RECOMMENDATION ITU-R SM.1541[^1] **RCG-2**

Unwanted emissions in the out-of-band domain

(Question ITU-R 211/1)

\(2001\)

The ITU Radiocommunication Assembly,

considering

a\) that Recommendation ITU‑R SM.329 -- Spurious emissions, relates to
the effects, measure­ments and limits to be applied to unwanted emissions
in the spurious domain;

b\) that Recommendations ITU‑R SM.329 and ITU‑R SM.1539 provide guidance
for deter­mining the boundary between the out-of-band (OoB) and spurious
domains in a transmitted radio frequency spectrum;

c\) that considerations of out-of-band domain and necessary bandwidths
are included by necessity in Recommendation ITU-R SM.328 -- Spectra and
bandwidth of emissions;

d\) that unwanted emissions occur after a transmitter is brought into
operation and can be reduced by system design;

e\) that OoB limits have been successfully used as national or regional
regulations in areas having a high radiocommunications density; such
limits are generally designed according to specific and detailed local
needs for coexistence with other systems;

f\) that nevertheless there is a need, for each service, for a limited
number of a more broadly generic ITU-R OoB limits, generally based on an
envelope of the least restrictive OoB limits described in the above
*considering* e);

g\) that where frequency assignments are provided to the
Radiocommunication Bureau (BR) in accordance with Appendix 4 of the
Radio Regulations (RR), the necessary bandwidth of an emission with a
single carrier is given by the bandwidth portion of the emission
designator;

h\) that the necessary bandwidth, referred to in RR Appendix 4 is for a
single carrier transmission, and may not adequately cover the case of
systems with multiple carriers,

recognizing

that the following terms are defined in the RR:

### Unwanted emissions (RR No. 1.146) {#unwanted-emissions-rr-no.-1.146 .heading_b}

Consist of spurious emissions and OoB emissions.

### Spurious emission (RR No. 1.145) {#spurious-emission-rr-no.-1.145 .heading_b}

Emission on a frequency or frequencies which are outside the necessary
bandwidth and the level of which may be reduced without affecting the
corresponding transmission of information. Spurious emissions include
harmonic emissions, parasitic emissions, intermodulation products and
frequency conversion products, but exclude OoB emissions.

### Out-of-band emission (RR No. 1.144) {#out-of-band-emission-rr-no.-1.144 .heading_b}

Emission on a frequency or frequencies immediately outside the necessary
bandwidth which results from the modulation process, but excluding
spurious emissions.

### Occupied bandwidth (RR No. 1.153) {#occupied-bandwidth-rr-no.-1.153 .heading_b}

The width of the frequency band which is just sufficient such that,
below the lower and above the upper frequency limits, the mean powers
emitted are each equal to a specified percentage β/2 of the total mean
power of a given emission.

Unless otherwise specified in an ITU-R Recommendation for the
appropriate class of emission, the value of β/2 should be taken as 0.5%.

### Necessary bandwidth (RR No. 1.152) {#necessary-bandwidth-rr-no.-1.152 .heading_b}

For a given class of emission, the width of the frequency band which is
just sufficient to ensure the transmission of information at the rate
and with the quality required under specified conditions.

### Assigned frequency band (RR No. 1.147) {#assigned-frequency-band-rr-no.-1.147 .heading_b}

The frequency band within which the emission of a station is authorized;
the width of the band equals the necessary bandwidth plus twice the
absolute value of the frequency tolerance. Where space stations are
concerned, the assigned frequency band includes twice the maximum
Doppler shift that may occur in relation to any point of the Earth\'s
surface.

### Assigned frequency (RR No. 1.148) {#assigned-frequency-rr-no.-1.148 .heading_b}

The centre of the frequency band assigned to a station,

noting

a\) that Recommendation ITU-R SM.1540 additionally covers cases of
unwanted emissions in the OoB domain falling into adjacent allocated
bands;

b\) that the studies required by Question ITU-R 222/1, approved by
Radiocommunication Assembly 2000, could have formal and substantial
impact to basic definitions used in this Recommendation. It may be
necessary to revise this Recommendation in the future to reflect the
results of these studies,

recommends

# 1 Terminology and definitions

that the following additional terms and definitions should be used:

## 1.1 Spurious domain[^2]

(of an emission): the frequency range beyond the OoB domain in which
spurious emissions generally predominate.

## 1.2 OoB domain1

(of an emission): the frequency range, immediately outside the necessary
bandwidth but excluding the spurious domain, in which OoB emissions
generally predominate.

## 1.3 dBsd and dBasd

dBsd: decibels relative to the maximum value of power spectral density
(psd) within the necessary bandwidth. The maximum value of psd of a
random signal is found by determining the mean power in the reference
bandwidth when that reference bandwidth is positioned in frequency such
that the result is maximized. The reference bandwidth should be the same
regardless of where it is centred and is as specified in § 1.6.

dBasd: decibels relative to the average value of psd within the
necessary bandwidth. The average value of psd of a random signal is
found by computing the mean power in the reference bandwidth and
averaging that result over the necessary bandwidth. The reference
bandwidth is as specified in § 1.6.

![](media/image1.wmf){width="5.247222222222222in"
height="3.313888888888889in"}

## 1.4 dBc

Decibels relative to the unmodulated carrier power of the emission. In
the cases which do not have a carrier, for example in some digital
modulation schemes where the carrier is not accessible for measurement,
the reference level equivalent to dBc is dB relative to the mean power
*P*.

## 1.5 dBpp

Decibels relative to the maximum value of the peak power, measured with
the reference bandwidth within the occupied bandwidth. The in-band peak
power is expressed in the same reference bandwidth as the OoB peak
power. Both the in-band and the unwanted emissions should be evaluated
in terms of peak values. For radar systems, the reference bandwidth
should be selected according to Recommendation ITU-R M.1177.

![](media/image2.wmf){width="3.160416666666667in"
height="3.0104166666666665in"}

## 1.6 Reference bandwidth

The bandwidth required for uniquely defining the out-of-band limits. If
not explicitly given with the OoB limit, the reference bandwidth should
be 1% of the necessary bandwidth. For radar systems the reference
bandwidth should be selected in line with Recommendation ITU-R M.1177.

## 1.7 Measurement bandwidth

The bandwidth which is technically appropriate for the measurement of a
specific system. In common spectrum analysers this is generally referred
as the resolution bandwidth.

NOTE 1 -- The measurement bandwidth may differ from the reference
bandwidth, provided the results can be converted to the required
reference bandwidth.

## 1.8 psd

For the purpose of this Recommendation, psd is the mean power per
reference bandwidth.

## 1.9 Mean power 

Power integrated over a specified frequency band using measurements of
the psd or an equivalent method.

## 1.10 Adjacent channel mean power

Power integrated over the bandwidth of a channel adjacent to an occupied
channel using measure­ments of the psd or an equivalent method.

## 1.11 Peak power

Power measured with the peak detector using a filter the width and shape
of which is sufficient to accept the signal bandwidth.

## 1.12 Adjacent channel peak power

Peak power measured in the bandwidth of a channel adjacent to an
occupied channel using a specified channel filter.

## 1.13 Total assigned band

Sum of contiguous assigned bands of a system consistent with the RR
Appendix 4 data provided to the Radiocommunication Bureau and as
authorized by an administration.

NOTE 1 -- For space services, when a system has multiple
transponders/transmitters that operate in adjacent bands separated by a
guardband, the total assigned band should include the guardbands. In
such cases, the guardbands should be a small percentage of the
transponder/transmitter bandwidth.

## 1.14 Total assigned bandwidth

The width of the total assigned band;

# 2 Application of definitions

that, when applying this Recommendation, guidance should be taken from
the following:

## 2.1 OoB domain emissions

Any emission outside the necessary bandwidth which occurs in the
frequency range separated from the assigned frequency of the emission by
less than 250% of the necessary bandwidth of the emission will generally
be considered an emission in the OoB domain. However, this frequency
separation may be dependent on the type of modulation, the maximum
symbol rate in the case of digital modulation, the type of transmitter,
and frequency coordination factors. For example, in the case of some
digital, broadband, or pulse modulated systems, the frequency separation
may need to differ from the 250% factor.

Transmitter non-linearities may also spread in-band signal components
into the frequency band of the OoB frequency ranges described in
Annex 1, § 1.3. Further, transmitter oscillator sideband noise also may
extend into that frequency range described in Annex 1, § 1.3. Since it
may not be practical to isolate these emissions their level will tend to
be included during OoB power measurements.

## 2.2 Spurious domain emissions 

For the purpose of this Recommendation all emissions, including
intermodulation products, conversion products and parasitic emissions,
which fall at frequencies separated from the centre frequency of the
emission by 250% or more of the necessary bandwidth of the emission will
generally be considered as emissions in the spurious domain. However,
this frequency separation may be dependent on the type of modulation,
the maximum symbol rate in the case of digital modulation, the type of
transmitter, and frequency coordination factors. For example, in the
case of some digital, broadband, or pulse-modulated systems, the
frequency separation may need to differ from the 250% factor.

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 either the assigned bandwidth of the station
or of the\
--3 dB bandwidth of the transmitter/transponder, using the lesser of the
two bandwidths.

## 2.3 Necessary bandwidth and OoB domain

In the case of narrow-band or wideband emissions (as defined in
Recommendation ITU-R SM.1539, the extent of the OoB domain should be
determined by using Table 1.

TABLE 1

Start and end of OoB domain

### 2.3.1 Single carrier emissions

The value of necessary bandwidth that should be used for checking
whether a single carrier emission complies with limits in the OoB domain
should coincide with the value in the emission designator provided to
the BR in accordance with RR Appendix 4.

Some systems specify the OoB mask in terms of channel bandwidth or
channel separation. These may be used as a substitute for necessary
bandwidth provided they are found in ITU-R Recommen­dations or in
relevant regional and national regulations.

### 2.3.2 Multicarrier emissions

Multicarrier transmitters/transponders are those where multiple carriers
may be transmitted simul­taneously from a final amplifier or an active
antenna.

For systems with multiple carriers, the OoB domain should start at the
edges of the total assigned bandwidth. For satellite systems, the
necessary bandwidth used in the OoB masks provided in Annex 5 of this
Recommendation and to determine the width of the OoB domain should be
taken to be the lesser of 3 dB transponder bandwidth or the total
assigned bandwidth (Annex 2 provides two examples showing how to
calculate the start and end of the OoB domain for multicarrier systems
with single and multiple transponders per satellite).

For space services, the above definition of necessary bandwidth applies
when all or some of the carriers are being transmitted simultaneously.

## 2.4 Considerations on dBsd, dBc, and dBpp

### 2.4.1 Positive and negative signs for dBsd, dBc, and dBpp

Since dBsd is defined as relative to some reference power spectral
density, the OoB dBsd value is expressed using a negative number (for
the usual case where the OoB psd is lower than the reference psd).
However, if a term such as "dBsd below" or "Attenuation (dBsd)" is used,
then the OoB domain emission value is expressed using a positive number.

Since dBc is defined as relative to some reference power, the OoB dBc
value is expressed using a negative number. However, if a term such as
"dBc below" or "Attenuation (dBc)" is used, then the OoB domain emission
value is expressed using a positive number.

Since dBpp is defined as relative to some reference peak power, the OoB
dBpp value is expressed using a negative number. However, if a term such
as "dBpp below" or "Attenuation (dBpp)" is used, then the OoB domain
emission value is expressed using a positive number.

Annex 3 provides the way to label X and Y axes on dBc and dBsd masks.

### 2.4.2 Comparisons of dBsd and dBc 

Since dBsd and dBc do not have the same 0 dB reference, the same numeric
dB value may cause dBsd emission limits that are more stringent than dBc
emission limits. The chosen reference bandwidth will affect the amount
of this difference. Thus, the type of mask, reference bandwidth, and
mask values need to be established together.

### 2.4.3 Practical application of dBsd, dBc, and dBpp limits

dBsd may be more practical for the following applications:

-- digital modulation;

-- modulation formats in which measurement of the carrier is
impractical.

dBc may be more practical for the following applications:

-- analogue modulation;

-- specific digital modulation systems;

-- subsidiary limits for discrete emissions contained in the OoB domain
when spectral density is specified in dBsd values.

dBpp may be more practical for the following applications:

-- specific pulsed modulation systems, e.g. radar, and certain specific
analogue transmission systems;

# 3 Methods to determine conformance to OoB limits

that the adjacent channel and alternate adjacent channel power method or
the OoB spectrum mask method described in Annex 1 should be used to
determine conformance to OoB domain emission requirements;

# 4 OoB limits for transmitters in the range of 9 kHz to 300 GHz[^3]

that the spectrum limits specified in this Recommendation should be
regarded as generic limits, which generally constitute the least
restrictive OoB emission limits successfully used as national or
regional regulations. These are sometimes called safety net limits. They
are intended for use in bands where tighter limits are not otherwise
required to protect specific applications (e.g. in areas having a high
radiocommunications density).

On this basis, the OoB domain emissions, to be applied to transmitters
in the range of 9 kHz to 300 GHz, should be limited as given in Table 2.

