A terminal receives a power saving signal sent by a network device, where the power saving signal indicates N time units, and where N is greater than 0. The terminal determines a state of the terminal in a first time period corresponding to the N time units on a first frequency domain resource and a state in a second time period corresponding to the N time units on a second frequency domain resource. The state of the terminal includes a sleep state or a wake-up state. The sleep state indicates that the terminal monitors no first signal, and the wake-up state indicates that the terminal monitors a first signal based on a configuration parameter.