What is the difference between ISO/IEC 14443 Type A and ISO/IEC 14443 Type B?
The ISO/IEC 14443 standard defines a way to provide power and communicate between a reader and a contactless smart card. The standard specifies 13.56 MHz as the frequency and also defines a communication protocol between the card and the reader. Type A and Type B are the two communication methods defined by the standard. Differences include the modulation of the magnetic field used for coupling, the coding format and the anticollision method (i.e., how the cards and readers respond when more than one card responds at the same time to a readers request for data). In 1994, when standardization began, Type A and Type B had slightly different application focus. Todays technological advances have removed this application differentiation. By including both in the final version of the ISO/IEC 14443 standard, the widest base of vendors are able to offer standardized contactless technology.