The applicability of Recommendations ITU‑R SM.1541 and ITU‑R SM.1540 is
described in Annex 14.

The development of more specific OoB limits for each system and in each
frequency band should be encouraged by administrations. These limits
would take into account the actual application, modulation, filtering
capabilities of the system and would take care about co-frequency or
adjacent bands operating systems, with a view to enhancing compatibility
with other radio services.

Examples of ITU-R Recommendations providing such more specific OoB
emission limits for some systems in some frequency bands are listed in
Annex 4.

TABLE 2

OoB domain emission spectrum limiting curves

Compliance with emission limits contained in this Recommendation may not
preclude the occurrence of interference. Therefore, compliance with the
standard does not obviate the need for cooperation in resolving and
implementing engineering solutions to harmful interference problem;

# 5 Adaptation of OoB masks provided in Annexes 5 to 12 in the cases of narrow‑band and wideband systems

a\) that in cases where the necessary bandwidth *BN* is less than *BL*
as defined in Recommen­dation ITU-R SM.1539, the OoB mask should be
scaled. This can be done by replacing *BN* by *BL*;

b\) in cases where the necessary bandwidth *BN* is greater than *BU* as
defined in Recommen­dation ITU-R SM.1539, the value of *BN* will remain
unchanged in the application of the OoB mask but the mask should be
truncated. Accordingly, the OoB mask will only be applicable from 50% of
*BN* to (150 + 100 *BU */*BN*)% of *BN*;

# 6 Measurement methods

that the methods for measurement of OoB described in detail in Annex 13
should be used.

ANNEX 1

Methods to determine conformance to OoB limits

Two possible methods can be used to quantify the OoB emission energy.
Section 1 provides a method by which the power is measured in an
adjacent channel. Section 2 discusses a method of assessment based on
the determination of the power spectral density in the OoB domain.

# 1 Adjacent channel and alternate adjacent channel power method

This methodology is based on the concept defined in Recommendation ITU-R
SM.328 -- Spectra and bandwidth of emissions, § 1.12 and has become
popular since the commercial availability of spectrum analysers with
digital signal processing capability which can perform numerical
inte­gration within a specified bandwidth.

A limit for permissible OoB domain power can be derived from the limits
imposed by a permissible OoB spectrum mask by integrating the
mathematical expression for the curve over a specified frequency band.
An example of this translation is provided in Appendix 1 for an example
emission mask used in the land mobile service, the primary user of this
method. Comparisons of limits so derived with actual limits adopted in
mobile service standards reveal that mobile radio industry practice has
been to establish limits significantly more stringent than those derived
from an OoB mask in order to achieve spectrum efficiency.

One key advantage of this method in a defined bandwidth approach is that
the same approach is defined in Recommendation ITU-R SM.329 for limits
of the power of spurious domain emissions displaced relatively far in
the frequency spectrum from a transmitter\'s assigned frequency band
(i.e. channel).

Another advantage is that it tends to facilitate frequency management if
the reference bandwidth is chosen comparable to that of receivers used
in the assigned frequency bands adjacent to that of a transmitter as
this leads to more efficient use of the electromagnetic spectrum. This
can be especially significant in new channel splitting "refarming"
environments wherein the close packing of channels in an allocated band
has resulted in frequency assignment co-ordination based on adjacent
channel considerations in addition to co-channel considerations. It also
provides a convenient means of assessing the interference potential
between two different modulation methods used on adjacent channels or
bands. This has proved useful in spectrum allocation planning in various
countries to determine compatible neighbouring technologies and link
directions.

## 1.1 Parameters to be measured

The parameters to be measured are the occupied bandwidth of an emission,
and the mean power in several defined bands. The same modulation
condition is employed for all measurement bands.

The maximum value of 99% power occupied bandwidth permitted by a
particular emission mask can be determined by calculating the frequency
difference between the 23 dB attenuation levels for any emission mask.

## 1.2 Units of measurement

The units of power measurement are the same as those used for
measurement of spurious domain emissions, as given in Annex 1 of
Recommendation ITU-R SM.329 (mean power is specified for

most measurements). Appropriate conversion factors (discussed in more
detail in § 1.1.1 and § 1.1.2 of Annex 13) must be used to correct for
differences between:

-- the detection method employed in the signal analyser used to perform
a measurement and the detection method specified for the limits; as well
as

-- the resolution bandwidth of the filter contained in the signal
analyser used to perform a measurement and the detection method
specified for the limits.

## 1.3 Measurement bands

Figure 3 graphically portrays the succeeding band descriptions.

![](media/image3.wmf){width="5.3069444444444445in"
height="1.6770833333333333in"}

### 1.3.1 Adjacent band

The band properties follow, which provide several means for assessment
of the amount of interference power that might be intercepted by a
receiver on the adjacent channel. The power in this band is termed the
adjacent band power (ABP).

#### 1.3.1.1 Location of the adjacent band

This band is centred on the adjacent assigned frequency band in the
allocated band in which the transmitter operates.

For worst‑case considerations, this band is located closer to the
transmitter by an amount equal to that of the permissible frequency
drift of the transmitter, plus any Doppler frequency difference.

#### 1.3.1.2 Bandwidth of the adjacent band

Its width is equal to the equivalent noise bandwidth of the adjacent
channel receiver. If not known then the default value should be equal to
the transmitter\'s occupied bandwidth.

### 1.3.2 Alternate adjacent band

This band is centred relative to the adjacent band in the same manner in
which the adjacent band is centred relative to the assigned frequency
band. Its width equals that of the adjacent band.

In some services (e.g. FM broadcast) channels are assigned by
alternating two interlaced sets of assigned frequency band plans so this
provides an assessment of the amount of interference power that might be
intercepted by a receiver on the adjacent authorized channel. The power
in this band is termed the alternate ABP.

For worst-case considerations, the centre of this band is located closer
to the transmitter by an amount equal to that of the permissible
frequency drift of the transmitter, plus that of a typical receiver used
on the adjacent channel, plus any Doppler frequency difference.

## 1.4 Adjacent band power ratio (ABPR)

ABPR is calculated in the following manner:

-- in power, as *ABPR* = *P*/*Pad*

-- in decibels, as *ABPR* = *P* − *Pad* (dB)

where:

*P* : transmitter mean power

*Pad* : mean power in the adjacent frequency band.

This calculation is performed as a routine operation automatically on
many modern spectrum analysers equipped with digital signal processing
capabilities.

The concept of measuring the power in the bandwidth of an adjacent
channel can be extended to neighbouring bands in an allocated band which
are *N* times further displaced than the adjacent band, where *N* is an
integer multiple of the assigned frequency band. The designation *ABPRN*
should be used to denote the power of the OoB emission in the *N*-th
adjacent channel.

# 2 OoB mask method

This methodology is based on the concept defined in Recommendation ITU-R
SM.328 § 1.10.

## 2.1 Parameters to be measured

The transmitter spectrum should be measured using a measurement
bandwidth in line with *recommends* 1.7 and should be characterized in
terms of dBsd, dBc or dBpp.

## 2.2 Measurement range

Measurements are to be conducted in the OoB domain which is between the
assigned frequency band boundary and the boundary between the OoB and
spurious domains.

## 2.3 OoB mask

In accordance with Note 1 of § 1.10 of Recommendation ITU-R SM.328, the
mask does not limit emissions within the necessary bandwidth as it is
applicable in the OoB domain of the spectrum.

NOTE 1 -- Within the OoB domain, there may be line spectra present at
levels higher than the OoB mask. A mask which allows for these
individual spectra might not be stringent enough. Therefore an approach
may need to be considered for some emissions which allows for a limited
number of such spectra at given levels above the mask; those specific
limits, when necessary, are specified in the relevant Annexes dealing
with specific radiocommunication services.

APPENDIX 1\
\
TO ANNEX 1

Example calculation of a permissible OoB power ratio and
power limits from a permissible OoB mask

# 1 Introduction

Integration of an OoB mask over a specific frequency range permits
calculation of the maximum permitted OoB domain power in that band
permitted by that mask and serves to relate the two methods used for
limiting OoB domain emissions. This relationship may be calculated using
either a discrete method or a continuous method. The former method
emulates the manner in which a spectrum analyser or a vector signal
analyser with digital power measurement capability functions while the
latter provides a purely mathematical approach. Due to advances in
digital technology this capability is now available in many commercially
available spectrum analyser families. Both methods are valid and lead to
the same resultant within negligible difference as will be demon­strated
in the following examples.

The examples will utilize the digital emission mask formula described in
Table 3 used in many countries, sometimes referred to as emission mask
G. This example calculates the total power in an adjacent band of 25 kHz
width. Simple adjustment of the integration range limits permit
calculation for other bandwidths.

TABLE 3

Attenuation equations for emission mask G\
(used in some countries for non‑voice transmitters used with 25 kHz\
channel spacing (based on RBW = 300 Hz))

Discontinuities in the mask formula (i.e. breakpoints) of *P* = 1 W
transmitter occur, as evident in Table 4 and Fig. 4, necessitating
integration over multiple ranges.

TABLE 4

Breakpoints in OoB mask G\
(based on RBW = 300 Hz)

The G mask is graphically portrayed in Fig. 4.

![](media/image4.wmf){width="5.206944444444445in" height="4.04375in"}

# 2 Discrete method

This example is for a 1 W transmitter and notation follows that is used
in a software program to calculate the results. This mask has a
transition in the midst of the adjacent frequency band, and 2 breakpoint
frequency displacements from the centre of the emission need to be
determined. First is a transmitter power level dependent frequency
breakpoint at which attenuation reaches 50 + 10 log (*P*) dB, where *P*
is the transmitter power (W). Second is the breakpoint at which
attenuation equals 70 dB. For the side of the adjacent band which is
nearest the emission, the power level independent attenuation formula
for the example power spectral density attenuation mask is given in
equation (1), while equation (11) contains the power level dependent
formula for the frequency range on the far side of the appropriate
breakpoint frequency. Power in both regions must be summed to determine
the total adjacent band power.

In the following equations the notation ":=" means "defined as" and "\[
\]", when used in mathematical equations, are not temporary but agreed
text.

The near side attenuation equation is represented in this Appendix by:

$\text{AN}(\text{fd}): = \text{116}\ \text{log}\ (\frac{\text{fd}}{6}\text{.}1)\ \text{dB}$
(1)

where *fd* is the frequency displacement (kHz) from the centre of the
emission.

To determine the adjacent band power it is necessary to convert this
logarithmic representation of the permissible emission spectral power
density limit to a linear representation, so the attenuation can be
integrated or summed over the frequency range of the adjacent band,
using:

$\text{an}(\text{fd}): = \text{10}^{- \text{AN}(\text{fd}\frac{)}{\text{10}}}$
(2)

To determine the power limited by the mask, the attenuation must be
summed at equal intervals equal to the resolution bandwidth specified
for emission mask measurements (i.e. numerical integration) over the
frequency band being assessed. For this mask:

$\text{RBW}: = 0\text{.}3\ \text{kHz}$ (3)

and the adjacent band is assigned a bandwidth of 25 kHz. The adjacent
band is centred at a displacement of 25 kHz, thus the adjacent assigned
band starts at a frequency displacement of\
25 -- 25/2 = 12.5 kHz and ends at 37.5 kHz. However, an adjustment equal
to half the bandwidth of the resolution filter bandwidth is needed to
preclude inclusion of energy outside the adjacent band, so power
summation needs to begin at 12.5 + 0.3/2 = 12.65 kHz. The power level
dependent breakpoint frequency, *fb*, is given by rearranging equation
(1) to be

$\text{fb}: = 6\text{.}1\  \times \ \text{10}^{\left\lbrack \left( \text{50}\  + \ \text{10}\ \text{log}\ (P\frac{)}{\text{116}} \right) \right\rbrack}$
(4)

For a *P* = 1 W transmitter the 50 dB breakpoint lies at 16.46 kHz. The
70 dB breakpoint, which applies as well to all transmitters of 100 W or
more power, occurs at 24.48 kHz.

The power attenuation in the near side region of the adjacent band may
then be determined by summing over the frequency displacement range
12.65 kHz to 16.46 kHz which, after adjustment, is represented by

$\text{fd}: = \text{12}\text{.}\text{65},\ \text{12}\text{.}\text{95},\ \text{.}\text{.}\text{.},\ \text{16}\text{.}\text{31}\ \text{kHz}$
(5)

The near side portion of the emission mask in the adjacent band
logarithmically appears in Fig. 5:

![](media/image5.wmf){width="4.454166666666667in"
height="2.513888888888889in"}

and the linear representation for this mask follows in Fig. 6.

![](media/image6.wmf){width="4.530555555555556in" height="2.49375in"}

The total adjacent band power relative to the total emission power is a
ratio which is determined by summing the power in the adjacent band
bandwidth shown in Fig. 6 using the following equation:

$\text{abprn}: = \sum_{\text{fd}}^{}{\text{an}(\text{fd})}$ (6)

This equates to:

$\text{abprn}\  = \ 8\text{.}\text{99}\  \times \ \text{10}^{- 4}$ (7)

This can be converted back to attenuation for the adjacent band power
limit in (dB) using:

$\text{ABPRN}: = \text{10}\ \text{log}\ (\text{abprn})$ (8)

which evaluates as

$\text{ABPRN}\  = \  - \text{30}\text{.}\text{46}\ \text{dB}$ (9)

The formula for the example psd attenuation mask in the far side region
of the adjacent frequency band for a 1 W radio is:

$\text{AF}(\text{fd}): = \text{50} + \text{10}\ \text{log}\ (1)\ \text{dB}$
(10)

where *fd* is the frequency displacement in kHz from the centre of the
emission.

