SMART PRE-FETCHING FOR PEER ASSISTED ON-DEMAND MEDIA

• US 20080205291A1
• Filed: 02/23/2007
• Published: 08/28/2008
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Li, Jin, Huang, Cheng, Ross, Keith W.
• Granted Patent: US 8,832,290 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/722 at the destination endpoint, e.g. reservation of terminal resources or buffer space
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/108 characterised by resources being split in blocks or fragments
• CPC Class Codes: H04L 67/1091 Interfacing with client-server systems or between P2P systems
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics

Abstract

A “Media Sharer” operates within peer-to-peer (P2P) networks to provide a dynamic peer-driven system for streaming high quality multimedia content, such as a video-on-demand (VoD) service, to participating peers while minimizing server bandwidth requirements. In general, the Media Sharer provides a peer-assisted framework wherein participating peers assist the server in delivering on-demand media content to other peers. Participating peers cooperate to provide at least the same quality media delivery service as a pure server-client media distribution. However, given this peer cooperation, many more peers can be served with relatively little increase in server bandwidth requirements. Further, each peer limits its assistance to redistributing only portions of the media content that it also receiving. Peer upload bandwidth for redistribution is determined as a function of surplus peer upload capacity and content need of neighboring peers, with earlier arriving peers uploading content to later arriving peers.

Claims

1. A method for streaming a media file in a peer-to peer (P2P) network, comprising each peer using a computing device to perform steps for:

evaluating connected neighbor peers in the P2P network to determine an aggregate server rate to support real-time playback of a media file;

streaming packets comprising the media file from a combination of server uploads and peer re-transmission of received streaming packets from one or more of the peers to other later arriving peers using a first portion of an upload bandwidth capability of re-retransmitting peers, such that between the server uploads and the peer re-transmissions, all peers receive sufficient data packets of the media file to provide local full quality playback of the media file according to the aggregate server rate;

allocating any surplus upload bandwidth capacity remaining at each peer, after using the first portion of the upload bandwidth capacity, to one or more specific downstream peers, and using that allocated surplus upload bandwidth capacity to transmit additional packets in excess of those needed to provide local full quality playback of the media file to a local content buffer maintained by each of the corresponding peers; and

wherein streaming packets of the media file across the P2P network enables a user selected video-on-demand (VoD) service to provide real-time streaming of user selected videos.

2. The method of claim 1 wherein connected peers are evaluated in order of their arrival to determine the aggregate server rate to support real-time playback of the media file and the upload bandwidth capability of each peer.

3. The method claim 1 wherein allocating any surplus upload bandwidth capacity remaining at each peer further comprises periodically evaluating each connected peer and reallocating any surplus upload bandwidth capacity remaining at each peer based on a level of the local content buffer maintained by each connected peer.

4. The method of claim 1 further comprising a step wherein each peer self reports its upload bandwidth capability as it arrives in the P2P network.

5. The method of claim 1 further comprising steps for periodically adjusting a magnitude of the first portion of the upload bandwidth capability of the re-retransmitting peers to account for changes to a connection status of neighbor peers.

6. The method of claim 1 further comprising steps for allowing any peer to temporarily pause playback of the streaming media file, thereby changing an effective arrival order of that peer as a function of a local current playback point of the media file.

7. The method of claim 1 wherein the server maintains a plurality of unique media files for streaming, and further comprising steps for assigning each peer that selects a unique media file for streaming to a corresponding unique group of other peers that has also selected that same media file for streaming.

