Apparatus and methods for utilizing variable rate program streams in a network

• US 20070121678A1
• Filed: 11/30/2005
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Inc. (Charter Communications Incorporated)
• Inventors: Rieger, Remi, Brooks, Paul
• Granted Patent: US 7,889,765 B2
• Time in Patent Office: Days
• US Class Current: 370/505
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 2007/045 Fill bit or bits, idle words
• CPC Class Codes: H04N 21/2221 being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/23611 Insertion of stuffing data into a multiplex stream, e.g. to obtain a constant bitrate synchronisation arrangements in time-division multiplex systems using bit stuffing for systems with different or fluctuating information rates H04J3/073
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

Apparatus and methods for transparently using otherwise wasted bandwidth associated with variable-rate program streams to deliver additional content. In one embodiment, the network comprises a broadcast switched architecture (BSA), and the program streams are loaded up to a target rate using “null” packets and then delivered over the network infrastructure to a plurality of hub sites. The streams are then unloaded to reproduce the original variable streams, and the bandwidth vacated by removal of the null packets used as the transport mechanism for additional (e.g., non time-sensitive) content to be delivered to the subscribers. The process can also be substantially automated and anticipatory (through, e.g., transmission of null bit insertion data downstream). The invention can also advantageously be implemented with minimal modifications to existing infrastructure, and supports business and operational supervisory processes. Network server, QAM modulator, and CPE apparatus implementing the aforementioned methodologies are also disclosed.

Claims

1. A method of operating a broadcast switched architecture network, comprising:

receiving a plurality of variable-rate content streams at a first node of said network;

determining a target rate for said plurality of streams;

determining a required rate for each of said streams;

determining the amount of null data to be inserted into each of said streams based at least in part on said target rate and respective ones of said required rates;

inserting said null data into respective ones of said streams to produce a plurality of substantially constant rate streams;

transmitting said substantially constant rate streams over said network to a distribution node;

removing said null data from each of said substantially constant rate streams to substantially recover said variable rate streams;

inserting additional data either into said recovered streams, or in one or more new streams, in place of at least a portion of the bandwidth associated with said removed null data; and

distributing said streams, and said additional data, to a plurality of subscribers of said network.

2. The method of claim 1, wherein said additional data comprises non-time sensitive data, and said act of inserting additional data comprises:

determining the amount of null data removed from at least one of said streams; and

inserting an amount of said non-time sensitive data substantially similar to that of said null data removed into said at least one stream.

3. The method of claim 1, further comprising communicating information relating to the determined number of null data, said information being used at least for said act of removing.

4. The method of claim 3, wherein said information is further used during said act of inserting to provide anticipatory insertion of said additional data.

5. The method of claim 1, wherein said act of inserting additional data is performed on a time-delayed basis.

6. The method of claim 1, wherein said act of determining the amount of null data comprises subtracting the required rate for each stream from the target rate.

7. The method of claim 1, wherein said act of inserting additional data comprises inserting said additional data at a rate which is lower than the rate at which null data are removed from said stream so as to compensate for variations in removal or insertion timing.

8. The method of claim 1, wherein said act of inserting additional data either into said recovered streams, or in one or more new streams, comprises forming one or more additional transport streams substantially separate from said recovered streams, and said act of distributing said streams, and said additional data, to said plurality of subscribers comprises transmitting said recovered streams and additional transport streams over one or more QAM channels.

9. A method of transmitting both time-sensitive and non-time sensitive content over at least a portion of a content-based network, comprising:

receiving a plurality of variable-rate content streams at a first node of said network, said streams comprising time-sensitive content;

inserting a plurality of null data into at least one of said streams to produce one or more streams having a target bit rate;

transmitting said streams over said network to a distribution node;

removing said null data from each of said streams to substantially reproduce the original streams; and

transmitting non-time sensitive content along with said substantially reproduced streams on an as-available basis.

10. The method of claim 9, wherein said content-based network comprises a switched broadcast network, and said act of inserting non-time sensitive content comprises substantially matching the transmission rate of said non-time sensitive data to that of a rate of said of said null data.

11. The method of claim 9, wherein said act of transmitting streams comprises combining said plurality of streams including null data using an encapsulation protocol, and transmitting the combination directly or indirectly to a broadcast switching hub site.

12. Apparatus for optimizing bandwidth utilization in a broadcast switched, content-based network having at least one content transmission node and a plurality of hub sites, comprising:

a distribution-side process running on said at least one transmission node and adapted to receive a plurality of variable rate streams said data, said process being adapted to dynamically load at least some of said streams with a plurality of non-content data in order to achieve a substantially constant data rate for said streams;

a combining process adapted to combine said plurality of loaded streams onto a transport means for transmission to said hub sites;

a recovery process adapted to recover said plurality of loaded streams from said transport means;

a removal process adapted to remove at least a portion of said non-content data; and

an insertion process adapted to insert secondary data along with said streams;

wherein said insertion of said secondary content is based at least in part on the volume or rate of said non-content data loaded into said streams by said distribution-side process.

13. The apparatus of claim 12, wherein said at least one transmission node comprises a cable network head-end, and said plurality of hub sites each comprise at least one switch adapted to selectively switch a plurality of said program streams have said secondary content to individual ones or groups of said subscribers.

14. Modulator apparatus adapted for use in a broadcast switched digital network, said network having a distribution network in communication therewith and being adapted to carry a plurality of program streams, said apparatus comprising:

a processor;

a storage device in data communication with said processor;

a network interface adapted to at least receive loaded program streams from said distribution network; and

a computer program operative to run on said modulator apparatus, said computer program being adapted to;

receive said plurality of program streams;

identify and remove null data loaded into said loaded streams to obtain original variable rate streams therefrom;

insert secondary content along with said obtained variable rate streams; and

transmit said variable bit rate streams and said secondary content to a plurality of client devices downstream of said modulator apparatus.

