Apparatus and method for peer-to-peer link monitoring of a wireless network with centralized control

Abstract

Centrally controlled wireless networks require reliable communications between the central controller and each of the stations within the wireless networks. The structure of a wireless network is often dynamic, or ad-hoc, as stations enter and exit the network, or are physically relocated. The selection of the central controller for the network may also be dynamic, either because the current central controller desires to exit the network, or because the communication between the current central controller and one or more of the stations is poor. This invention discloses a method and apparatus for assessing the quality of the communication paths among all stations in the network. This assessment is useful as a continual monitor of the quality of the network, and can be utilized to select an alternative central control station based upon the quality of communication paths to and from this station. Additionally, the quality assessment can be utilized to establish relay communication paths, as required.

1 . A communications system comprising a plurality of communication stations associated with a network, 
 one of said stations being designated as a central station,    each of said stations comprising a transmitter and a receiver,    said network comprising a transmit-receive path between each transmitter of each of said stations and each receiver of each of said other stations,    each of said transmitters comprising a means for transmitting a message for reception by one or more of the receivers of the other stations,    each of said receivers comprising: 
 a means for receiving a received message, said received message being a transmitted message from one of said transmitters,  
 a means for identifying the transmitter of the received message,  
 a means for measuring the quality of the received message, and  
 a means for determining a quality factor associated with the transmitter in dependence upon the measured quality of the received message; and,  
   said central station comprising: 
 a means for obtaining the quality factor associated with one or more transmitters from each station, and  
 a means for determining a quality measure associated with the transmit-receive paths in dependence upon said obtained quality factors.  
   
   
   
       2 . A communications system as claimed in  claim 1 , wherein 
 said means for measuring the quality of the received message comprises means for measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said received message.    
   
   
       3 . A communications system as claimed in  claim 1 , wherein 
 said means for measuring the quality of the received message comprises means for measuring a bit error rate associated with said received message.    
   
   
       4 . A communications system as claimed in  claim 1 , wherein the central station further comprises: 
 a means for assessing said quality measures, and a means for determining one of said stations for designation as an alternative central station in dependence upon said assessment of the quality measures.    
   
   
       5 . A communications system as claimed in  claim 1 , wherein the central station further comprises: 
 a means for assessing said quality measures, and    a means for determining an alternative relay transmission path for one or more of said transmit-receive paths in dependence upon said assessment of the quality measures.    
   
   
       6 . A communication device for communicating in a network comprising a plurality of communication stations, wherein each of said communication stations comprise a means for transmitting messages intended to be received at one or more of the other communication stations, 
 said communication device comprising: 
 a means for receiving a message transmitted from the communication stations,  
 a means for identifying the communication stations which transmitted the message,  
 a means for measuring the quality of the message, and  
 a means for determining a quality factor associated with each communication station in dependence upon the measured quality of one or more of said received messages; and  
 a means for communicating said quality factors to a central station.  
   
   
   
       7 . A communication device as claimed in  claim 6 , wherein 
 said means for measuring the quality of the message comprises means for measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said message.    
   
   
       8 . A communication device as claimed in  claim 6 , wherein 
 said means for measuring the quality of the message comprises means for measuring a bit error rate associated with said message.    
   
   
       9 . A communications device as claimed in  claim 6 , wherein the communications device also comprises: 
 a means for obtaining the quality factor associated with one or more communication stations from each of the other communications stations, and a means for determining a quality measure associated with the network in dependence upon said obtained quality factors.    
   
   
       10 . A communications device as claimed in  claim 9 , wherein the communications device also comprises: 
 a means for determining one of said stations for designation as an alternative central station in dependence upon said quality measure.    
   
   
       11 . A communications system as claimed in  claim 9 , wherein the communications device also comprises: 
 a means for determining an alternative relay transmission path for one or more of said transmit-receive paths in dependence upon said quality measure.    
   
   
       12 . A method for assessing the quality of a communications network, said network comprising communication stations comprising means of transmitting and receiving messages,  
     wherein said method comprises the steps of: 
 transmitting a message from a transmitting communication station,  
 receiving the message at a plurality of receiving communication stations,  
 and, at each receiving communication station, 
 identifying the transmitting communication station, measuring the quality of the received message, and  
 determining a quality factor associated with the transmitting communication station in dependence upon the measured quality of the received message; and,after repeating the above steps for other transmitting communication stations,  
 
 having each communication station communicate the quality factors associated with each of said transmitting communication stations to a central station,  
 said central station thereby assessing the quality of the communication network in dependence upon said quality factors.  
 
   
   
       13 . A method as claimed in  claim 12 , wherein 
 said step of measuring the quality of the received message comprises a step of measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said received message.    
   
   
       14 . A method as claimed in  claim 12 , wherein 
 said step of measuring the quality of the received message comprises a step of measuring a bit error rate associated with said received message.    
   
   
       15 - 20 . (canceled)