I don't think that Chris stands corrected!!  I think the Mr. Pozner made
some errors in his reading and interpretation of the code and left out
important information in his technical paper.  First, Sec 15.201
specifically deals with the certification of Carrier Current Systems which
does not apply to 802.11.  Sec 15.203 deals with non-removable antennas
(baby monitors, phones) but makes exception for Carrier Current Systems and
other intentional radiators which must be measured in accordance with Sec
15.31(d).  Mr Pozner's concentration on point (c) of sec 15.204 was a
misrepresentation of that section as set forth by the sectional premise

Here is the Kicker.  None of the above matters because it is ALL superceded
by the specific allowances set forth in Sec 15.247 and 15.249 with regards
to operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850
MHz.  In this case an antenna just needs to meet the technical requirements.

I have included below the aboved referenced items.   :-)

For those of you that like to read go to:
http://www.access.gpo.gov/cgi-bin/cfrassemble.cgi?title=199947
Better than a glass of warm milk to put you to sleep.

S. Earl Jarosh (ex. Steve?)
N0HZ  (ex. KA0VYB) No Hertz, No Gain
612-868-1313
earl at jarosh.org
earljarosh at moneycenters.com
www.moneycenters.com

> Chris Cox wrote:
> > Well, I stand corrected!  I was sure that I had read somewhere that
using
> > gain antennae was fine, as long as you reduced the TX power by 1dB for
> > each 3dB of gain added. Perhaps that only applies though if you're using
> > an antenna supplied by the manufacturer of the equipment.

> Andy Warner wrote:
> I think Matthew's point was FCC part 15 certification, or
> lack thereof in anything modified after purchase (where
> modification can be interpreted as adding a 3rd party
> antenna) - which is a rat-hole I don't intend to get sucked
> down. Correct me if I'm wrong, Matthew.


                       TITLE 47--TELECOMMUNICATION

              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION

PART 15--RADIO FREQUENCY DEVICES--Table of Contents

                    Subpart C--Intentional Radiators

Sec. 15.203  Antenna requirement.

    An intentional radiator shall be designed to ensure that no antenna
other than that furnished by the responsible party shall be used with
the device. The use of a permanently attached antenna or of an antenna
that uses a unique coupling to the intentional radiator shall be
considered sufficient to comply with the provisions of this section. The
manufacturer may design the unit so that a broken antenna can be
replaced by the user, but the use of a standard antenna jack or
electrical connector is prohibited. This requirement does not apply to
carrier current

[[Page 693]]

devices or to devices operated under the provisions of Sec. 15.211,
Sec. 15.213, Sec. 15.217, Sec. 15.219, or Sec. 15.221. Further, this
requirement does not apply to intentional radiators that must be
professionally installed, such as perimeter protection systems and some
field disturbance sensors, or to other intentional radiators which, in
accordance with Sec. 15.31(d), must be measured at the installation
site. However, the installer shall be responsible for ensuring that the
proper antenna is employed so that the limits in this part are not
exceeded.

[54 FR 17714, Apr. 25, 1989, as amended at 55 FR 28762, July 13, 1990]



                       TITLE 47--TELECOMMUNICATION

              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION

PART 15--RADIO FREQUENCY DEVICES--Table of Contents

                    Subpart C--Intentional Radiators

Sec. 15.204  External radio frequency power amplifiers and antenna
modifications.

    (a) Except as otherwise described in paragraph (b) of this section,
no person shall use, manufacture, sell or lease, offer for sale or lease
(including advertising for sale or lease), or import, ship, or
distribute for the purpose of selling or leasing, any external radio
frequency power amplifier or amplifier kit intended for use with a Part
15 intentional radiator.
    (b) A transmission system consisting of an intentional radiator, an
external radio frequency power amplifier, and an antenna, may be
authorized, marketed and used under this part. However, when a
transmission system is authorized as a system, it must always be
marketed as a complete system and must always be used in the
configuration in which it was authorized. An external radio frequency
power amplifier shall be marketed only in the system configuration with
which the amplifier is authorized and shall not be marketed as a
separate product.
    (c) Only the antenna with which an intentional radiator is
authorized may be used with the intentional radiator.

[62 FR 26242, May 13, 1997]





                       TITLE 47--TELECOMMUNICATION

              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION

PART 15--RADIO FREQUENCY DEVICES--Table of Contents

      Subpart D--Unlicensed Personal Communications Service Devices

Sec. 15.319  General technical requirements.

