A method, comprising: monitoring each of a first link and a second link in a multi-link operation in wireless communications, with the first link being a primary link and the second link being a secondary link; obtaining a transmission opportunity, in the following also referred to as TXOP, on one of the first link and the second link as a result of performing a contention-based channel access on the first link and the second link; checking channel status of the other of the first link and the second link; and transmitting one or more frames on the first link but not on the second link, on the second link but not on the first link, or on both the first link and the second link synchronously, responsive to the channel status of the other link given the TXOP being obtained on the one of the first link and the second link; wherein, responsive to the TXOP being obtained on the second link, the checking of the channel status comprises checking channel status of the first link, further comprising: responsive to the channel status of the first link being idle, transmitting one or more frames on both the first link and the second link synchronously; characterized in that responsive to the TXOP being obtained on the second link, the checking of the channel status comprises the checking of the channel status of the first link, further comprising: responsive to the channel status of the first link being not idle, not transmitting any frame on either the first link or the second link. monitoring each of a first link and a second link in a multi-link operation in wireless communications, with the first link being a primary link and the second link being a secondary link; obtaining a transmission opportunity, in the following also referred to as TXOP, on one of the first link and the second link as a result of performing a contention-based channel access on the first link and the second link; checking channel status of the other of the first link and the second link; and transmitting one or more frames on the first link but not on the second link, on the second link but not on the first link, or on both the first link and the second link synchronously, responsive to the channel status of the other link given the TXOP being obtained on the one of the first link and the second link; wherein, responsive to the TXOP being obtained on the second link, the checking of the channel status comprises checking channel status of the first link, further comprising: responsive to the channel status of the first link being idle, transmitting one or more frames on both the first link and the second link synchronously; characterized in that responsive to the TXOP being obtained on the second link, the checking of the channel status comprises the checking of the channel status of the first link, further comprising: responsive to the channel status of the first link being not idle, not transmitting any frame on either the first link or the second link. responsive to the channel status of the first link being idle, transmitting one or more frames on both the first link and the second link synchronously; characterized in that responsive to the TXOP being obtained on the second link, the checking of the channel status comprises the checking of the channel status of the first link, further comprising: responsive to the channel status of the first link being not idle, not transmitting any frame on either the first link or the second link.