Ordered and duplicate-free delivery of wireless data frames

• US 20060256722A1
• Filed: 05/13/2005
• Published: 11/16/2006
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Yang, Luiyang Lily, Taha, Samer
• Granted Patent: US 7,746,866 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers

Abstract

Methods and apparatus for delivering ordered and duplicate-free wireless data frames are generally described and claimed herein. Other embodiments may also be described herein. In an embodiment, a source address, a destination address, and a message sequence number are acquired from a wireless data frame. The message sequence number is compared against a last-received message sequence number and a last-delivered message sequence number. The destination address is also compared to a current address. In response to the compares, a decision is made to forward the wireless data frame to the destination address, discard the wireless frame as a duplicate wireless data frame, queue the wireless data frame, or release the wireless data frame to a next protocol layer.

Claims

1. A method, comprising:

acquiring a source address, a destination address, and a message sequence number from a media access control header of a wireless data frame;

comparing a last-received message sequence number for the source address against the message sequence number and comparing the destination address to a current address; and

deciding, in response to the compares, whether to perform at least one of;

forwarding the wireless data frame to a next processing node;

discarding the wireless data frame;

queuing the wireless data frame;

or

releasing the wireless data frame to a next protocol layer.

2. The method of claim 1, wherein deciding further includes performing the forwarding of the wireless data frame to the next processing node if the destination address does not equal the current address.

3. The method of claim 1, wherein deciding further includes performing the discarding of the wireless data frame if the destination address equals the current address and if at least one of:

the message sequence number is equal to the last-received message sequence number;

the message sequence number is equal to an entry message sequence number in a queue associated with the source address;

or

the message sequence number is equal to or less than a last-delivered message sequence number.

4. The method of claim 1, wherein deciding further includes performing the queuing of the wireless data frame if the destination address equals the current address and if:

the message sequence number is greater than a last-delivered message sequence number; and

the message sequence number is not equal to an entry message sequence number in a queue associated with the source address.

5. The method of claim 1, wherein deciding further includes performing the releasing of the wireless data frame to the next protocol layer if the destination address equals the current address and if at least one of:

the last-received message sequence number is equal to zero; and

the last-received message sequence number equals a last-delivered message sequence number, and the message sequence number is equal to the last-received message sequence number plus one.

6. The method of claim 1 further comprising:

periodically inspecting queue entry message sequence number'"'"'s associated with a queue of the source address, if the queue includes at least one queue entry, wherein each queue entry message sequence number is removed from the queue once released to the next protocol layer; and

purging the queue of remaining ones of the queue entry message sequence number'"'"'s after a threshold amount of elapsed time is reached.

7. The method of claim 6 further comprising, maintaining each queue entry message sequence number in a sequential order within the queue relative to one another while each queue entry message sequence number resides in the queue.

8. A machine accessible medium having associated instructions, which when processed, result in a machine performing:

inspecting headers of received wireless data frames for source addresses, destination addresses, and message sequence numbers; and

performing an action on each of the received wireless data frames, in response to the source addresses, the destination addresses, and the message sequence numbers wherein the action includes at least one of;

forwarding a number of the received wireless data frame to a next processing node;

discarding a number of the received wireless data frame;

queuing a number of the received wireless data frame;

a or

releasing a number of the received wireless data frames to a next protocol layer.

9. The medium of claim 8, further including instructions for:

generating modified headers for new wireless data frames, wherein each modified header includes a unique and sequential message sequence number within that header for each new wireless data frame generated; and

forwarding the new wireless data frames to the next processing node.

10. The medium of claim 8, further including instructions for maintaining an order of the received wireless data frames, which is free of duplicates, in response to the source addresses, the destination addresses, and the message sequence numbers, wherein the order is maintained for queued wireless data frames.

11. The medium of claim 8, wherein performing further includes processing the discarding if it is determined that a number of the wireless data frames are duplicates of previously received wireless data frames.

12. The medium of claim 8, further including instructions for purging queues, associated with the source addresses, of received wireless data frames which have been queued and which are determined to be stale.

13. An apparatus, comprising:

a wireless network processing node; and

a control data structure accessible to the wireless network processing node, wherein the control data structure is managed by the wireless network processing node to maintain a duplicate free and ordered delivery of wireless data frames from a'"'"'source address to a next protocol layer, if the wireless network processing node is a destination address which is associated with the wireless data frames.

14. The apparatus of claim 13 further comprising, a queue associated with the source address to maintain undelivered ones of the wireless data frames, wherein the undelivered ones of the wireless data frames are maintained with the queue in sequential order based on a unique message sequence number associated with each wireless data frame.

15. The apparatus of claim 13, wherein the control data structure includes entries for the source address, a message sequence number for a last-delivered one of the wireless data frames, a last-received message sequence number for one of the wireless data frames, and a time stamp to indicate a last update made to one of the entries in the control data structure.

16. The apparatus of claim 15, wherein the control data structure includes multiple additional entries for multiple different source addresses supplying the wireless data frames.

17. The apparatus of claim 13, wherein the wireless network processing node includes a message sequence number generator to generate unique MSN'"'"'s for headers of wireless data frames, which originate on the wireless processing node.

18. The apparatus of claim 13, wherein the wireless network processing node ignores the control data structure for select ones of the wireless data frames and forwards the select ones of wireless data frames onto a next processing node if the destination address of the select ones of the wireless data frames does not equal an address associated with the wireless network processing node.

19. A system, comprising:

a wireless network processing node;

a control data structure accessible to the wireless network processing node, wherein the control data structure is managed by the wireless network processing node to maintain a duplicate free and ordered delivery of wireless data frames from a source address to a next protocol layer, if the wireless network processing node is a destination address which is associated with the wireless data frames; and

an omni-directional antenna interfaced to the wireless processing node to transmit or receive the wireless data frames.

20. The system of claim 19 further comprising, a display interfaced to the wireless processing node to present a current state of the control data structure and to present activity associated with the wireless processing node.

21. The system of claim 19 further comprising, a log residing in memory or storage which accessible to the wireless processing node to record activity associated with the wireless processing node and to record states associated with the control data structure.

22. The system of claim 19, wherein the control data structure includes entries for the source address, a message sequence number for a last-delivered one of the wireless data frames, a last-received message sequence number for one of the wireless data frames, and a time stamp to indicate a last update made to one of the entries in the control data structure.

23. The system of claim 19 further comprising, a queue associated with the source address to maintain undelivered ones of the wireless data frames, wherein the undelivered ones of the wireless data frames are maintained with the queue in sequential order based on a unique message sequence number associated with each wireless data frame.

24. The system of claim 23, wherein the wireless network processing node is to purge the queue of selective ones of the undelivered wireless data frames if they are determined to be stale.