A wireless communications system configured to use a predetermined bandwidth of an unlicensed bandwidth, the wireless communications system including: a base station configured to transmit a control signal that includes information indicating an offset time from a reference timing; and a terminal connected to the base station and configured to: receive the control signal from the base station; perform a process of detecting a wireless signal of the predetermined bandwidth in a standard period; and start transmission from a transmission start timing according to the offset time after no wireless signal of the predetermined bandwidth is detected in the process, the transmission start timing being a timing at which the terminal is allowed to start transmission of wireless signals.