Maximum bandwidth Broadcast-like streams

• US 20100094956A1
• Filed: 10/14/2009
• Published: 04/15/2010
• Est. Priority Date: 10/15/2008
• Status: Active Grant

• Current Assignee: Xenogenic Development Limited Liability Company (Intellectual Ventures LLC)
• Original Assignee: Patentvc Limited
• Inventors: Thieberger, Gil, Zuckerman, Gal
• Granted Patent: US 7,827,296 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Methods and systems for maximum bandwidth broadcast-like streams, including a plurality of assembling devices; each assembling device retrieves, approximately simultaneously, erasure-coded fragments from a plurality of fractional-storage CDN servers, whereby the broadcast-like streaming contents are reconstructed from the fragments, and wherein different mixtures of broadcast-like streaming contents can be retrieved by the assembling devices until the aggregated bandwidth used by the assembling devices to retrieve the fragments approaches the aggregated fragment delivery bandwidth capabilities of the servers.

Claims

1. ) A system for broadcast-like streaming contents, comprising:

a plurality of assembling devices, each assembling device configured to obtain, approximately simultaneously, erasure-coded fragments from a plurality of fractional-storage CDN servers, whereby the broadcast-like streaming contents are reconstructed from the fragments;

wherein different mixtures of broadcast-like streaming contents can be obtained by the assembling devices until the aggregated bandwidth used by the assembling devices to obtain the fragments approaches the aggregated fragment delivery bandwidth capabilities of the servers.

2. ) The system of claim 1, wherein the broadcast-like streaming contents comprise segments, the assembling devices use a fragment pull protocol to obtain the fragments from the servers, and the aggregated bandwidth used to deliver each segment does not exceed the aggregated bandwidth capabilities of the servers storing the fragments associated with the segment.

3. ) The system of claim 2, wherein the assembling devices are configured to obtain the fragments from the least loaded servers.

4. ) The system of claim 2, wherein the erasure-coding is rateless-coding, and the assembling devices are configured to approximately randomly select the servers from which to obtain the fragments.

5. ) The system of claim 1, wherein the broadcast-like streaming contents comprise segments, and approximately each server is configured to store at least one fragment per each segment per each broadcast-like streaming content, whereby approximately any mixture of broadcast-like streaming contents can be obtained.

6. ) The system of claim 1, wherein at least some of the broadcast-like streaming contents are live streams, and the erasure-coding is rateless-coding.

7. ) The system of claim 1, wherein the bandwidth demand for each broadcast-like streaming content is not known prior to the actual consumption of the streams by the assembling devices, and the erasure-coding is rateless-coding.

8. ) The system of claim 1, wherein approximately any unutilized bandwidth of the servers can be utilized by the assembling devices to obtain any broadcast-like streaming content.

9. ) The system of claim 8, wherein the broadcast-like streaming content draws new, previously inactive assembling devices, as a result of beginning a new program on the broadcast-like streaming content.

10. ) The system of claim 8, wherein at least some of the assembling devices that start obtaining the broadcast-like streaming content do so as a result of switching from a previously obtained stream.

11. ) A system configured to provide erasure-coded broadcast-like streaming contents, comprising:

a plurality of fractional-storage servers configured to store erasure-coded fragments;

the servers can support various mixtures of demand for the erasure-coded broadcast-like streaming contents up to the point where the total bandwidth demand approaches the total outgoing fragment delivery bandwidth of the servers.

12. ) The system of claim 11, wherein the servers are fractional-storage CDN servers, and approximately each server is configured to store at least one erasure-coded fragment per each segment per each broadcast-like streaming content;

whereby the servers can support approximately any mixture of demand for the broadcast-like streaming contents.

13. ) The system of claim 12, wherein the broadcast-like streaming contents are live channels, a significant percentage of assembling devices of the live channels can obtain the same live channel, the system is configured to support drastic changes in the demand for the various live channels, and the erasure-coding is rateless-coding.

14. ) The system of claim 11, wherein the erasure-coded broadcast-like streaming contents are transmitted using the erasure-coded fragments, and further comprising assembling devices configured to use a fragment pull protocol to retrieve the required fragments.

15. ) The system of claim 14, wherein the servers are fractional-storage CDN servers, and the fragment pull protocol comprises a process for selecting the least loaded fractional-storage CDN servers to serve each assembling device or group of assembling devices.

16. ) The system of claim 14, wherein the servers are fractional-storage CDN servers, and the fragment pull protocol comprises a process for approximately randomly selecting the fractional-storage CDN servers that serve each assembling device or group of assembling devices.

17. ) The system of claim 11, further comprising assembling devices configured to use a fragment pull protocol to retrieve the erasure-coded fragments required for the erasure-coded broadcast-like streaming contents, the fragments are encoded with a high redundancy factor, and the system amplification factor (Bout/Bin) may approach the ratio (Tout/(R*Bstream)), where Bout is the total average output bandwidth at which the fragments are obtained by the assembling devices, Bin is the total average bandwidth needed to deliver the fragments for storage on the servers, Tout is the total aggregated outgoing bandwidth of all servers, R is the redundancy factor, and Bstream is the average bandwidth of the streaming content.

18. ) A method comprising:

retrieving, by assembling devices, from a plurality of fractional-storage CDN servers, using a fragment pull protocol, erasure-coded fragments associated with broadcast-like streams, whereby the broadcast-like streams are reconstructed from the fragments;

balancing the servers using the fragment pull protocol; and

allowing additional assembling devices to retrieve fragments until the aggregated bandwidth used by the assembling devices to retrieve the fragments approaches the aggregated fragment delivery bandwidth capabilities of the servers.

19. ) The method of claim 18, wherein the step of balancing the servers comprises retrieving fragments from the least loaded servers, and the erasure-coding is rateless-coding.

20. ) The method of claim 18, wherein the step of balancing the servers comprises retrieving fragments from the servers having lower latencies than most of their alternatives.