A method for providing a broadcast service based on a broadcast network and a broadband network in a digital transmitter, includes generating multiple service components of the broadcast service and service layer signaling (SLS) information for the broadcast service; generating a service list table (SLT) for providing bootstrap information that allows a receiver to discover the SLS information for the broadcast service; transmitting a first signal comprising a first service component among the multiple service components, the SLS information and the SLT via the broadcast network, wherein the first service component is carried via a first Layered Coding Transport (LCT) channel included in a Real-time Object delivery over Unidirectional Transport (ROUTE) session, wherein the bootstrap information included in the SLT is used to represent a second LCT channel that carries the SLS information; and transmitting a second signal comprising a second service component among the multiple service components via the broadband network.