After determining, based on the service feature of the terminal device, the first category to which the terminal device belongs, the core network device may send the first category to which the terminal device belongs to the terminal device, so that the terminal device obtains the first category to which the terminal device belongs. It should be noted that, when sending the first category to which the terminal device belongs to the terminal device, the network device may first send the first category to which the terminal device belongs to the network device, and then send the first category to which the terminal device belongs to the terminal device through the network device, so that the terminal device obtains the first category to which the terminal device belongs. Similarly, in a transmission process of the first category to which the terminal device belongs, the first category to which the terminal device belongs may be transmitted through NAS signaling, and the network device only plays a role of transparent transmission.

It should be noted that, the two steps of S201 in which the core network device determines, based on the service feature of the terminal device, the first category to which the terminal device belongs and S202 in which the core network device sends the first category to which the terminal device belongs to the terminal device may be understood as a process in which the terminal device and the core network device negotiate to classify terminal devices based on service features to determine a category to which a terminal device belongs. The negotiation process is transparent to the network device, that is, the network device cannot obtain content of the negotiation process.

S203: The network device sends a configuration of a plurality of wake up signals to the terminal device.