Methods and apparatuses for identification

Abstract

An identification system includes a reader and one or more tags. The reader identifies tags such as radio frequency (RF) tags. The system divides a number space into n bins, wherein each bin is associated with m unique bits of the number space, and the number space contains the identification codes of the tags. A command is issued to test v bits of the number space. A response is received from a tag, wherein the response occurs when a first portion of an identification code of the tag matches the v bits of the number space, a timing of the response corresponds to a particular bin and m unique bits associated with the particular bin correspond to a second portion of the identification code.

1 . A method to identify a tag of a plurality of tags, each tag having an identification code stored in a memory, said method comprising: 
 broadcasting a command having a first data; and    receiving a response to said command from a tag; wherein said response is associated with a bin of a plurality of bins, said bin corresponding to a value of a selected set of bits of information stored in said tag, the selected set of bits being a function of said first data.    
     
     
         2 . A method performed by a tag of a plurality of tags, each tag of the plurality of tags having an identification code stored in a memory of said tag, said method comprising: 
 receiving a first data from a reader;    correlating said first data with a selected set of bits of information stored in the memory of said tag, the selected set of bits being a function of said first data; and    transmitting a response to said reader if said first data correlates with said set of bits, the response being associated with a bin of a plurality of bins, wherein the bin of said response corresponds to a value of the selected set of bits.    
     
     
         3 . A method performed by a reader to identify a tag of a plurality of tags, each tag of the plurality of tags having an identification code and a memory, said method comprising: 
 dividing a number space into n bins, wherein each bin is associated with a different value defined by m bits of said number space, and said number space being associated with information stored in the memories of said plurality of tags, n being an integer greater than two;    issuing a command to test a value defined by v bits of said number space; and    receiving a response from a tag of the plurality of tags, wherein said response occurs when a set of v bits of said information stored in said tag matches said value of v bits of said command, a timing of said response corresponding to a bin of said n bins, the value of the m bits associated with said bin matching a value of m selected bits of said selected information.    
     
     
         4 . A method performed by a reader, said method comprising: 
 issuing a command to a tag; and    receiving a response from said tag, wherein said response includes an identification code of said tag and said receiving and said issuing do not occur concurrently.    
     
     
         5 . A method to identify a tag of a plurality of tags, each tag of the plurality of tags having an identification code and a memory, said method comprising: 
 receiving, by a tag of the plurality of tags, a command from a reader to test v bits of a number space, said number space corresponding to information stored by said tag; and    issuing a response to said reader if a value of said received v bits match a value of v corresponding bits of said information, wherein a timing of said response corresponds to a value of m bits of said stored information.    
     
     
         6 . A method performed by a tag to identify a tag of the plurality of tags, each tag of the plurality of tags having an identification code, said method comprising: 
 receiving a command from a reader to test v bits of a number space; and    issuing a response to said reader if a value of said v bits of the received command match a value of a first portion of said tag's identification code, wherein said response includes said identification code.    
     
     
         7 . A machine readable medium containing executable instructions, which when executed by a machine cause said machine to perform operations comprising: 
 broadcasting a command having a first data; and    receiving a response to said command from a tag; wherein the response is associated with a bin of a plurality of bins, the bin corresponding to a value of a selected set of bits of information stored in said tag, the selected set of bits being a function of said first data.    
     
     
         8 . A machine readable medium containing executable instructions that when executed by a machine cause said machine to perform operations comprising: 
 receiving a command broadcast by a reader, the command having a first data;    correlating said first data with a selected set of bits of information stored in a memory of said machine, the selected set of bits being a function of said first data; and    transmitting a response to said reader if said first data correlates with said set of bits, the response being associated with a bin of a plurality of bins, wherein the bin of said response corresponds to a value of the selected set of bits.    
     
     
         9 . A machine readable medium containing executable instructions that when executed by a machine cause said machine to perform operations comprising: 
 issuing a command to test a value defined by v bits of a number space, the number space having n bins, wherein each bin is associated with a different value defined by m bits of said number space, and said number space being associated with information stored in memories of a plurality of tags, n being an integer greater than two; and    receiving a response from a tag of the plurality of tags, wherein said response occurs when a set of v bits of said information stored in said tag matches said value of v bits of said command, a timing of said response corresponding to a bin of said n bins, the value of the m bits associated with said bin matching a value of m selected bits of said selected information.    
     
     
         10 . A machine readable medium containing executable instructions that when executed by a machine, cause said machine to perform operations comprising: 
 issuing a command to a tag of a plurality of tags; and    receiving a response from said tag, wherein said response includes an identification code of said tag and said receiving and said issuing do not occur concurrently.    
     
     
         11 . A machine readable medium containing executable instructions that when executed by a machine cause said machine to perform operations comprising: 
 receiving a command from a reader to test v bits of a number space, said number space corresponding to information stored by said machine; and    issuing a response to said reader if a value of said received v bits match a value of v corresponding bits of said information, wherein a timing of said response corresponds to a value of m bits of said stored information.    
     
