United States of America

**DRAFT PROPOSAL FOR THE WORK OF THE CONFERENCE**

# Agenda Item 1.8.1: consideration of the results of studies regarding the boundary between spurious and out-of-band emissions, with a view to including the boundary in Appendix 3;

**Background Information**: The proposal herein amends Article **1**,
Article **3** and Appendix **3** to take into account the most recent
studies identifying the unwanted emissions to which the limits of
Appendix **3** Section II apply. These studies define the out-of-band
and spurious domains of an emission and determine the boundary between
them.

In developing proposed text for Section II of Appendix **3** of the
Radio Regulations, WRC-97, following guidance from Task Group 1/3, used
an assumption that all unwanted emissions of a transmitter separated
from the center frequency by more than 250% of the necessary bandwidth
(2.5*B~n~*) would generally be considered spurious emissions, for the
purpose of applying spurious emission limits. Realizing, however, that
2.5*B~n~* was not an appropriate threshold for all emissions, the WRC
included exceptions for certain modulation types, bit rates, transmitter
types, and coordination factors.

From 1997 through 2000, Task Group 1/5 continued the studies as to what
frequencies the spurious emission limits of Appendix **3**, Section II
should apply. While maintaining the 2.5*B~n~* boundary for most systems,
the group developed guidance for narrowband and wideband emissions in
various frequency ranges to avoid excessive variations in the boundary.
The guidance, eventually promulgated in Recommendation ITU-R SM.1539,
also addressed exceptions for certain radio systems, radio services, and
frequency bands.

Recognizing a conflict in terminology, since no "boundary" exists in the
frequency domain between out-of-band and spurious emissions, Task
Group 1/5 adopted definitions for the out-of-band and spurious "domains"
of an emission that would be disjoint in frequency, and thus have the
intended boundary.

**Proposal**:

**CHAPTER I**

**Article 1**

Terms and definitions

**Section VI -- Characteristics of emissions and radio equipment**

**USA/ /**

**ADD**

**1.146*bis *** *out-of-band domain* (of an emission): The frequency
range, immediately outside the necessary bandwidth but excluding the
*spurious domain*, in which *out-of-band emissions* generally
predominate.

Out-of-band *emissions*, defined based on their source, occur in the
out-of-band domain and, to a lesser extent, in the spurious domain.
Spurious emissions likewise may occur in the out-of-band domain as well
as in the spurious domain.

1.146*ter spurious domain* (of an emission): The frequency range beyond
the *out-of-band domain* in which *spurious emissions* generally
predominate.

**Reasons**: Adoption of these two definitions will provide a means to
distinguish between frequency ranges within which the emission limits of
Appendix **3**, Section II either apply or do not apply.

Article 3

Technical characteristics of stations

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#### MOD

**3.6** Transmitting stations shall conform to the maximum permitted
unwanted emission power levels specified in Appendix **3**.

**Reasons**: Section I of Appendix **3** pertains to spurious emissions,
while Section II, as a consequence of the revisions proposed herein,
will pertain to emissions in the spurious domain. The term "unwanted
emission" covers both cases.

**USA/ /**

#### MOD

**3.7** Transmitting stations shall conform to the maximum permitted
power levels for out-of-band emissions, or unwanted emissions in the
out-of-band domain, specified for certain services and classes of
emission in the present Regulations. In the absence of such specified
maximum permitted power levels transmitting stations should, to the
maximum extent possible, satisfy the requirements relating to the
limitation of the out-of-band emissions, or unwanted emissions in the
out-of-band domain, specified in the most recent ITU-R Recommendations
(see Resolution **27 (Rev. WRC-97)**).

**Reasons:** As a result of recent revisions, some ITU-R
Recommendations, including Recommendation ITU-R SM.1541, now address
unwanted emissions in the out-of-band domain instead of out-of-band
emissions as before. Other provisions and Recommendations still address
out-of-band emissions.

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**MOD**

APPENDIX 3

Table of maximum permitted power levels for certain unwanted emissions

(See Article **3**)

**Reasons**: Section I of this Appendix applies to spurious emissions,
while Section II applies to unwanted emissions in the spurious domain.
The proposed title encompasses both types of emission limits.

