The present disclosure relates to a notification method. In one example method, a first base station configures a first cell identity for a first cell. The first cell identity comprises a first identifier field and a second identifier field. A reserved bit in the second identifier field and the first identifier field identify the first base station. A remaining bit in the second identifier field identifies the first cell. The first base station notifies a second base station or a core network device of a part of the first cell identity that identifies the first base station.