Clock synchronization method and apparatus

A clock synchronization method, comprising:

• separately performing, by an access network device, clock synchronization with clock sources of N clock domains;
• and
• after completing the clock synchronization with the clock sources of the N clock domains, sending, by the access network device, information about the N clock domains to a terminal,
• wherein information about a clock domain comprises first time information and a clock domain number of the clock domain, the first time information comprises a time of a clock source of the clock domain when the access network device sends the information about the clock domain, the clock domain number identifies the clock domain, and N is an integer greater than 1.

An apparatus, comprising:

• a receiver configured to receive information that is about N clock domains and that is sent by an access network device, wherein information about a clock domain comprises first time information and a clock domain number of the clock domain, the first time information comprises a time of a clock source of the clock domain when the access network device sends the information about the clock domain, the clock domain number identifies the clock domain, and N is an integer greater than 1;
• at least one processor;
• and
• one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to perform operations comprising:
• determining M clock domains that are associated with the apparatus and that are in the N clock domains, wherein M is an integer greater than 1;
• and
• separately performing clock synchronization with clock sources of the M clock domains based on information about the M clock domains.