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**MOD**

1 The following sections indicate the maximum permitted levels of
certain unwanted emissions, in terms of power as indicated in the
tables, of components supplied by a transmitter to the antenna
transmission line. Section I, which provides spurious emissions limits,
is applicable until 1 January 2012 to transmitters installed on or
before 1 January 2003; Section II, which limits emissions in the
spurious domain, is applicable to transmitters installed after 1 January
2003 and to all transmitters after 1 January 2012. The provisions of No.
**4.5** apply to unwanted emissions not covered in Sections I and II.

2 Spurious and spurious domain emissions (covered by Sections I and II)
from any part of the installation, other than the antenna and its
transmission line, shall not have an effect greater than would occur if
this antenna system were supplied with the maximum permitted power at
the frequency of that emission.

3 These levels shall not, however, apply to emergency
position-indicating radiobeacon (EPIRB) stations, emergency locator
transmitters, ships' emergency transmitters, lifeboat transmitters,
survival craft stations or maritime transmitters when used in emergency
situations.

4 For technical or operational reasons, more stringent levels than those
specified may be applied to protect specific services in certain
frequency bands. The levels applied to protect these services, such as
safety and passive services, shall be those agreed upon by the
appropriate world radiocommunication conference. More stringent levels
may also be fixed by specific agreement between the administrations
concerned. Additionally, special consideration of transmitter spurious
or spurious domain emissions may be required for the protection of
safety services, radio astronomy and space services using passive
sensors. Information on the levels of interference detrimental to radio
astronomy, Earth exploration satellites and meteorological passive
sensing is given in the most recent version of Recommendation
ITU-R SM.329.

5 Spurious or spurious domain emission limits (covered by Sections I and
II) for combined radiocommunication and information technology equipment
are those for the radiocommunication transmitters.

**Reasons**: The revised paragraphs reflect the distinction between the
types of emissions to which the limits of Sections I and II apply.

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**NOC**

Section I -- Spurious emission limits for transmitters installed on\
or before 1 January 2003 (valid until 1 January 2012)

**Reasons**: The provisions of Section I apply to spurious emissions and
are not affected by this Agenda Item.

**USA/ /**

**MOD**

Section II -- Spurious domain emission limits for transmitters installed
after 1 January 2003 and for all transmitters after 1 January 2012

*Application of these limits*

7 The frequency range of the measurement of spurious domain emissions is
from 9 kHz to 110 GHz or the second harmonic if higher.

8 Guidance regarding the methods of measuring spurious domain emissions
is given in the most recent version of Recommendation ITU-R SM.329. The
e.i.r.p. method specified in that Recommendation should be used when it
is not possible to accurately measure the power supplied to the antenna
transmission line (for example, radars), or for specific applications
where the antenna is designed to provide significant attenuation in the
spurious domain. Additionally, the e.i.r.p. method may need some
modification for special cases, e.g. beam forming radars.

9 Guidance regarding the methods of measuring spurious domain emissions
from radar systems is given in the most recent version of Recommendation
ITU-R M.1177. The reference bandwidths required for proper measurement
of radar spurious domain emissions should be calculated for each
particular radar system. Thus, for the three general types of radar
pulse modulation utilized for radio­navigation, radiolocation,
acquisition, tracking and other radiodetermination functions, the
reference bandwidth values should be:

-- for fixed-frequency, non-pulse-coded radar, one divided by the radar
pulse length, in seconds (e.g. if the radar pulse length is 1 μs, then
the reference bandwidth is 1/1 μs = 1 MHz);

-- for fixed-frequency, phase coded pulsed radar, one divided by the
phase chip length, in seconds (e.g. if the phase coded chip is 2 μs
long, then the reference bandwidth is 1/2 μs = 500 kHz);

-- for frequency modulated (FM) or chirped radar, the square root of the
quantity obtained by dividing the radar bandwidth in MHz by the pulse
length, in seconds (e.g. if the FM is from 1 250 MHz to 1 280 MHz or
30 MHz during the pulse of 10 μs, then the reference bandwidth is
(30 MHz/10 μs)1/2 = 1.73 MHz).

For those radar systems for which acceptable methods of measurement do
not exist, the lowest practicable power of spurious domain emission
should be achieved.

