Custom Search

More than 10,000 searchable pages indexed.

Greetings: There is so much good stuff on RF Cafe that there is no way to list or link to all of it here. Please use the Search box or the Site Map to find what you want - there is a good chance I have it. Thanks!

•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<
Job Board
About RF Cafe™
Copyright 1999-2015

FCC Part 15 Radio Frequency Devices
Section 15.403

The Federal Communications Commission (FCC) is the authority in the United States of America that creates and enforces the use of airwaves throughout the entire radio frequency spectrum. This group of documents contains the entirety of the FCC Part 15 regulations that concern unlicensed radio frequency devices. As with all government documents, this material is in the public domain and may be freely copied so long as the content is not changed. This copy is provided as a convenience for RF Cafe visitors. 

Click here for the Table of Contents.

[Code of Federal Regulations]
[Title 47, Volume 1]
[Revised as of October 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR15.403]
[Page 835-836]
                       TITLE 47--TELECOMMUNICATION
    Subpart E_Unlicensed National Information Infrastructure Devices
Sec. 15.403  Definitions.
    (a) Access Point (AP). A U-NII transceiver that operates either as a 
bridge in a peer-to-peer connection or as a connector between the wired 
and wireless segments of the network.
    (b) Available Channel. A radio channel on which a Channel 
Availability Check has not identified the presence of a radar.
    (c) Average Symbol Envelope Power. The average symbol envelope power 
is the average, taken over all symbols in the signaling alphabet, of the 
envelope power for each symbol.
    (d) Channel Availability Check. A check during which the U-NII 
device listens on a particular radio channel to identify whether there 
is a radar operating on that radio channel.
    (e) Channel Move Time. The time needed by a U-NII device to cease 
all transmissions on the current channel upon detection of a radar 
signal above the DFS detection threshold.
    (f) Digital modulation. The process by which the characteristics of 
a carrier wave are varied among a set of predetermined discrete values 
in accordance with a digital modulating function as specified in 
document ANSI C63.17-1998.
    (g) Dynamic Frequency Selection (DFS) is a mechanism that 
dynamically detects signals from other systems and avoids co-channel 
operation with these systems, notably radar systems.
[[Page 836]]
    (h) DFS Detection Threshold. The required detection level defined by 
detecting a received signal strength (RSS) that is greater than a 
threshold specified, within the U-NII device channel bandwidth.
    (i) Emission bandwidth. For purposes of this subpart the emission 
bandwidth shall be determined by measuring the width of the signal 
between two points, one below the carrier center frequency and one above 
the carrier center frequency, that are 26 dB down relative to the 
maximum level of the modulated carrier. Determination of the emissions 
bandwidth is based on the use of measurement instrumentation employing a 
peak detector function with an instrument resolution bandwidth 
approximately equal to 1.0 percent of the emission bandwidth of the 
device under measurement.
    (j) In-Service Monitoring. A mechanism to check a channel in use by 
the U-NII device for the presence of a radar.
    (k) Non-Occupancy Period. The required period in which, once a 
channel has been recognized as containing a radar signal by a U-NII 
device, the channel will not be selected as an available channel.
    (l) Operating Channel. Once a U-NII device starts to operate on an 
Available Channel then that channel becomes the Operating Channel.
    (m) Peak Power Spectral Density. The peak power spectral density is 
the maximum power spectral density, within the specified measurement 
bandwidth, within the U-NII device operating band.
    (n) Maximum Conducted Output Power. The total transmit power 
delivered to all antennas and antenna elements averaged across all 
symbols in the signaling alphabet when the transmitter is operating at 
its maximum power control level. Power must be summed across all 
antennas and antenna elements. The average must not include any time 
intervals during which the transmitter is off or is transmitting at a 
reduced power level. If multiple modes of operation are possible (e.g., 
alternative modulation methods), the maximum conducted output power is 
the highest total transmit power occurring in any mode.
    (o) Power Spectral Density. The power spectral density is the total 
energy output per unit bandwidth from a pulse or sequence of pulses for 
which the transmit power is at its peak or maximum level, divided by the 
total duration of the pulses. This total time does not include the time 
between pulses during which the transmit power is off or below its 
maximum level.
    (p) Pulse. A pulse is a continuous transmission of a sequence of 
modulation symbols, during which the average symbol envelope power is 
    (q) RLAN. Radio Local Area Network.
    (r) Transmit Power Control (TPC). A feature that enables a U-NII 
device to dynamically switch between several transmission power levels 
in the data transmission process.
    (s) U-NII devices. Intentional radiators operating in the frequency 
bands 5.15-5.35 GHz and 5.470-5.825 GHz that use wideband digital 
modulation techniques and provide a wide array of high data rate mobile 
and fixed communications for individuals, businesses, and institutions.
[69 FR 2687, Jan. 20, 2004, as amended at 69 FR 54036, Sept. 7, 2004]

Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeKirt Blattenberger… single-handedly redefining what an engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem!
(Seize the Day!)

5th MOB: My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website