At present, CBS (Cell Broadcast Service, cell broadcast service), which provides a means for an operator to send group messages to group users in a specific geographical location, is often used to send emergency notices such as weather, earthquake, and tsunami warnings. On one hand, after the CBS service is activated, a UE (User Equipment, user equipment) needs to periodically acquire an enabled or disabled state of the CBS service in a cell where the UE is located so that the UE can learn from SIB5 (System Information Block 5, system information block 5) in time whether a CBS channel is enabled. Due to reasons such as a poor network environment, however, the UE cannot acquire the state of CBS through SIB5. Therefore, after CBS is disabled, the UE continuously attempts to acquire CBS information, which increases power consumption of the UE and occupies communication resources.
On the other hand, when system information in the cell changes, a paging message is used to notify the UE. In this way, after receiving the paging message, the UE acquires the changed information by decoding the system information. However, due to problems such as restricted base station coverage or interference, the paging message cannot be received by the UE in time. As a result, the UE cannot acquire the changed system information by decoding, which delays reception of the information and increases power consumption of the UE.