Is Tag Collision a Problem With Near Field Communication?

By RFID Journal

  • TAGS
Ask The ExpertsIs Tag Collision a Problem With Near Field Communication?
RFID Journal Staff asked 6 years ago

Would the presence of three or four RFID chips confuse an NFC reader by simultaneously transmitting data from all of the chips at once, thereby blocking it from getting any clear and useful card information?

—Jeff (New Mexico)



No. The NFC protocol has an anti-collision algorithm enabling a reader to interrogate one tag at a time. So any reader using the NFC protocol could read multiple transponders in a single card sequentially. This is true of virtually all passive RFID systems. The reader would ask the tags to respond, in much the same way that a teacher might ask children in a large classroom to respond one by one. The teacher might ask all students whose last name started with A to respond. If two or more children stood up, the teacher might ask only those whose first and last names began with A to remain standing, and so forth. This kind of system allows the reader to very quickly isolate tags and communicate with them one at a time.

—Mark Roberti, Founder and Editor, RFID Journal

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