PURPOSE: To obtain a pre-paid type portable telephone set reused in which the service is received without registration of user information to an exchange and a charging memory but replacing a storage device in the telephone.
CONSTITUTION: The system is provided with a pre-paid type portable telephone set 100 having a charging arithmetic operation function and a base station 200 having a charging signal transmission section sending a charging signal from an exchange 300 to the portable telephone set, and it is controlled that the line is interrupted during talking and dialing is disabled at dialing when call units do not remain, without need of user information to an exchange and registration of a charging memory. Then a storage element of the residual call unit storage section of the portable telephone set 100 is replaced with a storage element in which new speech available call unit is stored to attain succeeding talking.
KAWAMURA MIKIO
MURAKAMI YOSUKE