10 The spurious domain emission levels are specified in the following
reference bandwidths:

-- 1 kHz between 9 kHz and 150 kHz

-- 10 kHz between 150 kHz and 30 MHz

-- 100 kHz between 30 MHz and 1 GHz

-- 1 MHz above 1 GHz.

As a special case, the reference bandwidth of all space service spurious
domain emissions should be 4 kHz.

**Reasons**: The provisions of this Section apply to unwanted emissions
in the spurious domain, here called "spurious domain emissions," as
opposed to the spurious emissions addressed in Section I.

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**MOD**

11 The emission limits of this section apply to all emissions, including
harmonic emissions, intermodulation products, frequency conversion
products and parasitic emissions, at frequencies in the spurious domain
(see Figure 1). The upper and lower parts of the spurious domain extend
outward from a boundary determined using Annex I.

**Reasons**: Since the boundary between the out-of-band and spurious
domains is determined using Annex I, the information is no longer needed
here.

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**ADD**

![](media/image1.wmf){width="5.997916666666667in"
height="3.75in"}FIGURE 1

## Out-of-band and spurious domains

**Reasons**: The figure illustrates the text description of the
locations of the out-of-band and spurious domains from the previous
paragraph.

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SUP

**Reasons**: The information used to determine the boundary between the
out-of-band and spurious domains is now found in Annex I.

**USA/ /**

**MOD**

11*[bis]{.underline}~~ter~~* For the case of a single satellite
operating with more than one transponder in the same service area, and
when considering the limits for spurious domain emissions as indicated
in § 11 of this Appendix, spurious domain emissions from one transponder
may fall on a frequency at which a second, companion transponder is
transmitting. In these situations, the level of spurious domain
emissions from the first transponder is well exceeded by the fundamental
or out-of-band domain emissions of the second transponder. Therefore,
the limits of this Appendix should not apply to those emissions of a
satellite that fall within either the necessary bandwidth or the
out-of-band domain of another transponder on the same satellite, in the
same service area (see Fig. 2).

FIGURE 2

**Example of the applicability of spurious domain** **emission limits**

**to a satellite transponder**

![](media/image2.wmf)

Transponders A, B, C and D are operating on the same satellite in the
same service area. Transponder A is not required to meet spurious domain
emission limits in frequency ranges  and , but is required to meet
them in frequency ranges  and .

# 12 Examples of applying 43 + 10 log (*P*) to calculate attenuation requirements

Where specified in relation to mean power, spurious domain emissions are
to be at least *x* dB below the total mean power *P*, i.e. --  *x* dBc.
The power *P* (W) is to be measured in a bandwidth wide enough to
include the total mean power. The spurious domain emissions are to be
measured in the reference bandwidths given in the Recommendation. The
measurement of the spurious domain emission power is independent of the
value of necessary bandwidth. Because the absolute emission power limit,
derived from 43 + 10 log (*P*), can become too stringent for high-power
transmitters, alternative relative powers are also provided in Table II.

*Example 1*

A land mobile transmitter, with any value of necessary bandwidth, must
meet a spurious domain emission attenuation of 43 + 10 log (*P*), or
70 dBc, whichever is less stringent. To measure spurious domain
emissions in the frequency range between 30 MHz and 1 GHz,
Recommendation ITU‑R SM.329-9 *recommends* 4.1 indicates the use of a
reference bandwidth of 100 kHz. For other frequency ranges, the
measurement must use the appropriate reference bandwidths given in
*recommends* 4.1.

With a measured total mean power of 10 W:

-- Attenuation relative to total mean power = 43 + 10 log (10) = 53 dBc.

-- The 53 dBc value is less stringent than the 70 dBc, so the 53 dBc
value is used.

-- Therefore: Spurious domain emissions must not exceed 53 dBc in a
100 kHz bandwidth, or converting to an absolute level, they must not
exceed 10 dBW -- 53 dBc = \_ 43 dBW in a 100 kHz reference bandwidth.

With a measured total mean power of 1 000 W:

-- Attenuation relative to total mean power = 43 + 10 log (1 000) = 73
dBc.

-- The 73 dBc value is more stringent than the 70 dBc limit, so the
70 dBc value is used.

-- Therefore: Spurious domain emissions must not exceed 70 dBc in a
100 kHz bandwidth, or converting to an absolute level, they must not
exceed 30 dBW -- 70 dBc = \_ 40 dBW in a 100 kHz reference bandwidth.

*Example 2*

A space service transmitter with any value of necessary bandwidth must
meet a spurious domain emission attenuation of 43 + 10 log (*P*), or
60 dBc, whichever is less stringent. To measure spurious domain
emissions at any frequency, Note 10 to Table II indicates using a
reference bandwidth of 4 kHz.

With a measured total mean power of 20 W:

-- Attenuation relative to total mean power = 43 + 10 log (20) = 56 dBc.

-- The 56 dBc value is less stringent than the 60 dBc limit, so the
56 dBc value is used.

-- Therefore: Spurious domain emissions must not exceed 56 dBc in a
4 kHz reference bandwidth, or converting to an absolute level, they must
not exceed 13 dBW -- 56 dBc = \_ 43 dBW in a 4 kHz reference bandwidth.

TABLE II (WRC-2000)

Attenuation values used to calculate maximum permitted spurious domain
emission\
power levels for use with radio equipment

TABLE II (*end*)

**Reasons**: These revisions again reflect the change in terminology
from "spurious emissions" to "spurious domain emissions."

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**ADD**

ANNEX I

Determination of the boundary between the out-of-band and spurious
domains

1 Except as provided below, the boundary between the out-of-band and
spurious domains occurs at frequencies that are separated from the
centre frequency of the emission by the values shown in Table 1. For
most systems, the centre frequency of the emission is the centre of the
necessary bandwidth. For multichannel or multicarrier
transmitters/transponders, where several carriers may be transmitted
simultaneously from a final output amplifier or an active antenna, the
centre frequency of the emission is taken to be the centre of the 3 dB
bandwidth of the transmitter or transponder and the transmitter or
transponder bandwidth is used in place of the necessary bandwidth for
determining the boundary. Some systems specify unwanted emissions
relative to channel bandwidth, or channel spacing. These may be used as
a substitute for the necessary bandwidth in Table 1, provided they are
found in ITU--R Recommendations.

TABLE 1

Values for frequency separation between the centre frequency\
and the boundary of the spurious domain

  -------------------- ------------- ------------ ------------ ---------- --------------
  Frequency\           Narrow-band                Normal\      Wideband   
  range                case                       separation   case       

                       for B~n~ \<   Separation                for B~n~   Separation
                                                               \>         

  9 kHz \< *f~c~* \<   250 Hz        625 Hz       2.5 *B~n~*   10 kHz     1.5 *B~n~* +
  150 kHz                                                                 10 kHz

  150 kHz \< *f~c~* \< 4 kHz         10 kHz       2.5 *B~n~*   100 kHz    1.5 *B~n~* +
  30 MHz                                                                  100 kHz

  30 MHz \< *f~c~* \<  25 kHz        62.5 kHz     2.5 *B~n~*   10 MHz     1.5 *B~n~* +
  1 GHz                                                                   10 MHz

  1 GHz \< *f~c~* \< 3 100 kHz       250 kHz      2.5 *B~n~*   50 MHz     1.5 *B~n~* +
  GHz                                                                     50 MHz

  3 GHz \< *f~c~* \<   100 kHz       250 kHz      2.5 *B~n~*   100 MHz    1.5 *B~n~* +
  10 GHz                                                                  100 MHz

  10 GHz \< *f~c~* \<  300 kHz       750 kHz      2.5 *B~n~*   250 MHz    1.5 *B~n~* +
  15 GHz                                                                  250 MHz

  15 GHz \< *f~c~* \<  500 kHz       1.25 MHz     2.5 *B~n~*   500 MHz    1.5 *B~n~* +
  26 GHz                                                                  500 MHz

  *f~c~* \> 26 GHz     1 MHz         2.5 MHz      2.5 *B~n~*   500 MHz    1.5 *B~n~* +
                                                                          500 MHz

