A device providing an emergency alert service includes an RS frame encoder configured to generate an RS frame in a manner of performing an RS (Reed-Solomon)-CRC (Cyclic Redundancy Check) encoding on an ensemble comprising a mobile data for a mobile broadcasting service and a service signaling channel containing an access information on the mobile broadcasting service, a divider configured to divide the generated RS frame into a plurality of RS frame portions, a signaling encoder configured to generate a signaling data comprising a TPC (Transmission Parameter Channel) for signaling a transmission parameter of the mobile broadcasting and a FIC (Fast Information Channel) containing a connection information between the ensemble and the broadcasting service, and a data group formatter configured to generate a data group containing a part of the signaling data and the RS frame portion.