[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR90.210]
[Page 350-354]
TITLE 47--TELECOMMUNICATION
COMMISSION (CONTINUED)
PART 90--PRIVATE LAND MOBILE RADIO SERVICES--Table of Contents
Subpart I--General Technical Standards
Sec. 90.210 Emission masks.
Except as indicated elsewhere in this part, transmitters used in the
radio services governed by this part must comply with the emission masks
outlined in this section. Unless otherwise stated, per paragraphs
(d)(4), (e)(4), and (m) of this section, measurements of emission power
can be expressed in either peak or average values provided that emission
powers are expressed with the same parameters used to specify the
unmodulated transmitter carrier power. For transmitters that do not
produce a full power unmodulated carrier, reference to the unmodulated
transmitter carrier power refers to the total power contained in the
channel bandwidth. Unless indicated elsewhere in this part, the table in
this section specifies the emission masks for equipment operating in the
frequency bands governed under this part.
Applicable Emission Masks
------------------------------------------------------------------------
Mask for equipment Mask for equipment
Frequency band (MHz) with Audio low without audio low
pass filter pass filter
------------------------------------------------------------------------
Below 25 \1\.................... A or B A or C
25-50........................... B C
72-76........................... B C
150-174 \2\..................... B, D, or E C, D, or E
150 Paging-only................. B C
220-222......................... F F
421-512 \2\..................... B, D, or E C, D, or E
450 Paging-only................. B G
806-821/851-866 \3\............. B G
821-824/866-869................. B H
896-901/935-940................. I J
902-928......................... K K
929-930......................... B G
5850-5925....................... K K
All other bands................. B C
------------------------------------------------------------------------
\1\ Equipment using single sideband J3E emission must the requirements
of Emission Mask A. Equipment using other emissions must meet the
requirements of Emission Mask B or C, as applicable.
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\2\ Equipment designed to operate with a 25 kHz channel bandwidth must
meet the requirements of Emission Mask B or C, as applicable.
Equipment designed to operate with a 12.5 kHz channel bandwidth must
meet the requirements of Emission Mask D, and equipment designed to
operate with a 6.25 kHz channel bandwidth Must meet the requirements
of Emission Mask E.
\3\ Equipment used in this licensed to EA or non-EA systems shall comply
with the emission mask provisions of Sec. 90.691.
(a) Emission Mask A. For transmitters utilizing J3E emission, the
carrier must be at least 40 dB below the peak envelope power and the
power of emissions must be reduced below the output power (P in watts)
of the transmitter as follows:
(1) On any frequency removed from the assigned frequency by more
than 50 percent, but not more than 150 percent of the authorized
bandwidth: At least 25 dB.
(2) On any frequency removed from the assigned frequency by more
than 150 percent, but not more than 250 percent of the authorized
bandwidth: At least 35 dB.
(3) On any frequency removed from the assigned frequency by more
than 250 percent of the authorized bandwidth: At least 43 + 10 log P dB.
(b) Emission Mask B. For transmitters that are equipped with an
audio low-pass filter pursuant to Sec. 90.211(a), the power of any
emission must be below the unmodulated carrier power (P) as follows:
(1) On any frequency removed from the assigned frequency by more
than 50 percent, but not more than 100 percent of the authorized
bandwidth: At least 25 dB.
(2) On any frequency removed from the assigned frequency by more
than 100 percent, but not more than 250 percent of the authorized
bandwidth: At least 35 dB.
(3) On any frequency removed from the assigned frequency by more
than 250 percent of the authorized bandwidth: At least 43 + 10 log (P)
dB.
(c) Emission Mask C. For transmitters that are not equipped with an
audio low-pass filter pursuant to Sec. 90.211(b), the power of any
emission must be attenuated below the unmodulated carrier output power
(P) as follows:
(1) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 5 kHz, but not more than 10 kHz: At least 83 log (fd/5)
dB;
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 10 kHz, but not more than 250 percent of the authorized bandwidth:
At least 29 log (fd\2\/11) dB or 50 dB, whichever is the
lesser attenuation;
(3) On any frequency removed from the center of the authorized
bandwidth by more than 250 percent of the authorized bandwidth: At least
43 + 10 log (P) dB.
(d) Emission Mask D--12.5 kHz channel bandwidth equipment. For
transmitters designed to operate with a 12.5 kHz channel bandwidth, any
emission must be attenuated below the power (P) of the highest emission
contained within the authorized bandwidth as follows:
(1) On any frequency from the center of the authorized bandwidth
f0 to 5.625 kHz removed from f0: Zero dB.
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 5.625 kHz but no more than 12.5 kHz: At least 7.27(fd -
2.88 kHz) dB.
(3) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 12.5 kHz: At least 50 + 10 log (P) dB or 70 dB, whichever is the
lesser attenuation.
