Battery assisted RFID command set and interference control
First Claim
1. A method for generating, an RFID activation command that is transmitted from an RFID reader and processed in an RFID tag, the method comprising:
- generating a reader identification code that provides identification of the RFID reader to the RFID tag, the reader identification code provides authentication information that enables the RFID tag to exclusively lock onto the RFID reader after activation;
inserting the reader identification code in a first field within a command that communicate activation information between the RFID reader and the RFID tag; and
transmitting the command to the RFID tag,wherein the activation of the RFID tag is based on a timer controlled session/inventory flag state that is related to system transmit power control operations such that when the RFID tag is accessed at a first reader transmit power level, it temporarily does not respond to reader commands transmitted at a higher power level than the first power level.
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Accused Products
Abstract
Specialized battery assisted command set design methods are disclosed that provide for interference rejection using highly sensitive but relatively broadband RFID tags. The command set design also supports RFID system RF power control for further interference control. The command set design also allows for convenient expansion to active transmitters and receivers in tags operating within the same system. Embodiments of the present invention provide RFID systems having battery-assisted, Semi-Passive RFID tags that operate with sensitive transistor based square law tag receivers utilizing a plurality of tag receiver dynamic range states. Additional enhancement attained via power leveling methods that optimize the amount of transmitted power and interference from a reader in relation to the sensitivity of the RFID tags, their ranges from the reader, and the unique physics of the backscatter RFID radio link.
9 Citations
20 Claims
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1. A method for generating, an RFID activation command that is transmitted from an RFID reader and processed in an RFID tag, the method comprising:
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generating a reader identification code that provides identification of the RFID reader to the RFID tag, the reader identification code provides authentication information that enables the RFID tag to exclusively lock onto the RFID reader after activation; inserting the reader identification code in a first field within a command that communicate activation information between the RFID reader and the RFID tag; and transmitting the command to the RFID tag, wherein the activation of the RFID tag is based on a timer controlled session/inventory flag state that is related to system transmit power control operations such that when the RFID tag is accessed at a first reader transmit power level, it temporarily does not respond to reader commands transmitted at a higher power level than the first power level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for generating an RFID activation command that is transmitted from an RFID reader and processed in an RFID tag, the command structure comprising:
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generating a session/inventory flag identification code that specifies a session that the RFID reader will use after a set of RFID tags has been activated; generating a session/inventory care/don'"'"'t care code that indicates whether the RFID tag, within the set of RFID tags, is to check a hibernate mode state of a session/inventory flag as a parameter upon which to base activation of the RFID tag; generating a control code that specifies if tag session locking is to be in effect after activation of the RFID tag; inserting the session/inventory flag identification code, the session/inventory care/don'"'"'t care code, and the control code within a plurality of fields in the RFID activation command; and wherein the RFID reader specifies a value that places the RFID tag in a tag session locked mode to prevent a response to a normal mode command with a differing session code than one indicated in the activation command structure, wherein the activation of the RFID tag based on a timer controlled session/inventory flag state is related to system transmit power control operations such that the RFID tag accessed at a first reader transmit power level temporarily does not respond to reader commands transmitted at a higher power level than the first power level. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification