47 C.F.R. Subpart C—Emissions
Title 47 - Telecommunication
Title 47: Telecommunication
PART 2—FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS
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Subpart C—Emissions
§ 2.201 Emission, modulation, and transmission characteristics.
The following system of designating emission, modulation, and transmission characteristics shall be employed.
(a) Emissions are designated according to their classification and their necessary bandwidth.
(b) A minimum of three symbols are used to describe the basic characteristics of radio waves. Emissions are classified and symbolized according to the following characteristics:
(1) First symbol—type of modulation of the main character;
(2) Second symbol—nature of signal(s) modulating the main carrier;
(3) Third symbol—type of information to be transmitted.
Note: A fourth and fifth symbol are provided for additional information and are shown in Appendix 6, part A of the ITU Radio Regulations. Use of the fourth and fifth symbol is optional. Therefore, the symbols may be used as described in Appendix 6, but are not required by the Commission.
(c) First Symbol—types of modulation of the main carrier:
(1) Emission of an N unmodulated carrier (2) Emission in which the main carrier is amplitude- modulated (including cases where sub-carriers are angle- modulated): _Double-sideband. A _Single-sideband, H full carrier.... _Single-sideband, R reduced or variable level carrier......... _Single-sideband, J suppressed carrier......... _Independent B sidebands....... _Vestigial C sideband........ (3) Emission in which the main carrier is angle- modulated: _Frequency F modulation...... _Phase modulation G
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Note: Whenever frequency modulation “F” is indicated, Phase modulation “G” is also acceptable.
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(4) Emission in D which the main carrier is amplitude and angle-modulated either simultaneously or in a pre- established sequence (5) Emission of pulses:\1\ _Sequence of P unmodulated pulses.......... _A sequence of pulses: _Modulated in K amplitude..... _Modulated in L width/duration _Modulated in M position/phase _In which the Q carrier is angle- modulated during the period of the pulse......... _Which is a V combination of the foregoing or is produced by other means (6) Cases not W covered above, in which an emission consists of the main carrier modulated, either simultaneously or in a pre- established sequence, in a combination of two or more of the following modes: amplitude, angle, pulse (7) Cases not X otherwise covered
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1 Emissions where the main carrier is directly modulated by a signal which has been coded into quantized form (e.g. pulse code modulation) should be designated under (2) or (3).
(d) Second Symbol—nature of signal(s) modulating the main carrier:
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(1) No modulating 0 signal (2) A single 1 channel containing quantized or digital information without the use of a modulating sub- carrier, excluding time-division muliplex (3) A single 2 channel containing quantized or digital information with the use of a modulating sub- carrier, excluding time-division multiplex (4) A single 3 channel containing analogue information (5) Two or more 7 channels containing quantized or digital information (6) Two or more 8 channels containing analogue information (7) Composite 9 system with one or more channels containing quantized or digital information, together with one or more channels containing analogue information (8) Cases not X otherwise covered
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(e) Third Symbol—type of information to be transmitted:2
2 In this context the word “information” does not include information of a constant, unvarying nature such as is provided by standard frequency emissions, continuous wave and pulse radars, etc.
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(1) No information N transmitted (2) Telegraphy_for A aural reception (3) Telegraphy_for B automatic reception (4) Facsimile C (5) Data D transmission, telemetry, telecommand (6) Telephony E (including sound broadcasting) (7) Television F (video) (8) Combination of W the above (9) Cases not X otherwise covered
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(f) Type B emission: As an exception to the above principles, damped waves are symbolized in the Commission's rules and regulations as type B emission. The use of type B emissions is forbidden.
(g) Whenever the full designation of an emission is necessary, the symbol for that emission, as given above, shall be preceded by the necessary bandwidth of the emission as indicated in §2.202(b)(1).
[49 FR 48697, Dec. 14, 1984] § 2.202 Bandwidths.
(a) Occupied bandwidth. The frequency bandwidth such that, below its lower and above its upper frequency limits, the mean powers radiated are each equal to 0.5 percent of the total mean power radiated by a given emission. In some cases, for example multichannel frequency-division systems, the percentage of 0.5 percent may lead to certain difficulties in the practical application of the definitions of occupied and necessary bandwidth; in such cases a different percentage may prove useful.
