Method and system for improving wireless link efficiency

Abstract

One embodiment of the present invention provides a system for improving transmission efficiency of a wireless link. During operation, the system receives a packet for transmission, where in the packet includes an original sequence number. The system then modifies the packet by including a virtual sequence number in a header of the packet and including the original sequence number in a payload of the modified packet. The system further aggregates a number of modified packets into an aggregate frame and transmits the aggregate frame to a destination device. The virtual sequence number facilitates stateless transmission of the encapsulated packets and allows the aggregate frame to have a maximum allowable number of packets while accommodating both re-transmitted packets and regular packets.

What is claimed is: 
     
       1. A method of wireless link transmission, comprising:
 selecting a virtual sequence number for each of a first set of packets to be transmitted in an aggregate frame, wherein the first set of packets includes one or more regular packets, and includes one or more retransmission packets to be retransmitted with the one or more regular packets in the aggregate frame; 
 modifying a respective packet of the first set of packets by:
 modifying a payload of the respective packet to include an original sequence number of the respective packet; and 
 modifying a header of the respective packet to include a virtual sequence number selected for the respective packet; 
 
 generating an aggregate frame which includes the first set of packets modified to include a corresponding virtual sequence number; and 
 transmitting the aggregate frame to a destination device over a wireless link. 
 
     
     
       2. The method of  claim 1 , wherein generating the aggregate frame involves generating an aggregate frame that includes packets associated with different original traffic categories. 
     
     
       3. The method of  claim 1 ,
 wherein the packet further includes an original traffic category indicator; and 
 wherein modifying the respective packet further comprises including a virtual traffic category indicator in the header of the respective packet and including the original traffic category indicator in the payload of the respective packet. 
 
     
     
       4. The method of  claim 3 , wherein modifying the respective packet involves modifying the header of the respective packet to include the same virtual traffic category indicator as other packets in the aggregate frame. 
     
     
       5. The method of  claim 1 , further comprising monitoring an error rate for a respective original traffic category. 
     
     
       6. The method of  claim 5 , further comprising duplicating, in the aggregate frame, a number of packets associated with the original traffic category for which the error rate is monitored, in response to the error rate surpassing a predetermined threshold. 
     
     
       7. The method of  claim 1 , wherein transmitting the aggregate frame to the destination over the wireless link involves transmitting the aggregate frame over an IEEE 802.11 wireless link. 
     
     
       8. A method of wireless link transmission, comprising:
 receiving, over a wireless link, an aggregate frame which comprises a set of one or more regular packets and one or more retransmission packets, each modified to include a header with a virtual sequence number; 
 de-aggregating the set of packets from the aggregate frame; 
 decapsulating a respective packet of the set by:
 obtaining an original sequence number from a payload of the respective packet; 
 obtaining an original traffic category identifier from the payload of the respective packet; and 
 updating a header of the respective packet to include the original sequence number and the original traffic category; and 
 
 ordering the decapsulated packets based on their original sequence number and original traffic category indicator. 
 
     
     
       9. The method of  claim 8 , wherein ordering the decapsulated packets involves ordering a set of decapsulated packets with non-contiguous original sequence numbers. 
     
     
       10. The method of  claim 8 , wherein ordering the decapsulated packets involves ordering a set of decapsulated packets with non-uniform original traffic categories. 
     
     
       11. The method of  claim 8 , wherein ordering the decapsulated packets involves ordering a set of decapsulated packets with contiguous original sequence numbers. 
     
     
       12. The method of  claim 8 , wherein receiving the aggregate frame over the wireless link involves receiving the aggregate frame over an IEEE 802.11 wireless link. 
     
     
       13. A system of wireless link transmission, comprising:
 a protocol stack operable to select a virtual sequence number for each of a first set of packets to be transmitted in an aggregate frame, wherein the first set of packets includes one or more regular packets, and includes one or more retransmission packets to be retransmitted with the one or more regular packets in the aggregate frame; 
 a virtual sequence number management module operable to modify a respective packet of the first set of packets by:
 modifying a payload of the respective packet to include an original sequence number of the respective packet; and 
 modifying a header of the respective packet to include a virtual sequence number selected for the respective packet; 
 
 an aggregation module operable to generate an aggregate frame which includes the first set of packets modified to include a corresponding virtual sequence number; and 
 a transmitter operable to transmit the aggregate frame to a destination device over a wireless link. 
 
     
     
       14. The system of  claim 13 , wherein while generating the aggregate frame, the aggregation module is further operable to generate an aggregate frame that includes packets associated with different traffic categories. 
     
     
       15. The system of  claim 13 ,
 wherein the packet further includes an original traffic category indicator; and 
 wherein while modifying the respective packet, the virtual sequence number management module is further operable to include a virtual traffic category indicator in the header of the respective packet and including the original traffic category indicator in the payload of the respective packet. 
 
     
     
       16. The system of  claim 15 , wherein while modifying the respective packet, the virtual sequence number management module is further operable to modify the header of the respective packet to include the same virtual traffic category indicator as other packets in the aggregate frame. 
     
     
       17. The system of  claim 13 , further comprising a packet error rate monitoring module operable to monitor an error rate for a respective original traffic category. 
     
     
       18. The system of  claim 17 , wherein the aggregation module is further operable to duplicate, in the aggregate frame, a number of packets associated with the original traffic category for which the error rate is monitored, in response to the error rate surpassing a predetermined threshold. 
     
     
       19. The system of  claim 13 , wherein the transmitter is operable to transmit the aggregate frame over an IEEE 802.11 wireless link. 
     
     
       20. A system of wireless link transmission, comprising:
 a receiving module operable to receive, over a wireless link, an aggregate frame which comprises a set of one more regular packets and one or more retransmission packets, each modified to include a header with a virtual sequence number; 
 a de-aggregation module operable to de-aggregate the set of packets from the aggregate frame; 
 a decapsulation module operable to decapsulate a respective packet of the set by:
 obtaining an original sequence number from a payload of the respective packet; 
 obtaining an original traffic category identifier from the payload of the respective packet; and 
 updating a header of the respective packet to include 
 
 the original sequence number and the original traffic category; and 
 an reordering module operable to order the decapsulated packets based on their original sequence number and original traffic category indicator. 
 
     
     
       21. The system of  claim 20 , wherein while ordering the decapsulated packets, the ordering module is further operable to order a set of decapsulated packets with non-contiguous original sequence numbers. 
     
     
       22. The system of  claim 20 , wherein while ordering the decapsulated packets, the ordering module is further operable to order a set of decapsulated packets with non-uniform original traffic categories. 
     
     
       23. The system of  claim 20 , wherein while ordering the decapsulated packets, the ordering module is further operable to order a set of decapsulated packets with contiguous original sequence numbers. 
     
     
       24. The system of  claim 20 , wherein while receiving the aggregate, the receiving module is operable to receive the aggregate frame over an IEEE 802.11 wireless link.