The AP periodically sends Discovery Request messages to check the status of the original primary link. When the link recovers, the AP detects that the priority level of the link is higher than that…

The AP periodically sends Discovery Request messages to check the status of the original primary link. When the link recovers, the AP detects that the priority level of the link is higher than that of the current primary link, and triggers a switchback. In order to avoid frequent switching caused by network vibration, after waiting for 6 echo cycles, the AC is notified to perform active/standby simultaneous switching, and at the same time, the AP sends the data services of the STAs to the newly upgraded AC.