ACCELERATED CHANNEL CHANGE IN RATE-LIMITED ENVIRONMENTS

• US 20090077255A1
• Filed: 11/24/2008
• Published: 03/19/2009
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Barrett, Peter T., Baldwin, James A., Green, Dustin L., Mohr, Grant D., Clifford, David C., Smith, Geoffrey R., Dodd, Michael D.
• Granted Patent: US 7,944,863 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• CPC Class Codes: H04N 21/2401 Monitoring of the client buffer
• 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 21/2404 Monitoring of server processing errors or hardware failure error or fault detection G06F11/07; monitoring in general G06F11/30
• 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 21/26616 for merging a unicast channel into a multicast channel, e.g. in a VOD application, when a client served by unicast channel catches up a multicast channel to save bandwidth data multicast over packet-switching network H04L12/18
• CPC Class Codes: H04N 21/4383 Accessing a communication channel
• 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 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/4424 Monitoring of the internal components or processes of the client device, e.g. CPU or memory load, processing speed, timer, counter or percentage of the hard disk space used error monitoring in general G06F11/30; arrangements for monitoring conditions of receiving stations in broadcast systems H04H60/32; diagnosis, testing or measuring for television receivers H04N17/04
• CPC Class Codes: H04N 21/6375 for requesting retransmission , e.g. of data packets lost or corrupted during transmission from serverARQ protocols H04L1/18; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/6408 Unicasting
• CPC Class Codes: H04N 21/6473 Monitoring network processes errors for recovering from a failure of a protocol instance or entity H04L69/40
• 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 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Accelerated channel change (ACC) strategies are described for supplying a client module with media information by transitioning between a first delivery of media information provided by first delivery functionality and a second delivery of media information provided by second delivery functionality without exceeding prescribed data rate limitations. The first delivery functionality can represent server-based functionality for delivering a unicast stream of media information at a data rate (or maximum data rate) of some excess amount over the nominal rate of delivery, starting at a selected location within the media information. The second delivery functionality can represent any functionality for delivering the media information at the data rate (or maximum data rate) of the nominal rate of delivery. A join interval separates the first delivery at the excess rate and the second delivery at the nominal rate. In that period, the first delivery functionality can provide media information at a join interval data rate. The join interval data rate, if it is below the nominal data rate, will cause the client module to miss packets of media information. The client module can receive these missing packets by issuing retry requests to the first delivery functionality or to some other entity. The client module can determine the excess amount available by investigating the amount of missing information that occurs at different data rates; or the excess amount can be defined in advance.

Claims

1. A method for delivering resource information to a client module, comprising:

delivering the resource information, using first delivery functionality, at above nominal data rate levels during an initial burst period of data transmission to the client module;

delivering the resource information at join interval data rate levels during a join interval following the initial burst period, wherein, following the join interval, the client module switches to second delivery functionality for providing the resource information; and

responding to requests from the client module to supply parts of the resource information which the client module missed.

2. The method of claim 1 wherein the resource information provided by the first delivery functionality and the resource information provided by the second delivery functionality combine together to provide a resultant stream of resource information in which the primary mode of resource information delivery transitions from the first delivery functionality to the second delivery functionality, and wherein the resultant stream has a data rate that remains below a prescribed data rate limit.

3. The method of claim 2, wherein delivering the resource information, using a first delivery functionality is initiated upon a commencement event.

4. The method of claim 3, wherein the resource information is media information.

5. The method of claim 4, wherein the commencement event is associated with a change by the client module from a previous state to a new state, wherein the new state involves a selection of a new program that provides the resource information to be consumed by the client module.

6. The method of claim 5, wherein the commencement event is associated with a change by the client module from an old program, associated with the previous state, to the new program, associated with the new state.

7. The method of claim 4, wherein the prescribed data rate limit provides an amount of excess capacity beyond an amount required to delivery the resource information in a steady-state condition.

8. The method of claim 7, further comprising:

measuring the amount of excess capacity; and

selecting data rate levels at which the resource information is delivered using the first delivery functionality and/or the second delivery functionality based on the measured amount of excess capacity.

