Communicating messages over transient connections in a peer-to-peer network

• US 7,966,368 B2
• Filed: 05/02/2003
• Issued: 06/21/2011
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Su, Philip Ti-Fei, Jarrett, Robert J.
• Primary Examiner(s): Serrao; Ranodhi N
• Assistant Examiner(s): Cloud; Joiya M
• Application Number:
  US10/427,941
• Publication Number:
  US 20040221043A1
• Time in Patent Office: 2,972 Days
• Field of Search: 709/227, 713/164
• US Class Current: 709/204
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/1827 Network arrangements for conference optimisation or adaptation
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 76/40 for selective distribution or broadcast
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Systems and methods useful in communicating messages over a peer-to-peer network, optionally over transient connections to participants in a collaborative session (e.g., an “electronic whiteboard” session), are described. Examples include establishing a session for data transfer, wherein participants easily enter and leave the session without losing data or connections between the participants. Participants in a session may gain access to and catch up with data previously transmitted. Various data structures are useful for communicating messages. Such data structures may be used for transmitting message data or identification data to participants.

Claims

1. A method of transferring data on a network, comprising

using one or more processors to perform the following computer executable acts:

adding a first computer as a participant in a collaborative session including a plurality of computers after determining, by the first computer, that the first computer is included in a session participation list;

receiving, at the first computer, after adding the first computer as a participant, a first broadcast message from the session, the first broadcast message being a message generated by a second computer different from the first computer, wherein the first broadcast message includes at least;

a broadcasting participant identifier, a message identifier, session information, and a message payload;

responsive to determining that the first computer is a participant in the session, processing the first broadcast message generated by the second computer for display on the first computer, the message payload including electronic ink data;

deleting, by the first computer, at least a portion of the electronic ink data that was included in the first broadcast message; and

broadcasting to the session, by the first computer, a dependent broadcast message, the message payload of the dependent broadcast message including the deletion of the at least a portion of the electronic ink data included in the first broadcast message,

wherein the dependent broadcast message is dependent on the first broadcast message, and

wherein the session comprises a virtual whiteboard on which session computers are configured to add new messages, delete existing messages, or modify existing messages.

2. A method according to claim 1, wherein, prior to processing the broadcast message for the first computer, the method further includes:

determining whether one or more messages were previously sent in the session; and

determining whether the first computer has received all previous messages in the session.

3. A method according to claim 2, further including:

obtaining any previous messages in the session that were previously not received by the first computer.

4. A method according to claim 3, wherein the obtaining of the previous messages that were not received includes receiving the previous messages that were not received through a broadcast from at least one of the plurality of computers in the session.

5. A method according to claim 4, wherein the plurality of computers randomly determine whether to broadcast one of more of the previous messages that were not received according to an algorithm.

6. A method according to claim 2, wherein when it is determined that the first computer has not received all previous messages in the session, the method further includes:

(a) sending the request, by the first computer, for at least one previous message that was not received;

(b) broadcasting the at least one previous message that was not received to the first computer by at least one of the plurality of computers in the session; and

(c) repeating (a) and (b) until all messages in the session are received by the first computer.

7. A method according to claim 6, wherein each of the plurality of computers in the session randomly determines whether to broadcast one or more of the previous messages that was not received by the first computer according to an algorithm.

8. A method according to claim 1, wherein the session involves peer-to-peer communications.

9. A method according to claim 1, wherein the computers are not operatively connected to a common server.

10. A method according to claim 1, wherein at least one of the plurality of computers or the first computer is connected to the network via a wireless connection.

11. A method according to claim 1, wherein the message is broadcast using user datagram protocol.

12. A method executed on a first workstation comprising:

connecting the first workstation and a second workstation in a peer-to-peer manner, the workstations not being operatively connected to a common server, wherein each of the workstations is configured to broadcast message data to other workstations in a session in a peer-to-peer manner and receive broadcast message data from other workstations in the session in a peer-to-peer manner;

receiving, at the first workstation, a first message created by the second workstation and broadcast by the second workstation, the first message including a payload containing electronic ink data, the electronic ink data comprising at least one electronic ink stroke;

processing, by the first workstation, the first message for display on the first workstation;

modifying, by the first workstation, the at least one electronic ink stroke of the electronic ink data;

creating, by the first workstation, a second message including a payload containing the modification of the at least one electronic ink stroke of the electronic ink data, the second message being dependent on the first message;

including a message history in the second message, the message history including the dependency of the second message on the first message; and

broadcasting, by the first workstation, the second message,

wherein the session comprises a virtual whiteboard on which session computers are configured to add new messages, delete existing messages, or modify existing messages.

13. A method according to claim 12, further including:

adding a new workstation to the session; and

obtaining the first message for the new participant workstation from a workstation present in the session other than the second workstation.

14. A method according to claim 12, wherein the first message is broadcast using user datagram protocol.

15. A method according to claim 12, wherein the second workstation leaves the session before the first message is broadcast by the first workstation.