(4) The reference level for showing compliance with the emission
mask shall be established using a resolution bandwidth sufficiently wide
(usually two to three times the channel bandwidth) to capture the true
peak emission of the equipment under test. In order to show compliance
with the emissions mask up to and including 50 kHz removed from the edge
of the authorized bandwidth, adjust the resolution bandwidth to 100 Hz
with the measuring instrument in a peak hold mode. A sufficient number
of sweeps must be measured to insure that the emission profile is
developed. If video filtering is used, its bandwidth must not be less
than the instrument resolution bandwidth. For emissions beyond 50 kHz
from the edge of the authorized bandwidth, see paragraph (m) of this
section. If it can be shown that use of the above instrumentation
settings do
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not accurately represent the true interference potential of the
equipment under test, then an alternate procedure may be used provided
prior Commission approval is obtained.
(e) Emission Mask E--6.25 kHz or less channel bandwidth equipment.
For transmitters designed to operate with a 6.25 kHz or less bandwidth,
any emission must be attenuated below the power (P) of the highest
emission contained within the authorized bandwidth as follows:
(1) On any frequency from the center of the authorized bandwidth
f0 to 3.0 kHz removed from f0: Zero dB.
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 3.0 kHz but no more than 4.6 kHz: At least 30 + 16.67(fd
- 3 kHz) or 55 + 10 log (P) or 65 dB, whichever is the lesser
attenuation.
(3) On any frequency removed from the center of the authorized
bandwidth by more than 4.6 kHz: At least 55 + 10 log (P) or 65 dB,
whichever is the lesser attenuation.
(4) The reference level for showing compliance with the emission
mask shall be established using a resolution bandwidth sufficiently wide
(usually two to three times the channel bandwidth) to capture the true
peak emission of the equipment under test. In order to show compliance
with the emissions mask up to and including 50 kHz removed from the edge
of the authorized bandwidth, adjust the resolution bandwidth to 100 Hz
with the measuring instrument in a peak hold mode. A sufficient number
of sweeps must be measured to insure that the emission profile is
developed. If video filtering is used, its bandwidth must not be less
than the instrument resolution bandwidth. For emissions beyond 50 kHz
from the edge of the authorized bandwidth, see paragraph (m) of this
section. If it can be shown that use of the above instrumentation
settings do not accurately represent the true interference potential of
the equipment under test, then an alternate procedure may be used
provided prior Commission approval is obtained.
(f) Emission Mask F. For transmitters operating in the 220-222 MHz
frequency band, any emission must be attenuated below the power (P) of
the highest emission contained within the authorized bandwidth as
follows:
(1) On any frequency from the center of the authorized bandwidth
fo to the edge of the authorized bandwidth fe:
Zero dB.
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 2 kHz up to and including 3.75 kHz: 30 + 20(fd -2) dB or
55 + 10 log (P), or 65 dB, whichever is the lesser attenuation.
(3) On any frequency beyond 3.75 kHz removed from the center of the
authorized bandwidth fd: At least 55 + 10 log (P) dB.
(g) Emission Mask G. For transmitters that are not equipped with an
audio low-pass filter pursuant to Sec. 90.211(b), the power of any
emission must be attenuated below the unmodulated carrier power (P) as
follows:
(1) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 5 kHz, but no more than 10 kHz: At least 83 log (fd/5)
dB;
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 10 kHz, but no more than 250 percent of the authorized bandwidth:
At least 116 log (fd/6.1) dB, or 50 + 10 log (P) dB, or 70
dB, whichever is the lesser attenuation;
(3) On any frequency removed from the center of the authorized
bandwidth by more than 250 percent of the authorized bandwidth: At least
43 + 10 log (P) dB.
(h) Emission Mask H. For transmitters that are not equipped with an
audio low-pass filter pursuant to Sec. 90.211(b), the power of any
emission must be attenuated below the unmodulated carrier power (P) as
follows:
(1) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of 4 kHz or
less: Zero dB.
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 4 kHz, but no more than 8.5 kHz: At least 107 log (fd/4)
dB;
(3) On any frequency removed from the center of the authorized
bandwidth
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by a displacement frequency (fd in kHz) of more than 8.5 kHz,
but no more than 15 kHz: At least 40.5 log (fd/1.16) dB;
(4) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 15 kHz, but no more than 25 kHz: At least 116 log (fd/
6.1) dB;
(5) On any frequency removed from the center of the authorized
bandwidth by more than 25 kHz: At least 43 + log (P) dB.
(i) Emission Mask I. For transmitters that are equipped with an
audio low pass filter pursuant to Sec. 90.211(a), the power of any
emission must be attenuated below the unmodulated carrier power of the
transmitter (P) as follows:
(1) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency of more than 6.8 kHz, but no more
than 9.0 kHz: At least 25 dB;
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency of more than 9.0 kHz, but no more
than 15 kHz: At least 35 dB;
(3) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency of more than 15 kHz: At least 43 +
10 log (P) dB, or 70 dB, whichever is the lesser attenuation.
