During path switching between sidelink (SL) and uplink (UL) for vehicle-to-everything (V2X) message transmission, a path switching layer of a user equipment (UE), which may be located right above a packet data convergence protocol (PDCP) layer of the UE, stores a vehicle-to-everything (V2X) message, which is not transmitted yet on an old path, in a transmission buffer. And then, the path switching layer of the UE re-submits the V2X message stored in the transmission buffer to a lower layer of a new path.