The first category may include a plurality of different representation manners. Manner 1: The first category may be a specific probability value. Manner 2: The first category may be qualitative information indicating a probability value, for example, a high probability, a medium probability, or a low probability. Manner 3: The first category may alternatively be uplink service trigger or downlink service trigger. Although the uplink service trigger and the downlink service trigger do not explicitly reflect a probability that the terminal device is paged, the uplink service trigger and the downlink service trigger may indirectly reflect the probability that the terminal device is paged. Generally, the uplink service trigger may be understood as that a probability of being paged is low, and the downlink service trigger may be understood as that a probability of being paged is medium or high. Manner 4: The first category may alternatively be directly a category identifier of the first category. Certainly, the four representation manners are merely used as an example for description in this embodiment of this application, but this does not mean that this embodiment of this application is limited thereto.