    (a) The 1910-1920 MHz and 2390-2400 MHz bands are limited to use by
asynchronous devices under the requirements of Sec. 15.321. The 1920-
1930 MHz sub-band is limited to use by isochronous devices under the
requirements of Sec. 15.323.
    (b) All transmissions must use only digital modulation techniques.
    (c) Peak transmit power shall not exceed 100 microwatts multiplied
by the square root of the emission bandwidth in hertz. Peak transmit
power must be measured over any interval of continuous transmission
using instrumentation calibrated in terms of an rms-equivalent voltage.
The measurement results shall be properly adjusted for any instrument
limitations, such as detector response times, limited resolution
bandwidth capability when compared to the emission bandwidth,
sensitivity, etc., so as to obtain a true peak measurement for the
emission in question over the full bandwidth of the channel.
    (d) Power spectral density shall not exceed 3 milliwatts in any 3
kHz bandwidth as measured with a spectrum analyzer having a resolution
bandwidth of 3 kHz.
    (e) The peak transmit power shall be reduced by the amount in
decibels that

[[Page 714]]

the maximum directional gain of the antenna exceeds 3 dBi.
    (f) The device shall automatically discontinue transmission in case
of either absence of information to transmit or operational failure. The
provisions in this section are not intended to preclude transmission of
control and signaling information or use of repetitive codes used by
certain digital technologies to complete frame or burst intervals.
    (g) Notwithstanding other technical requirements specified in this
subpart, attenuation of emissions below the general emission limits in
Sec. 15.209 is not required.
    (h) Where there is a transition between limits, the tighter limit
shall apply at the transition point.
    (i) Unlicensed PCS devices are subject to the radiofrequency
radiation exposure requirements specified in Secs. 1.1307(b), 2.1091 and
2.1093 of this chapter, as appropriate. All equipment shall be
considered to operate in a ``general population/uncontrolled''
environment. Applications for equipment authorization of devices
operating under this section must contain a statement confirming
compliance with these requirements for both fundamental emissions and
unwanted emissions. Technical information showing the basis for this
statement must be submitted to the Commission upon request.

[58 FR 59180, Nov. 8, 1993, as amended at 59 FR 32852, June 24, 1994; 59
FR 40835, Aug. 10, 1994; 60 FR 13073, Mar. 10, 1995; 61 FR 41018, Aug.
7, 1996]


[Page 705-707]

                       TITLE 47--TELECOMMUNICATION

              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION

PART 15--RADIO FREQUENCY DEVICES--Table of Contents

                    Subpart C--Intentional Radiators

Sec. 15.247  Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and
5725-5850 MHz.

    (a) Operation under the provisions of this section is limited to
frequency hopping and direct sequence spread spectrum intentional
radiators that comply with the following provisions:
    (1) Frequency hopping systems shall have hopping channel carrier
frequencies separated by a minimum of 25 kHz or the 20 dB bandwidth of
the hopping channel, whichever is greater. The system shall hop to
channel frequencies that are selected at the system hopping rate from a
pseudorandomly ordered list of hopping frequencies. Each frequency must
be used equally on the average by each transmitter. The system receivers
shall have input bandwidths that match the hopping channel bandwidths of
their corresponding transmitters and shall shift frequencies in
synchronization with the transmitted signals.
    (i) For frequency hopping systems operating in the 902-928 MHz band:
if the 20 dB bandwidth of the hopping channel is less than 250 kHz, the
system shall use at least 50 hopping frequencies and the average time of
occupancy on any frequency shall not be greater than 0.4 seconds within
a 20 second period; if the 20 dB bandwidth of the hopping channel is 250
kHz or greater, the system shall use at least 25 hopping frequencies and
the average time of occupancy on any frequency shall not be greater than
0.4 seconds within a 10 second period. The maximum allowed 20 dB
bandwidth of the hopping channel is 500 kHz.

[[Page 706]]

