The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for transmitting data in a wireless communication system. According to an aspect of the present invention, the method comprising: receiving, from a network node, uplink scheduling information with an indicator indicating a network node associated with the uplink scheduling information, identifying the network node indicated by the indicator, wherein the identified network node supports at least one service, generating a data unit including data of the at least one service supported by the identified network node, and transmitting, to the network node, the generated data unit via a radio resource indicated by the uplink scheduling information.