registration means;
• wherein said terminal movement notification signal transmission means transmits said terminal movement notification signal to said first and third exchanges through said network;
• wherein said first exchange refers to said first registration means upon receipt of said terminal movement notification signals and transmits an answer signals including the identification code of said first exchange:
• to said second exchange if the identification of said radio telephone has been registered as well as information indicating that it is the home exchange of said radio telephone;
• and
• wherein said third exchange does not transmit said answer signal to said second exchange.