DATA RETRIEVAL BASED ON BANDWIDTH COST AND DELAY

• US 20100306373A1
• Filed: 06/01/2010
• Published: 12/02/2010
• Est. Priority Date: 06/01/2009
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Swarmcast, Inc.
• Inventors: Wormley, Nicholas A.
• Granted Patent: US 9,948,708 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer

Abstract

The invention provides for a download agent executing on a computing device. The download agent determines the status of each of the source servers, and downloads from source servers that are in the available state. Additionally the download agent tracks characteristics of the source servers. The download agent determines the required bandwidth of portions of the media content stored on the source servers. Based on the characteristics of the source servers and the required bandwidth of the portions of the media content, the download agent determines how much media content should be downloaded from which source servers and at what time.

Claims

1. A method comprising:

determining, with a client computing device, a status and characteristics of a plurality of source servers;

computing, with the client computing device, a bandwidth required to download a first portion of a media asset stored on the plurality of source servers, wherein the first portion corresponds to data for a specific playback time period of the media asset;

determining, with the client computing device, how much of the first portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the first portion of the media asset;

transmitting, from the client computing device, a plurality of requests for the first portion of the media asset to the plurality selected source servers, wherein each of the requests specifies how much of the first portion to download from each of the selected ones of the source servers;

receiving the first portion of the media asset from the selected ones of the plurality of source servers; and

displaying the first portion of the media asset with the client device via a media player.

2. The method of claim 1, further comprising:

continuously determining, with the client computing device, the status and characteristics of a plurality of source servers;

computing, with the client computing device, a bandwidth required to download a second portion of a media asset stored on the plurality of source servers, wherein the second portion corresponds to data for a specific playback time period of the media asset that temporally follows the playback time period of the first media asset;

determining, with the client computing device, how much of the second portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the second portion of the media asset;

transmitting, from the client computing device, a plurality of requests for the second portion of the media asset to the plurality selected source servers, wherein each of the requests specifies how much of the second portion to download from each of the selected ones of the source servers;

receiving the second portion of the media asset from the selected ones of the plurality of source servers; and

displaying the second portion of the media asset with the client device via the media player after the media player has finished displaying the first portion of the media asset.

3. The method of claim 1, wherein receiving the first portion of the media asset comprises:

serializing the first portion of the media asset received from the plurality of selected source servers into a stream; and

verifying the stream to determine whether there are corrupt bytes.

4. The method of claim 1, further comprising:

monitoring the plurality of servers with the client device; and

maintaining, with the client device, state data for each of the source servers to represent the status of each of the source servers,

wherein the status of the plurality of source servers comprises at least one of an untested state, a test pending state, an untested retry state, an available state, an unavailable retry state, an available busy state, and an unavailable state.

5. The method of claim 4, wherein determining how much of the media asset to download from which of the source servers comprises determining how much of the media asset to download from source servers in the available state.

6. The method of claim 1, wherein the characteristics of the plurality of source servers comprises one or more of throughput rates of the source servers, peak download times of source servers, geographic location of the source servers, the privilege level of a client device, client-side autonomous system (AS) number, and bandwidth utilization for billing of the source servers.

7. The method of claim 1, wherein one or more of the characteristics of the plurality of source servers is provided by the source servers.

8. The method of claim 1, wherein the portions of the media assets are based on key frames of the media assets.

9. The method of claim 1, wherein computing the bandwidth required to download the first portion of the media asset comprises:

downloading metadata from at least one of the source servers, wherein the metadata describes timestamps and corresponding byte offsets for content of the media asset; and

computing the required bandwidth for the first portion based on starting and ending byte offsets for the first portion and starting and ending timestamps for the first portion.

10. The method of claim 9, wherein the metadata is separately downloadable.

11. The method of claim 9, wherein the metadata is embedded at the beginning of the media asset.

12. The method of claim 1, wherein computing the bandwidth required to download the first portion of the media asset comprises:

downloading header information from encoded frames yet to be downloaded, wherein the encoded frames represent the first portion, wherein content of the frames has not been downloaded, and wherein the header information indicates timestamps and corresponding byte offsets for the encoded frames; and

computing the required bandwidth for the first portion based on starting and ending byte offsets for the encoded frames and starting and ending timestamps for the encoded frames.

13. The method of claim 1, wherein computing the bandwidth required to download the first portion of the media asset comprises:

tracking a required bandwidth for previously downloaded frames;

averaging the required bandwidth for previously downloaded frames;

calculating a standard deviation based on the average of the required bandwidth for previously downloaded frames; and

estimating the required bandwidth based on the average and standard deviation.

