[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR101.111]
[Page 642-644]
TITLE 47--TELECOMMUNICATION
COMMISSION (CONTINUED)
PART 101_FIXED MICROWAVE SERVICES--Table of Contents
Subpart C_Technical Standards
Sec. 101.111 Emission limitations.
(a) The mean power of emissions must be attenuated below the mean
output power of the transmitter in accordance with the following
schedule:
(1) When using transmissions other than those employing digital
modulation techniques:
(i) On any frequency removed from the assigned frequency by more
than 50 percent up to and including 100 percent of the authorized
bandwidth: At least 25 decibels;
(ii) On any frequency removed from the assigned frequency by more
than 100 percent up to and including 250 percent of the authorized
bandwidth: At least 35 decibels;
(iii) On any frequency removed from the assigned frequency by more
than 250 percent of the authorized bandwidth: At least 43+10
Log10 (mean output power in watts) decibels, or 80 decibels,
whichever is the lesser attenuation.
(2) When using transmissions employing digital modulation techniques
(see Sec. 101.141(b)) in situations not covered in this section:
(i) For operating frequencies below 15 GHz, in any 4 KHz band, the
center frequency of which is removed from the assigned frequency by more
than 50 percent up to and including 250 percent of the authorized
bandwidth: As specified by the following equation but in no event less
than 50 decibels:
A = 35 + 0.8(P -50) + 10 Log10 B. (Attenuation greater than 80 decibels
or to an absolute power of less than -13 dBm/1MHz is not required.)
where:
A = Attenuation (in decibels) below the mean output power level.
P = Percent removed from the center frequency of the transmitter
bandwidth.
B = Authorized bandwidth in MHz.
Note: MVDDS operations in the 12.2-12.7 GHz band shall use 24
megahertz for the value of B in the emission mask equation set forth in
this section. The emission mask limitation shall only apply at the 12.2-
12.7 GHz band edges and does not restrict MVDDS channelization bandwidth
within the band.
(ii) For operating frequencies above 15 GHz, in any 1 MHz band, the
center frequency of which is removed from the assigned frequency by more
than 50 percent up to and including 250 percent of the authorized
bandwidth: As specified by the following equation but in no event less
than 11 decibels:
A = 11 + 0.4(P-50) + 10 Log10 B. (Attenuation greater than 56
decibels or to an absolute power of less than -13 dBm/1MHz is not
required.)
(iii) In any 1 MHz band, the center frequency of which is removed
from the assigned frequency by more than 250 percent of the authorized
bandwidth: At least 43 + 10 Log10 (the mean output power in
watts) decibels, or 80 decibels, whichever is the lesser attenuation.
The authorized bandwidth includes the nominal radio frequency bandwidth
of
[[Page 643]]
an individual transmitter/modulator in block-assigned bands. Equipment
licensed prior to April 1, 2005 shall only be required to meet this
standard in any 4 kHz band.
(iv) The emission mask for LMDS and the 24 GHz Service shall use the
equation in paragraph (a)(2)(ii) of this section and apply it only to
the band edge of each block of spectrum, but not to subchannels
established by licensees. The value of P in the equation is the
percentage removed from the carrier frequency and assumes that the
carrier frequency is the center of the actual bandwidth used. The
emission mask can be satisfied by locating a carrier of the subchannel
sufficiently far from the channel edges so that the emission levels of
the mask are satisfied. The LMDS or 24 GHz emission mask shall use a
value B (bandwidth) of 40 MHz, for all cases even in the case where a
narrower subchannel is used (for instance the actual bandwidth is 10
MHz) and the mean output power used in the calculation is the sum of the
output power of a fully populated channel. For block assigned channels,
the out-of-band emission limits apply only outside the assigned band of
operation and not within the band.
(v) The emission mask for the 71-76 GHz, 81-86 GHz, 92-94 GHz, and
94.1-95 GHz bands used in the equation in paragraph (a)(2)(ii) of this
section applies only to the edge of each channel, but not to sub-
channels established by licensees. The value of P in the equation is for
the percentage removed from the carrier frequency and assumes that the
carrier frequency is the center of the actual bandwidth used. The value
of B will always be 500 MHz. In the case where a narrower sub-channel is
used within the assigned bandwidth, such sub-carrier will be located
sufficiently far from the channel edges to satisfy the emission levels
of the mask. The mean output power used in the calculation is the sum of
the output power of a fully populated channel.
