Patent ID: 9070003
Filing Date: 2015-06-30
Classification: G06K,G08B,H04Q

Abstract:
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.