Apparatus and method for transmitting and receiving signal in multimedia system

A method of operating a transmitting apparatus in a broadcasting system, the method comprising:

• identifying at least one network layer packet;
• generating at least one link layer packet based on the at least one network layer packet;
• and
• transmitting the at least one link layer packet,
• wherein a first link layer packet of the at least one link layer packet includes a header and a payload,
• wherein the header comprises a base header including payload configuration information indicating a configuration of the payload,
• wherein when the payload configuration information is set as a first value, the payload configuration information indicates that the payload carriers a single network layer packet and header mode information is included in the base header, the header mode information indicating whether an additional header for the single network layer packet is included in the header,
• wherein the header further comprises an extension header including sub-stream identification information when flag information included in the additional header indicates that the sub-stream identification information is included in the extension header
• wherein the sub-stream identification information is used to filter a packet stream in a link layer level, the packet stream including one or more of the at least network layer packet.