METHODS AND APPARATUS FOR CONTENT CACHING IN A VIDEO NETWORK

• US 20090083279A1
• Filed: 09/26/2007
• Published: 03/26/2009
• 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.
• Granted Patent: US 8,561,116 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 a request for a content element rendered in a first format;

determining whether said request comprises a first request for said content element rendered in said first format within a period of time;

if said determining indicates that said request comprises the first request within said period of time, then transforming a source content element into said content element rendered in said first format; and

if said determining indicates that said request is not the first request for said content element rendered in said first format within said period of time, then checking a cache for said content element rendered in said first format.

2. The method of claim 1, wherein if said content element rendered in said first format is not stored within said cache, transforming said source content element into said content element rendered in said first format, and caching said transformed content element.

3. The method of claim 1, wherein if said content element rendered in said first format is stored within said cache, serving said request from said cache.

4. 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.

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

6. 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.

7. Network apparatus for use is a cable network, comprising:

a server adapted to serve at least video content elements;

a storage device adapted to store a plurality of video content elements;

a transformation entity adapted to transform ones of said video content elements from a first form to a second form; and

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

wherein said controller is adapted to evaluate requests for said video content elements to determine whether said ones of said content elements in said second form should be stored in said storage device or not.

8. The apparatus of claim 7, wherein said transformation entity is adapted to perform at least one of:

(i) trancryption;

(ii) transcoding; and

(iii) transrating.

9. The apparatus of claim 8, wherein said controller comprises a computer program, and said evaluation of said requests comprises determining whether a requested one of said video content elements has been previously requested at a predetermined frequency or higher.

10. The apparatus of claim 8, wherein said evaluation of said requests comprises determining whether a requested one of said video content elements has been previously stored in said storage device in said second form.

11. The apparatus of claim 7, further comprising a database adapted to store information relating to attributes of said video content elements stored on said storage device.

12. A method of operating a content-based network having a content storage device and a plurality of client devices associated therewith, comprising:

selectively and temporarily storing a plurality of content elements within said storage device;

selectively removing ones of said content elements from said storage device when one or more criteria for removal are met, said criteria relating at least in part to requests for said content elements from said plurality of client devices.

13. The method of claim 12, wherein said one or more criteria comprises the frequency of request for said ones of said content elements falling below a predetermined threshold.

14. The method of claim 12, wherein said network comprises a cable television network, and said plurality of devices have a plurality of different decoding and bitrate capabilities, said selective storing of said plurality of content elements being based at least in part on plurality of different decoding and bitrate capabilities.

15. The method of claim 12, wherein said selectively removing comprises removing said ones of said content elements according to a priority scheme or hierarchy.

16. The method of claim 12, wherein said selective removal is performed only when storage space restrictions exist which necessitate said removal.

17. 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 request for one of said content elements in a particular format;

evaluating said request to determine whether said request can be serviced by using a cached version of said requested content element rendered in said particular format; and

where said request cannot be serviced using a cached version, transforming another version of said requested one of said content element into a version rendered in said particular format, and delivering said transformed version.

18. The method of claim 17, wherein said network comprises a cable television network, and said particular format comprises a particular video encoding type.

19. The method of claim 18, wherein said transforming comprises transcoding.

20. The method of claim 17, further comprising speculatively caching said transformed version based at least in part on a prediction of future demand for said transformed version.

21. The method of claim 17, further comprising:

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

caching said transformed version based at least in part on said second request.

22. Network server apparatus for use is a cable network, comprising:

a server adapted to receive video content in a first format from a content source, and serve said video content to one or more users of said network;

a controller operatively communicating with said server, said controller adapted to evaluate requests for said video content from said users to determine whether to;

serve an individual one of said content requests from a storage device associated with server;

cause transformation of said content from said first format to a second format to produce transformed content, and serve said one request using said transformed content, and not cache said transformed content;

or

cause transformation of said content from said first format to a second format to produce transformed content, and serve said one request using said transformed content, and cache said transformed content for use in serving a subsequent request for said video content in said second format.

23. The server apparatus of claim 22, wherein said server comprises a video on demand (VOD) server.

24. The server apparatus of claim 23, wherein said controller comprises a computer program, and said evaluation of said requests comprises determining whether said video content has been previously requested at a predetermined frequency or higher.

25. The server apparatus of claim 24, wherein said evaluation of said requests comprises determining whether said video content has been previously stored in a storage device in said second format.