Method for handling collision in an identification system
First Claim
1. A method for handling collision in an identification system the method comprising the following steps:
- a reader device transmits an initialization command to a first transponder and to a second transponder;
upon receiving the initialization command, the first transponder and the second transponder enter into a muted state, and in the muted state the first transponder and the second transponder do not respond to commands from the reader device;
in a first start time slot randomly determined by the first transponder, the first transponder enters into an un-muted state from the muted state and the first transponder remains in the un-muted state until the reader device sends a mute command to the first transponder;
in a second start time slot randomly determined by the second transponder, the second transponder enters into an un-muted state from the muted state and the second transponder remains in the un-muted state until the reader device sends a mute command to the second transponder;
wherein, when the first start time slot and the second time slot occur at the same randomly determined time slot, then;
when a transponder has a weaker signal modulation than another transponder, then the transponder with the weaker signal modulation re-enters into a muted state until a third start time slot randomly determined by the transponder corresponding to the weaker signal modulation; and
when the signal modulation of the first transponder and the second transponder have substantially the same strength, then the first transponder and the second transponder re-enter into a muted state until a start time slot randomly determined by the corresponding transponder.
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Accused Products
Abstract
A method for handling collision in an identification system where the identification system includes a reader, a first transponder and a second transponder. The method involves the reader transmitting an initialization command to the first transponder and to the second transponder; upon receiving the initialization command, the first transponder and the second transponder enter into a muted state where the first transponder and the second transponder do not respond to commands from the reader; in a randomly determined first start time slot the first transponder enters into an un-muted state and the first transponder remains in the un-muted state until the reader sends a mute command to the first transponder; in a randomly determined second start time slot the second transponder enters into an un-muted state and the second transponder remains in the un-muted state until the reader sends a mute command to the second transponder.
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Citations
12 Claims
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1. A method for handling collision in an identification system the method comprising the following steps:
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a reader device transmits an initialization command to a first transponder and to a second transponder; upon receiving the initialization command, the first transponder and the second transponder enter into a muted state, and in the muted state the first transponder and the second transponder do not respond to commands from the reader device; in a first start time slot randomly determined by the first transponder, the first transponder enters into an un-muted state from the muted state and the first transponder remains in the un-muted state until the reader device sends a mute command to the first transponder; in a second start time slot randomly determined by the second transponder, the second transponder enters into an un-muted state from the muted state and the second transponder remains in the un-muted state until the reader device sends a mute command to the second transponder; wherein, when the first start time slot and the second time slot occur at the same randomly determined time slot, then; when a transponder has a weaker signal modulation than another transponder, then the transponder with the weaker signal modulation re-enters into a muted state until a third start time slot randomly determined by the transponder corresponding to the weaker signal modulation; and when the signal modulation of the first transponder and the second transponder have substantially the same strength, then the first transponder and the second transponder re-enter into a muted state until a start time slot randomly determined by the corresponding transponder. - View Dependent Claims (2, 3, 4, 6)
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5. An identification system comprising a reader device, a first transponder and a second transponder,
wherein the reader device is arranged to transmit an initialization command to the first transponder and to the second transponder; -
wherein the first transponder and the second transponder are arranged to enter into a muted state upon receipt of the initialization command; wherein, in the muted state, the first transponder and the second transponder are arranged to refrain from responding to commands from the reader device; wherein, in a first start time slot randomly determined by the first transponder, the first transponder is arranged to enter into an un-muted state from the muted state and the first transponder is arranged to remain in the un-muted state until the reader device sends a mute command to the first transponder; wherein, in a second start time slot randomly determined by the second transponder, the second transponder is arranged to enter into an un-muted state from the muted state and the second transponder is arranged to remain in the un-muted state until the reader device sends a mute command to the second transponder; wherein, when the first start time slot and the second time slot occur at the same randomly determined time slot, then; when a transponder has a weaker signal modulation than another transponder, then the transponder with the weaker signal modulation re-enters into a muted state until a third start time slot randomly determined by the transponder corresponding to the weaker signal modulation; and when the signal modulation of the first transponder and the second transponder have substantially the same strength, then the first transponder and the second transponder re-enter into a muted state until a start time slot randomly determined by the corresponding transponder.
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7. A method for handling collision by a transponder in an identification system, the method comprising:
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upon receiving an initialization command from a reader device, a transponder enters into a muted state and, in the muted state, the transponder does not respond to external commands; in a start time slot randomly determined by the transponder, the transponder enters into an un-muted state from the muted state and remains in the un-muted state until at least one of; a collision occurs with another transponder having a stronger modulated signal, upon which the transponder re-enters into a muted state until a second start time slot randomly determined by the transponder;
ora collision occurs with another transponder having a substantially similar strength modulated signal, upon which the transponder re-enters into a muted state until a second start time slot randomly determined by the transponder. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification