Abstract: Disclosed herein are a terminal device including: a state determining unit to determine a connection state of a voice call or a data call at a specific time prior to a transfer period of a keep-alive message designated to a specific application; and an application interworking unit to transfer the keep-alive message through the data call according to the determined connection state of the voice call or the data call to notify of a driving state of the specific application.

Abstract: 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.

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