To determine the adjacent band power it is necessary to convert this
logarithmic representation of the emission psd to a linear
representation, so the power can be integrated or summed over the
frequency range of the adjacent band, using:

$\text{af}(\text{fd}): = \text{10}^{\frac{- \text{AF}(\text{fd})}{\text{10}}}$
(11)

To determine the power limited by the mask the power must be summed at
equal intervals equal to the resolution bandwidth specified for emission
mask measurements (i.e. numerical integration) over the frequency band
being assessed. For this mask:

$\text{RBW}: = 0\text{.}3\ \text{kHz}$ (12)

The adjacent band power limit relative to the total emission power may
then be calculated by summing the attenuation over the range 16.46 kHz
to 37.5 kHz which, after adjustment, is represented in this Appendix by:

$\text{fd}: = \text{16}\text{.}\text{61},\ \text{16}\text{.}\text{91},\ \text{.}\text{.}\text{.},\ \text{37}\text{.}\text{35}\ \text{kHz}$
(13)

The far side of the emission mask in the adjacent band logarithmically
appears in Fig. 7:

![](media/image7.wmf){width="4.6402777777777775in"
height="2.4770833333333333in"}

The total ABP relative to the total emission power is a ratio which is
determined by summing the power in the adjacent band bandwidth using the
following formulation:

$\text{abprf}: = \sum_{\text{fd}}^{}{\text{af}(\text{fd})}$ (14)

This equates to:

$\text{abprf}\  = \ 7\  \times \ \text{10}^{- 4}$ (15)

and evaluates as:

$\text{ABPRF}\  = \ –\text{31}\text{.}\text{55}\ \text{dB}$ (16)

The total power is the sum of those in equations (6) and (14)

$\text{abpr}\  = \ \text{abprn}\  + \ \text{abprf}$ (17)

which evaluates to:

$\text{abpr}\  = \ \text{15}\text{.}\text{99}\  \times \ \text{10}^{- 4}$
(18)

This translates to:

$\text{ABPR}: = - \text{10}\ \text{log}\ (\text{abpr})\ \text{dB}$ (19)

which evaluates as:

$\text{ABPR} = \text{27}\text{.}\text{96}\ \text{dB}$ (20)

This attenuation establishes *ABPR*1 = +30 dBm -- 27.96 dB,
i.e. 2.04 dBm.

# 3 Continuous method

In general, the emission mask curves have several line segments and the
power spectral density can be represented by a linear equation on each
segment.

$S_{\text{dB}}(f)\  = \ \text{af}\  + \ b$ (21)

To calculate the unwanted power levels injected into the adjacent band,
it is needed to relate spectra measured with 300 Hz bandwidth, denoted
by *G*, to the true power spectral density, denoted by *S*. If we assume
that power levels of *G* are also represented by a linear equation
$G = a^{'}f\  + \ b^{'},$ the problem is to relate the linear line
coefficients $a^{'}$ and $b^{'}$ of the *G* function behaviour to the
*S* function coefficients *a* and *b*. The relationship between *G*(
*fc *) and *S*( *fc *) can be represented as follows:

$G(f_{c})\  = \ \int_{f_{c} - \frac{B}{2}}^{f_{c} + \frac{B}{2}}{\ S\ (f)\ df}$

$= \ \int_{}^{}{\text{10}\ ^{\lbrack s_{\text{dB}}(f\frac{)}{\text{10}}\rbrack}}df = \int_{}^{}{\text{10}\ ^{\lbrack(\text{af} + b\frac{)}{\text{10}}\rbrack}}df = \int_{}^{}{e\ ^{\text{ln}\text{10}\lbrack(\text{af} + b\frac{)}{\text{10}}\rbrack}}df$

$= \ \int_{}^{}{\ \text{exp}\ (k(\text{af} + b))}\ df\  = \ \frac{1}{\text{ka}}\ e_{\text{kb}}\ \lbrack e_{\text{kaf}}\rbrack\ _{f_{c} - \frac{B}{2}}^{f_{c} + \frac{B}{2}}$

$= \ \text{exp}\ \left( k(\text{af}_{c} + b) \right)\ \frac{\text{sinh}(\alpha B)}{\alpha}$
(22)

where $k\  = \ \text{ln}\ (\text{10}\frac{)}{\ }\text{10}$, α = *ka*/2
and *fc* is the centre frequency of resolution bandwidth *B*. Also the
measured power spectral density in decibels based on resolution
bandwidth is calculated by equation (23) and equating the coefficients
yields (24) and (25).

$G_{\text{dB}}\ (f_{c})\  = \ \text{10}\ \text{log}\ \left( G(f_{c}) \right)\  = \ \frac{1}{k}\ \text{ln}\ \left( G(f_{c}) \right)\  = \ a^{'}f_{c}\  + b^{'}$
(23)

$a\  = \ a^{'}$ (24)

$b\  = \ b^{'}\  - \ \frac{1}{k}\text{ln}\ \left( \frac{\text{sinh}\ (\alpha B)}{\alpha} \right)$
(25)

If $a^{'}$ approaches zero, the equation for *b* becomes:

$b\  = \ b^{'}\  - \ \frac{1}{k}\text{ln}\ (B)$ (26)

To calculate the permissible OoB domain power using the above procedure,
one must first derive the equation *S*~dB~ ( *f* ) = *af* + *b* and
integrate this equation over the adjacent channel bandwidth.

Permissible out-of-band domain power
$= \ \int_{W}^{}{\text{10}\ ^{\left\lbrack S_{\text{dB}}(f\frac{)}{\text{10}}\  \right\rbrack}df}$

where *W* is the adjacent channel bandwidth.

Using transmitter power *P* equal to 1 W in a 25 kHz band system, based
on a resolution bandwidth of 300 Hz the emission mask appears as shown
in Fig. 5. Also, the breakpoint reference levels of emission mask are
given in Table 4 so the calculation interval can be divided into two sub
intervals adjacent channel bandwidth according to the emission curve
shape, that is, (12.5 kHz-16.46 kHz) and (16.46 kHz-37.5 kHz). From
Table 3, we can get a linear function equation (27) based on Table 4
breakpoints (12.5 kHz, --36.14 dB) and (16.46 kHz, --50 dB). And also,
in the frequency range larger than 16.46 kHz, a constant level of
--50 dB results as given by equation (28).

$\text{For}\ \text{12}\text{.}5\ \text{kHz}\  \leq f \leq \text{16}\text{.}\text{46}\ \text{kHz}\ G_{\text{dB}}(f)\  = \ 7\text{.}\text{61}\ –\ 3\text{.}5\ f$
(27)

$\text{For}\ \text{12}\text{.}\text{46}\ \text{kHz} \leq f \leq \text{37}\text{.}5\ \text{kHz}\ G_{\text{dB}}(f)\  = \ –\text{50}$
(28)

Equations (27) and (28) can be converted to the following equations
using (24), (25) and (26).

$\text{For}\ \text{12}\text{.}5\ \text{kHz}\  \leq f \leq \text{16}\text{.}\text{46}\ \text{kHz}\ S_{\text{dB}}(f)\  = \ \text{12}\text{.}\text{84}\ –\ 3\text{.}5\ f$
(29)

$\text{For}\ \text{12}\text{.}\text{46}\ \text{kHz} \leq f \leq \text{37}\text{.}5\ \text{kHz}\ S_{\text{dB}}(f)\  = \ –\text{44}\text{.}\text{77}$
(30)

The total power levels in adjacent channel bandwidth are the summation
of two integration results over respective sub intervals.

Permissible OoB emission attenuation

$= \ \int_{\text{12}\text{.}5}^{\text{16}\text{.}\text{46}}{\text{10}^{\lbrack(\text{12}\text{.}\text{84} - 3\text{.}5f\frac{)}{\text{10}}\rbrack}\ df}\  + \ \int_{\text{16}\text{.}\text{46}}^{\text{37}\text{.}5}{\text{10}^{\lbrack - \text{44}\text{.}\frac{\text{77}}{\text{10}}\rbrack}\ df}$\
= 0.00095  +  0.0007 = 0.00165 (31)

In decibels, the above attenuation requirement is converted as follows.

$\text{10}\ \text{log}\ (0\text{.}\text{00165})\  = \ –\text{27}\text{.}8\ \text{dB}$
(32)

This attenuation establishes *ABP*1 = +30 dBm -- 27.8 dB, i.e. 2.2 dBm,
a result very close to that obtained using the discrete method.

ANNEX 2

Calculation of the start and end of the OoB domain for multicarrier
systems with single and multiple transponders per satellite

This Annex provides two examples showing how to calculate the start and
end of the OoB domain for multicarrier systems with single and multiple
transponders per satellite.

# 1 Example 1: Multiple transponders per satellite

Figure 8 is one example of a satellite with multiple transponders. In
this example, the width of the band in which the satellite is licensed
or authorized to transmit is 20 MHz, the 3 dB bandwidth of the
transponder is 5 MHz, and the necessary bandwidth of a single carrier
emission is 1 MHz.

![](media/image8.wmf){width="5.063888888888889in"
height="2.620138888888889in"}

This Recommendation equates necessary bandwidth, *BN*, of a multicarrier
emission to the lesser of the --3 dB bandwidth of the transponder and of
total assigned bandwidth. Hence, for the example above, the necessary
bandwidth would be 5 MHz. The OoB domain begins at the edges of each
total assigned bandwidth that is part of the band over which the system
is authorized.

The OoB domain is taken to be those frequencies that are separated from
the centre frequency by more than 50% of the necessary bandwidth and
less than 250% of the necessary bandwidth (the bandwidth of transponders
A and D). Consequently, the width of the OoB domain is 200% of the
necessary bandwidth. So for the example shown in Fig. 9, the width of
OoB domain above *fAU* and below *fAL* is 10 MHz. The OoB and spurious
domains are shown in Fig. 9.

![](media/image9.wmf){width="5.077083333333333in"
height="2.0243055555555554in"}

# 2 Example 2: Single transponder per satellite

When all carriers in Fig. 8, A1 through D4, are passed through a single
transponder the OoB domain should start at the edges of the total
assigned bandwidth and the width of the OoB domain should equal 200% of
the necessary bandwidth where the necessary bandwidth is set to the
minimum of the total assigned bandwidth and 3 dB transponder bandwidth.

ANNEX 3

Graph labelling for dBc and dBsd masks

This Annex shows the way to label the axes of dBc and dBsd spectrum
masks.

# 1 Y-axis labelling of OoB masks

Figure 10 shows the preferred way to label the Y-axis on dBc and dBsd
spectrum masks, where negative relative level values are used. Figure 11
shows an alternate way using positive attenuation values. Note that the
masks for symmetric limits are drawn the same in Fig. 10 and Fig. 11;
only the labelling of the Y-axis is different. For dBsd graphs, the
reference bandwidth should be included in the label, e.g. dBsd
(BW = 50 kHz).

The convention of having zero at the top of the Y-axis follows the usual
industry practice for specifying limit masks and displaying spectra on
spectrum analysers and other test equipment.

![](media/image10.wmf){width="6.324305555555555in"
height="2.6805555555555554in"}

![](media/image11.wmf){width="6.310416666666667in"
height="2.6173611111111112in"}

# 2 X-axis labelling of OoB masks

The frequency offset is usually given as the per cent of necessary
bandwidth, but sometimes it may be more convenient to give it as a per
cent of channel bandwidth. The frequency offset may also be given in
absolute units of kHz or MHz.

Usually, the mask limits are symmetric about the centre frequency, and
only positive frequency offset values are shown; which are interpreted
to be absolute values that represent both positive and negative
frequency offsets. In this case, only the positive frequency offset
values are shown. However, for limits that are asymmetric about the
centre frequency, the X-axis needs to include both positive and negative
frequency offsets. Figure 12 shows an example graph that can be used for
either asymmetric or symmetric limits.

![](media/image12.wmf){width="5.317361111111111in"
height="2.4006944444444445in"}

ANNEX 4

List of ITU-R texts concerning OoB domain emissions\
related to specific services

Recommendation ITU-R F.1191 -- Bandwidths and unwanted emissions of
radio relay service systems

Recommendation ITU-R M.478 -- Technical characteristics of equipment and
principles governing the allocation of frequency channels between 25 and
3 000 MHz for the FM land mobile service

Report ITU-R M.2014 -- Spectrum efficient digital land mobile systems
for dispatch traffic

Recommendation ITU-R BS.1114 -- System for terrestrial digital sound
broadcasting to vehicular, portable and fixed receivers in the frequency
range 30-3 000 MHz

Recommendation ITU-R M.1480 -- Essential technical requirements of
mobile earth stations of geostationary mobile-satellite systems that are
implementing the global mobile personal communications by satellite
(GMPCS) -- Memorandum of understanding arrangements in parts of the
frequency bands 1-3 GHz

Recommendation ITU-R M.1343 -- Essential technical requirements of
mobile earth stations for global non-geostationary mobile-satellite
service systems in the bands 1-3 GHz

NOTE 1 -- Recommendation ITU-R M.1343 could be applied also to terminals
in regional non-geostationary satellite systems, although the title
refers to global systems.

