What is the difference between EPC’s Gen 1 tags and Gen 2 tags?
With regard to Generation 1, there are Class 0 and Class 1 specifications for tags in the UHF band. Class 0 was originated as a protocol by Matrics Technology Systems (acquired by Symbol Technologies) and Class 1 was originated as a protocol by Alien Technologies. Class 0 has been defined by EPCglobal as a read-only device. Class 1 is defined in the EPCglobal specification as a tag that is one-time programmable. In practice, the products that are available from Alien Technologies are reprogrammable. And Matrics/Symbol has released “Class 0+” products, which are based on the same protocol as the Class 0 device, but are, in fact, fully re-writeable. With regard to Generation 2, Class 1 (Class 0 was dropped) standards were ratified at the end of 2004 as a response to the limitations of the Generation 1 standards. Gen 2 provides expanded data functionality and better performance, is designed to support EPC codes up to 256 bits long, and has the provision for extra data to be carried in the
