Patent ID: 8559372

Claim:
A method for processing a digital broadcast signal, the method comprising: processing by a processor the digital broadcast signal in at least two transmission modes, wherein the processing comprises: first processing for a first transmission mode, the first processing comprising: forming a first data group including mobile service data and place holder data for main service data, an MPEG-2 header and non-systematic RS parity data; removing the place holder data for main service data and non-systematic RS parity data in the first data group, replacing the place holder data for the MPEG-2 header with an MPEG-2 header having a packet ID of mobile service data packets in order to form and output 118 mobile service data packets including data in the first data group; multiplexing the output mobile service data packets and 38 main service data packets; second processing for a second transmission mode, the second processing comprising: encoding signaling data including a transmission parameter for the second transmission mode; forming a second data group including mobile service data and the transmission parameter; forming and outputting M numbers of mobile service data packets including data in the second data group, wherein M is an integer equal to or greater than 118 and equal to or less than 156; multiplexing the output mobile service data packets and N numbers of main service data packets when N is not zero, wherein a sum of M and N is 156, wherein the second data group includes a region in which a scalable number of mobile service data packets are inserted, wherein the transmission parameter includes a group extension mode field specifying a number of mobile service data packets included in the region; and transmitting the processed digital broadcast signal.