Gen 2: Sowing UHF Tags Worldwide

• By David Essex
• Sep 07, 2006

In December 2004, EPC Global, the association that sets standards for bar codes and RFID tags, issued its second-generation UHF standard, Class 1 Gen 2. It unifies the air-interface protocols readers use to communicate with tags. Proponents predict it will speed development of cheaper hardware and spread UHF technology worldwide.
Gen 2 also:

• Provides four communication speeds that maximize throughput of multiple tag reads under adverse conditions, and under strict regulations in Europe and Asia. The previous generation's one-size-fits-all speed didn't adapt as well to varying conditions. Gen 2 nearly quadruples the number of possible tag reads per second.


• Improves reading of tags at the edge of transmission range.


• Expands tag ID size from 96 to 512 bits, though users are experimenting with tags that hold hundreds of kilobits, industry sources said.


• Introduces a 'dense-reader' mode that improves read rates of multiple readers in close proximity.


• Tightens security by raising the number of bits available in passwords for deactivating tags from 8 to 32 bits; allowing tags to generate hard-to-crack, 16-bit random numbers; and scrambling reader signals to make it 'virtually impossible' for intruders to read tag numbers, said EPC Global.

In the future, systems such as larger-memory tags, better security and battery-backed active tags with sensors will be possible through planned Class 2 and 3 updates, according to the organization.

Critics supporting competing HF cards insist, however, that Gen 2 still doesn't support the encryption and random numbers needed for secure passwords.