Radio frequency communication network having adaptive communication parameters

Abstract

Improved apparatus for a radio communication network having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which communicate with one or two host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. The radio network is adaptive in that in order to compensate for the wide range of operating conditions a set of variable network parameters are exchanged between transceivers in the network. These parameters define optimized communication on the network under current network conditions. Examples of such parameters include: the length and frequency of the spreading code in direct-sequence spread spectrum communications; the hop frame length, coding, and interleaving in frequency-hopping spread spectrum communications; the method of source encoding used; and the data packet size in a network using data segmentation. The invention is preferably to be applicable as an upgrade of an existing data capture system wherein a large number of hand-held transceiver units operate over an extensive area to gather data in various places, requiring the use of multiple base stations. In a variety of such installations such as warehouse facilities, distribution centers, and retail establishments, it may be advantageous to utilize not only multiple bases capable of communication with a single host, but with multiple hosts as well.

1 - 47 . (canceled)  
     
     
         48 . A communications network for collecting data, segmenting the data and communicating the data segments, comprising: 
 a first transceiver;    a second transceiver;    said first transceiver identifying the occurrences of failed transmissions from said first transceiver to said second transceiver, and, based on an evaluation of such occurrences, said first transceiver adjusts the size of data segments to be transmitted.    
     
     
         49 . The network of  claim 48 , wherein the data segments are sized in proportion to a failure rate.  
     
     
         50 . The network of  claim 48 , wherein a default data segment size is based on a correlation distance.  
     
     
         51 . The network of  claim 48 , wherein a default data segment size is a largest normal segment size.  
     
     
         52 . The network of  claim 48 , wherein the data segment size is reduced until a number of failed transmissions is reduced to an acceptable level.  
     
     
         53 . The network of  claim 48 , wherein the data segment size is reduced in response to a received signal strength indicator transmitted to the first transceiver.  
     
     
         54 . The network of  claim 48 , wherein the data segment size is adjusted based on a weighted average of failed transmissions.  
     
     
         55 . The network of  claim 48 , wherein said second transceiver indicates a failed data segment transmission by sending a “not acknowledged” signal to said first transceiver.  
     
     
         56 . The network of  claim 48 , wherein said second transceiver indicates a failed data segment transmission by not sending an “acknowledged” signal to said first transceiver.  
     
     
         57 . A method for use by a first controller in a wireless communications network, said method comprising: 
 transmitting data segments to a second controller;    determining at least one occurrence of a failed transmission from said first controller to said second controller; and    adjusting, after said determining said at least one occurrence of a failed transmission, the size of data segments to be transmitted.    
     
     
         58 . The method of  claim 57 , comprising determining an occurrence of a failed transmission based on the failure of said second controller to acknowledge said transmission.  
     
     
         59 . The method of  claim 57 , comprising determining an occurrence of a failed transmission based on receipt of a not acknowledged signal from said second controller.  
     
     
         60 . The method of  claim 57 , wherein the data segment size is adjusted based on a weighted average of a number of failed transmissions.  
     
     
         61 . The method of  claim 57 , wherein the data segment size is adjusted based on a received signal strength indicated by said second controller.  
     
     
         62 . The method of  claim 57 , wherein the data segment size is reduced until failed transmissions are reduced to an acceptable level.  
     
     
         63 . The method of  claim 57 , wherein a normal data segment size is based on a correlation distance.  
     
     
         64 . The method of  claim 57 , wherein the data segments are sized in inverse proportion to an average rate of failed transmissions.  
     
     
         65 . The method of  claim 57 , wherein adjusting the size of data segments to be transmitted to said second controller is based on a number of failed transmissions from said first controller to said second controller.  
     
     
         66 . The method of  claim 57 , wherein said first controller and said second controller each comprise a transceiver.  
     
     
         67 . A method of communicating between a first controller and a second controller over a wireless medium, said method comprising: 
 sending, by said first controller, a data transmission to said second controller where said data transmission has a predetermined segment size;    determining, by said first controller, whether there was a failure by said second controller to receive at least one segment;    reducing, by said first controller, the segment size of said data transmission based on a determination of a failure of said second controller to receive at least one segment; and    resending, by said first controller, said data transmission to said second controller using said reduced segment size.    
     