(j) Emission Mask J. For transmitters that are not equipped with an
audio low-pass filter pursuant to Sec. 90.211(b), the power of any
emission must be attenuated below the unmodulated carrier power of the
transmitter (P) as follows:
(1) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 2.5 kHz, but no more than 6.25 kHz: At least 53 log (fd/
2.5) dB;
(2) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 6.25 kHz, but no more than 9.5 kHz: At least 103 log
(fd/3.9) dB;
(3) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in kHz) of more
than 9.5 kHz: At least 157 log (fd/5.3) dB, or 50 + 10 log
(P) dB or 70 dB, whichever is the lesser attenuation.
(k) Emission Mask K--(1) Wideband multilateration transmitters. For
transmitters authorized under subpart M to provide forward or reverse
links in a multilateration system in the subbands 904-909.75 MHz,
921.75-927.25 MHz and 919.75-921.75 MHz, and which transmit an emission
occupying more than 50 kHz bandwidth: in any 100 kHz band, the center
frequency of which is removed from the center of authorized sub-band(s)
by more than 50 percent of the authorized bandwidth, the power of
emissions shall be attenuated below the transmitter output power, as
specified by the following equation, but in no case less than 31 dB:
A=16+0.4 (D-50)+10 log B (attenuation greater than 66 dB is not
required)
Where:
A = attenuation (in decibels) below the maximum permitted output power
level
D = displacement of the center frequency of the measurement bandwidth
from the center frequency of the authorized sub-band, expressed as a
percentage of the authorized bandwidth B
B = authorized bandwidth in megahertz.
(2) Narrowband forward link transmitters. For LMS multilateration
narrowband forward link transmitters operating in the 927.25-928 MHz
frequency band the power of any emission shall be attenuated below the
transmitter output power (P) in accordance with following schedule:
On any frequency outside the authorized sub-band and removed from the
edge of the authorized sub-band by a displacement frequency
(fd in kHz): at least 116 log ((fd+10)/6.1) dB or
50 + 10 log (P) dB or 70 dB, whichever is the lesser attenuation.
(3) Other transmitters. For all other transmitters authorized under
subpart M that operate in the 902-928 MHz band and for Dedicated Short
Range Communication Services in the 5.850-5.925 GHz band, the peak power
of any emission shall be attenuated below the power of the highest
emission contained within the licensee's sub-band in accordance with the
following schedule:
(i) On any frequency within the authorized bandwidth: Zero dB.
(ii) On any frequency outside the licensee's sub-band edges: 55 + 10
log(P) dB, where (P) is the highest emission (watts) of the transmitter
inside the licensee's sub-band.
[[Page 354]]
(4) The resolution bandwidth of the instrumentation used to measure
the emission power shall be 100 kHz, except that, in regard to paragraph
(2) of this section, a minimum spectrum analyzer resolution bandwidth of
300 Hz shall be used for measurement center frequencies within 1 MHz of
the edge of the authorized subband. If a video filter is used, its
bandwidth shall not be less than the resolution bandwidth.
(5) Emission power shall be measured in peak values.
(6) The LMS sub-band edges for non-multilateration systems for which
emissions must be attenuated are 902.00, 904.00, 909.5 and 921.75 MHz.
(l) Other frequency bands. Transmitters designed for operation under
this part on frequencies other than listed in this section must meet the
emission mask requirements of Emission Mask B. Equipment operating under
this part on frequencies allocated to but shared with the Federal
Government, must meet the applicable Federal Government technical
standards.
(m) Instrumentation. The reference level for showing compliance with
the emission mask shall be established, except as indicated in
Secs. 90.210 (d), (e), and (k), using standard engineering practices for
the modulation characteristic used by the equipment under test. When
measuring emissions in the 150-174 MHz and 421-512 MHz the following
procedures will apply. A sufficient number of sweeps must be measured to
insure that the emission profile is developed. If video filtering is
used, its bandwidth must not be less than the instrument resolution
bandwidth. For frequencies more than 50 kHz removed from the edge of the
authorized bandwidth a resolution of at least 10 kHz must be used for
frequencies below 1000 MHz. Above 1000 MHz the resolution bandwidth of
the instrumentation must be at least 1 MHz. If it can be shown that use
of the above instrumentation settings do not accurately represent the
true interference potential of the equipment under test, then an
alternate procedure may be used provided prior Commission approval is
obtained.
[60 FR 37264, July 19, 1995, as amended at 61 FR 4235, Feb. 5, 1996; 61
FR 6155, Feb. 16, 1996; 61 FR 18986, Apr. 30, 1996; 62 FR 41214, July
31, 1997; 62 FR 52044, Oct. 6, 1997; 64 FR 66409, Nov. 26, 1999]