(3) For Digital Termination System channels used in the Digital
Electronic Message Service (DEMS) operating in the 10,550-10,680 MHz
band:
(i) In any 4 KHz band, the center frequency of which is removed from
the edge of the DEMS channel by up to and including 1.125 times the DEMS
subchannel bandwidth: As specified by the following equation may in no
event be less than 50+10 log10 N decibels:
A = 50 + 0.0333(F - 0.5B) + 10 log10 N decibels
Where:
A = Attenuation (in decibels) below means output power level contained
within the DEMS channel for a given polarization.
B = Bandwidth of DEMS channel (in KHz).
F = Absolute value of the difference between the center frequency of the
4 KHz band measured and the center frequency of the DEMS channel (in
KHz).
N = Number of active subchannels of the given polarization within the
DEMS channel.
(ii) In any 4 KHz band within the authorized DEMS band the center
frequency of which is removed from the center frequency of the DEMS
channel by more than the sum of 50% of the DEMS channel bandwidth plus
1.125 times the subchannel bandwidth: As specified by the following
equation but in no event less than 80 decibels:
A = 80 + 10 log10 N decibels
(iii) In any 4 KHz band the center frequency of which is outside the
authorized DEMS band: At least 43+10 log10 (mean output power
in watts) decibels.
(4) For DEMS channels in the 17,700-19,700 MHz band:
(i) In any 4 KHz band, the center frequency of which is removed from
the frequency of the center of the DEMS channel by more than 50 percent
of the DEMS channel bandwidth up to and including 50 percent plus 500
KHz: As specified by the following equation but in no event be less than
50+10 log10 N decibels:
A = 50 + 0.06(F -0.5B) + 10 log10 N decibels
Where:
A = Attenuation (in decibels) below means output power level contained
within the DEMS channel for a given polarization.
B = Bandwidth of DEMS channel (in KHz).
F = Absolute value of the difference between the center frequency of the
4 KHz band measured and the center frequency of the DEMS channel (in
KHz).
N = Number of active subchannels of the given polarization within the
DEMS channel.
[[Page 644]]
(ii) In any 4 KHz band within the authorized DEMS band, the center
frequency of which is removed from the center frequency of the DEMS
channel by more than the sum of 50 percent of the channel bandwidth plus
500 KHz: As specified by the following equation but in no event less
than 80 decibels:
A=80+10 log10 N decibels
(iii) In any 4 KHz band the center frequency of which is outside the
authorized Digital Message Service band: At least 43+10 log10
(mean output power in watts) decibels.
(5) When using transmissions employing digital modulation techniques
on the 900 MHz multiple address frequencies with a 12.5 KHz bandwidth,
the power of any emission must be attenuated below the unmodulated
carrier power of the transmitter (P) in accordance with the following
schedule:
(i) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in KHz) of more than 2.5 KHz
up to and including 6.25 KHz: At least 53 log10 (fd/2.5)
decibels;
(ii) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in KHz) of more than 6.25 KHz
up to and including 9.5 KHz: At least 103 log10 (fd/3.9)
decibels;
(iii) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in KHz) of more than 9.5 KHz
up to and including 15 KHz: At least 157 log10 (fd/5.3)
decibels; and
(iv) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency greater than 15 KHz: At least 50
plus 10 log10(P) or 70 decibels, whichever is the lesser
attenuation.
(6) When using transmissions employing digital modulation techniques
on the 900 MHz multiple address frequencies with a bandwidth greater
than 12.5 KHz, the power of any emission must be attenuated below the
unmodulated carrier power of the transmitter (P) in accordance with the
following schedule:
(i) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in KHz) of more than 5 KHz up
to and including 10 KHz: At least 83 log10 (fd/5) decibels;
(ii) On any frequency removed from the center of the authorized
bandwidth by a displacement frequency (fd in KHz) of more than 10 KHz up
to and including 250 percent of the authorized bandwidth: At least 116
log10 (fd/6.1) decibels or 50 plus 10 log10 (P) or
70 decibels, whichever is the lesser attenuation; and
(iii) On any frequency removed from the center of the authorized
bandwidth by more that 250 percent of the authorized bandwidth: At least
43 plus 10 log10 (output power in watts) decibels or 80
decibels, whichever is the lesser attenuation.
(b) When an emission outside of the authorized bandwidth causes
harmful interference, the Commission may, at its discretion, require
greater attenuation than specified in paragraph (a) of this section.
(c) The emission of an unmodulated carrier is prohibited except for
test purposes as required for proper station and system maintenance.
[61 FR 26677, May 28, 1996, as amended at 62 FR 24582, May 6, 1997; 65
FR 59358, Oct. 5, 2000; 67 FR 43038, June 26, 2002; 68 FR 4957, Jan. 31,
2003; 69 FR 3266, Jan. 23, 2004; 69 FR 31746, June 7, 2004]