US 12,034,558 B2
Content distribution system, multicast unicast / multicast multicast converter, multicast unicast converter, content distribution method and content distribution program
Toshihito Fujiwara, Musashino (JP); Yasunobu Kasahara, Musashino (JP); and Satoshi Ikeda, Musashino (JP)
Assigned to NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Appl. No. 17/627,845
Filed by NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
PCT Filed Jul. 23, 2019, PCT No. PCT/JP2019/028909
§ 371(c)(1), (2) Date Jan. 18, 2022,
PCT Pub. No. WO2021/014591, PCT Pub. Date Jan. 28, 2021.
Prior Publication US 2022/0263673 A1, Aug. 18, 2022
Int. Cl. H04L 12/18 (2006.01); H04L 67/02 (2022.01)
CPC H04L 12/185 (2013.01) [H04L 67/02 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A content delivery system in which a terminal and a content server are connected through an intermediate section using a multicast communication network in a unicast communication web delivery system, the content delivery system comprising:
a unicast-multicast converting apparatus includes a computer processor and a storage medium having first computer-executable instructions executed by the computer processor, wherein the first instructions perform to convert a communication from a unicast communication to a multicast communication to send the communication to a first multicast communication network for transmitting a multicast communication;
a multicast-unicast/multicast-multicast converting apparatus includes a computer processor and a storage medium having second computer-executable instructions executed by the computer processor, wherein the second instructions perform to send to a second multicast communication network for transmitting, again in multicast communication, the communication transmitted in a multicast manner in the first multicast communication network; and
a multicast-unicast converting apparatus includes a computer processor and a storage medium having third computer-executable instructions executed by the computer processor, wherein the third instructions perform to convert the communication transmitted in the multicast manner in the second multicast communication network to a unicast communication,
wherein the third instructions of the multicast-unicast converting apparatus includes perform to:
a first content receiving cache unit configured to identify content groups each including a plurality of contents grouped, receive content transmitted using either one or both of unicast communication and multicast communication schemes for each of the content groups from the second multicast communication network, and store the content included in the content group,
a unicast transmission unit configured to transmit content in unicast communication from the first content receiving cache unit included in the multicast-unicast converting apparatus in response to a request from a first terminal connected through the second multicast communication network, and
a first content request unit configured to selectively make, in a case that content corresponding to the request from the first terminal is not stored in the first content receiving cache unit, a requisition for a content group including the content corresponding to the request, using either one or both of unicast communication and multicast communication schemes,
the second instructions of the multicast-unicast/multicast-multicast converting apparatus perform as:
a second content receiving cache unit configured to-identify the content group, receive content transmitted using either one or both of unicast communication and multicast communication schemes for each of the content groups from the first multicast communication network, and store the content included in the content group,
a unicast transmission unit configured to transmit content from the second content receiving cache unit included in the multicast-unicast/multicast-multicast converting apparatus in unicast communication in response to the request from the first terminal,
a first content transmission unit configured to transmit content from the second content receiving cache unit included in the multicast-unicast/multicast-multicast converting apparatus using either one or both of unicast communication and multicast communication schemes for each of the content groups in response to a request from the multicast-unicast converting apparatus, and
a second content request unit configured to selectively make, in a case that content corresponding to the request from the first terminal or the multicast-unicast converting apparatus is not stored in the second content receiving cache unit, a requisition for a content group including the content corresponding to the request using either one or both of unicast communication and multicast communication schemes, and
the first instructions of the unicast-multicast converting apparatus perform to:
a unicast receiving cache unit configured to receive content in unicast communication from the content server and store the content,
a second content transmission unit configured to read, from the unicast receiving cache unit, a content group corresponding to the request from the multicast-unicast converting apparatus or the multicast-unicast/multicast-multicast converting apparatus, and transmit the read content group to the first multicast communication network using either one or both of unicast communication and multicast communication schemes, and
a unicast request unit configured to make, in a case that the content group corresponding to the request from the multicast-unicast converting apparatus or the multicast-unicast/multicast-multicast converting apparatus is not stored in the unicast receiving cache unit, a requisition to the content server for the content group corresponding to the request from the multicast-unicast converting apparatus or the multicast-unicast/multicast-multicast converting apparatus in unicast communication.