Standardisation - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 249

9.2.3 ISO 15693 - Vicinity coupling smart cards

The ISO standard 15693 entitled 'Identification cards — contactless integrated cir-
cuit(s) cards — Vicinity Cards' describes the method of functioning and operating
parameters of contactless vicinity coupling smart cards . These are smart cards with
a range of up to 1m, like those used in access control systems. The data carriers
used in these smart cards are predominantly cheap memory modules with simple state
machines (see Section 10.1.2.1).
The standard is made up of the following parts:

•

Part 1: Physical characteristics

•

Part 2: Radio frequency power, signal interface and frames (still in preparation)

•

Part 3: Protocols (in preparation)

• Part 4: Registration of applications/issuers (in preparation)

9.2.3.1 Part 1 - Physical characteristics

Part 1 of the standard defines the mechanical properties of proximity coupling smart
cards. The dimensions of the smart card correspond with those specified in ISO 7810,
i.e. 85 . 72 mm × 54 . 03 mm × 0 . 76 mm ± tolerances.
Furthermore, this part of the standard includes additional notes for the testing of
the dynamic bending stress and the dynamic torsion stress, plus irradiation with UV,
x-ray and electromagnetic radiation.

9.2.3.2 Part 2 - Air interfaceand initialisation

The power supply of the inductively coupled vicinity card ( VICC ) is provided by the
magnetic alternating field of a reader ( PCD ) at a transmission frequency of 13.56MHz.
The vicinity card incorporates a large area antenna coil for this purpose, typically with
3-6 windings of wire (see Figures 2.11 and 2.12).
The magnetic field to be generated by the reader must lie within the limit values
115mA/m ≤ H ≤ 7 . 5 A/m. Thus, it is automatically the case for the interrogation field
strength H min of a proximity coupling smart card that H min ≤ 115mA/m.
Datatransferreader card Both 10% ASK and 100% ASK modulation are used for

the data transfer from a reader to a vicinity smart card (see Section 6.2.1). Regardless
of the selected modulation index, moreover, one of two different coding procedures
can be selected: a '1 of 256' code or a '1 of 4' code.
A vicinity smart card must, in principle, support both modulation and coding pro-
cedures. However, not all combinations are equally practical. For example, 10% ASK
modulation in combination with '1 of 256' coding should be given preference in 'long
distance mode'. The lower field strength of the modulation sidebands in comparison
to the field strength of the (13.56MHz) carrier signal in this combination permits the
full exploitation of the permissible magnetic field strength for the power supply of the

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