Method and system for notifying 1xEV-DO system of switching from 1xEV-DO system to 1X system

The present invention comprises: a hybrid access terminal, operating in both a 1X mode for being provided with a low-rate data transmission service from a 1X system and a 1xEV-DO mode for being provided with a high-rate data transmission service from a 1xEV-Do system, periodically switching over to the 1X system while in traffic with the 1xEV-DO system, for transmitting a notice signal for advising the switching over a base station transceiver subsystem including 1xEV-DO transceiver subsystem for exchanging a packet data with the hybrid access terminal and a 1X transceiver subsystem for exchanging a voice or data with the hybrid access terminal and a base station controller including a 1xEV-DO controller for controlling a packet data transmission service, of the 1xEV-DO transceiver subsystem and a 1X controller for controlling transmission service of the 1X transceiver subsystem.