It should be noted that, in this embodiment of this application, when the to-be-monitored wake up signal that the terminal device needs to monitor is determined based on the service feature, at least two possible implementations below may be used for determining. In a possible implementation, the first category to which the terminal device belongs may be first determined based on the service feature, and then the to-be-monitored wake up signal that the terminal device needs to monitor is determined based on the first category and a mapping relationship between category information and a wake up signal. In a second possible implementation, the to-be-monitored wake up signal that the terminal device needs to monitor may be determined with reference to the service feature and a grouping factor (for example, the identifier of the terminal device). In other words, the first category to which the terminal device belongs may be first determined based on the service feature, and then the to-be-monitored wake up signal that the terminal device needs to monitor is determined based on both the first category and the grouping factor. The following describes in detail, by using detailed embodiments, wake up signal sending methods that each include the two possible implementations.

In a possible implementation, for example, FIG. 2 is a schematic diagram of a wake up signal sending method according to an embodiment of this application. The wake up signal sending method may include the following steps.

S201: A core network device determines, based on a service feature of a terminal device, a first category to which a terminal device belongs.