Systems and methods for collision avoidance in a multiple RFID interrogator environment

摘要

A method for collision avoidance in a multi-reader environment comprising a plurality of Radio Frequency Identification (RFID) interrogators, the method comprises each of the plurality of interrogators entering a quiet state during which none of the interrogators transmits, each of the plurality of interrogators selecting a transmit time after the quiet period during which each of the interrogator will attempt to transmit, each of the plurality of interrogators monitoring their associated receive path, an interrogator of the plurality of interrogators transmitting an instruction during its selected transmit time indicating the beginning of a session when the interrogator does not detect data on its receive path prior to its select transmit time, the interrogator comparing its receive path to its transmit path when it transmits the instruction, the interrogator returning to the quiet state when the receive path does not match the transmit path, and the interrogator completing the session when the receive path matches the transmit path.

主权项

1. An RFID interrogator, comprising;
a transmit circuit configured to generate transmit data; a receive circuit configured to decode receive data; a collision detection circuit configured to compare the transmit data with the receive data; a processor coupled with the transmit circuit and the receive circuit, the processor configured to execute instructions; and a memory coupled with the processor, the memory configured to store instructions, the instructions configured to cause the processor to: enter a quiet state during which the processor prevents the transmit circuit from generating the transmit data, select a first transmit time after the quiet state during which the interrogator will attempt to transmit a first set of transmit data via the transmit circuit, return to the quiet state if the receiver detects data on its receive path prior to the first transmit time and select a new first transmit time, transmit the first set of transmit data during the first transmit time or the new first transmit time when the receiver does not detect data on its receive path prior to the first transmit time or the new first transmit time, return to the quiet state when the collision detection circuit detects that the receive path does not match the transmit path after the first set of transmit data is transmitted, wait a predetermined period of time different than the quiet state when the collision detection circuit does not detect that the receive path does not match the transmit path after the first set of transmit data is transmitted, select a second transmit time after the first set of transmit data has been transmitted during which the interrogator will attempt to transmit a second set of transmit data via the transmit circuit, return to the quiet state if the receiver detects data on its receive path prior to the second transmit time, transmit the second set of transmit data during the second transmit time, and return to the quiet state when the collision detection circuit detects that the receive path does not match the transmit path after the second set of transmit data is transmitted.