The standard for contactless smart card communications is ISO/IEC 14443. The standard defines two types of contactless cards called "A" and "B". This standard defines the communications of the card to the reader at distances up to 10 cm.
There had been proposals for ISO/IEC 14443 types C, D, E, F and G that have been rejected by the International Organization for Standardization.[citation needed] An alternative standard for contactless smart cards is ISO 15693, which allows communications at distances up to 50 cm.
Like smart cards with contacts, contactless cards do not have a battery. Instead, they use a built-in inductor to capture some of the incident radio-frequency interrogation signal, rectify it, and use it to power the card's electronics.
A related contactless technology is RFID (radio frequency identification). In certain cases, it can be used for applications similar to those of contactless smart cards, such as for electronic toll collection. RFID devices usually do not include writeable memory or microcontroller processing capability as contactless smart cards often do.
Communication protocols
The common communication protocol of contactless smartcard are as follows:
Communication protocols Name Description
T=0 Character-level transmission protocol, defined in ISO/IEC 7816-3
T=1 Block-level transmission protocol, defined in ISO/IEC 7816-3
ISO/IEC 14443 APDU transmission via contactless interface, defined in ISO/IEC 14443-4