  NOTE---In Table 1,                                                      
  *f~c~* is the centre                                                    
  frequency of the                                                        
  emission and *B~n~*                                                     
  is the necessary                                                        
  bandwidth. If the                                                       
  assigned frequency                                                      
  band of the                                                             
  emissions extends                                                       
  across two frequency                                                    
  ranges, then the                                                        
  values corresponding                                                    
  to the higher                                                           
  frequency range                                                         
  shall be used for                                                       
  determining the                                                         
  boundary.                                                               
  -------------------- ------------- ------------ ------------ ---------- --------------

*Example 1*: The necessary bandwidth of an emission at 26 MHz is 1.8
kHz. Since 2.5*B~n\ ~*is only 4.5 kHz, the minimum separation applies.
The spurious domain begins 10 kHz each side of the centre of the
necessary bandwidth.

*Example 2*: The necessary bandwidth of an emission at 8 GHz is 200 MHz.
Since the wideband case applies for *B~n~* \> 100 MHz at that frequency,
the spurious domain begins 400 MHz each side of the centre of the
necessary bandwidth. Using the general separation formula, the
out-of-band domain would have extended to 2.5 × 200 MHz = 500 MHz either
side of the centre frequency.

2 Tables 2 and 3 show exceptions to Table 1 for narrow-band and wideband
cases, respectively, applicable to particular systems or services and
frequency bands.

TABLE 2

Narrow-band variations for systems or services and frequency bands

+----------------+-------------------------+-----------+--------------+
| System or      | Frequency range         | Na        |              |
| service        |                         | rrow-band |              |
|                |                         | case      |              |
+----------------+-------------------------+-----------+--------------+
|                |                         | for B~n~  | Separation   |
|                |                         | \<        |              |
+----------------+-------------------------+-----------+--------------+
| FS             | 14 kHz - 1.5 MHz        | 20 kHz^1^ | 50 kHz       |
+----------------+-------------------------+-----------+--------------+
| FS             | 1.5-30 MHz              | 80 kHz^2^ | 200 kHz      |
+----------------+-------------------------+-----------+--------------+
| ^1^ This is    |                         |           |              |
| based on an    |                         |           |              |
| assumption     |                         |           |              |
| that the       |                         |           |              |
| maximum value  |                         |           |              |
| of the         |                         |           |              |
| necessary      |                         |           |              |
| bandwidth is   |                         |           |              |
| about 3 kHz    |                         |           |              |
| for the        |                         |           |              |
| frequency      |                         |           |              |
| range 14 kHz - |                         |           |              |
| 1.5 MHz. The   |                         |           |              |
| value of 50    |                         |           |              |
| kHz separation |                         |           |              |
| is extremely   |                         |           |              |
| large as       |                         |           |              |
| compared with  |                         |           |              |
| the necessary  |                         |           |              |
| bandwidth. It  |                         |           |              |
| is because     |                         |           |              |
| unwanted       |                         |           |              |
| emissions of   |                         |           |              |
| high power     |                         |           |              |
| transmitters   |                         |           |              |
| under          |                         |           |              |
| modulated      |                         |           |              |
| conditions     |                         |           |              |
| have to be     |                         |           |              |
| below the      |                         |           |              |
| spurious limit |                         |           |              |
| (70 dBc) at    |                         |           |              |
| the boundary   |                         |           |              |
| between the    |                         |           |              |
| out-of-band    |                         |           |              |
| and spurious   |                         |           |              |
| domains.       |                         |           |              |
|                |                         |           |              |
| ^2^ This is    |                         |           |              |
| based on an    |                         |           |              |
| assumption     |                         |           |              |
| that the       |                         |           |              |
| maximum value  |                         |           |              |
| of the         |                         |           |              |
| necessary      |                         |           |              |
| bandwidth is   |                         |           |              |
| about 12 kHz   |                         |           |              |
| for the        |                         |           |              |
| frequency      |                         |           |              |
| range 1.5-30   |                         |           |              |
| MHz. The value |                         |           |              |
| of 200 kHz     |                         |           |              |
| separation is  |                         |           |              |
| extremely      |                         |           |              |
| large as       |                         |           |              |
| compared with  |                         |           |              |
| the necessary  |                         |           |              |
| bandwidth. It  |                         |           |              |
| is because     |                         |           |              |
| unwanted       |                         |           |              |
| emissions of   |                         |           |              |
| high power     |                         |           |              |
| transmitters   |                         |           |              |
| under          |                         |           |              |
| modulated      |                         |           |              |
| conditions     |                         |           |              |
| have to be     |                         |           |              |
| below the      |                         |           |              |
| spurious limit |                         |           |              |
| (70 dBc) at    |                         |           |              |
| the boundary   |                         |           |              |
| between the    |                         |           |              |
| out-of-band    |                         |           |              |
| and spurious   |                         |           |              |
| domains. Also, |                         |           |              |
| if future      |                         |           |              |
| systems in the |                         |           |              |
| fixed service  |                         |           |              |
| operating in   |                         |           |              |
| this frequency |                         |           |              |
| range require  |                         |           |              |
| a necessary    |                         |           |              |
| bandwidth      |                         |           |              |
| larger than 12 |                         |           |              |
| kHz, it may    |                         |           |              |
| become         |                         |           |              |
| necessary to   |                         |           |              |
| review the 200 |                         |           |              |
| kHz            |                         |           |              |
| separation. It |                         |           |              |
| should be      |                         |           |              |
| noted that for |                         |           |              |
| medium or low  |                         |           |              |
| power          |                         |           |              |
| transmitters   |                         |           |              |
| (e.g. below    |                         |           |              |
| 1 kW), a       |                         |           |              |
| smaller value  |                         |           |              |
| may be         |                         |           |              |
| appropriate as |                         |           |              |
| the minimum    |                         |           |              |
| separation.    |                         |           |              |
| This matter    |                         |           |              |
| requires       |                         |           |              |
| further study. |                         |           |              |
+----------------+-------------------------+-----------+--------------+