9. The method of claim 8, wherein the amount of excess capacity is measured by investigating the amount of degradation produced by transmission of resource information at different data rates.

12. The method of claim 1, wherein:

the first delivery functionality comprises unicast server-based functionality configured to deliver the resource information in a unicast stream at first data rate levels for an initial period of time; and

the second delivery functionality comprises the unicast server-based functionality configured to deliver the resource information in a unicast stream at second data rate levels following the initial period of time.

10. A method for receiving a stream of resource information at a client module, comprising:

receiving, via first delivery functionality, resource information at above-nominal data rate levels during an initial burst period of data transmission;

receiving the resource information at join interval data rate levels during a join interval following the burst period;

receiving, via second delivery functionality, the resource information following the join interval;

requesting parts of the resource information which the client module missed;

receiving the missing parts of resource information concurrently with the receipt of the resource information; and

using the received missing parts for filling in holes created in the stream.

11. The method of claim 10, wherein:

the first delivery functionality comprises unicast server-based functionality, and the first delivery of resource information provides a unicast stream of the resource information; and

the second delivery functionality comprises multicast functionality, and the second delivery of resource information provides a multicast stream of the resource information.

13. The method of claim 10, wherein the resource information is video on demand (VOD) resource information.

14. The method of claim 10, wherein:

the first delivery functionality comprises delivering the resource information at first data rate levels for an initial period of time; and

the second delivery functionality comprises delivering the resource information at second data rate levels.

15. The method of claim 14, wherein the first data rate levels and the second data rate levels define constant respective data rates.

16. The method of claim 14, wherein the first data rate levels and the second data rate levels define varying respective data rates.

17. The method of claim 14, wherein the first data rate levels are data rates which exceed a nominal data rate used to deliver the resource information by an excess amount, and the second data rate levels are data rates which remains at or below the nominal data rate.

18. The method of claim 17, wherein the excess amount is less than the nominal data rate.

19. The method of claim 17, wherein the excess amount is equal to or greater than the nominal data rate.

20. The method of claim 17, wherein the excess amount varies depending on a time-varying amount of excess capacity available.

21. The method of claim 17, wherein the excess amount is specified as a fraction E of the nominal data rate.

22. The method of claim 14, wherein there is a join interval that separates the delivery of resource information at the first data rate levels and the delivery of resource information at the second data rate levels, wherein, in the join interval, the first delivery of resource information is provided at join interval date rate levels.

23. The method of claim 22, wherein a length of the join interval is based an amount of time required by the client module to couple to the second delivery functionality to receive the second delivery of the resource information.

24. The method of claim 23, wherein the join interval is shortened to a minimum amount of time that is required by the client module to couple to the second delivery functionality, wherein the first delivery functionality continues to deliver the resource information in a time period defined by that minimum amount of time.

25. The method of claim 22, wherein the join interval data rates dynamically vary based on a time-varying amount of excess capacity available to deliver resource information.

26. The method of claim 22, wherein the join interval data rate levels are data rates at or above a nominal data rate used to deliver the resource information.

27. The method of claim 22, wherein the join interval data rate levels are data rates below a nominal data rate used to deliver the resource information.

28. The method of claim 27, wherein the join interval data rate levels are data rates of 0.

29. The method of claim 27, wherein the join interval data rates are specified as a fraction E of the nominal data rate.

30. The method of claim 27, wherein the delivery of the resource information at below-nominal join interval rates during the join interval causes parts of the first stream of resource information to be missed by the client module.

31. A method for delivering resource information to a client module, comprising:

delivering the resource information, using first delivery functionality, at above-nominal data rate levels during an initial burst period of data transmission to the client module;

delivering the resource information at join interval data rate levels during a join interval following the burst period, wherein, following the join interval, the client module switches to second delivery functionality for providing the resource information; and

responding to requests from the client module to supply parts of the resource information which the client module missed as a result of its receipt of the resource information.

32. The method of claim 31, wherein the first delivery functionality and the second delivery functionality comprise unicast delivery functionality and multicast delivery functionality, respectively.