Communication system and method for distributing content

A transmitting device which transmits a content to a receiving device, the transmitting device comprising:

• a first content receiver configured to receive, via a first communication path, a Multicast frame which stores the content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• a converter configured to convert the received Multicast frame into a Unicast frame addressed to the receiving device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame, the Unicast frame also having a Media Access Control (MAC) address of the receiving device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• and
• a first content transmitter configured to transmit the converted Unicast frame to the receiving device via a second communication path, based on a protocol having a re-transmission processing,
• wherein the re-transmission processing is performed at a Media Access Control (MAC) layer that is a layer lower than a layer of a communication protocol defining the Multicast frame.

A receiving device which receives a content transmitted from a transmitting device,

• wherein the transmitting device includes:
• a first content receiver configured to receive, via a first communication path, a Multicast frame which stores the content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• a first converter configured to convert the received Multicast frame into a Unicast frame addressed to the receiving device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame, the Unicast frame also having a Media Access Control (MAC) address of the receiving device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• and
• a first content transmitter configured to transmit the converted Unicast frame to the receiving device via a second communication path, based on a protocol having a re-transmission processing, and
• the receiving device comprising:
• a second content receiver configured to receive the Unicast frame transmitted from the transmitting device based on the protocol having the re-transmission processing;
• and
• a second converter configured to convert the Unicast frame received by the second content receiver to a Multicast frame,
• wherein the re-transmission processing is performed at a Media Access Control (MAC) layer that is a layer lower than a layer of a communication protocol defining the Multicast frame.

A communication method for transmitting a content to a receiving device, the communication method comprising:

• receiving, via a first communication path, a Multicast frame which stores a content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• converting the received Multicast frame into a Unicast frame addressed to the receiving device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame, the Unicast frame also having a Media Access Control (MAC) address of the receiving device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• and
• transmitting the converted Unicast frame to the receiving device via a second communication path, based on a protocol having a re-transmission processing,
• wherein the re-transmission processing is performed at a Media Access Control (MAC) layer that is a layer lower than a layer of a communication protocol defining the Multicast frame.

A content distribution system for distributing a content to a seat in the content distribution system, the content distribution system comprising:

• a first communication device and a second communication device,
• wherein the first communication device includes:
• a first content receiving unit operable to receive, via a first communication path, a Multicast frame which stores a content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• a conversion unit operable to convert the received Multicast frame into a Unicast frame addressed to the second communication device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame, the Unicast frame also having a Media Access Control (MAC) address of the second communication device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• and
• a first content transmission unit operable to transmit the converted Unicast frame to the second communication device via a second communication path, based on a protocol having a re-transmission processing, and
• the second communication device includes:
• a second content receiving unit operable to receive the Unicast frame transmitted from the first communication device via the second communication path based on the protocol having the re-transmission processing;
• and
• a second content transmission unit operable to transmit the content included in the Unicast frame received by the second content receiving unit to the seat,
• wherein the re-transmission processing is performed at a Media Access Control (MAC) layer that is a layer lower than a layer of a communication protocol defining the Multicast frame.

A communication method which is performed by a communication system including a first communication device and a second communication device, the communication method comprising:

• receiving, by the first communication device, via a first communication path, a Multicast frame which stores a content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• converting, by the first communication device, the received Multicast frame into a Unicast frame addressed to the second communication device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame the Unicast frame also having a Media Access Control (MAC) address of the second communication device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• transmitting, by the first communication device, the converted Unicast frame to the second communication device via a second communication path, based on a protocol having a re-transmission processing;
• and
• receiving, by the second communication device, the Unicast frame transmitted via the second communication path from the first communication device based on the protocol having the re-transmission processing,
• wherein the re-transmission processing is performed at a layer lower than a layer of a communication protocol defining the Multicast frame.

A communication method which is performed by a receiving device which receives a content transmitted from a transmitting device,

• the transmitting device executing:
• receiving, via a first communication path, a Multicast frame which stores the content and has a Multicast IP address as a destination address at a Network Layer of the Multicast frame;
• converting the received Multicast frame into a Unicast frame addressed to the receiving device, the Unicast frame having only one IP header storing only one Multicast IP address, which is the same as the Multicast IP address of the Multicast frame, as a destination address at a Network Layer of the Unicast frame, the Unicast frame also having a Media Access Control (MAC) address of the receiving device as a destination address at a Data Link Layer of the Unicast frame, the only one Multicast IP address in the Unicast frame being stored in an IP header of the Unicast frame, the MAC address in the Unicast frame being stored in a MAC header of the Unicast frame, the IP header and the MAC header being adjacent to each other with no information therebetween, and the IP header storing the Multicast IP address, wherein there is no IP address between the Multicast IP address stored in the IP header and the MAC header;
• and
• transmitting the converted Unicast frame to the receiving device via a second communication path, based on a protocol having a re-transmission processing,
• the communication method comprising:
• receiving, by the receiving device, the Unicast frame transmitted from the transmitting device based on the protocol having the re-transmission processing;
• and
• converting, by the receiving device, the received Unicast frame to a Multicast frame,
• wherein the re-transmission processing is performed at a Media Access Control (MAC) layer that is a layer lower than a layer of a communication protocol defining the Multicast frame.