Interference suppression methods for 802.11

Abstract

An 802.11 source station transmits a message, such as a CF-End message, to reset a network allocation vector at a time other than that required for indicating the end of the contention free period. That is, the source station uses the CF-End message to spoof stations within range of the message into resetting the stations' network allocation vectors as if the contention free period were active. Thus, the spoofing source station is allowed to release the medium for general use after the medium has been reserved for a specific use, for a greater time than necessary. Accordingly, spoofed stations may, for example, 1) delay transmission until a more critical transmission has completed, 2) allow unknown or foreign protocol to have preferential use of the medium, 3) prevent interference from hidden stations, and 4) allow sharing of the medium by overlapping basic service sets. After the specific use, if the medium is still reserved, the medium may be released for general use.

1 . A method for spoofing stations while transmitting data through a medium, the method comprising: 
 sending a message to reset a network allocation vector at a time other than an end of a contention free period;    wherein at least one of the stations is an obeying station that resets a network allocation vector of the obeying station in accordance with the sent message.    
     
     
         2 . The method of  claim 1 , wherein the sent message indicates an end of a time period for suppressing transmissions by the obeying station.  
     
     
         3 - 11 . (canceled)  
     
     
         12 . The method of  claim 2 , wherein transmissions of unknown protocols are given preferential use of the medium when the transmissions by the obeying station are suppressed.  
     
     
         13 . The method of  claim 2 , wherein transmissions of hidden stations are given preferential use of the medium when the transmissions by the obeying station are suppressed.  
     
     
         14 . The method of  claim 2 , wherein critical transmissions are given preferential use of the medium when the transmissions by the obeying station are suppressed.  
     
     
         15 . The method of  claim 2 , wherein at least some of the stations are provided in an overlapping basic service set, and stations of the overlapping basic service set are given preferential use of the medium when the transmissions by the obeying station are suppressed.  
     
     
         16 . The method of  claim 2 , wherein stations of an enhanced version of a standard are given preferential use of the medium when the transmissions by the obeying station are suppressed.  
     
     
         17 . A machine-readable medium having stored thereon a plurality of executable instructions, the plurality of executable instructions comprising instructions to: 
 send a message to reset a network allocation vector at a time other than an end of a contention free period, wherein at least one of a plurality of stations is an obeying station that resets a network allocation vector of the obeying station in accordance with the sent message.    
     
     
         18 . The machine-readable medium of  claim 17 , wherein the sent message indicates an end of a time period for suppressing transmissions by the obeying station.  
     
     
         19 . The machine-readable medium of  claim 18 , wherein the plurality of executable instructions further includes instructions to give preferential use of a medium to transmissions of unknown protocols when the transmissions by the obeying station are suppressed.  
     
     
         20 . The machine-readable medium  claim 18 , wherein the plurality of executable instructions further includes instructions to give preferential use of a medium to transmissions of hidden stations when the transmissions by the obeying station are suppressed.  
     
     
         21 . The machine-readable medium  claim 18 , wherein the plurality of executable instructions further includes instructions to give preferential use of a medium to critical transmissions when the transmissions by the obeying station are suppressed.  
     
     
         22 . The machine-readable medium  claim 18 , wherein at least some stations in a plurality of stations are provided in an overlapping basic service set and the plurality of executable instructions further includes instructions to give preferential use of a medium to stations of the overlapping basic service set when the transmissions by the obeying station are suppressed.  
     
     
         23 . The machine-readable medium  claim 18 , wherein the plurality of executable instructions further includes instructions to give preferential use of a medium to stations of an enhanced version of a standard when the transmissions by the obeying station are suppressed.