(b) Necessary bandwidth. For a given class of emission, the minimum value of the occupied bandwidth sufficient to ensure the transmission of information at the rate and with the quality required for the system employed, under specified conditions. Emissions useful for the good functioning of the receiving equipment as, for example, the emission corresponding to the carrier of reduced carrier systems, shall be included in the necessary bandwidth.
(1) The necessary bandwidth shall be expressed by three numerals and one letter. The letter occupies the position of the decimal point and represents the unit of bandwidth. The first character shall be neither zero nor K, M or G.
(2) Necessary bandwidths:
between 0.001 and 999 Hz shall be expressed in Hz (letter H);
between 1.00 and 999 kHz shall be expressed in kHz (letter K);
between 1.00 and 999 MHz shall be expressed in MHz (letter M);
between 1.00 and 999 GHz shall be expressed in GHz (letter G).
(3) Examples:
0.002 Hz—H002
0.1 Hz—H100
25.3 Hz—25H3
400 Hz—400H
2.4 kHz—2K40
6 kHz—6K00
12.5 kHz—12K5
180.4 kHz—180K
180.5 kHz—181K
180.7 kHz—181K
1.25 MHz—1M25
2 MHz—2M00
10 MHz—10M0
202 MHz—202M
5.65 GHz—5G65
(c) The necessary bandwidth may be determined by one of the following methods:
(1) Use of the formulas included in the table, in paragraph (g) of this section, which also gives examples of necessary bandwidths and designation of corresponding emissions;
(2) For frequency modulated radio systems which have a substantially linear relationship between the value of input voltage to the modulator and the resulting frequency deviation of the carrier and which carry either single sideband suppressed carrier frequency division multiplex speech channels or television, computation in accordance with provisions of paragraph (f) of this section and formulas and methods indicated in the table, in paragraph (g) of this section;
(3) Computation in accordance with Recommendations of the International Radio Consultative Committee (C.C.I.R.);
(4) Measurement in cases not covered by paragraph (c) (1), (2), or (3) of this section.
(d) The value so determined should be used when the full designation of an emission is required. However, the necessary bandwidth so determined is not the only characteristic of an emission to be considered in evaluating the interference that may be caused by that emission.
(e) In the formulation of the table in paragraph (g) of this section, the following terms are employed:
Bn = Necessary bandwidth in hertz
B = Modulation rate in bauds
N = Maximum possible number of black plus white elements to be transmitted per second, in facsimile
M = Maximum modulation frequency in hertz
C = Sub-carrier frequency in hertz
D = Peak frequency deviation, i.e., half the difference between the maximum and minimum values of the instantaneous frequency. The instantaneous frequency in hertz is the time rate of change in phase in radians divided by 2
t = Pulse duration in seconds at half-amplitude
tr = Pulse rise time in seconds between 10% and 90% of maximum amplitude
K = An overall numerical factor which varies according to the emission and which depends upon the allowable signal distortion.
Nc = Number of baseband telephone channels in radio systems employing multichannel multiplexing
P = Continuity pilot sub-carrier frequency (Hz) (continuous signal utilized to verify performance of frequency-division multiplex systems).
(f) Determination of values of D and Bn for systems specified in paragraph (c)(2) of this section:
(1) Determination of D in systems for multichannel telephony:
(i) The rms value of the per-channel deviation for the system shall be specified. (In the case of systems employing preemphasis or phase modulation, this value of per-channel deviation shall be specified at the characteristic baseband frequency.)
