Vicinity card

ISO/IEC 15693, is an ISO standard for vicinity cards, i.e. cards which can be read from a greater distance as compared with proximity cards.

ISO/IEC 15693 systems operate at the 13.56 MHz frequency, and offer maximum read distance of 1–1.5 meters. As the vicinity cards have to operate at a greater distance, the necessary magnetic field is less (0.15 to 5 A/m) than that for a proximity card (1.5 to 7.5 A/m).

Communication from the reader to the card uses an amplitude-shift keying with 10% or 100% modulation index.

The data coding is:

The card has two ways to send its data back to the reader:

Amplitude-shift keying 100% modulation index on a 423.75 kHz subcarrier. The data rate can be:

A logic 0 starts with eight pulses of 423.75 kHz followed by an unmodulated time of 18.88 µs (256/ fc); a logic 1 is the other way round. The data frame delimitors are code violations, a start of frame is:

and the end of a frame is:

The data are sent using a Manchester code.

Frequency-shift keying by switching between a 423.75 kHz sub carrier (operating frequency divided by 32) and a 484.25 kHz sub carrier (operating frequency divided by 28). The data rate can be:

A logic 0 starts with eight pulses of 423.75 kHz followed by nine pulses of 484.28 kHz; a logic 1 is the other way round. The data frame delimitors are code violations, a start of frame is:

and the end of a frame is:

The data are sent using a Manchester code.

see ISO/IEC 7816-6

The first byte of the UID should always be 0xE0. iCLASS family of cards and tags by HID Global, with a maximum read range 45 centimetres (18 in).

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