ANNEX 5

OoB emissions limits for space services (earth and space stations)

# 1 Introduction

In certain cases, it has been deemed that the OoB masks (of sections 2
through 4) should not apply.

For the case of a single satellite operating with more than one
transponder in the same service area, and when considering the limits
for OoB emissions described below, OoB emissions from one transponder
may fall on a frequency at which a second companion transponder is
transmitting. In these situations, the level of OoB emissions from the
first transponder is well exceeded by fundamental emissions of the
second transponder. Therefore, the limits below should not be applied to
those OoB emissions of a satellite which fall within the necessary
bandwidth of another transponder, on the same satellite, into the same
service area.

![](media/image13.wmf){width="6.134027777777778in"
height="2.3743055555555554in"}

Transponders A and B are operating on the same satellite in the same
service area. Transponder B is not required to meet OoB limits in
frequency range 2 but is required to meet them in frequency ranges 1, 3
and 4. In frequency range 3, OoB limits do not apply if it is a
guardband.

# 2 OoB masks for fixed-satellite service (FSS) earth and space stations

## 2.1 Generic OoB mask

The OoB domain emissions of a station operating in the bands allocated
to the FSS should be attenuated below the maximum psd, in a reference
bandwidth of 4 kHz (for systems operating above 15 GHz a reference
bandwidth of 1 MHz may be used in place of 4 kHz) within the necessary
bandwidth, by the following:

$\text{40}\ \text{log}\ \left( \frac{F}{\text{50}} + 1 \right)\ \text{dBsd}$

where *F* is the frequency offset from the edge of the total assigned
band, expressed as a percentage of necessary bandwidth. It is noted that
the OoB emission domain starts at the edges of the total assigned band.

The OoB mask rolls off to the spurious boundary or to the point where it
is equal to the RR Appendix 3 spurious limit, whichever comes first. The
spurious attenuation for space services is 43 + 10 log *P* or 60 dBc in
a reference bandwidth of 4 kHz, whichever is less attenuation, or
equivalently, 19 + 10 log *P* or 36 dBc in a reference bandwidth of
1 MHz, whichever is less attenuation.

## 2.2 Example application of the mask

The Figs. 14 and 15 below show two examples, one for a spurious limit
equivalent to 25 dBsd, and the other for a spurious limit equivalent to
40 dBsd. The spurious boundary is assumed to be 200% of the necessary
bandwidth removed from the edge of the total assigned band.

It is worth noting that the spurious limit is given in dBc units,
whereas, the OoB mask is given in dBsd units. In order to be able to
show the spurious limit on the same plot as the OoB mask, the dBc unit
has to be converted to dBsd as is done in Examples 1 and 2 of Figs. 14
and 15.

In *Example 1*, it is assumed that 6 dBW (4 W) is transmitted in a 1 MHz
necessary bandwidth. Assuming the power is uniformly distributed across
the necessary bandwidth, the power in a 4 kHz bandwidth would be
--18 dBW. The spurious limit for this example is computed as:

43 + 10 log (4) = 49 dBc

Since 49 dBc is less attenuation than the 60 dBc, it will be the
spurious limit for this case.

To convert this dBc attenuation to dBsd units, we can use the following
expression:

*A*(dBsd) = *A*(dBc) -- *PT* (dBW) + *P*4kHz (dB(W/4 kHz))

where:

*A*(dBsd) : attenuation (dBsd)

*A*(dBc) : attenuation (dBc)

*PT *(dBW) : total power (dBW)

*P*~4kHz~ (dB(W/4 kHz)) : maximum power in a 4 kHz reference bandwidth
(dBW), within the necessary bandwidth.

Using the above expression

*A*(dBsd) = 49 -- 6 -- 18 = 25 dBsd

as is shown in Fig. 14.

Similarly, in *Example 2*, shown in Fig. 15, assuming 6 dBW (4 W) of
power transmitted in a 32 kHz necessary bandwidth, and uniform
distribution of power across the necessary bandwidth, the power in a
4 kHz bandwidth would be --3 dBW. The spurious limit would be the same
as in Example 1 (same total power is transmitted), i.e. 49 dBc.

Again using the above expression, we get:

*A*(dBsd) = 49 -- 6 -- 3 = 40 dBsd

as is shown in Fig. 15.

![](media/image14.wmf){width="4.1875in" height="4.0569444444444445in"}

![](media/image15.wmf){width="4.1875in" height="4.054166666666666in"}

Care should be taken in cases where OoB masks have been proposed to
apply to both earth stations and space stations. This is because, for
multicarrier applications, the necessary bandwidth, upon which the masks
are based, is defined to be that of the final amplifier of the
transmitter. Earth stations often have amplifiers with much wider
bandwidth than those of space stations.

# 3 OoB masks for mobile-satellite service (MSS) earth and space stations

The masks contained in Recommendation ITU‑R M.1480 can be used for
mobile earth stations of geostationary-satellite orbit (GSO) MSS systems
implementing the GMPCS memorandum of understanding in parts of the
frequency band 1-3 GHz.

The masks contained in Recommendation ITU‑R M.1343, representing non-GSO
mobile earth stations in the band 1-3 GHz can form one input for the
mobile earth station data.

For earth stations not covered in the above‑mentioned Recommendations
and for all space stations, the following generic OoB mask, considered
as an upper bound for MSS systems, is to be used:

Attenuation of OoB emissions in the reference bandwidth of 4 kHz for MSS
systems below 15 GHz (otherwise in reference bandwidth of 1 MHz for MSS
systems above 15 GHz) is:

$\text{40}\ \text{log}\ \left( \frac{F}{\text{50}} + 1 \right)\ \text{dBsd}$

where *F* is the frequency offset from the edge of the total assigned
band, expressed as a percentage of necessary bandwidth, which will range
from 0% to the spurious boundary (which is usually 200%).

The OoB mask rolls off to the spurious boundary or the point where it is
equal to the RR Appendix 3 spurious limit, whichever comes first. The
spurious attenuation for space services is 43 + 10 log *P* or 60 dBc in
a reference bandwidth of 4 kHz, whichever is less attenuation, or
equivalently, 19 + 10 log *P* or 36 dBc in a reference bandwidth of
1 MHz, whichever is less attenuation.

The examples given in § 2.2 can be used in converting the spurious limit
in dBc to dBsd.

The above-proposed mask may not be applicable in detailed examination of
adjacent band compatibility.

# 4 OoB masks for broadcasting-satellite service (BSS) space stations

The following mask in dBc is proposed for BSS space stations.

![](media/image16.wmf){width="4.0569444444444445in" height="5.8875in"}

# 5 OoB mask for the space research service (SRS), space operations service (SOS), and Earth exploration‑satellite service (EESS) telecommunication space-to-Earth links operating in the 1-20 GHz band

## 5.1 Introduction

This annex provides an OoB mask for the SRS, SOS, and EESS space-ground
links operating in the 1‑20 GHz bands. The mask is not applicable to
deep space stations, active sensors, or space-to‑space links.

## 5.2 OoB masks for SRS, SOS and EESS systems operating in the space‑to‑Earth and Earth-to-space directions

The mask shown in Fig. 17 applies to single carrier emissions from SRS,
SOS, and EESS earth stations and space stations operating at centre
frequencies between 1 GHz and 20 GHz.

![](media/image17.wmf){width="5.4743055555555555in"
height="3.2569444444444446in"}

### 5.2.1 Emission mask parameters

The emission mask is specified in dBsd units measured in a 4 kHz
reference bandwidth.

The emission mask is defined to be:

$\text{Attenuation}\  = \ –\text{15} + \text{15}\ (\frac{X}{\text{50}}\text{\%})\ \text{dBsd}\ \text{for}\ \text{50}\text{\%}\  < X \leq \ \text{150}\text{\%}$
(33)

$\text{Attenuation}\  = \  + \text{12} + 6\ (\frac{X}{\text{50}}\text{\%})\ \text{dBsd}\ \text{for}\ \text{150}\text{\%} < X \leq \text{250}\text{\%}$
(34)

where *X* is specified as a percentage of the necessary bandwidth.

### 5.2.2 Emission mask applicability

The emission mask herein is only applicable to single-carrier emissions
in the space research, space operation and Earth exploration-satellite
stations in bands between 1 GHz and 20 GHz. It does not apply to
emissions of deep space stations, stations operating space-to-space
links (SSLs), or active sensors. Emission masks for SSLs and
space-to-ground links below 1 GHz and above 20 GHz require further
study.

### 5.2.3 Basis for the emission masks

The emission mask given by equations (33) and (34) was selected because
simulations show that the emission mask can be met without unnecessarily
constraining SRS, SOS and EESS ground stations and spacecraft.
Furthermore, it generally provides sufficient protection against
unwanted emissions. Further, the mask is consistent with the safety net
concept, i.e. that the general OoB recommended limits will generally be
a worst-case envelope based on least restrictive OoB emission limits
successfully used as national or regional regulations and they will not
include more stringent regional or national limits.

ANNEX 6

OoB limits for television broadcasting systems

This annex provides the OoB limits to be applied to broadcast television
systems. According to the safety net principle (see *recommends *4), it
should be noted that more stringent limits are not affected in cases
where special agreements for the broadcasting services for coordination
and compatibility reasons exist. The more stringent limits specified in
the relevant agreements and standards shall be used in all cases where a
special need can be indicated and the scope of an agreement would be
affected.

NOTE 1 -- All the masks presented are overall emission masks inclusive
of OoB limits.

# 1 Digital TV -- 6 MHz channelling to Recommendation ITU-R BT.1306

OoB limits for 6 MHz digital television systems should be based on the
national rules of the countries using such systems.

# 2 Spectrum masks for 7 and 8 MHz channelling analogue and digital television systems

## 2.1 Analogue television systems

Spectrum limit masks for analogue television are shown in Figs. 18, 19
and 20. A generic approach is used to cover the following types of
system:

-- 7 MHz analogue television, negative modulation, 0.75 MHz vestigial
bandwidth VSB;

-- 8 MHz analogue television, negative modulation, 0.75 and 1.25 MHz
VSB;

-- 8 MHz analogue television, positive modulation, 0.75 and 1.25 MHz
VSB.

Each graph is drawn to represent the spectrum limits for transmitters in
the output power range 39 dBW to 50 dBW. Associated with each graph is a
table of break points and a table of end point values, together with the
corresponding spurious levels, for a range of transmitter output powers.

For 7 MHz analogue television, the OoB domain extends from ± 3.5 MHz
(i.e. ± 0.5 × 7 MHz) to ± 17.5 MHz (i.e. ± 2.5 × 7 MHz).

For 8 MHz analogue television, the OoB domain extends from ± 4 MHz (i.e.
± 0.5 × 8 MHz) to ± 20 MHz (i.e. ± 2.5 × 8 MHz).

For both 7 MHz and 8 MHz analogue television, a 50 kHz measurement
bandwidth is used. The 0 dB reference level corresponds to the peak
synch power for negative modulation television systems, or the peak
white power for positive modulation television systems. The highest mean
power for negative modulation is assumed to be 2.5 dB below peak synch
power, and for positive modulation it is assumed to be 1.2 dB below peak
white power.

![](media/image18.wmf){width="6.134027777777778in" height="5.3375in"}

Table 5 provides break points corresponding to the graph shown in
Fig. 18 for 7 MHz analogue television, negative modulation, 0.75 MHz
VSB.

TABLE 5

Break points for 7 MHz\
analogue television, negative modulation, 0.75 MHz VSB

Table 6 provides end point values to be used in conjunction with Table 5
and Fig. 18, applicable to a range of transmitter output powers, for
7 MHz analogue television, negative modulation, 0.75 MHz VSB.

TABLE 6

End point values for 7 MHz analogue television, negative modulation,
0.75 MHz VSB

![](media/image19.wmf){width="6.070138888888889in"
height="5.350694444444445in"}

Table 7 provides break points corresponding to the graph shown in
Fig. 19, for 8 MHz analogue television, negative modulation, 0.75 MHz
and 1.25 MHz VSB.

TABLE 7

Break points for 8 MHz analogue television, negative modulation,\
0.75 MHz and 1.25 MHz VSB

Table 8 provides end point values to be used in conjunction with Table 7
and Fig. 19, applicable to a range of transmitter output powers, for 8
MHz analogue television, negative modulation.

TABLE 8

End point values for 8 MHz analogue television, negative modulation

![](media/image20.wmf){width="6.070138888888889in"
height="5.120138888888889in"}

Table 9 provides break points corresponding to the graph shown in
Fig. 20, for 8 MHz analogue television, positive modulation, 0.75 MHz
and 1.25 MHz VSB.

