Patent ID: 11882340
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A content distribution system in which a midstream zone between a terminal and a content server in a web distribution system of unicast communication is connected by using a multicast communication network, the content distribution system comprising:
a unicast-multicast conversion device configured to convert unicast communication into multicast communication and send the multicast communication to the multicast communication network; and
a multicast-unicast conversion device configured to convert multicast communication transmitted through the multicast communication network into unicast communication, wherein
the multicast-unicast conversion device includes a processor and a storage medium having a computer program instructions stored herein, when executed by the processor, perform to:
(i) identify a content group from a plurality of content groups, receive, from the multicast communication network, a content transmitted by using any one or both of unicast and multicast communication schemes for each content group, and store a content included in the content group, (ii) transmit the content to the terminal based on a request from the terminal, and (iii) selectively make a demand for a content group including the content corresponding to the request from the terminal by any one or both of unicast and multicast communication schemes; and
the unicast-multicast conversion device includes a processor and a storage medium having a computer program instructions stored herein, when executed by the processor, perform to:
(i) receive the content received from the content server by using unicast communication and store the content, (ii) read the content group of the content corresponding to the demand of the multicast-unicast conversion device and transmit the content group to the multicast communication network by using any one or both of unicast and multicast communication schemes, and (iii) make a demand on the content server for the content group corresponding to the request from the multicast-unicast conversion device when the content group corresponding to the request from the multicast-unicast conversion device is not stored;
wherein the unicast-multicast conversion device divides the content into a plurality of blocks, stores the content in units of the divided blocks, and performs multicast or unicast transmission in the units of blocks, and when having received the blocks, the multicast-unicast conversion device restores the content by using the blocks.