Physical protocol data unit transmission method employed by wireless fidelity multi-link device

A physical protocol data unit (PPDU) transmission method comprising:

• setting parameters of each of a plurality of links for enabling the plurality of links to have different capacity for PPDU transmission, wherein parameters of one of the plurality of links are different from parameters of another of the plurality of links, and highest capacity supported by said one of the plurality of links is higher than highest capacity supported by said another of the plurality of links;
• aligning an ending time instant of transmission of a first PPDU transmitted via said one of the plurality of links with an ending time instant of transmission of a second PPDU transmitted via said another of the plurality of links through setting, by a wireless fidelity (WiFi) multi-link device (MLD), a content that is carried by the first PPDU transmitted via said one of the plurality of links, wherein the ending time instant of transmission of the first PPDU and the ending time instant of transmission of the second PPDU are aligned with mismatch between the ending time instant of transmission of the first PPDU and the ending time instant of transmission of the second PPDU falling within a predefined tolerance range;
• and
• transmitting PPDUs via the plurality of links, wherein one PPDU is transmitted via each of the plurality of links, and the PPDUs comprise the first PPDU and the second PPDU.