TABLE 9

Break points for 8 MHz analogue television, positive modulation,\
0.75 MHz and 1.25 MHz VSB

Table 10 provides end point values to be used in conjunction with Table
9 and Fig. 20, applicable to a range of transmitter output powers, for
8 MHz analogue television, positive modulation.

TABLE 10

End point values for 8 MHz analogue television, positive modulation

## 2.2 Digital television systems

For 7 MHz analogue television, the OoB domain extends from ± 3.5 MHz
(i.e. ± 0.5 × 7 MHz) to ± 17.5 MHz (i.e. ± 2.5 × 7 MHz).

For 8 MHz analogue television, the OoB domain extends from ± 4 MHz (i.e.
± 0.5 × 8 MHz) to ± 20 MHz (i.e. ± 2.5 × 8 MHz).

For both 7 MHz and 8 MHz digital television, a 4 kHz measurement
bandwidth is used. The 0 dB reference level corresponds to the mean
output power measured in the channel bandwidth.

Spectrum limit masks for 7 MHz and 8 MHz DVB-T systems are shown in
Figs. 21 and 22 respectively. Each graph is drawn to represent the
spectrum limits for transmitters in the output power range 39 dBW to
50 dBW. Associated with each graph is a table of break points and a
table of end point and next-to-end point values, together with the
corresponding spurious levels, for a range of transmitter output powers.

![](media/image21.wmf){width="6.134027777777778in"
height="5.284027777777778in"}

Table 11 provides break points corresponding to Fig. 21, for 7 MHz DVB-T
systems.

TABLE 11

Break points for 7 MHz DVB-T systems

Table 12 provides end point value and next-to-end point values to be
used in conjunction with Fig. 21 and Table 11, applicable a range of
transmitter output powers, for 7 MHz DVB‑T systems.

TABLE 12

End point value and next-to-end point values\
for 7 MHz DVB-T systems

![](media/image22.wmf){width="6.070138888888889in"
height="5.254166666666666in"}

Table 13 provides break points corresponding to Fig. 22, for 8 MHz DVB-T
systems.

TABLE 13

Break points for 8 MHz DVB-T systems

Table 14 provides end point value and next-to-end point values to be
used in conjunction with Fig. 22 and Table 13, applicable to a range of
transmitter output powers, for 8 MHz DVB‑T systems.

TABLE 14

End point value and next-to-end point values for 8 MHz DVB-T systems

ANNEX 7

OoB limits for sound broadcasting systems

This Annex provides the OoB limits to be applied to sound broadcasting.
According to the safety net principle (see *recommends *4), it should be
noted that more stringent limits are not affected in cases where special
agreements for the broadcasting services for coordination and
compatibility reasons exist. The more stringent limits specified in the
relevant agreements and standards shall be used in all cases where a
special need can be indicated and the scope of an agreement would be
affected.

# 1 VHF FM sound broadcasting

The spectrum limit mask for VHF FM sound broadcasting is shown in
Fig. 23. The related break points are given in Table 15.

For 200 kHz channelling VHF FM sound broadcasting, the OoB domain
extends from ± 100 kHz (i.e. ± 0.5 × 200 kHz) to ± 500 kHz (i.e.
± 2.5 × 200 kHz).

Power level is measured in a 4 kHz bandwidth. The 0 dB reference level
corresponds to the mean output power measured in the channel bandwidth
(200 kHz).

![](media/image23.wmf){width="4.490277777777778in"
height="4.0569444444444445in"}

TABLE 15

Break points of spectrum limit mask\
for VHF FM sound broadcasting

# 2 Sound broadcasting below 30 MHz

OoB domain emissions for double-sideband and single-sideband sound
broadcasting transmitter operating below 30 MHz are estimated from
Recommendation ITU-R SM.328. Further study is required in order to
develop appropriate masks for sound broadcasting below 30 MHz.

# 3 Digital sound broadcasting

### Digital System A {#digital-system-a .Heading_i}

The spectrum limit mask for Digital System A is shown in Fig. 24. The
related break points are given in Tables 16 and 17.

For 1.54 MHz channelling Digital System A, the OoB domain extends from
± 0.77 MHz (i.e. ± 0.5 × 1.54 MHz) to ± 3.85 MHz (i.e.
± 2.5 × 1.54 MHz).

For Digital System A, a 4 kHz measurement bandwidth is used. The 0 dB
reference level corresponds to the mean output power measured in the
channel bandwidth (1.54 MHz).

![](media/image24.wmf){width="4.506944444444445in"
height="4.397222222222222in"}

Table 17 provides end point values to be used in conjunction with Table
16 and Fig. 24, applicable to a range of transmitter output powers, for
Digital System A.

TABLE 16

Break points of spectrum limit mask for Digital System A,\
all transmission modes (9 dBW \< *P* ≤ 29 dBW)

TABLE 17

End point values to be used in conjunction with Table 16

ANNEX 8

OoB limits for primary radar systems

# 1 Introduction

The RR define "primary radar" as "a radiodetermination system based on
the comparison of reference signals with radio signals reflected from
the position to be determined".

Terrestrial primary radars operate in the radionavigation service (air
surveillance radars and navigation radars on aircraft and ships), the
meteorological aids service (weather radars), and the radiolocation
service (most other terrestrial radars). Space-based radars include
active remote sensing satellites operating in the SRS and EESS, and
other radars in the SRS.

The following limits are not applicable inside exclusive
radiodetermination and/or EESS and SRS bands, but do apply at the band
edges. The topic of primary radar emission limits within these exclusive
service bands will be the subject of further studies.

Several categories of primary radars are not included in the OoB
emission limits defined in this Annex. These include pulsed radars with
rated peak power of 1 kW or less, non-pulsed radars with rated average
power of 40 W or less, radars operating above 40 GHz, man-portable
radars, and expendable radars on missiles. These categories of radars
will also be the subject of further studies to establish the appropriate
limits.

Throughout this Annex, in all formulas, bandwidth (*BN*, *Bc*, *Bs*,
*Bd*, *B*--40) is expressed in Hertz, while pulse duration and rise/fall
time are expressed in seconds.

# 2 Necessary bandwidth

Knowledge of the necessary bandwidth of a radar transmitter is required
both for specifying the OoB limits and for specifying the boundary
beyond which spurious limits apply.

Recommendation ITU-R SM.1138, to which the RR makes reference, provides
formulas to be used to calculate the necessary bandwidth when required
by the RR. However, the only formula applicable to radar gives results
that can vary by a factor of ten based on a constant chosen by the user.
Recommendation ITU-R SM.853, considering that the formulas in
Recommendation ITU‑R SM.1138 are incomplete, recommends numerous
supplemental formulas.

## 2.1 Un-modulated radar pulses

Recommendation ITU-R SM.853 provides guidance for determining the
necessary bandwidth (20 dB below the peak envelope value) for
rectangular and trapezoidal pulses. For these systems, the necessary
bandwidth *BN* is the smaller of:

$B_{N}\  = \ \frac{1\text{.}\text{79}}{\sqrt{t\  \cdot \ t_{r}}}\ \text{or}\ \frac{6\text{.}\text{36}}{t}$
(35)

where *t* is the pulse duration (at half amplitude) and *t~r~* is the
rise time, both in seconds[^4].

## 2.2 Other modulations

Necessary bandwidth formulas for frequency modulated pulse radars,
frequency hopping radars, and CW radars, both un-modulated and frequency
modulated are presented below. For frequency modulated pulse radars, the
necessary bandwidth (20 dB bandwidth) formula exceeds the symmetrical
trapezoidal pulse case (equation (35)) by twice the frequency deviation
*Bc*[^5]:

$B_{N}\  = \ \frac{1\text{.}\text{79}}{\sqrt{t\  \cdot \ t_{r}}}\  + \ 2\ B_{c}$
(36)

The formula for frequency hopping radars has an additional term *B~s~*,
the maximum range over which the carrier frequency will be shifted:

$B_{N}\  = \ \frac{1\text{.}\text{79}}{\sqrt{t\  \cdot \ t_{r}}}\  + \ 2\ B_{c} + \ B_{s}$
(37)

Although Recommendation ITU-R SM.1138 gives no formula under the heading
of "continuous wave emission" (here meaning a carrier without
modulation) a realistic value of necessary bandwidth for un-modulated
continuous wave (CW) radars depends on the frequency tolerance and
noise. For frequency modulated CW radars, the necessary bandwidth is
twice *Bd*, the maximum frequency deviation:

$B_{N}\  = \ 2\ B_{d}$ (38)

## 2.3 Typical values of necessary bandwidth

Table 18 below shows typical necessary bandwidths, followed by the
ranges of the necessary bandwidth values, for four types of radars.

TABLE 18

# 3 OoB limits for primary radars

A major difficulty in establishing general OoB limits for primary radars
is the diversity of systems and transmitted waveforms. OoB limits for
primary radars are based on the 40 dB bandwidth of the spectrum of the
transmitted waveform.

## 3.1 Formulas for the 40 dB bandwidth

Since the ratio of the 40 dB and necessary bandwidths is not in general
a constant, a formula for the 40 dB bandwidth is needed to relate the
mask to necessary bandwidth. The following formulas for the 40 dB
bandwidth (*B*--40) of primary radar transmitters have been established.

For non-FM pulse radars, including spread spectrum or coded pulse
radars, the bandwidth is the lesser of:

$B_{- \text{40}}\  = \ \frac{K}{\sqrt{t\  \cdot \ t_{r}}}\ \text{or}\ \frac{\text{64}}{t}$
(39)

where the coefficient *K* is 6.2 for radars with output power greater
than 100 kW and 7.6 for lower‑power radars and radars operating in the
radionavigation service in the 2 900-3 100 MHz and

9 200-9 500 MHz bands[^6]. The latter expression applies if the rise
time *t~r~* is less than about 0.0094*t* when *K* is 6.2, or about
0.014*t* when *K* is 7.6.

For FM-pulse radars, the 40 dB bandwidth is:

$B_{- \text{40}}\  = \ \frac{K}{\sqrt{t\  \cdot \ t_{r}}} + 2\ \left( B_{c} + \frac{A}{t_{r}} \right)$
(40)

where *A*[^7] is 0.105 when *K* = 6.2, and 0.065 when *K* = 7.6.

For FM-pulse radars with frequency hopping[^8]:

$B_{- \text{40}}\  = \ \frac{K}{\sqrt{t\  \cdot \ t_{r}}} + 2\ \left( B_{c} + \frac{A}{t_{r}} \right) + B_{s}$
(41)

For frequency hopping radars using non-FM pulses, including spread
spectrum or coded pulses:

$B_{- \text{40}}\  = \ \frac{K}{\sqrt{t\  \cdot \ t_{r}}} + B_{s}$ (42)

For un-modulated CW radars:

$B_{- \text{40}}\  = \ 0\text{.}\text{0003}\ F_{0}$ (43)

For FM/CW radars:

$B_{- \text{40}}\  = \ 0\text{.}\text{0003}\ F_{0}\  + \ 2\ B_{d}$ (44)

In equations (43) and (44), *F*0 is the operating frequency.

For radars with multiple pulse waveforms, the *B*--40 dB bandwidth
should be calculated for each individual pulse type and the maximum
*B*--40 dB bandwidth obtained shall be used to establish the shape of
the emission mask.

# 4 OoB mask

Figure 25 shows the OoB mask for primary radars, specified in terms of
psd and expressed in units of dBpp. The mask rolls off at 20 dB per
decade from the 40 dB bandwidth to the spurious level specified in RR
Appendix 3[^9]. The *B*--40 dB bandwidth can be offset from the
frequency of maximum emission level, but the necessary bandwidth (RR
No. 1.152) and preferably, the overall occupied bandwidth (RR
No. 1.153), should be contained completely within the allocated band.

![](media/image25.wmf){width="4.0569444444444445in"
height="3.3270833333333334in"}

## 4.1 Examples of emission masks in terms of necessary bandwidth

The OoB mask in Fig. 25 can be expressed in terms of necessary bandwidth
for a particular type of radar by comparing corresponding 40 dB and
necessary bandwidth equations. For this example, the value of the
coefficient *K* is 6.2 and the mask roll-off is 20 dB per decade.

## 4.2 Non-FM pulsed radar

For non-FM pulse radars, a comparison of equations (35) and (39) yields
a *B*--40 to *BN* ratio of about 3.5, except for pulses with very short
rise time. Figure 26 shows the OoB mask in terms of necessary bandwidth
for this case. However, for some cases of non-FM pulse radars, including
spread spectrum or coded pulse radars, the *B*--40 to *BN* ratio can be
as large as seven.

![](media/image26.wmf){width="4.0875in" height="3.2305555555555556in"}

## 4.3 Linear FM pulsed radar

For FM pulse compression radars, the *B*--40 to *BN* ratio may be
significantly less. Figure 27 shows a mask based on a trapezoidal pulse
with pulse width *t* of 100 μs, rise time *tr* of 2 μs, and frequency
deviation *Bc* of 10 MHz. Comparing equations (36) and (40) with these
values and *A* = 0.105, *B*--40 and *BN* are essentially equal.

