Patent ID: 7893836
Filing Date: 2011-02-22
Classification: G06K,H04Q

Abstract:
1. A method of avoiding a collision between each of RFID (radio frequency identification) readers communicating with a RFID tag via limited frequency channels, performed by an apparatus for avoiding a collision between each of RFID readers, the apparatus being wire-connected or wireless-connected to the RFID readers and comprising a channel control unit and a channel holding unit, the method comprising: dividing, in a management information unit of the channel control unit, the RFID readers into first RFID readers and second RFID readers according to a maximum output level, and setting first frequency channels to be used by the first RFID readers and second frequency channels to be used by the second RFID readers; setting frequency channel disposition information, in the management information unit, which allocates one or more available frequency channels from among the first frequency channels to each of the first RFID readers; generating a channel holding signal, in a control unit of the channel control unit, which limits a usage by the second RFID readers, in each of the first frequency channels; stopping a generation of the channel holding signal, in the control unit, in a selected frequency channel based on the frequency channel disposition information when a frequency channel usage request is received from one of the first RFID readers; and generating the channel holding signal, in the control unit, in a return requested frequency channel when a frequency channel return request is received from one of the first RFID readers.