    (ii) Frequency hopping systems operating in the 2400-2483.5 MHz and
5725-5850 MHz bands shall use at least 75 hopping frequencies. The
maximum 20 dB bandwidth of the hopping channel is 1 MHz. The average
time of occupancy on any frequency shall not be greater than 0.4 seconds
within a 30 second period.
    (2) For direct sequence systems, the minimum 6 dB bandwidth shall be
at least 500 kHz.
    (b) The maximum peak output power of the intentional radiator shall
not exceed the following:
    (1) For frequency hopping systems operating in the 2400-2483.5 MHz
or 5725-5850 MHz band and for all direct sequence systems: 1 watt.
    (2) For frequency hopping systems operating in the 902-928 MHz band:
1 watt for systems employing at least 50 hopping channels; and, 0.25
watts for systems employing less than 50 hopping channels, but at least
25 hopping channels, as permitted under paragraph (a)(1)(i) of this
section.
    (3) Except as shown in paragraphs (b)(3) (i), (ii) and (iii) of this
section, if transmitting antennas of directional gain greater than 6 dBi
are used the peak output power from the intentional radiator shall be
reduced below the stated values in paragraphs (b)(1) or (b)(2) of this
section, as appropriate, by the amount in dB that the directional gain
of the antenna exceeds 6 dBi.
    (i) Systems operating in the 2400-2483.5 MHz band that are used
exclusively for fixed, point-to-point operations may employ transmitting
antennas with directional gain greater than 6 dBi provided the maximum
peak output power of the intentional radiator is reduced by 1 dB for
every 3 dB that the directional gain of the antenna exceeds 6 dBi.
    (ii) Systems operating in the 5725-5850 MHz band that are used
exclusively for fixed, point-to-point operations may employ transmitting
antennas with directional gain greater than 6 dBi without any
corresponding reduction in transmitter peak output power.
    (iii) Fixed, point-to-point operation, as used in paragraphs
(b)(3)(i) and (b)(3)(ii) of this section, excludes the use of point-to-
multipoint systems, omnidirectional applications, and multiple co-
located intentional radiators transmitting the same information. The
operator of the spread spectrum intentional radiator or, if the
equipment is professionally installed, the installer is responsible for
ensuring that the system is used exclusively for fixed, point-to-point
operations. The instruction manual furnished with the intentional
radiator shall contain language in the installation instructions
informing the operator and the installer of this responsibility.
    (4) Systems operating under the provisions of this section shall be
operated in a manner that ensures that the public is not exposed to
radio frequency energy levels in excess of the Commission's guidelines.
See Sec. 1.1307(b)(1) of this chapter.
    (c) In any 100 kHz bandwidth outside the frequency band in which the
spread spectrum intentional radiator is operating, the radio frequency
power that is produced by the intentional radiator shall be at least 20
dB below that in the 100 kHz bandwidth within the band that contains the
highest level of the desired power, based on either an RF conducted or a
radiated measurement. Attenuation below the general limits specified in
Sec. 15.209(a) is not required. In addition, radiated emissions which
fall in the restricted bands, as defined in Sec. 15.205(a), must also
comply with the radiated emission limits specified in Sec. 15.209(a)
(see Sec. 15.205(c)).
    (d) For direct sequence systems, the peak power spectral density
conducted from the intentional radiator to the antenna shall not be
greater than 8 dBm in any 3 kHz band during any time interval of
continuous transmission.
    (e) The processing gain of a direct sequence system shall be at
least 10 dB. The processing gain represents the improvement to the
received signal-to-noise ratio, after filtering to the information
bandwidth, from the spreading/despreading function. The processing gain
may be determined using one of the following methods:
    (1) As measured at the demodulated output of the receiver: the ratio
in dB of the signal-to-noise ratio with the system spreading code turned
off to the

[[Page 707]]

signal-to-noise ratio with the system spreading code turned on.
    (2) As measured using the CW jamming margin method: a signal
generator is stepped in 50 kHz increments across the passband of the
system, recording at each point the generator level required to produce
the recommended Bit Error Rate (BER). This level is the jammer level.
The output power of the intentional radiator is measured at the same
point. The jammer to signal ratio (J/S) is then calculated, discarding
the worst 20% of the J/S data points. The lowest remaining J/S ratio is
used to calculate the processing gain, as follows: Gp = (S/N) o + Mj +
Lsys, where Gp = processing gain of the system, (S/N) o = signal to
noise ratio required for the chosen BER, Mj = J/S ratio, and Lsys =
system losses. Note that total losses in a system, including intentional
radiator and receiver, should be assumed to be no more than 2 dB.
    (f) Hybrid systems that employ a combination of both direct sequence
and frequency hopping modulation techniques shall achieve a processing
gain of at least 17 dB from the combined techniques. The frequency
hopping operation of the hybrid system, with the direct sequence
operation turned off, shall have an average time of occupancy on any
frequency not to exceed 0.4 seconds within a time period in seconds
equal to the number of hopping frequencies employed multiplied by 0.4.
The direct sequence operation of the hybrid system, with the frequency
hopping operation turned off, shall comply with the power density
requirements of paragraph (d) of this section.
    (g) Frequency hopping spread spectrum systems are not required to
employ all available hopping channels during each transmission. However,
the system, consisting of both the transmitter and the receiver, must be
designed to comply with all of the regulations in this section should
the transmitter be presented with a continuous data (or information)
stream. In addition, a system employing short transmission bursts must
comply with the definition of a frequency hopping system and must
distribute its transmissions over the minimum number of hopping channels
specified in this section.
    (h) The incorporation of intelligence within a frequency hopping
spread spectrum system that permits the system to recognize other users
within the spectrum band so that it individually and independently
chooses and adapts its hopsets to avoid hopping on occupied channels is
permitted. The coordination of frequency hopping systems in any other
manner for the express purpose of avoiding the simultaneous occupancy of
individual hopping frequencies by multiple transmitters is not
permitted.

    Note: Spread spectrum systems are sharing these bands on a
noninterference basis with systems supporting critical Government
requirements that have been allocated the usage of these bands,
secondary only to ISM equipment operated under the provisions of part 18
of this chapter. Many of these Government systems are airborne
radiolocation systems that emit a high EIRP which can cause interference
to other users. Also, investigations of the effect of spread spectrum
interference to U. S. Government operations in the 902-928 MHz band may
require a future decrease in the power limits allowed for spread
spectrum operation.

[54 FR 17714, Apr. 25, 1989, as amended at 55 FR 28762, July 13, 1990;
62 FR 26242, May 13, 1997]






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