Anti-collision method and system for reading data from multiple RFID tags

• US 20120068829A1
• Filed: 09/17/2011
• Published: 03/22/2012
• Est. Priority Date: 09/21/2010
• Status: Abandoned Application

• Current Assignee: Xiaoming Shi
• Original Assignee: Xiaoming Shi
• Inventors: Shi, Xiaoming
• Application Number:
  US13/200,121
• Publication Number:
  US 20120068829A1
• Time in Patent Office: Days
• US Class Current: 340/10.2
• CPC Class Codes: G06K 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08

Abstract

A radio frequency identification (RFID) system for reading data from multiple RFID tags without radio frequency (RF) signal collision. The system includes a RF caller (102) for transmitting a calling message (106) with a tag ID through a calling channel (104), a plurality of RFID tags (108) for receiving the calling message (106) on the calling channel (104), a RFID tag (110) of the RFID tags (108) for responding the calling message (106) to transmit a tag message (114) through a recording channel (112), and a RF recorder (116) for receiving the tag message (114) on the recording channel (112). At any time at most one message is transmitted through one RF channel, which can avoid any RF signal collision.

Claims

1. A radio frequency identification system, comprising:

a radio frequency (RF) caller for transmitting a calling message periodically through a RF calling channel;

a plurality of radio frequency identifier (RFID) tags for listening the calling message on the RF calling channel, each responding the calling message by transmitting a tag message through a RF recording channel; and

a RF recorder for receiving the tag message on the RF recording channel.

2. The system of claim 1, wherein each tag of said RFID tags is assigned with a unique identifier (tag ID).

3. The system of claim 2, wherein said RF caller maintains a tag IDs list of said RFID tags.

4. The system of claim 2, wherein said calling message contains a tag ID of one of said RFID tags.

5. The system of claim 4, wherein one of said RFID tags, which has the same tag ID as that contained in the calling message, is capable of transmitting a tag message through the RF recording channel.

6. A radio frequency identification system, comprising:

a radio frequency (RF) caller for transmitting a calling message through a RF calling channel;

a plurality of radio frequency identifier (RFID) tags for listening the calling message on the RF calling channel, each responding the calling message by transmitting a tag message through a RF recording channel; and

a plurality of radio frequency (RF) recorders for receiving the tag message on the RF recording channel.

7. A method of avoiding RF signal collision for reading data from multiple RFID tags, comprising the steps of:

(a) providing a plurality of RFID tags, each tag being assigned with an unique identifier number (tag ID);

(b) transmitting a calling message periodically from a radio frequency (RF) caller through a RF calling channel to the RFID tags, the calling message containing an tag ID of one of said RFID tags; and

(c) transmitting a tag message from the RFID tag having a tag ID that is the same as the tag ID in the calling message through a recording channel to a RF recorder.