The relatively low values of the normalized frequency separations that
appear in Fig. 27 are indicative of high compression-ratio chirped
pulses.

![](media/image27.wmf){width="4.0569444444444445in"
height="3.3069444444444445in"}

## 4.4 Frequency hopping radar

In terms of the necessary bandwidth, the permissible spectral expanse of
a frequency hopping radar is limited because the roll-off is based on
the emissions of the transmitter tuned to the outermost frequencies.
Figure 28 shows a mask based on a coded pulse with a chip width *t* of
0.2 μs, rise time *tr* of 0.08 μs, and frequency hopping range *Bs* of
200 MHz. The mask is determined based on equations (37) and (42) with a
frequency hopping range *Bs* of 0. Figure 28 also shows the roll‑off on
the lower side of the emission assuming the transmitter is tuned to the
uppermost frequency.

![](media/image28.wmf){width="4.040277777777778in"
height="3.263888888888889in"}

# 5 Boundary between the OoB and spurious domains

According to *recommends* 2.2 and RR Appendix 3, the spurious domain
generally begins at a frequency separation equal to 250% of the
necessary bandwidth, with exceptions for certain kinds of systems,
including those with digital or pulsed modulation. However, it is
difficult to apply the general boundary concept of 250% of the necessary
bandwidth to primary radar stations in the radiodetermination and other
services, such as the meteorological aids service, SRS and EESS.

For primary radar stations, the boundary between the OoB and spurious
domains is defined as at the frequency where the OoB limits defined
herein are equal to the spurious limit defined in Table II of RR
Appendix 3.

The boundary between the OoB and spurious domains in the case of primary
radars in the radiodetermination service and other relevant services can
be defined as separated from the assigned frequency by 2.5 α *BN*, where
α is a boundary correction factor depending on the total system
configuration, in particular the modulation waveform and modulating
technique, the radar output device, waveguide components and the antenna
type and its frequency dependent characteristics. The value of α will
also depend on the way the necessary bandwidth is evaluated.

The values of α corresponding to the mask in Fig. 25 can be determined
by setting the 60 dB point equal to 2.5 α *BN*. Assuming a 20 dB per
decade roll-off:

$5\ B_{- \text{40}}\  = \ 2\text{.}5\ \alpha\ B_{N}\  \rightarrow \ \alpha\  = \ 2\ \frac{B_{- \text{40}}}{B_{N}}$
(45)

Using the examples above, α would be about 2.0 for the linear FM pulse
radar and about 8.5 for the non-FM pulse radar. This equation does not
apply to the frequency hopping case shown in Fig. 28.

Assuming that the necessary bandwidth is evaluated as the 20 dB
bandwidth, technical information available so far has indicated that,
for existing and planned primary radars, the value of α would range from
1 to 10, or more.

From the standpoint of effective use of spectrum, it can be questioned:

-- whether the future primary radars will be able to meet an α value
closer to 1 or not;

-- whether α should be different depending on whether the boundary
between the OoB and spurious domains will be inside, outside or close to
a primary radar allocated band.

Further studies need to be conducted within the ITU-R to specify the
definition of the necessary bandwidth to be used in the calculation of
the boundary and to define the values of α for the different type of
radars, missions and platforms.

For non-FM pulsed radars, in a few exceptional cases where the system
architecture permits the use of filters and unusual performance
trade-offs can be tolerated, the value of α may approach 1. Also, for
wideband frequency agile radars, the value of α may be close to 1.5.

# 6 Design objective

The preceding sections of this Annex are based on the safety-net
principle of OoB limits. It is recognized that further reduction of OoB
emissions will enhance compatibility with other services.

Therefore, it is desirable to reduce the levels of unwanted emissions
from some radar systems in the future.

The following mask, Fig. 29, is the objective for the design of future
radar systems. The mask rolls off at 40 dB per decade from the 40 dB
bandwidth to the spurious level specified in RR Appendix 3.

![](media/image29.wmf){width="4.820138888888889in"
height="2.567361111111111in"}

NOTE 1 -- The feasibility of this mask is to be investigated in future
studies within ITU-R, taking account of the practical experience of its
application to some types of radar systems and technical developments in
radar technology.

NOTE 2 -- OoB limits within bands allocated to the radiodetermination
service on an exclusive basis are the subject of further study. This
study may result in a different design objective mask inside these
bands.

NOTE 3 -- The design objective mask is valid as such until the 2006
Radiocommunications Assembly. This is based on the understanding that
these studies will lead to the revision of this Recommendation to either
replace the OoB masks in the preceding sections with the design
objective mask; or to include other appropriate arrangements depending
on the type of radar.

NOTE 4 -- Some future systems may not be able to achieve the design
objective taking account of such factors as:

-- radar mission (safety of life, threat, etc.),

-- type and size of the platform (e.g. fixed, mobile, ship-borne,
airborne, etc.),

-- available technologies,

-- economic considerations.

# 7 Measurement techniques

The most recent version of Recommendation ITU-R M.1177 provides guidance
regarding the methods of measuring OoB domain emissions from radar
systems.

ANNEX 9

OoB domain emissions limits for the amateur services

Stations operating in the amateur and amateur satellite services should
meet the limits contained in the following spectrum masks.

![](media/image30.wmf){width="5.64375in" height="3.5840277777777776in"}

Where *BN* \< 4 kHz, the value of *BL* from Recommendation ITU-R SM.1539
is to be used instead of *BN*.

![](media/image31.wmf){width="5.420138888888889in"
height="3.6104166666666666in"}

![](media/image32.wmf){width="5.420138888888889in"
height="4.567361111111111in"}

In the narrow-band case, the value of *BL* derived from Recommendation
ITU-R SM.1539 is to be used instead of *BN*.

![](media/image33.wmf){width="5.420138888888889in" height="5.69375in"}

NOTE 1 -- All classes of emission using single sideband (SSB) are
included in the category SSB.

Where applicable, the modulation applied for test purposes is audio
frequency tones of 1 100 and 1 700 Hz for SSB transmissions, with 1 kHz
for emissions with a carrier, or in other cases, with modulation
representative of normal use.

NOTE 2 -- For stations using wideband frequency division multiple access
(FDMA), such as space stations operating in the amateur satellite
service, the necessary bandwidth shall be considered to be the 3 dB
bandwidth of the transmitter final amplifier.

ANNEX 10

OoB limits land mobile radio services

The masks contained in this annex are examples of some OoB masks used
for the land mobile service. A generic mask addressing all the systems
in the land mobile service needs to be further studied. This service has
indicated its preference to use adjacent band (or channel) power ratio
limits rather than limit curves as it facilitates frequency coordination
and system planning. Appendix 1 to Annex 1 shows how a band power limit
can be derived from an emission mask.

Table 19 provides break points corresponding to the graph shown in
Fig. 34 for 12.5 kHz channel bandwidth land mobile systems.

![](media/image34.wmf){width="4.824305555555555in"
height="2.2006944444444443in"}

TABLE 19

Break points

Table 20 provides break points corresponding to the graph shown in
Fig. 35 for 5 kHz channel bandwidth amplitude companded SSB.

![](media/image35.wmf){width="4.2875in" height="2.3375in"}

TABLE 20

Break points

Table 21 provides break points corresponding to the graph shown in
Fig. 36 for 6.5 kHz channel bandwidth land mobile systems.

![](media/image36.wmf){width="4.304166666666666in"
height="2.6840277777777777in"}

TABLE 21

Break points

Table 22 provides break points corresponding to the graph shown in
Fig. 37 for 30 kHz channel bandwidth analogue cellular systems.

![](media/image37.wmf){width="4.2875in" height="1.9375in"}

TABLE 22

Break points

ANNEX 11

OoB limits for aeronautical-mobile and maritime-mobile services

These emission masks are specified in terms of power in a reference
bandwidth relative to the total carrier power (dBc). OoB domain
emissions are specified in a bandwidth of 4 kHz, except for those from
single-sideband and aeronautical transmitters. Single-sideband emissions
are specified in a narrower bandwidth and aeronautical telemetry
emissions are specified in terms of the specific spectrum analyser
settings: 10 kHz resolution bandwidth, 1 kHz video bandwidth and max
hold. The boundary between the OoB and spurious domains for these
emission masks is 250% of the necessary bandwidth, in agreement with RR
Appendix 3.

# 1 Aeronautical telemetry

For aeronautical telemetry transmitters, the limits of any emission in
the OoB domain (50% to 250%) relative to the mean power of the
transmitter, are:

-- (55 + 10 log *P*)

or

$K + \text{90}\text{log}R - \text{100}\text{log}|f - fc|\ \ \text{for}\ \ |f - fc| \geq \frac{R}{m}$

where:

*K *= --20, for analogue signals

*K *= --28, for binary signals

*K *= --63, for quaternary signals (e.g. FQPSK-B)

*fc* : transmitter centre frequency (MHz)

*R* : bit rate (Mbit/s) for digital signals or\
$(\Delta f + f_{\text{max}})$(MHz) for analogue FM signals

*m* : number of states in modulating signal

*m* = 2, for binary signals

*m* = 4, for quaternary signals and analogue signals

$\Delta$*f* : peak deviation

*fmax*~ ~: maximum modulation frequency

whichever is less restrictive.

Figure 38 shows examples of OoB masks for aeronautical telemetry,
specified in terms of dBc. The occupied bandwidths used in generating
Fig. 38 were 1.16 times the bit rate for binary signals and 0.78 times
the bit rate for quaternary signals. Additional parameters used in
Fig. 38 were power, *P*, of 10 W and bit rate, *R*, of 5 Mbit/s. These
values vary from system to system and the resulting emission masks vary
according to the equation presented above. The emission masks roll off
at 100 dB/decade.

![](media/image38.wmf){width="3.7069444444444444in"
height="2.5840277777777776in"}

# 2 Other aeronautical-mobile and maritime-mobile transmitters

For aeronautical-mobile and maritime-mobile transmitters other than
aeronautical telemetry and exempted systems, the required attenuation of
the mean power of any emission in the OoB domain, relative to the mean
power of the transmitter, is:

50-150% 25 dBc

150-250% 35 dBc

![](media/image39.wmf){width="4.304166666666666in"
height="2.670138888888889in"}

ANNEX 12

OoB limits for fixed service

Recommendation ITU-R F.1191 requires that, for digital radio relay
systems, operating on a specific radio-frequency channel arrangement,
the frequency boundaries between spurious and OoB domains are ± 250% of
the relevant channel separation (CS). Therefore, for the purpose of this

Recommendation, the OoB limits of analogue and digital fixed service
systems are defined, whenever applicable, up to the ± 250% of the
relevant CS of the radio‑frequency channel arrangement where the system
is to be placed.

According to Recommendation ITU-R F.1191, the CS is taken as *XS*/2 for
alternated frequency channel arrangements and *XS* for co-channel and
interleaved frequency channel arrangements as defined by Recommendation
ITU-R F.746.

Where exclusive block assignments (See Note 1) are made, transmitters
operating on sub-channels devised by the licensed operator could, in
principle, be exempted, within the block, by the unwanted emissions
limit required to be met outside the block; however at country borders
this should require agreement between the administrations concerned due
to the fact that they may have licensed the band in a different way.

The spectrum masks specified in this annex are intended as generic
limits, which generally constitute the least restrictive OoB emission
limits successfully used as national or regional regulations. These are
sometimes called safety net limits. They are intended for use in bands
where tighter masks are not otherwise required to protect specific
applications.

These masks are a composite maximum limit for any application and
frequency band of deployment in any climatic zone; however actual
spectrum masks are usually designed more tightly according the adjacent
channel interference rejection required by the specific application
(e.g. frequency band, modulation format sensitivity and quality of
service required) in different geo-climatic conditions (*K* factor as
defined in Recommendation ITU-R P.530).

NOTE 1 -- A block-assignment (see definition in Recommendation ITU-R
F.1399) is the case of a block of spectrum assigned to one or more
stations of an operator under a single exclusive licence (see examples
in Recommendations ITU-R F.1488, ITU-R F.748 and ITU-R F.749). Inside a
single block‑assignment, the operator may, in general, subdivide the
block into suitable smaller sub-blocks or sub-channels in order to
deploy a radio network in the geographical area where the assignment has
been made.

# 1 Digital fixed service: spectrum emission masks

## 1.1 Systems operating above 30 MHz

Spectrum attenuation masks are shown in Fig. 40.

The 0 dBsd reference level is taken as the maximum value of the psd
inside the occupied bandwidth.

For measurement purposes the resolution bandwidth used should be around
1% of the occupied bandwidth.

![](media/image40.wmf){width="4.497222222222222in"
height="6.747222222222222in"}

TABLE 23

Digital fixed service operating above 30 MHz\
(Reference to Fig. 40)

## 1.2 Systems operating below 30 MHz

Spectrum attenuation masks are shown in Fig. 41.

The 0 dBsd reference level is taken as the maximum value of the psd
inside the occupied bandwidth.