14. The method of claim 1, wherein the media asset is encoded utilizing a variable bit rate (VBR) encoding technique.

15. The method of claim 1, wherein the media asset comprises time-critical content.

16. The method of claim 1, wherein the media asset comprises non time-critical content.

17. A device comprising:

a source manager that determines a status and characteristics of a plurality of source servers;

a temporal metadata module that computes a bandwidth required to download a first portion of a media asset stored on the plurality of source servers, wherein the first portion corresponds to data for a specific playback time period of the media asset; and

a stream agent that determines how much of the first portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the first portion of the media asset.

18. The device of claim 17, wherein:

the source manager continuously determines the status and characteristics of the plurality of source servers,

the temporal metadata module computes a bandwidth required to download a second portion of a media asset stored on the plurality of source servers, wherein the second portion corresponds to data for a specific playback time period of the media asset that temporally follows the playback time period of the first media asset, and

the stream agent determines how much of the second portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the second portion of the media asset.

19. The device of claim 17, wherein the stream agent:

transmits a plurality of requests for the first portion of the media asset to the plurality of selected source servers, via the source manager, wherein each of the requests specifies how much of the first portion to download from each of the selected ones of the source servers;

receives the first portion of the media asset from the selected ones of the plurality of source servers; and

provides the first portion of the media asset to a media player.

20. The device of claim 19, wherein the stream agent receives the first portion of the media asset by serializing the first portion of the media assets received form the plurality of selected source servers into a stream, and verifying the stream to determine whether there are corrupt bytes.

21. The device of claim 17, wherein the source manager monitors the plurality of servers, maintains state data for each of the source servers to represent the status of each of the source servers, and wherein the status of the plurality of source servers comprises at least one of an untested state, a test pending state, an untested retry state, an available state, an unavailable retry state, an available busy state, and an unavailable state.

22. The device of claim 21, wherein the stream agent determines how much of the media asset to download from which of the source servers based on source servers that are in the available state.

23. The device of claim 17, wherein the characteristics of the plurality of source servers comprises one or more of throughput rates of the source servers, peak download times of source servers, geographic location of the source servers, the privilege level of a client device, client-side autonomous system (AS) number, and bandwidth utilization for billing of the source servers.

24. The device of claim 17, wherein one or more of the characteristics of the plurality of source servers is provided by the source servers.

25. The device of claim 17, wherein the portions of the media assets are based on key frames of the media assets.

26. The device of claim 17, wherein the temporal metadata module computes the bandwidth required to download the first portion of the media asset by requesting the stream agent to download metadata from at least one of the source servers, wherein the metadata describes timestamps and corresponding byte offsets for content of the media asset, and computing the required bandwidth for the first portion based on starting and ending byte offsets for the first portion and starting and ending timestamps for the first portion.

27. The device of claim 26, wherein the metadata is separately downloadable.

28. The device of claim 26, wherein the metadata is embedded at the beginning of the media asset.

29. The device of claim 17, wherein the temporal metadata module computes the bandwidth required to download the first portion of the media asset by downloading header information from encoded frames yet to be downloaded, wherein the encoded frames represent the first portion, wherein content of the frames has not been downloaded, and wherein the header information indicates timestamps and corresponding byte offsets for the encoded frames, and computing the required bandwidth for the first portion based on starting and ending byte offsets for the encoded frames and starting and ending byte offsets for the encoded frames.

30. The device of claim 17, wherein the temporal metadata module computes the bandwidth required to download the first portion of the media asset by tracking a required bandwidth for previously downloaded frames, averaging the required bandwidth for previously downloaded frames, calculating a standard deviation based on the average of the required bandwidth for previously downloaded frames, and estimating the required bandwidth based on the average and standard deviation.

31. The device of claim 17, wherein the media asset is encoded utilizing a variable bit rate (VBR) encoding technique.

32. The device of claim 17, wherein the media asset comprises time-critical content.

33. The device of claim 17, wherein the media asset comprises non time-critical content.

34. The device of claim 17, wherein the device comprises at least one of a personal computer, a laptop computer, a mobile telephone, a personal media player, a device integrated into a vehicle, a network telephone, a network television, a television set-top box, and a network appliance.

35. A computer readable storage medium comprising instructions that cause one or more processors to:

determine a status and characteristics of a plurality of source servers;

compute a bandwidth required to download a first portion of a media asset stored on the plurality of source servers, wherein the first portion corresponds to data for a specific playback time period of the media asset; and

determine how much of the first portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the first portion of the media asset.

36. An apparatus comprising:

means for determining a status and characteristics of a plurality of source servers;

means for computing a bandwidth required to download a first portion of a media asset stored on the plurality of source servers, wherein the first portion corresponds to data for a specific playback time period of the media asset; and

means for determining how much of the first portion of the media asset to download from a plurality of selected ones of the source servers based on the status and characteristics of the plurality of source servers and the computed bandwidth for transmitting the first portion of the media asset.