(ii) The value of D is then calculated by multiplying the rms value of the per-channel deviation by the appropriate factors, as follows:
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---------------------------------------------------------------------------------------------------------------- Number of message circuits Multiplying factors Limits of X (Pavg (dBmO))----------------------------------------------------------------------------------------------------------------More than 3, but less than 12.......... 4.47 x [a factor specified by the equipment manufacturer or station licensee, subject to Commission approval]. 3.76 antilog (X+2 log10 Nc)At least 12, but less than 60.......... _____________ X: -2 to +2.6. 20 3.76 antilog (X+4 log10 Nc)At least 60, but less than 240......... _____________ X: -5.6 to -1.0. 20 3.76 antilog (X+10 log10 Nc)240 or more............................ _____________ X: -19.6 to -15.0. 20----------------------------------------------------------------------------------------------------------------Where X represents the average power in a message circuit in dBmO; Nc is the number of circuits in the multiplexed message load; 3.76 corresponds to a peak load factor of 11.5 dB.
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(2) The necessary bandwidth (Bn) normally is considered to be numerically equal to:
(i) 2M+2DK, for systems having no continuity pilot subcarrier or having a continuity pilot subcarrier whose frequency is not the highest modulating the main carrier;
(ii) 2P+2DK, for systems having a continuity pilot subcarrier whose frequency exceeds that of any other signal modulating the main carrier, unless the conditions set forth in paragraph (f)(3) of this section are met.
(3) As an exception to paragraph (f)(2)(ii) of this section, the necessary bandwidth (Bn) for such systems is numerically equal to 2P or 2M+2DK, whichever is greater, provided the following conditions are met:
(i) The modulation index of the main carrier due to the continuity pilot subcarrier does not exceed 0.25, and
(ii) In a radio system of multichannel telephony, the rms frequency deviation of the main carrier due to the continuity pilot subcarrier does not exceed 70 percent of the rms value of the per-channel deviation, or, in a radio system for television, the rms deviation of the main carrier due to the pilot does not exceed 3.55 percent of the peak deviation of the main carrier.
(g) Table of necessary bandwidths:
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-------------------------------------------------------------------------------------------------------------------------------------------------------- Necessary bandwidth Description of emission ------------------------------------------------------------------------------------------ Designation of emission Formula Sample calculation-------------------------------------------------------------------------------------------------------------------------------------------------------- I. NO MODULATING SIGNAL--------------------------------------------------------------------------------------------------------------------------------------------------------Continuous wave emission............. ...................................... ................................................ N0N (zero)-------------------------------------------------------------------------------------------------------------------------------------------------------- II. AMPLITUDE MODULATION 1. Signal With Quantized or Digital Information--------------------------------------------------------------------------------------------------------------------------------------------------------Continuous wave telegraphy........... Bn=BK, K=5 for fading circuits, K=3 25 words per minute; B=20, K=5, Bandwidth: 100 100HA1A for non-fading circuits HzTelegraphy by on-off keying of a tone Bn=BK+2M, K=5 for fading circuits, K=3 25 words per minute; B=20, M=1000, K=5, 2K10A2A modulated carrier. for non-fading circuits Bandwidth: 2100 Hz=2.1 kHzSelective calling signal, single- Bn=M Maximum code frequency is: 2110 Hz, M=2110, 2K11H2B sideband full carrier. Bandwidth: 2110 Hz=2.11 kHzDirect-printing telegraphy using a Bn=2M+2DK, M=B÷2 B=50, D=35 Hz (70 Hz shift), K=1.2, Bandwidth: 