CONTENT DELIVERY SYSTEM, CACHE SERVER, AND CONTENT DELIVERY METHOD

摘要

A cache server includes an accumulation unit that accumulates a content(s) stored in a delivery server apparatus. The cache server, by using information included in a request message from a mobile terminal, determines which one of the cache servers arranged on a mobile network accumulates a content requested by the mobile terminal. The cache server reads a file corresponding to the requested content from the determined cache server and outputs the file to the accumulation unit. In addition, the cache server estimates a bandwidth of the mobile network based on a signal from the mobile terminal, reads the file corresponding to the requested content from the accumulation unit, and extracts a stream from the file. The cache server generates a stream by deleting at least part of frames from the stream so that a bit rate of the generated stream does not exceed the band. The cache server stores the generated stream in a packet and transmits the packet to the mobile terminal.

主权项

1. A content delivery system, comprising:
a plurality of cache servers on a mobile network; wherein each of the plurality of cache servers comprises: a temporary content accumulation unit that temporarily accumulates at least part of contents stored in a delivery server apparatus delivering a content(s) on the Internet; a determination unit that by using information included in a content request message from a mobile terminal determines which one of the plurality of cache servers accumulates a content requested by the mobile terminal; a content acquisition unit that reads a file corresponding to the requested content from the determined cache server and outputs the file to the temporary content accumulation unit; and a delivery unit that estimates a bandwidth of the mobile network based on a predetermined signal from the mobile terminal, reads the file corresponding to the requested content from the temporary content accumulation unit, extracts a stream from the file, generates a stream by deleting at least part of frames from the stream so that a bit rate of the generated stream does not exceed the bandwidth, stores the generated stream in a packet, and transmits the packet to the mobile terminal; wherein, if the delivery unit receives a response packet from the mobile terminal in response to a transmitted packet transmitted to the mobile terminal, the delivery unit estimates the bandwidth of the mobile network based on a difference between a transmission time of the transmitted packet and a reception time of the response packet and based on a size of the transmitted packet.