8. A computer-readable medium having computer executable instructions for providing peer-assisted streaming media in a peer-to-peer (P2P) network, said computer executable instructions comprising:

recording an arrival time of each of a plurality of peers as each peer requests a common media file from a group of one or more servers;

periodically assigning each peer to one of a plurality of neighborhoods including one or more other peers;

periodically directing one or more of the peers to allocate a first portion of their available upload bandwidth capability to one or more other later arriving peers in the allocating peers neighborhoods;

streaming packets of the requested media file from the server to one or more of the peers and re-transmitting one or more of the streamed media packets from one or more of those peers to one or more of the later arriving peers in those peers neighborhoods according to the allocated first portion of available upload bandwidth capability of those peers in order to fully satisfy a real-time demand level to provide full quality streaming playback of the media file for all peers in the P2P network;

periodically directing one or more of the peers to allocate a second portion from their remaining available upload bandwidth capability to one or more other later arriving peers in those peers neighborhoods; and

transmitting additional data packets of the media file from one or more of the peers that allocated a second portion of their available upload bandwidth to one or more of the later arriving peers in those peers neighborhoods according to the allocated second portion of available upload bandwidth capability in order to fill the content buffers of peers receiving the additional data packets in excess of the data packets needed to provide full quality streaming playback of the media file.

9. The computer-readable medium of claim 8 wherein one or more peers receiving re-transmitted media packets further re-transmits one or more of those received re-transmitted media packets to one or more later arriving peers in those peers neighborhoods.

10. The computer-readable medium of claim 8 wherein periodically directing one or more of the peers to allocate the second portion from their remaining available upload bandwidth capability comprises evaluating all peers in reverse order of their arrival and directing each peer to allocate any remaining available upload bandwidth capability to one or more specific downstream peers.

11. The computer-readable medium of claim 8 wherein periodically directing one or more of the peers to allocate the second portion from their remaining available upload bandwidth capability comprises evaluating all peers in order of their arrival and directing each peer to allocate any remaining available upload bandwidth capability to the next later arriving peer.

12. The computer-readable medium of claim 8 wherein streaming packets of the requested media file enables a user selected video-on-demand (VoD) service to provide real-time streaming of user selected videos to a plurality of peers.

13. The computer-readable medium of claim 8 wherein the upload bandwidth capability of each peer is recorded as each peer requests the common media file from the group of one or more servers.

14. The computer-readable medium of claim 8 wherein the group of one or more servers maintains a plurality of unique media files for streaming, and wherein the computer readable medium further comprises instructions for assigning each peer that selects a unique media file for streaming to a corresponding unique group of other peers that has also selected that same media file for streaming.

15. A system for streaming media to peers in a peer-to-peer (P2P) network, comprising using a plurality of computing devices for:

connecting each of a plurality of peers to a P2P network, which includes one or more servers, and allowing each peer to request a specific media file from the one or more servers;

evaluating all peers to determine an aggregate server rate to support real-time playback of a media file for all peers and an upload bandwidth capacity of each peer;

streaming packets comprising the media file from a combination of server uploads and peer re-transmission of received streaming packets from one or more of the peers to other later arriving peers using a first portion of the upload bandwidth capacity of the re-retransmitting peers, such that between the server uploads and the peer re-transmissions, all peers receive sufficient data packets of the media file to provide local full quality playback of the media file according to the aggregate server rate;

periodically evaluating all peers and directing each peer to allocate any remaining available upload bandwidth capacity to the next later arriving peer; and

using that allocated remaining available upload bandwidth capacity to transmit additional packets in excess of those needed to provide local full quality playback of the media file to a local content buffer maintained by each of the corresponding peers.

16. The system of claim 15 further comprising drawing packets first from the local content buffer, and then from other peers when available to satisfy each peers local demand for providing local full quality playback of the media file before requesting any packet from the server.

17. The system of claim 15 further comprising a video-on-demand (VoD) service wherein the specific media file requested by each peer is selected from a list of available video files via a user interface.

18. The system of claim 15 wherein each peer periodically self-reports that peers upload bandwidth capacity to the one or more servers of the P2P network.

19. The system of claim 15 wherein periodically evaluating all peers and directing each peer to allocate any remaining available upload bandwidth capacity to the next later arriving peer further comprises evaluating all peers in the order of their connection to the P2P network.

20. The system of claim 15 wherein evaluating all peers to determine the aggregate server rate and the upload bandwidth capacity of each peer further comprises evaluating each peer in the order of their connection to the P2P network.