PORTABLE TERMINAL POSITION MANAGEMENT METHOD FOR COMMUNICATION SYSTEM, PORTABLE TERMINAL, EXCHANGE, POSITION MANAGEMENT DEVICE, AND PORTABLE TERMINAL RECONNECTION SYSTEM

PURPOSE:To reduce an ineffective load on the position management device in the communication system as much as possible and to simplify operation for connecting the portable terminal as much as possible. CONSTITUTION:Discrimination information on each exchange 100 is reported from the exchange 100 to each portable terminal 200 at all times (means 101) and when the terminal 200 requests the exchange 100 to register the position, it is decided whether or not there is a change of a connected exchange from after a last request; only when the change is detected, the position management device 300 is requested to change the registration of a movement destination exchange (means 102, 103, 202, 203, etc.). Further, each exchange 100 has connected portable terminals 200 (means 104) and only when an unconnected terminal is newly connected, a request to change the registration of the movement destination exchange 100 is made (means 105 and 106) and while a terminating portable terminal 200 moves to another exchange 100, the absence is reported (means 113). The informed exchange 100 inquires the movement destination of a transfer destination telephone number management device 400 to make a reconnection (means 111 and 112) or perform absence transfer (means 114).