![](media/image41.wmf){width="4.504166666666666in"
height="5.847222222222222in"}

TABLE 24

Digital fixed service operating below 30 MHz\
(Reference to Fig. 41)

# 2 Digital fixed service: discrete spectral lines within OoB emission boundaries

Discrete spectral lines are not considered within spectral density masks
but should be limited not to impair the unwanted emission power produced
by the spectrum itself as follows:

## 2.1 Systems operating above 30 MHz

-- Spectral lines inside ± 50% of channel separation: OoB limit is not
applicable.

-- Total mean power of all spectral lines between +50% and +150% or
between --50% and\
--150% of channel separation: 23 dBc.

-- Total mean power of all spectral lines between +150% and +250% or
between --150% and\
--250% of Channel Separation: 45 dBc.

NOTE 1 -- When no channel separation is defined the necessary bandwidth
could be used.

## 2.2 Systems operating below 30 MHz

The spectral lines falling in the OoB domain, between +50% and +250% or
between --50% and\
--250% of the necessary bandwidth should meet the spurious limit as
defined by Recommendation ITU-R SM.329.

# 3 Analogue fixed service

Radiocommunication Study Group 9 -- Fixed Service, decided in 1991 not
to support any longer development of Recommendations on analogue systems
(see Recommendation ITU-R F.745).

Even if still in operation, new development of analogue systems are not
likely to happen; therefore there is no need for safety net masks in
this Recommendation.

ANNEX 13

OoB domain emission measurements

# 1 Measuring equipment

## 1.1 Selective measuring receiver

A spectrum analyser or other suitable equipment with sufficient
amplitude dynamic range to accurately perform measurements over the
range of attenuation specified for the chosen method should be used for
the measurement of power supplied to the antenna. If the dynamic range
is not sufficient for the required measurements, filtering techniques
(e.g. pre‑selection or notch filters) may be applicable to solve the
measurement of OoB domain emissions.

Principally there are two ways of specifying OoB domain emission limits,
a) the spectrum mask method and b) the method of specifying adjacent
channel and alternate adjacent channel powers.

a\) For measurements using the OoB mask method (see Annex 1), the
measuring receiver needs the ability to simultaneously display the
limiting curve and the emission psd. Also needed is the ability to enter
the line segments needed to describe and store the various segments of
the limit curves, some of which need an algebraic equation.

b\) For measurements using the adjacent-channel and
alternate-adjacent-channel-power method (see Annex 1), the measuring
receiver needs the ability to compute the power in a specified bandwidth
using numerical summation of a set of measurements made in smaller
sub-bands. An alternative method is the use of channel filters for
direct power measurement in an adjacent or alternate adjacent channel.
Also needed is the ability to enter, store and display the channel
edges.

### 1.1.1 Detectors of measurement equipment

The measurement receiver may include the root mean square (r.m.s.),
sample and peak detector functions. It is important to note that these
will generally not report the same value depending on the
characteristics of the signal analysed so it is important to correct
readings for the detector function (i.e. the signal processing)
requirement for a specific measurement, if only one of the detectors is
provided.

Many analysers use the conventional detector function of the signal
passing through a logarithmic amplifier, then through an envelope
detector. This results in a signal processing error for non CW signals,
as the mean of the logarithmic value will not be equal to the logarithm
of the mean value. When measuring Gaussian noise this results in the log
average value reported to be low by 1.45 dB and a further additional
1.05 dB needs to be added to correct for the difference between the
linear average value and the mean power of this signal characteristic.
So, if the linear average value of Gaussian noise is measured instead of
the r.m.s. value, this results in a systematic error of --2.5 dB.

Those analysers which contain digital signal processing capability serve
to eliminate the need to provide these corrections by performing a true
mean power measurement function by prior digitizing of the incoming
signal and performing the power conversion numerically.

Errors of this type may be minimized or eliminated if a power ratio is
measured, rather than absolute power, if the settings remain constant.
This condition generally exists with those analysers equipped with an
adjacent channel power ratio capability. This however applies only where
the signal statistics of the occupied channel and the adjacent channel
are the same (e.g. Gaussian). Figure 42 gives an example where this is
not the case.

![](media/image42.wmf){width="4.7875in" height="6.940277777777778in"}

The level differences are different between the occupied and the
adjacent channels.

### 1.1.2 Resolution bandwidths

The resolution bandwidth should be ideally the recommended value of the
reference bandwidth. For the psd and the mean power (for dBc) the
bandwidth should be the same for in‑band and OoB measurements. However,
the actual value of the resolution bandwidth of the IF filter used in an
analyser may not be equal to that specified even though the setting may
agree. This will result in an error needing correction, generally not
exceeding 1.5 dB, for improved accuracy when measuring the psd of a
signal in the bandwidth of the filter.

Since those analysers which containing digital signal processing
functions also contain digital filtering, this type of analyser
generally has a more accurate implementation of the filter bandwidth
setting. Further any correction needed can be provided in the digital
processing algorithm; for example, to correct for the effective noise
bandwidth for the filter type employed in the analyser that is important
to measuring noise-like emissions from digitally modulated
transmissions.

Errors of this type may be minimized or eliminated if a power ratio is
measured, rather than absolute power, if the settings remain constant.
This condition generally exits in those signal analysers equipped with
an adjacent channel power ratio capability. This however applies only
where the signal statistics of the occupied channel and the adjacent
channel are the same (e.g. Gaussian).

For the adjacent channel and alternate adjacent channel power method,
high selectivity channel filters may be used for the measurement of the
adjacent channel power.

NOTE 1 -- If the measurement bandwidth differs from the reference
bandwidth, then for conversion of the results to the reference bandwidth
a methodology is required.

NOTE 2 -- When using a measurement bandwidth in the order of *n*% of the
occupied bandwidth, an overload factor depending on the signal type to
be measured, should be taken into consideration. This overload factor
will roughly be (10 log (100/*n*) + 14) dB for noise-like emissions and
can be up to 20 log (100/*n*) dB for impulsive emissions (e.g. for
radar).

### 1.1.3 Video bandwidth

For peak power measurements the video bandwidth must be at least as
large as the resolution bandwidth, and preferably be three to five times
as large as the resolution bandwidth. For adjacent and alternate
adjacent channel peak power measurements the combination of highly
selective channel filters and peak detection may be used.

For mean power measurement the use of a narrow-bandwidth filter (e.g.
10 Hz) involves logarithmic mean averaging. This means the mean power
resultant is lower than the actual power, the error magnitude depending
on the signal statistics. Analysers with true mean power measurement
function can avoid this type of error. For the adjacent and alternate
adjacent channel methods the use of highly selective channel filters or
an integration approach can avoid this type of error.

### 1.1.4 Sweep time

Using narrow-band resolution filters involves slow sweep times. In
addition, r.m.s. weighting needs time for the averaging of noise-like
signals and peak detection needs time until the highest peak occurs at
each frequency, which may increase the required sweep time by a factor
of 10 or more.

Assuming a resolution bandwidth *Bres* of 1% and a frequency span of
500% of the occupied bandwidth, the minimum sweep time *Tsmin* will be
approximately:

*Tsmin* = 1 000 (1/*Bres*)

e.g. for an occupied bandwidth of 10 kHz a resolution bandwidth of 100
Hz will be equal to the reference bandwidth. Consequently the minimum
sweep time will be *Tsmin* = 10 s.

The sweep and averaging times can considerably be reduced by using fast
Fourier transform (FFT) techniques especially for narrow-band signals
and by using channel filters for direct power measure­ments in adjacent
or alternate adjacent filters.

For deterministic impulsive signals (e.g. radar) at least one cycle time
*Tc* has to be taken per measurement if synchronization between
measurement and radar pulses occur. Assuming 500 measurements the
minimum sweep or scan time *Tsmin* = 500 *Tc*. If synchronization does
not occur, the minimum sweep or scan time will have to be multiplied by
a factor of 2.

## 1.2 Coupling device

Measurements are made using a directional coupler capable of handling
the power of the fundamental emission as illustrated in Fig. 43. To
assure attainment of the proper measurement result it is necessary that
this coupler present the proper impedance required for both states when
switching between the signal generator and the transmitter under test.

## 1.3 Terminal load

To measure the power of OoB domain emissions, while using measurement
Method 1 (see § 3), the transmitter should be connected to a test load
or terminal load. The level of spurious domain emission depends on
proper impedance matching between the transmitter, the transmission line
and the test load.

## 1.4 Measuring antenna

Measurements are using Method 2 made with a tuned dipole antenna or a
reference antenna with a known gain referenced to an isotropic antenna.

## 1.5 Conditions of modulation

The modulation conditions may be critical in assessing equipment
performance, and should be the same for both in-band and OoB power
measurements. Whenever it is possible, the measurements are made in the
presence of the maximum rated modulation under normal operating
conditions. Some examples follow.

### 1.5.1 Analogue voice modulation (e.g. A3E, F3E and J3E emission designators)

#### 1.5.1.1 Amplitude voice modulation (A3E, B8E, H3E, J3E and R3E emission designators)

Coloured Gaussian noise test signals may be employed in accordance with
Recommendation ITU‑R SM.328, Annex 1. Some additional suggestions
concerning adjustment of the input signal levels can be found in
Annexes 2 and 5 of the same Recommendation.

However, a number of current international standards (e.g. European
Telecommunication Standards Institute (ETSI) ETS 300 373) use multiple
tones for testing, as does Annex 9 (OoB domain emissions limits for the
amateur services) of this Recommendation on OoB limits.

#### 1.5.1.2 Frequency voice modulation (F3E and P3E emission designators)

For transmitters using narrow-band phase or frequency modulation, a
single modulation frequency of e.g. 1 kHz may be used.

### 1.5.2 Digital modulation (e.g. F1E, F7W, F9W, G1E, G7W, D7W emission designators)

A pseudo-random signal pattern such as that described in ITU-T
Recommendation O.153 should be employed at the maximum modulation level.
This may require the simultaneous employment of a set of multiple
specific Walsh codes for code division multiple access transmitters.

### 1.5.3 Other modulations

This subject is under study.

### 1.5.4 Test input for multicarrier channels

In cases where an amplifier will be used to transmit multiple carriers,
care must be taken to use an input to the system under test that
adequately characterizes the OoB performance. In such a case, the OoB
performance can be assessed using two unmodulated tones at the input of
the transmitter as a worst‑case test. Both tones should be set to have a
power level 6 dB below the peak envelope power of the transmitter. Other
inputs can be used if deemed appropriate.

# 2 Measurement limitations

## 2.1 Measurement time limitations

For any desired signal, where the psd changes with time (e.g.
non‑constant envelope modulation), ten or more averaged measurements
should be used for consistency.

## 2.2 Time division multiple access signals

For time division multiple access signals, the adjacent channel power
will have to be measured during time slots using gated measurements. A
distinction will have to be made between:

-- continuous modulation spectra and wideband noise, where averaging
over a number of time slots is usually required, and

-- switching transients spectra where peak hold will be required (see
e.g. ETSI EN 301 087).

# 3 Methods of measurement

## 3.1 Introduction

There are two methods for measurement of in-band and OoB emissions
described in this Annex. Method 2 is described in the International
Special Committee on Radio Interference (CISPR) Publication 16-2. Care
must be taken with Methods 1 and 2 that emissions from the test do not
cause interference to systems in the environment, nor receive
interference from the environment impacting the results of the test and
care must also be taken to utilize the appropriate weighting function
(see § 1.1.1 above).

-- Method 1 is the measurement of emission power supplied to the antenna
port of the equipment under test (EUT). This method should be used
whenever it is practical and appropriate.

-- Method 2 is the measurement of the equivalent isotropic radiated
power (e.i.r.p.), using a suitable test site.

NOTE 1 -- CISPR publication 16-2 describes the measurement of the
effective radiated power (e.r.p.) in the frequency range 30 MHz to
18 GHz. Since for e.r.p. a tuned half-wave dipole is used as the
reference antenna instead of the isotropic antenna, the e.r.p. is 2.1 dB
lower than the e.i.r.p.

In most cases the radiated OoB emission measurements can be simplified
to relative measurements, which do not require calibrated receiving
antennas and the determination of the e.i.r.p. Care must however be
taken when considering the use of active receiving antennas, since
harmonics or intermodulation products might be generated at higher field
strengths.

VLF/LF band transmitters should be measured using Method 2 since the
boundary between the transmitter, feeder cable and antenna is not always
clearly defined.

Method 2 can normally not be applied as an e.i.r.p. measurement in the
frequency range below 30 MHz, since substitution antennas (such as tuned
half-wave dipoles) do not exist. In most cases OoB domain emission
measurements are relative measurements, they can be made in the near
field. Moreover there is no need for *in situ* field-strength
measurements for systems below 30 MHz, since transmitters and antenna
systems are frequently from different manufacturers. Measurements at the
antenna port are generally acceptable and provide transmitter
manufacturers with a means of meeting OoB emission limits.

## 3.2 Method 1 -- Measurement of the in-band and OoB emission power supplied to the antenna port

No particular test site or anechoic chamber is required and
electromagnetic interferences should not affect the results of the
tests. Whenever it is possible, the measurement should include the
feeder cable. This method does not take into account attenuation due to
antenna mismatch and radiation inefficiencies presented to any OoB
domain emissions, or the active generation of OoB domain emissions by
the antenna itself. The block-diagram of the measurement set-up for the
OoB domain emission power to the antenna port is shown in Fig. 43.

