The system in accordance with the present invention recognizes in real time that a call connection of a hybrid access terminal be switched over to a 1X system, by sending an inquiry message inquiring the hybrid access terminal of whether the hybrid access terminal has received voice signal or a low-rate data signal and by receiving a confirmation message that the hybrid access terminal has received the voice signal or the low-rate data signal from a mobile switching center, if a low-level signal below a prescribed level is received from the hybrid access terminal while counting time initiated from a point of a call drop while the hybrid access terminal is being provided with a multimedia service.