     
         68 . The method of  claim 67 , wherein said first controller determines that there was failure to receive a segment based on the failure of said second controller to acknowledge the receipt of said segment.  
     
     
         69 . The method of  claim 67 , wherein said first controller determines that there was a failure to receive a segment based on the receipt from said second controller of a not acknowledged signal.  
     
     
         70 . The method of  claim 67 , wherein said first controller reduces the segment size based on a weighted average of failed transmissions.  
     
     
         71 . The method of  claim 67 , wherein said first controller reduces the segment size based on a moving average of failed transmissions.  
     
     
         72 . The method of  claim 67 , wherein said first controller sets the segment size based on a correlation distance.  
     
     
         73 . The method of  claim 67 , wherein said first controller sets the segment size inversely proportional to a rate of failed transmissions.  
     
     
         74 . The method of  claim 67 , wherein said first controller receives a received signal strength indicator from said second controller, and adjusts said segment sized based on said signal strength indicator.  
     
     
         75 . The method of  claim 67 , wherein said first controller reduces said segment size in increments.  
     
     
         76 . The method of  claim 67 , wherein said first controller and said second controller each comprise a transceiver.  
     
     
         77 . A system, for use in a communications network for collecting data, segmenting the data and communicating the data segments, comprising: 
 a first controller, said first controller identifying the occurrences of failed transmissions from said first controller to a second controller, and, based on an evaluation of such occurrences, said first controller adjusts the size of data segments to be transmitted.    
     
     
         78 . The system of  claim 77 , wherein the data segments are sized in proportion to a failure rate.  
     
     
         79 . The system of  claim 77 , wherein a default data segment size is based on a correlation distance.  
     
     
         80 . The system of  claim 77 , wherein a default data segment size is a largest normal segment size.  
     
     
         81 . The system of  claim 77 , wherein the data segment size is reduced until a number of failed transmissions is reduced to an acceptable level.  
     
     
         82 . The system of  claim 77 , wherein the data segment size is reduced in response to a received signal strength indicator transmitted to the first controller.  
     
     
         83 . The system of  claim 77 , wherein the data segment size is adjusted based on a weighted average of failed transmissions.  
     
     
         84 . The system of  claim 77 , wherein a failed data segment transmission is indicated by receipt at said first controller of a “not acknowledged” signal from said second controller.  
     
     
         85 . The system of  claim 77 , wherein a failed data segment transmission is indicated by non-receipt at said first controller of an “acknowledged” signal from said second controller.  
     
     
         86 . The system of  claim 77 , wherein said first controller and said second controller each comprise a transceiver.  
     
     
         87 . A system for use in a wireless communications network, said system comprising: 
 a first controller, said first controller transmits data segments to a second controller, said first controller determines at least one occurrence of a failed transmission to said second controller, and said first controller, after determining said at least one occurrence of a failed transmission, adjusts the size of data segments to be transmitted.    
     
     
         88 . The system of  claim 87 , wherein said first controller determines an occurrence of a failed transmission based on the failure of said second controller to acknowledge said transmission.  
     
     
         89 . The system of  claim 87 , wherein said first controller determines an occurrence of a failed transmission based on receipt of a not acknowledged signal from said second controller.  
     
     
         90 . The system of  claim 87 , wherein the data segment size is adjusted based on a weighted average of a number of failed transmissions.  
     
     
         91 . The system of  claim 87 , wherein the data segment size is adjusted based on a received signal strength indicated by said second controller.  
     
     
         92 . The system of  claim 87 , wherein the data segment size is reduced until failed transmissions are reduced to an acceptable level.  
     
     
         93 . The system of  claim 87 , wherein a normal data segment size is based on a correlation distance.  
     
     
         94 . The system of  claim 87 , wherein the data segments are sized in inverse proportion to an average rate of failed transmissions.  
     
     
         95 . The system of  claim 87 , the size of data segments to be transmitted is adjusted based on a number of failed transmissions from said first controller to said second controller.  
     
     
         96 . The system of  claim 87 , wherein said first controller and said second controller each comprise a transceiver.