134HJ2B frequency shifted modulating sub- 134 Hz carrier single-sideband suppressed carrier.Telegraphy, single sideband reduced Bn=central frequency+M+DK, M=B÷2 15 channels; highest central frequency is: 2805 2K89R7B carrier. Hz, B=100, D=42.5 Hz (85 Hz shift), K=0.7 Bandwidth: 2.885 Hz=2.885 kHz-------------------------------------------------------------------------------------------------------------------------------------------------------- 2. Telephony (Commercial Quality)--------------------------------------------------------------------------------------------------------------------------------------------------------Telephony double-sideband............ Bn=2M M=3000, Bandwidth=6000 Hz=6 kHz 6K00A3ETelephony, single-sideband, full Bn=2M M=3000, Bandwidth: 3000 Hz=3 kHz 3K00H3E carrier.Telephony, single-sideband suppressed Bn=M-lowest modulation frequency M=3000, lowest modulation frequency is 3000 Hz, 2K70J3E carrier. 2700 Hz Bandwidth: 2700Hz=2.7 kHzTelephony with separate frequency Bn=M Maximum control frequency is 2990 Hz, M=2990, 2K99R3E modulated signal to control the Bandwidth: 2990 Hz=2.99 kHz level of demodulated speech signal, single-sideband, reduced carrier.Telephony with privacy, single- Bn=Nc M-lowest modulation frequency in Nc=2, M=3000 lowest modulation frequency is 250 5K75J8E sideband, suppressed carrier (two or the lowest channel Hz, Bandwidth: 5750 Hz=5.75 kHz more channels).Telephony, independent sideband (two Bn=sum of M for each sideband 2 channels, M=3000, Bandwidth: 6000 Hz=6 kHz 6K00B8E or more channels).-------------------------------------------------------------------------------------------------------------------------------------------------------- 3. Sound Broadcasting--------------------------------------------------------------------------------------------------------------------------------------------------------Sound broadcasting, double-sideband.. Bn=2M, M may vary between 4000 and Speech and music, M=4000, Bandwidth: 8000 Hz= 8 8K00A3E 10000 depending on the quality kHz desiredSound broadcasting, single-sideband Bn=M, M may vary between 4000 and Speech and music, M=4000, Bandwidth: 4000 Hz= 4 4K00R3E reduced carrier (single channel). 10000 depending on the quality kHz desiredSound broadcasting, single-sideband, Bn=M-lowest modulation frequency Speech and music, M=4500, lowest modulation 4K45J3E suppressed carrier. frequency=50 Hz, Bandwidth: 4450 Hz=4.45 kHz-------------------------------------------------------------------------------------------------------------------------------------------------------- 4. Television--------------------------------------------------------------------------------------------------------------------------------------------------------Television, vision and sound......... Refer to CCIR documents for the Number of lines=525; Nominal video bandwidth: 5M75C3F bandwidths of the commonly used 4.2 MHz, Sound carrier relative to video television systems carrier=4.5 MHz ...................................... Total vision bandwidth: 5.75 MHz; FM aural 250KF3E bandwidth including guardbands: 250,000 Hz ...................................... Total bandwidth: 6 MHz 6M25C3F-------------------------------------------------------------------------------------------------------------------------------------------------------- 5. Facsimile--------------------------------------------------------------------------------------------------------------------------------------------------------Analogue facsimile by sub-carrier Bn=C-N÷2+DK, K=1.1 (typically) N=1100, corresponding to an index of cooperation 2K89R3C frequency modulation of a single- of 352 and a cycler rotation speed of 60 rpm. sideband emission with reduced Index of cooperation is the product of the drum carrier. diameter and number of lines per unit length C=1900, D=400 Hz, Bandwidth=2.890 Hz=2.89 kHzAnalogue facsimile; frequency Bn=2M+2DK, M=N/2, K=1.1 (typically) N=1100, D=400 Hz, Bandwidth: 1980 Hz=1.98 kHz 1K98J3C modulation of an audio frequency sub- carrier which modulates the main carrier, single-sideband suppressed carrier.