Embodiments of the present disclosure relate to a method and apparatus of data transmission in a wireless communication system and a method and apparatus of receiving data in a wireless communication system. The method of data reception comprises transmitting a request for the RRC message to the network node based on default transmission parameters; and receiving the RRC message from the network node at a predetermined time unit. With embodiments of the present disclosure, it is possible to request the RRC message when the terminal device need this message and therefore the RRC message transmission can be reduced and in turn, the inter-node interference can be limited, and the number of LBTs required for these signal transmissions can be reduced if they are transmitted on unlicensed spectrum.