Reliable multicast with automatic session startup and client backfil support

• US 8,018,933 B2
• Filed: 06/27/2007
• Issued: 09/13/2011
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Syed, Saad, Abdelhalim, Alaa H., Dickens, Christopher Scott, Sadler, Jeremy, Yaqoob, Asad
• Primary Examiner(s): Phillips; Hassan
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US11/823,143
• Publication Number:
  US 20090003342A1
• Time in Patent Office: 1,539 Days
• Field of Search: 370/328, 370/353, 370/390, 370/351, 370/352, 370/389, 370/400, 370/395, 370/401, 370/432, 370/408, 370/331, 709/223, 709/227, 709/219, 709/231, 709/217, 709/230, 725/93, 725/58, 725/98, 725/88, 725/87, 725/105, 725/116, 713/163
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership

Abstract

A form of multicast, referred to as “on-demand multicast,” provides a methodology that allows for “on demand” multicasting of data. On-demand multicast allows clients to join or leave a transmission at any point. There is no transmission session start or end time—the session is continuously available, although data is not necessarily continuously transmitted. Data blocks missed by late-joining clients are retransmitted per amalgamated client requests through multiple transmission cycles until all clients that have joined the transmission session receive all content. Once a client has received all data blocks comprising the content for the session, the client may exit the ongoing session.

Claims

1. A method on a client computer device for receiving multicast data comprising

sending a request to an on demand multicast server to receive a set of data;

receiving an authorization to join a transmission session transmitting the data set;

receiving a value indicating a number of blocks in the data set;

sending a request to join the transmission session;

receiving one or more of the blocks in a transmission cycle; and

responding to a poll by requesting a subset of the blocks not received in the transmission cycle.

2. The method of claim 1 further comprising exiting the transmission session upon receipt of all subsets of the data set.

3. The method of claim 1 further comprising:

monitoring which of the number of blocks have been received.

4. The method of claim 1 further comprising:

monitoring which of the number of blocks still need to be received.

5. The method of claim 1 wherein the receiving the one or more blocks comprises starting receiving the content of the requested set of data mid-stream.

6. The method of claim 1 further comprising:

after responding to the poll, receiving one or more of the subset of the blocks not received in the transmission cycle.

7. The method of claim 1 wherein the responding to the poll occurs prior to receiving one or more of the blocks.

8. The method of claim 1 wherein the transmission session was already in progress before receiving the authorization.

9. A computer-readable storage media, the computer-readable storage media not consisting of signals, the computer-readable storage media storing program modules, the program modules, when executed by a computing device, causing the computing device to perform a sequence of operations, the operations comprising:

sending a request to a multicast server to receive a set of data;

receiving an authorization to join a transmission session transmitting the data set;

receiving a value indicating a number of blocks in the data set;

sending a request to join the transmission session;

receiving one or more of the blocks in a transmission cycle; and

responding to a poll by requesting a subset of the blocks not received in the transmission cycle.

10. The computer-readable storage media of claim 9, the operations further comprising:

exiting the transmission session upon receipt of all subsets of the data set.

11. The computer-readable storage media of claim 9, wherein

the receiving the one or more blocks comprises starting receiving the content of the requested set of data mid-stream.

12. The computer-readable storage media of claim 9, the operations further comprising:

after responding to the poll, receiving one or more of the subset of the blocks not received in the transmission cycle.

13. The computer-readable storage media of claim 9, the operations further comprising:

the responding to the poll occurs prior to receiving one or more of the blocks.

14. The computer-readable storage media of claim 9, wherein the transmission session was already in progress before receiving the authorization.

15. A computing device comprising:

a processing unit; and

a means for storing computer-executable instructions, the means for storing computer-executable instructions storing computer-executable instructions which, when executed by the computing device, cause the computing device to perform a sequence of steps, the steps comprising;

sending a request to a multicast server to receive a set of data;

receiving an authorization to join a transmission session transmitting the data set;

receiving a value indicating a number of blocks in the data set;

sending a request to join the transmission session;

receiving one or more of the blocks in a transmission cycle; and

responding to a poll by requesting a subset of the blocks not received in the transmission cycle.

16. The computing device of claim 15, wherein the means for storing computer-executable instructions comprises at least one item selected from the group consisting of:

a system memory,

a read only memory (ROM),

a random access memory (RAM),

a basic input/output system (BIOS),

a hard disk,

a magnetic disk,

a removable optical disk,

a magnetic cassette,

a flash memory card,

a digital video disk, and

a memory storage device.

17. The computing device of claim 15, the steps further comprising:

the receiving the one or more blocks comprises starting receiving the content of the requested set of data mid-stream.

18. The computing device of claim 15, the steps further comprising:

after responding to the poll, receiving one or more of the subset of the blocks not received in the transmission cycle.

19. The computing device of claim 15, the steps further comprising:

the responding to the poll occurs prior to receiving one or more of the blocks.

20. The computing device of claim 15, wherein the transmission session was already in progress before receiving the authorization.