-------------------------------------------------------------------------------------------------------------------------------------------------------- 6. Composite Emissions--------------------------------------------------------------------------------------------------------------------------------------------------------Double-sideband, television relay.... Bn=2C+2M+2D Video limited to 5 MHz, audio on 6.5 MHz 13M2A8W frequency modulated subcarrier deviation=50 kHz: C=6.5x10\6\ D=50x10\3\ Hz, M=15,000, Bandwidth: 13.13x10\6\ Hz=13.13 MHzDouble-sideband radio relay system... Bn=2M 10 voice channels occupying baseband between 1 328KA8E kHz and 164 kHz; M=164,000 bandwith=328,000 Hz=328 kHzDouble-sideband emission of VOR with Bn=2Cmax+2M+2DK, K=1 (typically) The main carrier is modulated by: _a 30 Hz sub- 20K9A9W voice (VOR=VHF omnidirectional radio carrier_a carrier resulting from a 9960 Hz tone range). frequency modulated by a 30 Hz tone_a telephone channel_a 1020 Hz keyed tone for continual Morse identification. Cmax=9960, M=30, D=480 Hz, Bandwidth: 20,940 Hz=20.94 kHzIndependent sidebands; several Bn=sum of M for each sideband Normally composite systems are operated in 12K0B9W telegraph channels together with accordance with standardized channel several telephone channels. arrangements, (e.g. CCIR Rec. 348-2) 3 telephone channels and 15 telegraphy channels require the bandwidth 12,000 Hz=12 kHz-------------------------------------------------------------------------------------------------------------------------------------------------------- III-A. FREQUENCY MODULATION 1. Signal With Quantized or Digital Information--------------------------------------------------------------------------------------------------------------------------------------------------------Telegraphy without error-correction Bn=2M+2DK, M=B÷2, K=1.2 B=100, D=85 Hz (170 Hz shift), Bandwidth: 304 Hz 304HF1B (single channel). (typically)Four-frequency duplex telegraphy..... Bn2M+2DK, B=Modulation rate in bands Spacing between adjacent frequencies=400 Hz; 1K42F7B of the faster channel. If the Synchronized channels; B=100, M=50, D=600 Hz, channels are synchronized: Bandwidth: 1420 Hz=1.42 kHz M=B÷2, otherwise M=2B, K=1.1 (typically)-------------------------------------------------------------------------------------------------------------------------------------------------------- 2. Telephony (Commercial Quality)--------------------------------------------------------------------------------------------------------------------------------------------------------Commercial telephony................. Bn=2M+2DK, K=1 (typically, but under For an average case of commercial telephony, 16K0F3E conditions a higher value may be M=3,000, Bandwidth: 16,000 Hz=16 kHz necessary-------------------------------------------------------------------------------------------------------------------------------------------------------- 3. Sound Broadcasting--------------------------------------------------------------------------------------------------------------------------------------------------------Sound broadcasting................... Bn=2M+2DK, K=1 (typically) Monaural, D=75,000 Hz, M=15,000, Bandwidth: 180KF3E 18,000 Hz=180 kHz-------------------------------------------------------------------------------------------------------------------------------------------------------- 4. Facsimile--------------------------------------------------------------------------------------------------------------------------------------------------------Facsimile by direct frequency Bn=2M+2DK, M=N÷2, K=1.1 N=1100 elements/sec; D=400 Hz, Bandwidth: 1980 1K98F1C modulation of the carrier; black and (typically) Hz=1.98 kHZ white.Analogue facsimile................... Bn=2M+2DK, M=N÷2, K=1.1 N=1100 elements/sec; D=400 Hz, Bandwidth: 1980 1K98F3C (typically) Hz=1.98 kHz-------------------------------------------------------------------------------------------------------------------------------------------------------- 5. Composite Emissions (See Table III-B)--------------------------------------------------------------------------------------------------------------------------------------------------------Radio-relay system, frequency Bn=2P+2DK, K=1 Microwave radio relay system specifications: 60 2M45F8E division multiplex. telephone channels occupying baseband between 60 and 300 kHz; rms per-channel deviation 200 