It may be understood that the method in this embodiment of this application is not limited to be used for transmission of a power saving signal, and may also be used for transmission of another signal provided that DCI sizes are different and monitoring complexity of the terminal device needs to be reduced.

The following describes apparatus embodiments of this application with reference to FIG. 6 to FIG. 9.

FIG. 6 is a schematic diagram of a structure of a terminal device according to an embodiment of this application. The terminal device 600 shown in FIG. 6 may correspond to the foregoing terminal device. As shown in FIG. 6, the terminal device 600 includes a receiving module 610 and a processing module 630.

The receiving module 610 is configured to monitor, based on a size of first downlink control information (DCI), the first DCI and second DCI that are sent by a network device, where the first DCI is carried on a power saving signal shared by a plurality of terminal devices including the terminal device, and the second DCI is carried on a terminal device specific power saving signal.

The processing module 630 is configured to determine, based on the detected first DCI and/or the detected second DCI, whether to monitor a data channel in a first time period.

Optionally, the size of the first DCI is the same as a size of the second DCI.