System and method for reliably communicating information without explicit acknowledgements including retransmission of older, missed commands

• US 8,112,694 B1
• Filed: 10/03/2007
• Issued: 02/07/2012
• Est. Priority Date: 10/03/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Woo, Alec, Culler, David E
• Primary Examiner(s): Trimmings, John P
• Application Number:
  US11/906,965
• Time in Patent Office: 1,588 Days
• Field of Search: None
• US Class Current: 714/774
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 2001/0097 Relays

Abstract

A system and method communicates commands from a command originator to receiving devices, yet the receiving devices do not confirm receipt of the command. The most current command (e.g. the one with the highest sequence number) is rebroadcast by the command originator and the receiving devices, tending to be more frequent upon detection of an event indicating that the most current command was not received by at least one other device, and less frequently upon detection of an event indicating that the most current command was provided with sufficient duplication that if another device could receive it, the device likely did receive it, subject to a maximum and minimum rate.

Claims

1. A method of ensuring a plurality of devices receive communications intended for them, the method comprising:

at each of the plurality of devices, repeatedly performing a wireless rebroadcasting, each rebroadcasting comprising rebroadcasting a then highest ordered communication received by that device, the repeated rebroadcasting being directed to occur more frequently on average following a detection by that device of one or more events indicating that a different device did not receive at least the highest ordered communication received by that device, and less frequently on average following detection by that device of one or more events indicating that a different device likely received at least the highest ordered communication received by that device, at least one such communication not being received by a first at least one of the plurality of devices;

at a second at least one of the plurality of devices, detecting that the first at least one of the plurality of devices did not receive at least one communication other than the then current highest ordered communication received by the second at least one of the plurality of devices and that had been rebroadcast by at least some of the second at least one of the plurality of devices; and

rebroadcasting by at least one of the second at least one of the plurality of devices, at least one of the at least one communication other than the highest ordered communication responsive to the detecting step.

2. The method of claim 1, wherein the detecting is responsive to a receipt of a broadcast by the different device of a communication ordered more than one prior to the then current highest ordered communication received by said device.

3. The method of claim 1, wherein the detecting is responsive to a receipt from at least one of the first at least one of the plurality of devices of an indication that the first at least one of the plurality of devices did not receive the at least one communication.

4. The method of claim 1, wherein the indication is received with the rebroadcasted then current highest ordered communication received by each respective first at least one of the plurality of devices.

5. The method of claim 4, wherein the rebroadcasting the at least one of the at least one communication other than the highest ordered communication is additionally responsive to at least a pseudo random number.

6. A system for ensuring a plurality of devices receive communications intended for them, the system comprising:

a plurality of devices, each of the plurality of devices in wireless communication with at least one of the other devices in the plurality, each of the devices for repeatedly performing a wireless rebroadcasting, each rebroadcasting comprising rebroadcasting a then highest ordered communication received by that device, the repeated rebroadcasting being directed to occur more frequently on average following a detection by that device of one or more events indicating that a different device did not receive at least the highest ordered communication received by that device, and less frequently on average following detection by that device of one or more events indicating that a different device likely received at least the highest ordered communication received by that device, at least one such communication not being received by a first at least one of the plurality of devices; and

a second at least one of the plurality of devices for;

detecting that the first at least one of the plurality of devices did not receive at least one communication other than the then current highest ordered communication received by the second at least one of the plurality of devices and that had been rebroadcast by at least some of the second at least one of the plurality of devices; and

rebroadcasting by at least one of the second at least one of the plurality of devices, at least one of the at least one communication other than the highest ordered communication responsive to the detecting.

7. The system of claim 6, wherein the detecting is responsive to a receipt of a broadcast by the different device of a communication ordered more than one prior to the then current highest ordered communication received by said device.

8. The system of claim 6, wherein the detecting is responsive to a receipt from at least one of the first at least one of the plurality of devices of an indication that the first at least one of the plurality of devices did not receive the at least one communication.

9. The system of claim 6, wherein the indication is received with the rebroadcasted then current highest ordered communication received by each respective first at least one of the plurality of devices.

10. The system of claim 9, wherein the rebroadcasting the at least one of the at least one communication other than the highest ordered communication is additionally responsive to at least a pseudo random number.

11. A computer program product comprising a computer useable medium having computer readable program code embodied therein for ensuring a plurality of devices receive communications intended for them, the computer program product comprising computer readable program code devices configured to cause a computer system to:

at each of the plurality of devices, repeatedly perform a wireless rebroadcasting, each rebroadcasting comprising rebroadcasting a then highest ordered communication received by that device, the repeated rebroadcasting being directed to occur more frequently on average following a detection by that device of one or more events indicating that a different device did not receive at least the highest ordered communication received by that device, and less frequently on average following detection by that device of one or more events indicating that a different device likely received at least the highest ordered communication received by that device, at least one such communication not being received by a first at least one of the plurality of devices;

at a second at least one of the plurality of devices, detect that the first at least one of the plurality of devices did not receive at least one communication other than the then current highest ordered communication received by the second at least one of the plurality of devices and that had been rebroadcast by at least some of the second at least one of the plurality of devices; and

rebroadcast by at least one of the second at least one of the plurality of devices, at least one of the at least one communication other than the highest ordered communication responsive to the detecting step.

12. The computer program product of claim 11, wherein the computer readable program code devices configured to cause the computer system to detect are responsive to a receipt of a broadcast by the different device of a communication ordered more than one prior to the then current highest ordered communication received by said device.

13. The computer program product claim 11, computer readable program code devices configured to cause the computer system to detect are responsive to a from at least one of the first at least one of the plurality of devices of an indicate that the first at least one of the plurality of devices did not receive at least one communication.

14. The computer program product of claim 11, wherein the indication is received with the rebroadcasted then current highest ordered communication received by each respective at least one of plurality of devices.

15. The computer program product of claim 14, wherein the rebroadcasting the at least one of the at least one communication other the highest ordered communication is additionally responsive to at least a pseudo random number.