     
         12 . A machine readable medium containing executable instructions that when executed by a machine cause said machine to perform operations comprising: 
 receiving a command from a reader to test v bits of a number space; and    issuing a response to said reader if a value of said v bits of the received command match a value of a first portion of said machine's identification code.    
     
     
         13 . An apparatus to identify tags, each tag having an identification code, said apparatus comprising: 
 a processor to provide a first data;    a transmitter to transmit said first data to a plurality of tags; and    a receiver to receive a response to said first data and provide received data to said processor, said response sent from a tag, wherein said response is associated with a bin of a plurality of bins, said bin corresponding to a value of a selected set of bits of information stored in said tag, the selected set of bits being a function of said first data.    
     
     
         14 . A tag comprising: 
 a receiver to receive a first data from a reader;    a control unit to correlate said first data with a portion of information stored in said tag; and    a transmitter to transmit a response from said control unit to said reader if said first data matches said portion of said information, the response being associated with a bin of a plurality of bins, wherein the bin of said response corresponds to a value of a selected set of bits of said information, the selected set of bits being a function of the first data.    
     
     
         15 . An apparatus to identify tags, each tag having an identification code, said apparatus comprising: 
 a processor to send at least one command, wherein a number space is divided into n bins, wherein each bin is associated with m bits of said number space, and said number space containing said identification codes of said tags;    a transmitter to transmit said at least one command to test v bits of said number space; and    a receiver to receive a response from a tag and provide data from said response to the processor, wherein said response occurs when a first portion of an identification code of said tag matches a value of said v bits, a timing of said response corresponding to a particular bin, said particular bin being associated with a particular value of m bits of a second portion of said identification code.    
     
     
         16 . A tag of a plurality of tag each having an identification code, said tag comprising: 
 a receiver to receive a command from a reader, the command including v bits of a number space;    a processor to compare said received v bits with a first portion of said tag's identification code; and    a transmitter to issue a response from said processor to said reader if said received v bits match said first portion of said identification code, wherein a timing of said response corresponds to a second portion of said identification code.    
     
     
         17 . A reader to identify a tag of a plurality of tags, each tag having an identification code stored in a memory, said reader comprising: 
 means for broadcasting a command having a first data; and    means for receiving a response to said command from a tag;    wherein said response is associated with a bin of a plurality of bins, said bin corresponding to a value of a selected set of bits of information stored in said tag, the selected set of bits being a function of said first data.    
     
     
         18 . A tag of a plurality of tags each having an identification code, said tag comprising: 
 means for receiving a first data from a reader;    means for correlating said first data with a selected set of bits of information stored in said tag, the selected set of bits being a function of said first data; and    means for transmitting a response to said reader if said first data correlates with said set of bits, the response being associated with a bin of a plurality of bins, wherein the bin of said response corresponds to a value of the selected set of bits.    
     
     
         19 . A reader to identify a tag of a plurality of tags, each tag of the plurality of tags having an identification code, said reader comprising: 
 means for issuing a command to having a value defined by v bits of a number space, said number space having n bins, wherein each bin is associated with a different value defined by m bits of said number space, said number space being associated with information stored in said plurality of tags, n being an integer greater than two; and    means for receiving a response from a tag of the plurality of tags, wherein said response occurs when a set of v bits of said information stored in said tag matches said value of said v bits of said command, a timing of said response corresponding to a bin of said n bins, the value of the m bits associated with said bin matching a value of m selected bits of said selected information.    
     
     
         20 . A tag of a plurality of tags each having an identification code, said tag comprising: 
 means for receiving a command from a reader to test v bits of a number space, said number space corresponding to information stored by said plurality of tags; and    means for issuing a response to said reader if a value of said received v bits match a value of v corresponding bits of said information, wherein a timing of said response corresponds to a value of m bits of said stored information.    
     
     
         21 . A tag of the plurality of tags each having an identification code, said tag comprising: 
 means for receiving a command from a reader to test v bits of a number space; and    means for issuing a response to said reader if a value of said v bits of the received command match a value of a first portion of said tag's identification code, the response including said tag's identification code.    
     
     
         22 . An apparatus to identify tags, each tag having an identification code, said apparatus comprising: 
 a processor to send at least one command to a tag of a plurality of tags;    a transmitter to transmit said at least one command; and    a receiver to receive a response from said tag and provide data from said response to the processor, wherein said response includes a full identification code of said tag, said receiving and said issuing do not occur concurrently, and said tag being a passive backscatter tag powered by only the reader.    
     
     
         23 . A tag of a plurality of tags each having an identification code, said tag comprising: 
 a receiver to receive a command from a reader, the command including v bits of a number space;    a processor to compare said received v bits with a first portion of said tag's identification code; and    a transmitter to issue a response from said processor to said reader if said received v bits match said first portion of said identification code, wherein said response including said tag's full identification code.