FCC Title 47, Part 15 for Identity Applications

FCC Title 47, Part 15

Electronic products and boards which emit electromagnetic radiation intentionally or unintentionally need to get Federal Communications Commission certification in United States to confirm that it complies by the rules and guidelines of FCC. Usually, the finished product needs to be certified, but at times board level certification may be sufficient so that it can be added to the motherboard which has been certified. A certified board is presumed not to violate the FCC certification when added to the mother gadget.

Part 15 applies to all products which do not require a licence for its operation. For the same reason, RFID readers for smart cards and tags need to be certified and approved for compliance with the following emission requirements.

Subparts of Part 15 (Unlicensed Low Power Intentional Radiators)
Part 15 is further divided into other sub parts as follows.
Subpart A: Contains information about the testing, certification, legal implications, definitions, prohibitions and labeling.
Subpart B: Presents rules for unintentional radiators.
Subpart C: Contains rules for intentional radiators.
Subpart D: Unlicensed personal communication devices
Subpart E: Unlicensed NII (National Information Infrastructure Devices)
Subpart G: Rules for broadband over power line. (BPL)

Device Types - Class A and Class B

The intentional radiators are classified into two classes

1. Class A: A digital device that is marketed for use in a commercial, industrial or business environment, exclusive of a device which is marketed for use by the general public or is intended to be used in the home.



2. Class B: A digital device that is marketed for use in a residential environment notwithstanding use in commercial, business and industrial environments. Examples of such devices include personal computers, calculators, and similar electronics devices that are marketed for use by the general public
   

Identity card physical access readers are classified as Class B device since they are typically used in offices that have close proximity to the people. Based on the frequency of transmission, radiators are generally categorized as the following.

Device Types based on frequency

• low freq 125-190 kHz; 1 watt power; 15 m of antenna length


• med freq 510-1705 kHz; 0.1 watt power; 3 m of antenna length


• hi freq 14kHz wide band at 13.56 MHz; 4.8 milli-watt power; dipole or 1/4 pole vertical
  

Most of the identity tags are passive and are either low or high frequency (freq) receptors. The prox card technology from Casi-Rusco/GE and HID operates at 125kHz. However, the proximity and the vicinity technology operate at 13.56 MHz which has a different set of radiation requirements.

Nearest Frequency where Intentional Radiators (125kHz or 13.56MHz) can't Radiate

Intentional radiators, readers in this case can't emit in the mentioned frequency range. The range is more exhaustive as per part 15 but the following is a subset of frequencies that falls near the 125/13.56 readers.

• 90-110 kHz / 495-505 kHz
  
• 12.57675-12.57725 MHz / 13.36-13.41 MHz / 16.42-16.423 MHz
  

Field Strength limits for 13.56MHz Technology (Additional Provision, Section 15.225)

PIV/FIPS 201 doesn't specify either the low freq (125kHz) or high range ISO 15693 which is designed to work for distances up to 100 cm. For 13.56 MHz, the field strength at distance of 30 m should be as follows:

• 13.553-13.567 MHz field strength should not exceed 15,848 uV/m at 30m.



• 13.410-13.553 MHz and 13.567-13.710 MHz field strength shall not exceed 334 uV/m at 30m.



• 13.110-13.410 MHz and 13.710-14.010 MHz field strength shall not exceed 106 uV/m at 30 m.



• The freq tolerance of the carrier freq will be maintained between +/- 0.01% for the temperature range of -20 to +50 degrees C.

Field Strength limits for 125kHz Technology

For 125 kHz readers, the maximum radiated power allowed should be as follows;

• 9-490 kHz field strength should not exceed 2400/F(kHz) uV/m at 300 m. For frequency of 125 kHz, F=125 therefore, the field strength should not exceed 2400/125 = 19.2 uV/m

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