Accelerated channel change

• US 20070121629A1
• Filed: 11/30/2005
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Cuijpers, Maurice, Vink, Frans
• Granted Patent: US 8,135,040 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1859 adapted to provide push services, e.g. data channels
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• 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 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18

Abstract

Channel changing can be accelerated by multicasting a bouquet of multicast burst streams from a server. In an example implementation, each multicast burst stream is delayed sufficiently so that a past independent frame is available for delivery to and display by a client device without waiting for a future independent frame. A multicast burst segment of a multicast burst stream includes a portion in which the bandwidth exceeds the nominal data rate of the underlying resource being streamed. The temporal delay between adjacent multicast burst streams in a multicast bouquet is set responsive to a maximum client delay time for tuning to a new resource stream.

Claims

1. A method comprising:

replicating a media stream to produce multiple replicated media streams; and

multicasting the multiple replicated media streams with a temporal offset between adjacent ones of the multiple replicated media streams, the temporal offset shorter than a duration of a group of pictures (GOP) of the media stream.

2. The method as recited in claim 1, further comprising:

delaying the media stream by a time delay that equals or exceeds the duration of the GOP of the media stream;

wherein the delaying is performed prior to the multicasting, and the multiple replicated media streams that are multicasted comprise multiple delayed and replicated media streams.

3. The method as recited in claim 1, further comprising:

coding the media stream to produce a burst media stream having multiple burst segments, each burst segment including at least a portion of bandwidth that exceeds a nominal data rate of the media stream;

wherein the coding is performed prior to the multicasting, and the multiple replicated media streams that are multicasted comprise multiple replicated burst media streams.

4. The method as recited in claim 1, wherein the media stream is designed to be consumed by a decoding process at a nominal bandwidth;

and

wherein the multicasting comprises multicasting the multiple replicated media streams at a data rate that exceeds the nominal bandwidth by an excess bandwidth amount.

5. The method as recited in claim 4, wherein the multicasting comprises multicasting the multiple replicated media streams at a data rate of the excess bandwidth amount.

6. The method as recited in claim 1, wherein the multiple replicated media streams comprise multiple replicated burst media streams having multicast burst segments;

wherein the multicasting comprises multicasting a repeating bouquet of the multiple replicated burst media streams; and

wherein a number of the multiple replicated burst media streams of the repeating bouquet is set responsive to a maximum desired client delay time for a channel change and a length of a multicast burst segment.

7. The method as recited in claim 1, wherein the temporal offset is set responsive to a maximum delay time for tuning to a media stream.

8. A method for tuning to a resource stream, the method comprising:

receiving a multicast burst stream, which corresponds to the resource stream, at a data rate that exceeds a nominal data rate of the resource stream; and

receiving a multicast broadcast stream, which corresponds to the resource stream, at the nominal data rate of the resource stream.

9. The method as recited in claim 8, wherein the receiving actions are effectuated by a client device over a channel having a total bandwidth of the nominal data rate plus an excess data rate;

and wherein at least a portion of the receiving a multicast burst stream occurs prior to a start of the receiving a multicast broadcast stream.

10. The method as recited in claim 9, wherein the receiving a multicast burst stream comprises receiving the multicast burst stream at a bandwidth of the nominal data rate plus the excess data rate.

11. The method as recited in claim 10, wherein the receiving a multicast burst stream comprises receiving the multicast burst stream at a bandwidth of the excess data rate.

12. The method as recited in claim 8, wherein the resource stream comprises a media stream including multiple frames;

wherein the method further comprises;

playing the media stream upon first receipt of an independent frame and prior to receiving an amount of media data equaling a target client buffer size.

13. The method as recited in claim 8, further comprising:

issuing a join multicast burst command to a source of the multicast burst stream to initiate the receiving a multicast burst stream;

receiving a join multicast broadcast instruction from the source of the multicast burst stream;

responsive to receipt of the join multicast broadcast instruction, issuing a join multicast broadcast command to resource distribution apparatus to initiate the receiving a multicast broadcast stream; and

issuing a depart multicast burst command to the source of the multicast burst stream.

14. The method as recited in claim 8, further comprising:

determining a multicast burst address of the multicast burst stream by requesting the multicast burst address from a source of the multicast burst stream or by calculating the multicast address from known information.

15. The method as recited in claim 8, further comprising:

determining missing data in a region that is proximate to an overlap between receipt of the multicast burst stream and receipt of the multicast broadcast stream;

sending at least one request for retry data based on the determined missing data;

receiving the requested retry data; and

filling in the determined missing data using the requested retry data.

16. A network node to accelerate stream tunings, the network node transmitting a multicast bouquet of multicast burst streams;

adjacent multicast burst streams of the multicast bouquet separated by a temporal offset;

each multicast burst stream comprising a series of multicast burst segments in which data is transmitted at a data rate that exceeds a nominal data rate of an underlying resource stream;

wherein the temporal offset is set responsive to a desired maximum stream tuning delay.

17. The network node as recited in claim 16, wherein the multicast burst streams of the multicast bouquet are substantially identical to each other;

and wherein the temporal offset is less than one second.

18. The network node as recited in claim 16, wherein the network node comprises one or more media servers that transmit multiple respective multicast bouquets that correspond to multiple respective media channels;

and wherein the network node comprises distribution apparatus that transmits the underlying resource stream at the nominal data rate.

19. The network node as recited in claim 16, wherein the network node comprises one or more media servers that transmit multiple respective multicast bouquets that correspond to multiple respective media channels;

and wherein the multicast bouquets are activated for high-volume media channels or high-volume media programs.

20. The network node as recited in claim 16, wherein the network node tracks a number of resource stream change requests to the underlying resource stream during a preset time period and activates the multicast bouquet when the number exceeds a predetermined number of resource stream change requests.