Contact-less proximity chips operate at about five inches from the reader. This prevents activation by those only passing by and hackers reading them from a distance. They are used in payment cards and access control badges. Vicinity chips can be read at five feet. Vicinity chips are used for inventory management. These chips activate security systems when the product tagged with them is taken through store doors before deactivation.
ISO 14443-2 Type A and Type B smart cards use transmission protocols to communicate with smart card readers. Smart cards built according to ISO 14443-2 use the 13.56 MHz communication frequency. Smart card readers accept both types of communication protocols for Type A and Type B, alternating broadcasting communication protocols for Type A and Type B cards, since they use different anti-collision protocols.
Type A Cards
Type A smart cards are often called memory cards. Type A smart cards are activated after transmission of the answer to select (ATS) protocol. The smart card relays its credentials and authentication when requested by the card reader. Type A cards must also send information about data parameters like frame size. After authentication, the card reader can update the stored value on the smart card microchip or turn it off. According to "The RFID Handbook" by Klaus Finkenzeller, "In type A cards, 100% ASK modulation with modified Miller coding is defined as the modulation procedure used for the transfer of data from reader to card." Type A smart cards receive bursts of power from the reader while in communication.
Type B Cards
Type B smart cards are usually called microprocessor cards. Type B cards receive power continuously while they are in contact with the smart card reader. Type B cards handle bit rates up to 847 kilobytes (KB) per second. Type B smart cards include data parameters along with authentication information. According to "The RFID Handbook" by Klaus Finkenzeller, "In Type B cards, 10 per cent ASK modulation is used as the modulation procedure for data transfer from reader to card.