TABLE 3

Wideband variations for systems or services and frequency bands

  ------------- ----------------------------- ----------- ----------------
  System or     Frequency range               Wideband    
  service                                     case        

                                              for B~n~ \> Separation

  FS            14-150 kHz                    20 kHz      1.5 *B~n~* + 20
                                                          kHz

  FSS           3.4-4.2 GHz                   250 MHz     1.5 *B~n~* + 250
                                                          MHz

  FSS           5.725-6.725 GHz               500 MHz     1.5 *B~n~* + 500
                                                          MHz

  FSS           7.25-7.75 GHz and 7.9-8.4 GHz 250 MHz     1.5 *B~n~* + 250
                                                          MHz

  FSS           10.7-12.75 GHz                500 MHz     1.5 *B~n~* + 500
                                                          MHz

  BSS           11.7-12.75 GHz                500 MHz     1.5 *B~n~* + 500
                                                          MHz

  FSS           12.75-13.25 GHz               500 MHz     1.5 *B~n~* + 500
                                                          MHz

  FSS           13.75-14.8 GHz                500 MHz     1.5 *B~n~* + 500
                                                          MHz
  ------------- ----------------------------- ----------- ----------------

3 For primary radar stations, the boundary between the out-of-band and
spurious domains is the frequency at which the out-of-band limits
specified in applicable ITU--R Recommendations are equal to the spurious
limit defined in Table II of Appendix **3**. Further studies need to be
conducted within the ITU--R to determine the appropriate spurious domain
boundary for these systems.

**Reasons**: Annex I is added for the following reasons;

-   Section II of this Appendix states that the emission limits apply to
    unwanted emissions in the spurious domain. This Annex is needed to
    determine the boundary between the out-of-band and spurious domains,
    and thus the frequencies to which the emission limits of Section II
    apply.

-   Table 1, taken from Recommendation ITU--R SM.1539, shows the normal
    boundary of 2.5*B~n~*, along with the narrowband and wideband
    exception. The information in the Recommendation, along with the
    text of existing paragraphs 11 and 11*bis*, have been included,
    though they have been shortened to bring them in line with the form
    of other Appendices.

-   Tables 2 and 3 are also taken from Recommendation ITU--R SM.1539.

-   Studies regarding the frequencies to which the Section II limits for
    primary radar apply will not be completed in time for WRC--2003.
    This text is similar to that of Annex 8, § 5 of Recommendation
    ITU--R SM.1541.