Fast channel change on a bandwidth constrained network

• US 8,769,591 B2
• Filed: 02/12/2007
• Issued: 07/01/2014
• Est. Priority Date: 02/12/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Gahm, Joshua Bernard, Oran, David R., Sharma, Kapil
• Primary Examiner(s): TAYLOR, JOSHUA D
• Application Number:
  US11/674,093
• Publication Number:
  US 20080192839A1
• Time in Patent Office: 2,696 Days
• Field of Search: None
• US Class Current: 725/95
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/188 the unit being a video data packet, e.g. a network abstraction layer [NAL] unit
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/23418 involving operations for analysing video streams, e.g. detecting features or characteristics television picture signal circuitry for scene change detection H04N5/147; filtering for image enhancement G06T5/00; methods or arrangements for recognising scenes G06V20/00; arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• 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 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• 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 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/6408 Unicasting

Abstract

In one embodiment, a buffering server transfers a dynamic burst transfer of data encoded using an inter-coded compression technique. The dynamic burst transfer is timed so that an initial transfer rate is reduced to a remaining transfer rate at the same time or before a decoding endpoint joins a corresponding data stream. The decoding endpoint merges the video stream and the dynamic burst transfer to decode and quickly reconstruct a displayable video frame.

Claims

1. A method, comprising:

transmitting a burst transfer to a remote endpoint, the burst transfer including data packets extracted from a video stream;

wherein the burst transfer is a continuous data stream that includes an initial portion at an initial transfer rate ((1+E)R) and a subsequent portion at a reduced subsequent transfer rate (ER), wherein R is a transfer rate of the video stream and E is a fraction amount of excess bandwidth;

wherein transmission of the subsequent portion of the burst transfer begins at the transition instant and continues through a time that the remote endpoint actually joins the video stream;

wherein the burst transfer begins at an intra-coded frame;

wherein the initial portion includes the data packets from the intra-coded frame to a first latest occurring data packet (N);

wherein the subsequent portion includes the data packets from the first latest occurring data packet (N) to a second latest occurring data packet (Z), wherein the second latest occurring data packet is determined as;

2. The method of claim 1, further comprising:

identifying a bandwidth capability of a link used to transmit the burst transfer to the remote endpoint;

identifying a transfer rate of the video stream; and

selecting the initial transfer rate based on the bandwidth capability of the link and the transfer rate of the video stream.

3. The method of claim 1, further comprising:

determining a request time for the remote endpoint to transmit a request to join the video stream; and

transmitting a message to the remote endpoint to identify the determined request time to the remote endpoint and for causing the remote endpoint to transmit the request for receiving the video stream at the determined request time.

4. The method of claim 3, wherein the request time is determined based on a bandwidth capability of a link used to transmit the burst transfer to the remote endpoint and a transfer rate of the video stream.

5. The method of claim 4, further comprising:

identifying data containing a latest occurring sequence number for transfer using the burst transfer; and

determining a duration of the burst transfer, the duration based on a time delay range for the remote endpoint to receive the video stream after transmitting the request to join the video stream.

6. The method of claim 5, wherein the data having the latest occurring sequence number is transmitted before other burst-transferred data having earlier occurring sequence numbers.

7. The method of claim 1, wherein the transition instant is selected to occur no later than a time that the remote endpoint joins the video stream after transmitting a request to join the video stream.

8. The method of claim 1, wherein the video stream is transferred from a same transmitting source of the burst transfer to the remote endpoint.

9. The method of claim 1, wherein the video stream is encoded using Motion Pictures Experts Group (MPEG) encoding and the burst transfer includes I frame information for combining with other information transferred to the remote endpoint using the video stream.

10. The method of claim 1, further comprising:

identifying a sequence number difference between the video stream and a position of a preceding start of an intra-coded frame; and

determining a time for completing the reduced subsequent transfer rate based on the sequence number difference.

11. An apparatus, comprising:

a processor; and

a memory coupled to the processor comprising instructions executable by the processor, the processor operable when executing the instructions to;

send a dynamic burst request to a remote network device as a single data stream;

send a join request to join a video stream;

receive an initial portion of a dynamic burst transfer at a first average transfer rate ((1+E)R) and then transitions to receive a subsequent portion at a second average transfer rate (ER) at a predetermined transition time, wherein R is a transfer rate of the video stream and E is a fraction amount of excess bandwidth;

wherein the burst transfer begins at a start of an intra-coded frame;

wherein the initial portion includes data packets from the intra-coded frame to a first latest occurring data packet (N);

wherein the subsequent portion includes the data packets from the first latest occurring data packet (N) to a second latest occurring data packet (Z) in the video stream, wherein the second latest occurring data packet is determined as;

12. The apparatus of claim 11, wherein the join request is sent at a predetermined time that is determined by the remote network device.

13. The apparatus of claim 11, the processor further operable to combine intra-coded frame data included in the burst transfer with other data transferred over the video stream for locally reconstructing a displayable video frame.

14. The apparatus of claim 11, wherein the join request is sent to the remote network device.

15. A system, comprising:

a video server operatively connected to at least one network device capable of receiving a video stream, the video server configured to;

send a burst transfer to the network device using a dynamic transfer rate that is reduced at a transition time;

identify a minimum response time for the at least one network device to receive the video data after sending a request to join the data stream;

identify a maximum response time for the at least one network device to receive the video data after sending the join request;

determining a join latency Δ

J, wherein the join latency Δ

J is a difference between the minimum response time and the maximum response time;

wherein the burst transfer begins at a start of an intra-coded frame;

wherein an initial portion of the burst transfer is sent at a first average rate ((1+E)R, and includes frames from the intra-coded frame to a first latest occurring frame (N), wherein R is a transfer rate of the video stream and E is a fraction amount of excess bandwidth; and

wherein a subsequent portion of the burst transfer is sent at a second average rate ER, and includes frames from the first latest occurring frame (N) to a second latest occurring frame (Z), wherein the second latest occurring frame (Z) is a last frame transferred using the burst stream before the at least one network device seamlessly starts decoding the video stream, wherein the second latest occurring frame is determined as;

16. The system of claim 15, wherein the video server is further configured to:

determine a request time using the identified minimum response time and the identified maximum response time; and

send the request to join the data stream at the determined request time.

17. The system of claim 15, wherein the video server is further configured to reduce the dynamic burst transfer to a predetermined rate that is determined based a bandwidth capability of a link for the endpoint to receive the data stream.

18. The system of claim 17, wherein the rate reduction is configured to occur no later than a time that the network device actually joins the data stream.

19. The system of claim 15, wherein the first transfer rate that is greater than a transfer rate of the data stream but less than or equal to a bandwidth capability of a link that couples the network device to a network and a remaining transfer rate that, when combined with the transfer rate of the data stream, does not exceed the bandwidth capability of the link.

20. The system of claim 15, wherein the transition time occurs a calculated amount of time later than a beginning time of the burst transfer, the calculated amount affecting when the network device sends the request to join the data stream.