In an embodiment, the processor 301 may include one or more CPUs, for example, a CPU 0 and a CPU 1 in FIG. 3.

In an embodiment, the energy saving apparatus 30 may include a plurality of processors, for example, the processor 301 and a processor 308 in FIG. 3. Each of the processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor herein may refer to one or more devices, circuits, and/or processing cores configured to process data (for example, a computer program instruction).

In an embodiment, the energy saving apparatus 30 may further include an output device 305 and an input device 306. The output device 305 communicates with the processor 301, and may display information in a plurality of manners. The input device 306 communicates with the processor 301, and may receive an input of a user in a plurality of manners.

An embodiment of this application provides an energy saving method, applied to a communications system. The communications system includes a centralized controller and m RRUs connected to the centralized controller, where m is an integer greater than 1. As shown in FIG. 4, the energy saving method includes the following steps.