Multi-link synchronous transmission method and apparatus

A transmit multi-link device configured to communicate with a receive multi-link device over a first link and a second link, the transmit multi-link device comprising:

• a processor configured to determine that a first condition is met, wherein the first condition comprises:
• (1) a backoff counter of the first link is 0, and
• (2) a second transmission frame is located in a transmission opportunity (TXOP) on the second link;
• and
• a transceiver configured to, in response to the first condition being met, send a first transmission frame to the receive multi-link device at a first moment on the first link,
• wherein the processor is configured to determine the first moment based on at least one of:
• a second moment at which the backoff counter of the first link decreases to 0, or
• a third moment which is a sending moment of the second transmission frame on the second link,
• wherein the first condition further comprises:
• a third transmission frame on the first link fails to be transmitted, wherein
• the first transmission frame is used to retransmit an error part of the third transmission frame,
• the second transmission frame is the 1st transmission frame that is after a reference transmission frame on the second link and that has a same type as the reference transmission frame, and
• an end moment of the reference transmission frame is the same as an end moment of the third transmission frame, and
• wherein each of the first transmission frame and the third transmission frame is an uplink trigger frame.

A multi-link synchronous transmission method, wherein the method is performed at a transmit multi-link device (MLD) which is configured to communicate with a receive MLD over a first link and a second link, one of the transmit MLD and the receive MLD has a simultaneous transmit and receive (STR) capability, and the other does not have the STR capability, and the method comprises:

• sending, by the transmit MLD in response to a first condition being met, a first transmission frame to the receive MLD at a first moment on the first link,
• wherein the first moment is determined based on at least one of:
• a second moment at which a backoff counter of the first link decreases to 0, or
• a third moment which is a sending moment of a second transmission frame on the second link,
• wherein the first condition comprises:
• (1) the backoff counter of the first link is 0, and
• (2) the second transmission frame is located in a transmission opportunity (TXOP) on the second link, and
• wherein the first moment is a sending moment of a fourth transmission frame on the second link in response to the second moment being later than the third moment and earlier than a fourth moment, wherein
• the fourth moment is an end moment of the second transmission frame, and
• the fourth transmission frame is the 1st transmission frame that is after the second transmission frame and that has a same type as the second transmission frame.