DISTRIBUTING DIGITAL VIDEO CONTENT TO MULTIPLE END-USER DEVICES

• US 20090249421A1
• Filed: 03/26/2008
• Published: 10/01/2009
• Est. Priority Date: 03/26/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pickens, John, Liu, Xiaomei, Bernstein, Alon
• Granted Patent: US 8,468,572 B2
• Time in Patent Office: Days
• US Class Current: 725/116
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/41 by acting on aggregated flows or links
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/56 implementing delay-aware scheduling
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/722 at the destination endpoint, e.g. reservation of terminal resources or buffer space
• CPC Class Codes: H04L 47/745 Reaction in network
• CPC Class Codes: H04L 47/788 Autonomous allocation of resources
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9023 for implementing a jitter-buffer
• CPC Class Codes: H04L 49/9047 including multiple buffers, e.g. buffer pools
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/4344 Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• 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 21/64792 : Controlling the complexity of the content stream, e.g. by dropping packets intermediate media network packet handling H04L65/765; proxy provisioning conversion or adaptation for reducing the amount or size of exchanged application data H04L67/5651; negotiation of resources in wireless networks H04W28/16

Abstract

A technique for managing the distribution of digital video content to multiple end-user devices is disclosed. The technique involves statistically multiplexing multiple VBR encoded video streams into an access channel, such as a data over cable service interface specifications (DOCSIS) bonded group, and utilizing quality of service capabilities of an edge device, such as a cable modem termination system (CMTS) or an edge quadrature amplitude modulation (QAM) device, to buffer and schedule IP packets, which carry the VBR encoded video streams, so that packets are not dropped during periods of congestion. Utilizing the quality of service capabilities of an edge device makes it possible to statistically multiplex VBR encoded video streams in a narrowcast application such as Video on Demand (VOD) or Switched Digital Video (SDV) while eliminating the need for process intensive transrating/transcoding operations.

Claims

1. A method for distributing digital video content to multiple end-users, the method comprising:

encoding video streams using variable bitrate (VBR) encoding;

encapsulating the VBR encoded video streams in Internet Protocol (IP) packets;

identifying an access channel, wherein the access channel is associated with a bandwidth limitation;

admitting a plurality of the VBR encoded video streams to the access channel, wherein a sum of peak rates from all of the admitted VBR encoded video streams exceeds the bandwidth limitation of the access channel;

using buffering and scheduling of the IP packets to manage periods when bandwidth demand from the admitted VBR encoded video streams exceeds the bandwidth limitation of the access channel;

transmitting the VBR encoded video streams to at least one IP-compatible end-user device via the access channel; and

de-encapsulating the VBR encoded video stream from the IP packets at the IP-compatible end-user device.

2. The method of claim 1 wherein the VBR encoded video streams are admitted to the access channel based on post-buffering data rates.

3. The method of claim 1 wherein the IP packets are buffered and scheduled at an edge device.

4. The method of claim 3 wherein VBR encoded video streams are admitted to the access channel based on mean bitrates of the VBR encoded video streams, post buffering peak-to-mean ratios of the VBR encoded video streams, the number of VBR encoded video streams in the access channel, or a pre-established packet drop probability.

5. The method of claim 4 wherein the edge device is a cable modem termination system (CMTS) and wherein the VBR encoded video streams are transmitted to cable modems (CMs) using data over cable service interface specifications (DOCSIS), wherein the access channel is associated with a DOCSIS bonded group.

6. The method of claim 3 further comprising identifying a jitter tolerance at the IP-compatible end-user device and buffering the VBR encoded video streams at the edge device, wherein the VBR encoded video streams are buffered at the edge device such that the end-to-end jitter experienced by the VBR encoded video streams is less than the jitter tolerance at the IP-compatible end-user device.

7. The method of claim 1 further comprising decoding the VBR encoded video stream and displaying the video stream.

8. The method of claim 1 further comprising adjusting the peak to mean ratio of a VBR encoded video stream in order to adjust the efficiency with which the access channel is utilized.

9. A system for distributing digital video content to multiple end-users, the system comprising:

an edge device configured to receive video streams that are encoded using variable bitrate (VBR) encoding and encapsulated in Internet Protocol (IP) packets; and

end-user devices configured to receive and buffer IP packets of VBR encoded video streams and to de-encapsulate the VBR encoded video streams;

wherein the edge device is further configured to;

admit a plurality of the VBR encoded video streams to an access channel, wherein the access channel has a bandwidth limitation and wherein a sum of peak rates from all of the admitted video streams exceeds the bandwidth limitation of the access channel;

use buffering and scheduling of the IP packets to manage periods when bandwidth demand from the admitted VBR encoded video streams exceeds the bandwidth limitation of the access channel; and

transmit the VBR encoded video streams to the end-user devices in the IP packets.

10. The system of claim 9 wherein the edge device admits the VBR encoded video streams to the access channel based on post-buffering data rates.

11. The system of claim 10 wherein the edge device is a cable modem termination system (CMTS) and the end-user devices are IP set top boxes (STBs).

12. The system of claim 11 wherein the CMTS distributes the IP packets to cable modems (CMs) using data over cable service interface specifications (DOCSIS) and wherein the access channel is a DOCSIS bonded group.

13. The system of claim 9 wherein the edge device admits VBR encoded video streams to the access channels based on mean bitrates of the VBR encoded video streams, post buffering peak-to-mean ratios of the VBR encoded video streams, the number of VBR encoded video streams in the access channel, or a pre-established packet drop probability.

14. The system of claim 13 wherein the edge device is a cable modem termination system (CMTS) and wherein the VBR encoded video streams are transmitted to cable modems (CMs) using data over cable service interface specifications (DOCSIS), wherein the access channel is a DOCSIS bonded group.

15. The system of claim 9 wherein the end-user devices have a jitter tolerance and wherein the VBR encoded video streams are buffered at the edge device, the VBR encoded video streams being buffered at the edge device such that the end-to-end jitter experienced by the VBR encoded video streams is less than the jitter tolerance at the end-user devices.

16. The system of claim 9 further comprising encoded video sources connected to provide the VBR encoded video streams to the edge device, wherein the encoded video sources are controlled to adjust the peak to mean ratio of VBR encoded video streams in order to adjust the efficiency with which the access channel is utilized.

17. A method for distributing digital video content to multiple end-users, the method comprising:

encoding video streams using variable bitrate (VBR) encoding;

encapsulating the VBR encoded video streams in Internet Protocol (IP) packets;

transmitting the IP packets to an edge device;

identifying an access channel that is used by the edge device;

buffering the IP packets within the edge device;

admitting a plurality of the VBR encoded video streams to the access channel using bitrate information related to the VBR encoded streams, wherein the bitrate information reflects post-buffering bitrates of the VBR encoded streams;

transmitting the VBR encoded video streams to at least one IP-compatible end-user device; and

de-encapsulating the VBR encoded video streams from the IP packets at the end-user device.

18. The method of claim 17 further comprising adjusting the peak to mean ratio of a VBR encoded video stream in order to adjust the efficiency with which the access channel is utilized.

19. The method of claim 17 wherein the access channel is associated with a bandwidth limitation and wherein a sum of peak rates from all of the admitted video streams exceeds the bandwidth limitation of the access channel.

20. The method of claim 17 wherein the edge device is a cable modem termination system (CMTS) and wherein the VBR encoded video streams are transmitted to cable modems (CMs) using data over cable service interface specifications (DOCSIS), wherein the access channel is associated with a DOCSIS bonded group.