Content delivery system and content delivery method

• US 9,763,133 B2
• Filed: 07/04/2012
• Issued: 09/12/2017
• Est. Priority Date: 07/05/2011
• Status: Active Grant

• Current Assignee: Rakuten Group, Inc.
• Original Assignee: Rakuten, Inc. (Rakuten Group, Inc.)
• Inventors: Ozawa, Kazunori
• Primary Examiner(s): Yao, Kwang B
• Assistant Examiner(s): Patel, Hardikkumar
• Application Number:
  US14/130,850
• Publication Number:
  US 20140146669A1
• Time in Patent Office: 1,896 Days
• Field of Search: None
• CPC Class Codes: G06F 13/00 Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units interface circuits for specific input/output devices G06F3/00 ; multiprogram control therefor G06F9/46; multiprocessor systems G06F15/16
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/0894 Packet rate
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04N 21/231 Content storage operation, e.g. caching movies for short term storage, replicating data over plural servers, prioritizing data for deletion
• CPC Class Codes: H04N 21/23103 using load balancing strategies, e.g. by placing or distributing content on different disks, different memories or different servers storage management G06F3/0604; allocation of resources considering the load in multiprogramming arrangements G06F9/505; techniques for rebalancing the load in a distributed system G06F9/5083; access to distributed or replicated servers, e.g. load balancing, in data networks H04L67/1001
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04W 28/0273 adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A plurality of cache servers, connected to a packet forwarding apparatus, forwarding a packet transmitted and received between a storage apparatus that holds a content under management in store and a user terminal, temporarily holds at least part of the content under management in store. A controller decides an on-screen resolution at the terminal, based on information contained in a content request message from the terminal, and selects a cache server that holds a content of the on-screen resolution in store. The controller instructs the selected cache server to deliver the content. The cache server instructed calculates a bit rate based on a signal received from the terminal. The cache server reads content from the terminal, which is to have the on-screen resolution and a bit rate not higher than the calculated bit rate. The content is stored in a packet and transmitted, then delivered without reducing the user'"'"'s QoE.

Claims

1. A content delivery system, comprising, on a mobile network:

a plurality of cache servers connected to at least one of a plurality of packet forwarding apparatuses configured to forward packets between a storage apparatus holding a content under management in store, and a user terminal;

the plurality of cache servers caching at least part of the content under management in store stored in the storage apparatus; and

a controller that controls the plurality of cache servers, the controller comprises;

an on-screen resolution calculation unit that, based on a signal received from the user terminal requesting the content, calculates the on-screen resolution of the user terminal; and

selects a cache server from the plurality of cache servers based on the on-screen resolution of the user terminal to transmit the content;

wherein the selected cache server comprises;

a bit rate calculation unit that, based on the signal received from the user terminal, calculates a bit rate with which the content is sent out based on Transmission Control Protocol (TCP) response signal received from the user terminal; and

a transmission unit that reads out a file or a stream of the content requested from the user terminal, the file or the stream read out having a bit rate not higher than the calculated bit rate, stores the file or the stream in a packet of a predetermined protocol, and outputs the packet.

2. The content delivery system according to claim 1, wherein the bit rate calculation unit measures a response time of a packet as a difference between a time point of transmission of a pre-set packet from the transmission unit and a time point of reception from the user terminal of the TCP response signal for the pre-set packet to calculate the bit rate based on the response time.

3. The content delivery system according to claim 1, wherein the controller extracts a plurality of cache servers that store the content of the on-screen resolution, out of the plurality of cache servers, and selects a cache server out of the plurality of cache servers extracted, depending on in-service-area information for the user terminal.

4. The content delivery system according to claim 1, wherein the plurality of packet forwarding apparatuses are respectively Serving General packet radio service Support Node (SGSN) apparatuses, Gateway General packet radio service Support Node (GGSN) apparatuses or SGSN/GGSN apparatuses in the mobile network, Serving Gateway (S-GW) apparatuses, Packet data network Gateway (P-GW) apparatuses or S/P-GW apparatuses in a mobile Long Term Evolution (LTE)/Evolved Packet Core (EPC) network.

5. The content delivery system according to claim 1, wherein the content under management includes at least one of a moving picture, a still picture, voice, audio, software, application and data.

8. The content delivery system according to claim 2, wherein the plurality of packet forwarding apparatuses are respectively Serving General packet radio service Support Node (SGSN) apparatuses, Gateway General packet radio service Support Node (GGSN) apparatuses or SGSN/GGSN apparatuses in the mobile network, Serving Gateway (S-GW) apparatuses, Packet data network Gateway (P-GW) apparatuses or S/P-GW apparatuses in a mobile Long Term Evolution (LTE)/Evolved Packet Core (EPC) network.

9. The content delivery system according to claim 2, wherein the content under management includes at least one of a moving picture, a still picture, voice, audio, software, application and data.

10. The content delivery system according to claim 4, wherein the content under management includes at least one of a moving picture, a still picture, voice, audio, software, application and data.

6. A content delivery method, comprising:

by a plurality of cache servers, connected to at least one of a plurality of packet forwarding apparatuses configured to forward packets between a storage apparatus holding a content under management in store, and a user terminal, caching at least part of the content under management in store stored in the storage apparatus;

by a controller, calculating an on-screen resolution of the user terminal, based on a signal received from the user terminal requesting the content;

by the controller, selecting a cache server from the plurality of cache servers, based on the on-screen resolution of the user terminal to transmit the content;

by the selected cache server, instructed by the controller, calculating a bit rate with which the content is sent out, based on the signal received from the user terminal; and

by the selected cache server, reading out a file or a stream of the content requested from the user terminal and having a bit rate not higher than the calculated bit rate, storing the file or the stream in a packet of a predetermined protocol, and outputting the packet,

wherein the selected cache server calculates the bit rate based on a Transmission Control Protocol (TCP) response signal received from the user terminal.

7. The content delivery method according to claim 6, wherein

the cache server instructed measures a response time of a packet as a difference between a time point of transmission of a pre-set packet from the transmission unit and a time point of reception from the user terminal of the TCP response signal for the pre-set packet, and calculates the bit rate based on the response time.