![](media/image43.wmf){width="5.0569444444444445in"
height="4.120138888888889in"}

### 3.2.1 Direct conducted method

In this approach, it is required to calibrate all the measuring
components individually (filter(s), coupler, cables), or to calibrate
these connecting devices as a whole. In either case, the calibration is
performed by using a calibrated adjustable level generator at the input
of the measurement receiver. At each frequency, *f*, the calibration
factor is then determined as follows:

$k_{f}\  = \ I_{f}–O_{f}$

where:

*kf* : calibration factor at the frequency *f* (dB)

*If* : input power (delivered by the calibrated generator) at the
frequency *f* (dBW or dBm)

*Of* : output power (determined by the measurement receiver) at the
frequency *f* (dBW or dBm).

This calibration factor represents the total insertion loss of all the
devices connected between the generator and the measurement receiver.

If making individual device calibration measurements, calibration of the
whole measurement set-up is derived by using the following formula:

$k_{\text{ms},f} = \sum_{i}^{}k_{i,f}$

where:

*kms, f* : calibration factor of the measurement set-up at the frequency
*f* (dB)

*ki, f* : individual calibration factor of each device in the
measurement chain at the frequency *f* (dB).

During measurement of actual power levels, *Pr, f* (dBW or dBm) is the
power (read on the measuring receiver) from the OoB domain emission at
the frequency *f*, the OoB domain emission power *Ps, f* (same unit as
*Pr, f *) at the frequency, *f* , is calculated by using the following
formula:

$P_{s,f}\  = \ P_{r,f} + k_{\text{ms},f}$

### 3.2.2 Substitution method

This method does not require calibration of all measuring components.
Instead, the output power is recorded from the measuring receiver. Then
this power level is matched by a signal of the appropriate bandwidth
from a calibrated signal generator which is substituted for the EUT. The
power supplied by the generator is then equal to the power of the OoB
domain emission.

### 3.2.3 Specific measurements

Methodology follows for modulation and intermodulation generated
emissions.

#### 3.2.3.1 Occupied bandwidth

-- Activate the transmitter into a matched load using the appropriate
modulation condition (see § 1.5).

-- Using a spectrum analyser coupled to measure the power into the load,
display the emission psd characteristic for a span equal to 500% of the
emission necessary bandwidth. In that bandwidth integrate the total
emission power throughout the whole frequency span and designate the
result as *PREF*.

NOTE 1 -- The resolution bandwidth should be as close as possible to the
reference bandwidth, but in any case be less than 5% of the occupied
bandwidth if the measurement is to be used to verify an emission
designator.

-- Note the frequency above the emission centre frequency at which the
total power above that frequency is generally equal to 0.5% of *PREF*.

-- Note the frequency below the emission centre frequency at which the
total power below that frequency is generally equal to 0.5% of *PREF*.

The difference between these frequencies is the occupied bandwidth
measured for this emission.

#### 3.2.3.2 OoB emissions due to modulation

![](media/image44.wmf){width="5.374305555555556in"
height="1.2340277777777777in"}

a\) Connect the equipment as illustrated in Fig. 44. The transmitter is
set to produce rated at the assigned frequency.

b\) The measurement bandwidth settings and markers of the analyser
should be centred at the transmitter operating frequency, and
simultaneously, at both the upper and lower adjacent band frequencies.
The resolution and video bandwidths should be set appropriate to the
bandwidth of the modulation.

c\) Activate the transmitter into a matched load using the appropriate
modulation condition (see § 1.5).

d\) The power should be measured on the adjacent band power analyser in
the transmitter authorized bandwidth, and should be recorded as *PREF*.

e\) The power should then be measured on the adjacent band power
analyser in the specified measurement bandwidth centred at both the
upper and lower adjacent band frequencies. The lower frequency value
should be recorded as *PADJL*, and the upper frequency value should be
recorded as *PADJU*.

f\) Calculate the lower adjacent band power ratio, *ABPRL*, as follows:

*ABPRL* = *PREF* -- *PADJL*.

g\) Calculate the upper adjacent channel power ratio, *ABPRU*, as
follows:

*ABPRU* = *PREF* -- *PADJU*

h\) The adjacent band power ratio *ABPR*1 is the lesser of *ABPRL* or
*ABPRU*.

i\) Repeat the above steps for the *N*-th adjacent band.

#### 3.2.3.3 Measurement of the power spectral density

This measurement employs a spectrum analyser to simultaneously compare
the psd of an emission with a set of limit line segments to verify that
the emission does not exceed any limit at any given frequency in the
measurement frequency range.

## 3.3 Method 2 -- Measurement of the in-band and OoB e.i.r.p.

The block diagram of the measuring set-up for the OoB emission e.i.r.p.
is shown in Fig. 45.

![](media/image45.wmf){width="5.0569444444444445in" height="2.84375in"}

The OoB domain emission measurements may be made in the far field, but
also in the near field, since in relatively narrow bands, the radiation
conditions do not vary substantially and since only relative
measurements have to be performed. The measurements of the e.i.r.p. of
OoB domain emissions in any direction, in two polarizations and for any
frequency could be very time consuming, although techniques to check
compliance using relative measurements may reduce this workload. The use
of this method to measure radars should be guided by Recommendation
ITU‑R M.1177.

### 3.3.1 Test sites for radiated emission measurements

#### 3.3.1.1 Test site for the frequency range below 30 MHz

Below about 30 MHz, usually *in-situ* measurements are conducted instead
of measurements on a test site.

#### 3.3.1.2 Test site for radiated measurements in the frequency range 30 to 1 000 MHz

The test site is to be validated by making site attenuation measurements
for both horizontal and vertical polarization fields as described in
CISPR Publication 16-1:1999-10. A measurement site is to be considered
acceptable if the horizontal and vertical site attenuation measurements
are within ± 4 dB of the theoretical site attenuation.

The test site is to be characteristically flat, free of overhead wires
and nearby reflecting structures, sufficiently large to permit antenna
placement at the specified distance and provide adequate separation
between antenna, EUT and reflecting structures. Reflecting structures
are defined as those whose construction material is primarily
conductive. The test site is to be provided with a horizontal metal
ground-plane. Since for OoB domain emission, only relative measurements
are made, the measurement task is substantially alleviated.

Tests may also be conducted in an absorber lined shielded room. In that
case, the walls and the ceiling of a shielded room are covered with
absorber materials that ensure low reflections of power. Validation
measurements of such anechoic chambers are very important to ensure that
the site

attenuation measurements can be performed within the ± 4 dB criteria
(see also International Electrotechnical Committee (IEC)/CISPR
Publications 16-1 and 22).

A conducting ground-plane is to extend at least 1 m beyond the periphery
of the EUT and the largest measuring antenna, and cover the entire area
between the EUT and the antenna. It should be of metal with no holes or
gaps, having dimensions larger than one-tenth of the wavelength at the
highest frequency of measurement. A larger size conducting ground-plane
may be required if the site attenuation requirements of the test site
are not satisfied. These requirements are also applicable in the case of
semi-anechoic chambers.

Additional equipment is becoming available as the site for spurious
domain emission measurements. These are various chambers, such as fully
anechoic rooms (FAR), stirred mode chambers (SMC), and transverse
electromagnetic (TEM) or Gigahertz TEM (GTEM) systems. The SMC is
described in IEC/CISPR Publication 16-1. Drafts have been published (in
autumn 2000) for IEC 61000-4-20 (TEM) and IEC 61000-4-21 (SMC).

#### 3.3.1.3 Test site for the frequency range above 1 GHz

(See CISPR Publication 16-1:1999-10, validation requirements are under
consideration.)

Tests may be made in a fully anechoic chamber. Reverberation chambers
are also becoming available.

### 3.3.2 Direct method

In this approach, it is required to calibrate all the measuring
components individually (filter(s), cables), or to calibrate the whole
measuring set. See the direct approach in § 3.2.1 for the determination
of the calibration factor of the measuring set at the frequency *f*.

The OoB domain emission e.i.r.p., *Ps, f* , at the frequency *f*, is
given for free space conditions by the following formula:

$P_{s,f}\  = \ P_{r,f} + k_{\text{ms},f}–G_{f} + \text{20}\ \text{log}\ f + \text{20}\ \text{log}\ d–\text{27}\text{.}6$

where:

*Pr, f* : power of the OoB domain emission read on the measuring
receiver at the frequency *f* (dBW or dBm, same units as *Ps, f *)

*kms, f* : calibration factor of the measuring set-up at the frequency
*f* (dB)

*Gf* : gain of the calibrated measuring antenna at the frequency *f*
(dBi)

*f* : frequency of the OoB domain emission (MHz)

*d* : distance (m) between the transmitting antenna and the calibrated
measuring antenna.

### 3.3.3 Substitution method

In this approach, a calibrated substitution antenna and a calibrated
generator are used, the test source being adjusted for the same received
OoB signal (see CISPR Publication 16-2:1996-11 for details).

ANNEX 14

Application of Recommendations ITU-R SM.1540 and ITU-R SM.1541

These generic OoB masks are intended to be applied both:

-- outside the band assigned to the system whose OoB domain emissions
are considered, but within the band allocated to the service in which
the system considered operates; and

-- within the adjacent allocated bands. Recommendation ITU-R SM.1540
provides guidance in the case of emissions that are very close to the
edges of the total assigned band and that have OoB domain emissions
falling into an adjacent band allocated to another service.

This is summarized in Fig. 46.

![](media/image46.wmf){width="6.377083333333333in" height="2.74375in"}

[^1]: ^\*^ This Recommendation should be brought to the attention of
    Radiocommunication Study Groups 4, 6, 7, 8 and 9.

[^2]: ^1^ The terms "OoB domain" and "spurious domain" have been
    introduced in order to remove some inconsistency now existing
    between, on one hand, the definition of the terms "OoB emission" and
    "spurious emission" in RR Article 1 and, on the other hand, the
    actual use of these terms in RR Appendix 3, as revised by World
    Radiocommunication Conference (Istanbul, 2000) (WRC‑2000). OoB and
    spurious limits apply, respectively, to all unwanted emissions in
    the OoB and spurious domains.

[^3]: ^2^ OoB limits apply to unwanted emissions (both OoB and spurious
    emissions) in the OoB domain.

[^4]: ^1^ The pulse duration is the time, (s) between the 50% amplitude
    (voltage) points. For coded pulses, the pulse duration is the
    interval between 50% amplitude points of one chip (sub‑pulse). The
    rise time is the time taken (s) for the leading edge of the pulse to
    increase from 10% to 90% of the maximum amplitude on the leading
    edge. For coded pulses, it is the rise time of a sub-pulse; if the
    sub-pulse rise time is not discernable assume that it is 40% of the
    time to switch from one phase or sub-pulse to the next. When the
    fall time of the radar is less than the rise time, it should be used
    in place of the rise time in these equations. Using the smaller of
    the two expressions in equation (35) avoids excessively large
    calculated necessary bandwidth when the rise time is very short.

[^5]: ^2^ This value is the total frequency shift during the pulse
    duration.

[^6]: ^3^ These coefficients, *K* = 6.2 or 7.6 and 64, are related to
    theoretical values that would prevail in the case of constant
    frequency trapezoidal and rectangular pulses, respectively. Also, in
    the case of the trapezoidal pulses, the coefficient *K* has been
    increased somewhat to allow for implementing output device
    characteristics. For ideal rectangular pulses, the spectrum falls
    off at 20 dB per decade leading to a 20 dB bandwidth of 6.4/*t* and
    a 40 dB bandwidth ten times as large, i.e. 64/*t*. To discourage the
    use of pulses with abrupt rise and fall times, no margin is allowed.
    The spectra of trapezoidal pulses fall off firstly at 20 dB per
    decade and then ultimately at 40 dB per decade. If the ratio of rise
    time to pulse width exceeds 0.008 the 40 dB points will fall on the
    40 dB per decade slope, in which case the *B*--40 would be:

    $$\frac{5\text{.}7}{\sqrt{t \cdot t_{r}}}$$

    Allowance for unavoidable imperfections in implementation requires
    that the mask be based on values of at least:

    $$\frac{6\text{.}2}{\sqrt{t \cdot t_{r}}}\ \text{or}\ \frac{7\text{.}6}{\sqrt{t \cdot t_{r}}}$$

    depending upon the category of radar.

[^7]: ^4^ The term *A*/*tr* adjusts the value of *B*--40 to account for
    the influence of the rise time, which is substantial when the
    time-bandwidth product *Bct*, is small or moderate and the rise time
    is short.

[^8]: ^5^ Equations (41) and (42) yield the total composite *B*--40
    bandwidth of a frequency hopping radar as if all channels included
    within *Bs* were operating simultaneously. For frequency hopping
    radars, the OoB emission mask falls off from the edge of the 40 dB
    bandwidth as though the radar were a single frequency radar tuned to
    the edge of the frequency hopping range.

[^9]: ^6^ Appendix** **3 specifies a spurious attenuation of
    43 + 10 log* *(*PEP*), or 60 dB, whichever is less stringent. (PEP:
    peak envelope power).