Detecting a hidden node in a wireless local area network

Abstract

A method and system for detecting a hidden node in a wireless local area network having a first station, a second station, and an access point. The first station can send a message, where the message can be sent as a data frame. After receiving the message, the access point can send the message to the second station. The second station can receive the message from the access point. In response to receiving the message, the second station can send an acknowledgement to the access point, where the acknowledgement can be sent as a control frame. The first station can monitor for the acknowledgement sent from the second station to the access point.

1 - 64 . (canceled)  
     
     
         65 . A method of determining whether a station in a wireless local area network is a hidden node, the method comprising: 
 at a first station, receiving a message forwarded from an access point to a second station associated with the access point;    at the first station, after receiving the message, monitoring to detect an acknowledgement sent from the second station to the access point in response to the message forwarded from the access point to the second station; and    if the acknowledgement sent by the second station to the access point is detected by the first station, determining that the second station is not a hidden node of the first station.    
     
     
         66 . The method of  claim 65 , further comprising determining that the second station is a hidden node of the first station if the acknowledgement sent by the second station to the access point is not detected by the first station.  
     
     
         67 . The method of  claim 65 , wherein the message was sent from a third station to the second station through the access point.  
     
     
         68 . The method of  claim 65 , wherein the message was sent from the first station to the second station through the access point.  
     
     
         69 . The method of  claim 68 , further comprising: 
 a) repetitively sending messages from the first station to the second station through the access point; and    b) determining that the second station is not a hidden node of the first station if the first station detects at least one acknowledgement sent from the second station to the access point to any of the messages sent in a).    
     
     
         70 . The method of  claim 69 , further comprising: 
 c) determining that the second station is a hidden node of the first station if the first station fails to detect at least one acknowledgement sent from the second station to the access point to any of the messages sent in a).    
     
     
         71 . The method of  claim 65 , wherein the first station, the second station, and the access point operate according to an IEEE 802.11 standard.  
     
     
         72 . The method of  claim 65 , wherein the first station is a diagnostic tool.  
     
     
         73 . The method of  claim 65 , wherein the first station is an administrative tool.  
     
     
         74 . A computer-readable medium that stores a computer program for determining whether a station in a wireless local area network is a hidden node, the computer program includes computer instructions for: 
 at a first station, examining a message forwarded from an access point to a second station associated with the access point;    at the first station, after examining the message, monitoring to detect an acknowledgement sent from the second station to the access point in response to the message forwarded from the access point to the second station; and    if the acknowledgement sent by the second station to the access point is detected by the first station, determining that the second station is not a hidden node of the first station.    
     
     
         75 . The computer-readable medium of  claim 74 , further comprising computer instructions for: 
 determining that the second station is a hidden node of the first station if the acknowledgement sent by the second station to the access point is not detected by the first station.    
     
     
         76 . The computer-readable medium of  claim 74 , wherein the message was sent from a third station to the second station through the access point.  
     
     
         77 . The computer-readable medium of  claim 74 , wherein the message was sent from the first station to the second station through the access point.  
     
     
         78 . The computer-readable medium of  claim 77 , further comprising computer instructions for: 
 a) repetitively sending messages from the first station to the second station through the access point; and    b) determining that the second station is not a hidden node of the first station if the first station detects at least one acknowledgement sent from the second station to the access point to any of the messages sent in a).    
     
     
         79 . The computer-readable medium of  claim 78 , further comprising instructions for: 
 c) determining that the second station is a hidden node of the first station if the first station fails to detect at least one acknowledgement sent from the second station to the access point to any of the messages sent in a).    
     
     
         80 . The computer-readable medium of  claim 74 , wherein the first station, the second station, and the access point operate according to an IEEE 802.11 standard.  
     
     
         81 . A detector to be used in a wireless local area network to determine whether a station is a hidden node, the detector comprising: 
 an antenna configured to receive a message forwarded from an access point to a station associated with the access point; and    a computer-readable medium that stores a computer program, the computer program includes computer instructions for: 
 examining the received message; and  
 after examining the message, monitoring to detect an acknowledgement sent from the second station to the access point in response to the message forwarded from the access point to the second station; and  
 if the acknowledgement sent by the second station to the access point is detected by the first station, determining that the second station is not a hidden node of the first station.