Methods and apparatus for content caching in a video network

• US 8,561,116 B2
• Filed: 09/26/2007
• Issued: 10/15/2013
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Inventors: Hasek, Charles A.
• Primary Examiner(s): SCHNURR, JOHN R
• Application Number:
  US11/904,375
• Publication Number:
  US 20090083279A1
• Time in Patent Office: 2,211 Days
• Field of Search: 725/91, 725/92, 725/93, 725/94, 725/95, 725/96, 725/97, 725/98
• US Class Current: 725/92
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04N 21/21815 comprising local storage units
• CPC Class Codes: H04N 21/2183 Cache memory caches in web servers or browsers G06F16/9574; intermediate storage and caching in data networks H04L67/568
• 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 21/23113 involving housekeeping operations for stored content, e.g. prioritizing content for deletion because of storage space restrictions storage management, e.g. defragmentation G06F3/0604; snloading stored programs G06F9/445; housekeeping operations in file systems, e.g. deletion policies G06F16/10; buffering arrangements in a network node or in an end terminal in packet networks H04L49/90
• CPC Class Codes: H04N 21/2343 involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements video transcoding H04N19/40; media packet handling at the source H04L65/762
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2407 Monitoring of transmitted content, e.g. distribution time, number of downloads arrangements for monitoring programmes for broadcast or for distribution combined with broadcast H04H20/14
• CPC Class Codes: H04N 21/2408 Monitoring of the upstream path of the transmission network, e.g. client requests monitoring data switching networks utilization H04L43/0876; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/252 Processing of multiple end-users' preferences to derive collaborative data
• CPC Class Codes: H04N 21/25833 involving client hardware characteristics, e.g. manufacturer, processing or storage capabilities allocation of resources considering hardware capabilities in multiprogramming arrangements G06F9/5044; allocation of resources considering software capabilities in multiprogramming arrangements G06F9/5055
• CPC Class Codes: H04N 21/25891 being end-user preferences retrieval of video data in a video database based on user preferences G06F16/739; arrangements for recognizing users' preferences H04H60/46; user profiles in network data switching protocols H04L67/306; processing of user preferences or user profiles in wireless networks H04W8/18
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/6582 Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number arrangements where receivers interact with the broadcast H04H20/38
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments
• CPC Class Codes: H04N 7/17345 : Control of the passage of the selected programme

Abstract

Methods and apparatus for selectively caching (and de-caching) video content in network so as to reduce content transformation requirements and also cache storage requirements. In one embodiment, a content caching controller associated with a content server differentiates content requests based on content attributes such as the requested codec format (e.g., MPEG or Windows Media), resolution, bitrate, and/or encryption type or security environment. If the content requested by a user is not available with the requested attribute(s), the content server transfers to content to the user by first transforming it. The content server also speculatively caches the transformed content locally, so that a future request for the same content with the same attributes can be filled by transferring without the intermediate transformation step. The controller allows the network operator to optimize use of available storage and transcoding resources.

Claims

1. A method of operating a network having a plurality of client devices associated therewith, the method comprising:

receiving from a first user a first request for a content element rendered in a first format;

generating a record of said first request for storage at a database;

providing to said first user said content element rendered in said first format;

determining whether to cache said content element in said first format;

at a subsequent point in time, not exceeding a predetermined time limit from receipt of said first request, receiving from a second user a second request for said content element rendered in a second format;

accessing said database to determine whether a record of a previous request for said content element has been made;

in response to an identification of said record, checking a cache for said content element irrespective of a format thereof;

when said content element is identified within said cache in said first format, transforming said content element rendered in said first format into said content element rendered in said second format;

caching said content element in said second format only when said second request is received within said predetermined time limit; and

providing said content element rendered in said second format.

2. The method of claim 1, wherein said network comprises a cable network, and at least some of said client devices comprise Internet Protocol (IP) enabled devices.

3. The method of claim 1, wherein said network comprises a cable network, and said transforming comprises transforming from an encoding of said first format to an encoding of said second format.

4. The method of claim 1, wherein said network comprises a cable network, and said transforming comprises transforming from a first bitrate to a second bitrate.

5. A method of operating a network having a plurality of substantially heterogeneous client devices associated therewith, the method comprising:

making available a plurality of different content elements;

receiving a first request for one of said content elements in a first particular format;

evaluating said first request to determine whether said first request can be serviced by using a previously transformed and cached version of said first requested content element, said previously transformed and cached version of said first requested content element comprising a version of said first requested content element which, upon a previous user request was transformed from a source version thereof, to a version encoded according to a second particular format and cached, said second particular format being different than said first particular format;

transforming said previously transformed and cached version of said first requested one of said content element a second time into a version rendered in said first particular format, and delivering said second transformed version; and

caching said second transformed version when it is determined that a user associated with said first request and a user associated with said previous user request have at least one characteristic in common.

6. The method of claim 5, wherein said network comprises a cable television network, and said first particular format comprises a particular video encoding type.

7. The method of claim 6, wherein said act of transforming comprises transcoding.

8. Network apparatus for use in a content delivery network, comprising:

a server configured to serve at least a plurality of video content elements;

a storage device configured to store said plurality of video content elements;

a transformation entity configured to transform individual ones of said plurality of video content elements from a first format to a second format; and

a controller operatively communicating with said server, said storage device, and said transformation entity, said controller configured to;

evaluate a first request by a first user for a content element rendered in a first format to determine whether said content element in said first format has been previously requested; and

evaluate a second request from a second user for said content element rendered in a second format, said controller caching said content element in said second format when said second request is received within a predetermined time limit from receipt of the first request, and said first user and said second user have at least one common characteristic.

9. The apparatus of claim 8, wherein said transformation entity is further configured to perform at least one of:

(i) transcription;

(ii) transcoding; and

/or (iii) transrating;

of content.

10. The apparatus of claim 9, wherein said evaluation of said first and second requests further comprises a determination of whether a requested one of said video content elements has been previously stored in said storage device in said second format.

11. The apparatus of claim 10, further comprising a database configured to store information relating to attributes of said video content elements stored on said storage device.

12. Network server apparatus for use in a content distribution network, the apparatus comprising:

a server configured to receive a plurality of content elements from a content source, and serve one or more of said content elements to one or more users of said network; and

a controller in operative communication with said server, said controller configured to;

evaluate a first request by a first user for a content element rendered in a first format to determine whether said first request can be serviced by using a previously transformed and cached version of said first content element;

when said evaluation indicates that said content in said first format has not previously been requested, cause transformation of said content from said first format to a second format to produce transformed content, and serve said first request using said transformed content;

generate a record of said first request for storage at a database and not caching said second format;

evaluate a second request by a second user for said content element rendered in said second format; and

identify an instance where said first user and said second user have at least one common characteristic, and based at least in part on said identification, cache said content element in said second format, and serve said second request using said transformed content.

13. The server apparatus of claim 12, wherein said server comprises a video on demand (VOD) server.

14. The server apparatus of claim 13, wherein said controller comprises a computer program stored on a storage entity of said server apparatus.

15. The server apparatus of claim 14, wherein said evaluation of said requests further comprises a determination of whether said content element has been previously stored in a storage device in said second format.