15. The modulator apparatus of claim 14, wherein said transmission of said variable rate streams is performed using quadrature amplitude modulation (QAM).

16. The modulator apparatus of claim 14, wherein said loaded program streams comprise a plurality of content packets and at least one null packet, and said computer program is adapted to identify said null data based on a packet header of said at least one null packet.

17. Consumer premises equipment adapted for use in a cable network, comprising:

a processor;

a storage device in data communication with said processor;

a network interface in signal communication with said processor, said interface adapted to receive one or more signal streams from said cable network, said signal streams comprising primary content and non-time sensitive secondary content; and

a computer program operative to run on said processor, said computer program being configured to;

(a) identify at least a portion of said secondary content associated with said one or more streams;

(b) extract said identified at least portion of said secondary content; and

(c) store at least a portion of said extracted content in said storage device.

18. The consumer premises equipment of claim 17, further comprising tuner apparatus, said tuner apparatus adapted to receive quadrature amplitude modulated signals comprising said signal streams, and decoder apparatus configured to decode at least said primary content, said decoding being performed substantially contemporaneously with said identification and extraction of said secondary content.

19. The consumer premises equipment of claim 18, wherein said identification of said secondary content is based at least in part on one or more packet headers belonging to packets of which said secondary content is part.

20. The consumer premises equipment of claim 19, wherein said packets are routed to a computerized device based at least in part on an Internet Protocol (IP) transport mechanism.

21. The consumer premises equipment of claim 17, wherein said equipment further comprises a demultiplexer adapted to demultiplex said one or more streams.

22. A method of doing business within a content based network, said network being adapted to provide a plurality of variable rate program streams having at least video and audio portions to a plurality of subscribers having a client device coupled to said network, the method comprising:

selectively adding overhead to at least a portion of said streams to produce second streams;

transmitting said second streams to a distribution node of said network;

removing at least a portion of said overhead from said second streams;

selectively inserting secondary data along with said at least video and audio portions to create third streams; and

transmitting said third streams to at least one of said plurality of subscribers;

wherein said act of selectively inserting is performed substantially in response to said at least one subscriber selecting said secondary data for download.

23. The method of claim 22, wherein said download of said secondary data is performed in exchange for valuable consideration given by said at least one subscriber.

24. The method of claim 22, wherein the ability to perform a plurality of ones of said download of said secondary data is provided in exchange for valuable consideration given by said at least one subscriber pursuant to a subscription.

25. The method of claim 22, wherein said network comprises a broadcast switched architecture (BSA) network, and said transmitting comprises selectively switching one or more of said third streams for delivery to said at least one subscriber.

26. Network apparatus for use in a content-based network for receiving streams containing content and for transmitting secondary data to a set of customer premises equipment, said network apparatus comprising:

receiving apparatus adapted to receive a plurality of substantially constant rate data streams, said stream each including a variable rate stream and a plurality of null data;

processing apparatus adapted to remove at least a portion of said null data to substantially recover said variable rate streams, and insert secondary data at least along with said recovered streams; and

a server for supplying said secondary data to said processing apparatus.

27. The network apparatus as set forth in claim 26, wherein said processing apparatus generates information indicating an amount or rate of null data removed from said data streams, and said server provides said secondary data to said processing apparatus in an amount or rate that is less than or equal to said amount or rate of null data removed based at least in part on said information.

28. The network apparatus as set forth in claim 26, wherein said network apparatus receives information indicating an amount or rate of null data inserted into said data streams, and said server provides said secondary data to said processing apparatus in an amount or rate that is less than or equal to said amount or rate of null data removed based at least in part on said information

29. The network apparatus as set forth in claim 26, further comprising a buffer for queuing said secondary data before insertion by said processing apparatus.

30. The network apparatus as set forth in claim 26, wherein said network comprises a broadcast switched architecture (BSA), and said substantially constant rate streams are delivered via a switched data link.

31. The network apparatus as set forth in claim 26, wherein said server determines an amount or rate of said secondary data to insert at least along with one or more of said recovered streams.

32. The network apparatus as set forth in claim 26, wherein said processing apparatus comprise a QAM modulator, said modulator being adapted to transmit said recovered streams, at least one of which contains said secondary data, via a portion of said network to one or more of said premises devices.

33. The network apparatus as set forth in claim 26, wherein said insertion of said secondary data comprises inserting secondary data to achieve a second substantially constant data rate.

34. The network apparatus as set forth in claim 26, wherein said secondary data comprises non-time sensitive data selected from the group consisting of:

(i) application program files;

(ii) image data files, or (iii) audio data files.

35. The network apparatus as set forth in claim 26, wherein said secondary data comprises time-sensitive data, and said processing apparatus is adapted to determine in advance of said insertion of said time-sensitive data whether said a temporal requirement associated with said time-sensitive data can be accommodated.

36. The network apparatus as set forth in claim 26, wherein said substantially constant rate streams comprise a plurality of content packets and at least one null packet, and at least one of said server or processing apparatus comprises a computer program adapted to identify said null data based on a packet header of said at least one null packet.

37. The network apparatus as set forth in claim 26, wherein said insertion of secondary data at least along with said recovered streams comprises forming at least one separate transport stream to carry said secondary data.

38. A method of operating a content-based network, comprising:

providing information regarding at least one rate associated with a plurality of variable rate content streams as a function of time;

providing a maximum rate associated with said streams;

inserting data substantially in place of available bandwidth based at least in part on the information and said maximum rate; and

distributing the streams and data to at least one subscriber of the network.