With the basic electronics for interrogation, only one tag may be in the interrogation zone at a time, or responses will overlap, confusing the reader. Schemes which allow for multiple tags in the interrogation zone have been demonstrated such as "Supertag" software licensed by British Technology Group to eight companies. This is known as "anti-collision software" and standardised methodologies are emerging for all chip tags. This is an advantage over chipless tags, where anti-collision capability is primitive as yet.

 

Anti-collision will provide an important role in The Internet of Things. Large numbers of tags need to be read quickly, and if millions and billions of tags are being used it must be assumed that there will be more than one tag within the interrogatory zone of a reader at some time. It must distinguish and read tags from multiple suppliers, and be clever enough to 'ignore' tags within the interrogatory zone that should not be there. This technology is readily available today but will require the finalisation of smart labels standards for complete robustness.