Embodiments of the present disclosure relate to mechanism for transmission for wideband system in unlicensed spectrum. According to embodiments of the present application, a transmission coordination mechanism is proposed to facilitate transmission in a wideband system. The network device may puncture on-going transmission on neighbor bands to ensure no power leakage to the band with later transmission. In this way, it can minimize the in-device power leakage issue when the network device performs LBT for later transmission.