A mobile communication system is provided that performs bi-directional communications between a mobile station and a wireless access network device. The mobile station includes a connection set-up signal reception timing calculation unit for calculating a reception timing of a connection set-up signal when a connection request signal is transmitted, and a connection set-up signal reception determination unit that determines, according to the reception timing, whether the connection set-up signal is received, and performs a signal reception operation based on the determination. The wireless access network device includes a connection set-up signal scheduling unit that, after receiving a connection request signal from the mobile station, performs a connection set-up signal transmission assignment based on a reception timing of the connection request signal, a connection set-up signal generation unit that generates a connection set-up signal to be sent to the mobile station; and a connection set-up signal transmission unit that transmits the connection set-up signal based on the connection set-up signal transmission assignment.