Embodiments of the present disclosure relate to mechanism for interactions for entering into the sleep mode. According to embodiments of the present disclosure, the network device transmits the information of go-to-sleep, GTS, to the terminal device on a lower layer (for example, the physical layer). The lower protocol layer informs the higher protocol layer (for example, the MAC layer) of the information of GTS. The terminal device determines how to monitor the physical downlink channel based on the information of GTS. Further, the terminal device may switch bandwidth part based on the information of GTS. In this way, the GTS is able to significantly save power.