kHz; pilot at 331 kHz produces 200 kHz rms deviation of main carrier. Computation of Bn : D=(200x10\3\3x3.76x1.19), Hz=0.895x10\6\, P=0.331x10\6\ Hz; Bandwidth: 2.452x10\6\ HzRadio-relay system frequency division Bn=2M+2DK, K=1 Microwave radio relay relay systems 16M6F8E multiple. specifications: 1200 telephone channels occupying baseband between 60 and 5564 kHz; rms per channel deviation 200 kHz; continunity pilot at 6199 kHz produces 140 kHz rms deviation of main carrier. Computation of Bn : D=(20\0\x10\3\x3.76x3.63)=2.73x10\6\; M=5.64x10\6\ Hz; P=6.2x10\6\ Hz; (2M+2DK<2P; Bandwidth 16.59x10\6\ HzRadio-relay system, frequency Bn=2P Microwave radio relay system specifications: 17M0F8E division multiplex. Multiplex 600 telephone channels occupying baseband between 60 and 2540 kHz; continuity pilot at 8500 kHz produces 140 kHz rms deviation of main carrier. Computation of Bn : D=(200x10\3\x3.76x2.565)=1.93x10\6\ Hz; M=2.54x10\6\ Hz; 2DK)[le]2P Bandwidth: 17x10\6\ Hz--------------------------------------------------------------------------------------------------------------------------------------------------------Unmodulated pulse emission........... Bn=2K÷t, K depends upon the ratio Primary Radar Range resolution: 150 m, K=1.5 3M00P0N of pulse rise time. Its value usually (triangular pulse where t[sime]tr, only falls between 1 and 10 and in many components down to 27 dB from the strongest are cases it does not need to exceed 6 considered) Then t=2xrange resolution÷velocity of light=2x150÷3x10\8\=1x10-6 seconds, Bandwidth: 3x10\6\ Hz=3 MHz-------------------------------------------------------------------------------------------------------------------------------------------------------- 6. Composite Emissions--------------------------------------------------------------------------------------------------------------------------------------------------------Radio-relay system................... Bn=2K÷t, K=1.6 Pulse position modulated by 36 voice channel 8M00M7E baseband; pulse width at half amplitude=0.4 us, Bandwidth: 8x10\6\ Hz=8 MHz (Bandwidth independent of the number of voice channels)Radio-relay system................... Bn = 2K/t Pulse position modulated by 36 voice channel 8M00M7E K=1.6 baseband: pulse width at half amplitude 0.4 mS; Bn = 8x10 \6\ Hz = 8 MHz (Bandwidth independent of the number of voice channels)Composite transmission digital Bn = 2RK/log2S Digital modulation used to send 5 megabits per 5M00K7 modulation using DSB-AM (Microwave second by use of amplitude modulation of the radio relay system). main carrier with 4 signaling states R = 5x10 \6\ bits per second; K = 1; S = 4; Bn = 5 MHzBinary Frequency Shift Keying........ (0.03 < 2D/R < 1.0); Digital modulation used to send 1 megabit per 2M80F1D Bn = 3.86D + 0.27R second by frequency shift keying with 2 (1.0 < 2D/R <2) signaling states and 0.75 MHz peak deviation of Bn = 2.4D + 1.0R the carrier R = 1x10 \6\ bps; D = 0.75x10 \6\ Hz; Bn = 2.8 MHzMultilevel Frequency Shift Keying.... Bn = (R/log2S) + 2DK Digital modulation to send 10 megabits per 9M00F7D second by use of frequency shift keying with four signaling states and 2 MHz peak deviation of the main carrier R = 10x10 \6\ bps; D = 2 MHz; K = 1; S = 4; Bn = 9 MHzPhase Shift Keying................... Bn = 2RK/log2S Digital modulation used to send 10 megabits per 10M0G7D second by use of phase shift keying with 4 signaling states R = 10x10 \6\ bps; K = 1; S = 4; Bn = 10 MHzQuadrature Amplitude Modulation (QAM) Bn = 2R/log2S 64 QAM used to send 135 Mbps has the same 45M0W necessary bandwidth as 64-PSK used to send 135 Mbps; R = 135x10 \6\ bps; S = 64; Bn = 45 MHzMinimum Shift Keying................. 2-ary: Digital modulation used to send 2 megabits per 2M36G1D Bn = R(1.18) second using 2-ary minimum shift keying 4-ary: R = 2.36x10 \6\ bps; Bn = 2.36 MHz Bn = R(2.34)--------------------------------------------------------------------------------------------------------------------------------------------------------
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[28 FR 12465, Nov. 22, 1963, as amended at 37 FR 8883, May 2, 1972; 37 FR 9996, May 18, 1972; 48 FR 16492, Apr. 18, 1983; 49 FR 48698, Dec. 14, 1984; 68 FR 68543, Dec. 9, 2003]
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