Part 15 (FCC rules)
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In the U.S., Part 15 is an often-quoted section of Federal Communications Commission (FCC) rules and regulations, mainly regarding unlicensed transmissions. It is a part of CFR Title 45 of the Code of Federal Regulations (CFR), and regulates everything from spurious emissions to unlicensed broadcasting. It is cited as 47 CFR §15.
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Subparts
A - General
Subpart A includes 21 sections from 15.1 to 15.38 (note that the . is a separator not a decimal).
B - Unintentional radiators
Suubpart B deals with unintentional radiators --- devices that are not designed to produce radio waves, but do anyway, such as computers. There are 16 sections between 15.101 and 15.123.
C - Intentional radiators
Subpart C deals with devices that are specifically designed to produce coherent radio waves, such as small transmitters. Specific to broadcasting, 15.239 deals with the FM band, while 15.221 (and 15.219) deal with the AM band.
D - Unlicensed PCS devices
Sections 15.301 to 15.323 deal with unlicensed PCS devices from 1910 to 1930 and 2390 to 2400MHz.
E - Unlicensed NII devices
15.401 to 15.407 deal with unlicensed National Information Infrastructure (U-NII) devices.
F - Ultra-wideband operation
15.501 to 15.525 deal with ultra-wideband (UWB) devices, including ground-penetrating radar.
Subjects
Unlicensed broadcasting
Unlicensed broadcasts on the FM broadcast band are limited to a signal strength of 250µV/m² at a distance of 3m from the antenna.
Unlicensed broadcasts on the AM broadcast band are also limited to a signal strength of 250µV/m² at a distance of 3m, however this may instead be measured from the edge of a campus in order to allow for a college radio station to operate.
Unlicensed broadcasts on the TV broadcast bands are prohibited, except for certain medical telemetry devices. 87.5 to 88.0MHz is considered part of the VHF TV band (channel 6 audio is on 87.75), though it shows up on most FM tuners. For TV, 15.241 and 15.242 deal with high VHF (channels 7 to 13), 15.242 also deals with UHF.
Wireless devices in ISM bands
Unlicensed bands at 900MHz, 2.4GHz (2400~2483MHz), and 5.8GHz were originally considered to be used only for industrial, scientific, and medical (ISM) purposes, however the general lack of use of these bands has led the FCC to allow their use for cordless phones, and now for wireless networking, including Wi-Fi and Bluetooth. These are covered under sections 15.243 to 15.249.
Spurious emissions
Electronic equipment from computers to intentional transmitters can produce unwanted radio signals and are subject to FCC regulation. For digital devices including computers and peripherals, FCC Class B is the more stringent standard, applying to equipment marketed for use in the home, even if it could be used elsewhere. Home users are likely to be annoyed by interference to TV and radio reception. Class A is a looser standard for equipment intended only for business, industrial and commercial settings.
Transmitters also must adhere to a spectral mask, to prevent adjacent channel interference, intermediate frequency interference, and intermodulation.
See also
External links
- FCC OET rules (http://www.fcc.gov/oet/info/rules/)
- 2004 GPO index of 47 CFR §15 (http://www.access.gpo.gov/nara/cfr/waisidx_04/47cfr15_04.html)