Multicast signal processing method and device

1 . An apparatus for receiving a signal, the apparatus comprising:

a multicast gateway configured to receive a multicast signal from a multicast server; and

a content playback configured to display a service in the multicast signal,

wherein the multicast signal includes a multicast transport session carrying the service,

wherein the service is processed based on a User Datagram Protocol/Internet Protocol (UDP/IP), a Generic Stream Encapsulation (GSE) protocol, and a physical layer protocol,

wherein the signal includes Logical Layer Control (LLC) information which is based on the GSE protocol,

wherein the LLC information includes a multicast descriptor, wherein the multicast descriptor includes source address information, destination address information, source UDP port information, and destination UDP port information.

2 . The apparatus of claim 1 , the apparatus being further configured to:

receive a Physical Layer Pipe (PLP) carrying a GSE stream including

GSE data in which IP header compressed IP data is encapsulated,

GSE data in which IP header not compressed IP data is encapsulated, a descriptor for a multicast, and

Robust Header Compression (ROHC) descriptor related to an IP header compression from a GSE layer.

3 . The apparatus of claim 1 , the apparatus being further configured to:

receive the LLC information from a GSE layer,

wherein the LLC information further includes Network Control Data (NCD) and Link Control Data (LCD),

wherein the NCD includes a descriptor for a multicast,

wherein the LCD includes a link identifier for a physical layer.

4 . The apparatus of claim 3 , the apparatus further comprising:

a parser configured to parse the LLC information; and

a decompressor configured to receive a Robust Header Compression (ROHC) stream in a GSE stream in the GSE layer, and decompress a IP header.

5 . The apparatus of claim 1 , wherein the multicast descriptor further includes index information for multicast.

6 . A method of receiving a signal, the method comprising:

receiving a multicast signal from a multicast server; and

displaying a service in the multicast signal,

wherein the multicast signal includes a multicast transport session carrying the service,

wherein the service is processed based on a User Datagram Protocol/Internet Protocol (UDP/IP), a Generic Stream Encapsulation (GSE) protocol, and a physical layer protocol,

wherein the signal includes Logical Layer Control (LLC) information which is based on the GSE protocol,

wherein the LLC information includes a multicast descriptor, wherein the multicast descriptor includes source address information, destination address information, source UDP port information, and destination UDP port information.

7 . The method of claim 6 , the method further comprising:

receiving a Physical Layer Pipe (PLP) carrying a GSE stream including

GSE data in which IP header compressed IP data is encapsulated,

GSE data in which IP header non-compressed IP data is encapsulated, a descriptor for a multicast, and

Robust Header Compression (ROHC) descriptor related to an IP header compression from a GSE layer.

8 . The method of claim 6 , the method further comprising:

receiving the LLC information from a GSE layer,

wherein the LLC information further includes Network Control Data (NCD) and Link Control Data LCD,

wherein the NCD includes a descriptor for a multicast,

wherein the LCD includes a link identifier for a physical layer.

9 . The method of claim 8 , the method further comprising:

parsing the LLC information; and

receiving a Robust Header Compression (ROHC) stream in a GSE stream in the GSE layer, and decompressing a IP header.

10 . The method of claim 6 , wherein the multicast descriptor further includes index information for multicast.

11 . A method of transmitting a signal, the method comprising:

transmitting a multicast signal from a multicast server,

wherein the multicast signal includes a multicast transport session carrying a service,

wherein the service is processed based on a User Datagram Protocol/Internet Protocol (UDP/IP) a Generic Stream Encapsulation (GSE) protocol, and a physical layer protocol; and

generating Logical Layer Control, LLC, information based on the GSE protocol,

wherein the LLC information includes a multicast descriptor, wherein the multicast descriptor includes source address information, destination address information, source UDP port information, and destination UDP port information.