Clock synchronization information obtaining (or providing) method and communication apparatus

A communication system, comprising a radio device and a radio device controller, wherein:

• the radio device is configured to send clock synchronization information to the radio device controller, wherein the clock synchronization information indicates clock synchronization accuracy between the radio device and a clock source, the clock source is a network device that provides a reference time clock for a clock link, and the clock link is a link for clock synchronization between the clock source and the radio device;
• and
• the radio device controller is configured to:
• receive the clock synchronization information from the radio device;
• and
• determine, based on the clock synchronization information, first clock synchronization accuracy between the radio device and the radio device controller.