SIST EN 50492:2009

SLOVENSKI STANDARD
01-marec-2009
Osnovni standard za terensko merjenje jakosti elektromagnetnega polja v zvezi z
izpostavljenostjo ljudi v okolici baznih postaj
Basic standard for the in-situ measurement of electromagnetic field strength related to
human exposure in the vicinity of base stations
Grundnorm für die Messung der elektromagnetischen Feldstärke am Aufstell- und
Betriebsort von Basisstationen in Bezug auf die Sicherheit von in ihrer Nähe befindlichen
Personen
Norme de base pour la mesure du champ électromagnétique sur site, en relation avec
l’exposition du corps humain à proximité des stations de base
Ta slovenski standard je istoveten z: EN 50492:2008
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
33.070.01 Mobilni servisi na splošno Mobile services in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 50492
NORME EUROPÉENNE
November 2008
EUROPÄISCHE NORM
ICS 17.220.20; 33.070.01
English version
Basic standard for the in-situ measurement of electromagnetic field
strength related to human exposure in the vicinity of base stations

Norme de base pour la mesure du champ Grundnorm für die Messung
électromagnétique sur site, en relation der elektromagnetischen Feldstärke
avec l’exposition du corps humain am Aufstell- und Betriebsort
à proximité des stations de base von Basisstationen in Bezug
auf die Sicherheit von in ihrer Nähe
befindlichen Personen
This European Standard was approved by CENELEC on 2008-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50492:2008 E
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 106X, Electromagnetic
fields in the human environment.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50492 on
2008-09-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2009-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-09-01
This European Standard has been prepared under Mandate M/305 given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of EC Directive
RTTED (1999/5/EC).
__________
– 3 – EN 50492:2008
Contents
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Physical quantities, units and constants . 10
4.1 Quantities . 10
4.2 Constants . 10
5 General process . 10
6 Site analysis and case determination . 12
6.1 Introduction . 12
6.2 RF sources to be considered . 12
6.3 Case determination . 12
7 Determination of field quantity to measure in relation to the distance to source antennas . 13
8 Requirements of measurement systems . 13
8.1 General . 13
8.2 Technical requirements of measurement systems . 14
9 Measurement procedures . 16
9.1 General requirements . 16
9.2 Field strength assessment . 16
10 Assessment of the field strength at maximum traffic of a cellular network . 18
11 Uncertainty . 19
11.1 Requirement for expanded uncertainty . 19
11.2 Uncertainty estimation . 19
12 Presentation of results . 22
Annex A (informative) Main services operating RF . 23
Annex B (informative) Sweeping method . 24
B.1 Measurement setup . 24
B.2 Measurement method . 24
B.3 Discussion on advantages and disadvantages of the method . 24
B.4 References . 25
Annex C (informative) Example of broadband equipment use. 26
C.1 General . 26
C.2 Locating the point of maximum exposure . 26
Annex D (informative) Spectrum analyser settings . 28
D.1 Introduction . 28
D.2 Detection algorithms . 28
D.3 Resolution bandwidth and channel power processing . 29
D.4 Integration per service . 31

Annex E (informative) Measuring and evaluating different broadcast signals in respect to EMF . 32
E.1 FM radio . 32
E.2 DAB (Digital Audio Broadcasting; Digitalradio) . 32
E.3 Long wave, medium wave and short wave service . 32
E.4 DRM (Digital Radio Mondial) . 33
E.5 Analog (PAL and SECAM modulation) . 33
E.6 DVB-T . 34
Annex F (informative) WCDMA measurement and calibration using a code domain analyser . 35
F.1 General . 35
F.2 Requirements for the code domain analyser . 35
F.3 Antenna factor . 36
F.4 Calibration . 37
Annex G (informative)  Influence of human body on probe measurements of the electrical field
strength . 40
G.1 Simulations of the influence of human body on probe measurements based on the method of
moments (surface equivalence principle). 40
G.2 Comparison with measurements . 41
G.3 Conclusions . 42
Annex H (informative) Spatial averaging . 43
H.1 Introduction . 43
H.2 Small-scale fading variations . 44
H.3 Error on the estimation of local average power density . 44
H.4 Characterization of environment statistical properties . 45
H.5 Characterisation of different averaging schemes . 45
H.6 Example of uncertainty assessment . 49
H.7 References . 49
Annex I (informative) Maximum traffic estimation of cellular network contribution . 50
I.1 General . 50
I.2 GSM and estimation of the exposure at maximum traffic . 50
I.3 UMTS and estimation of the exposure at maximum traffic . 51
I.4 Influence of traffic in real operating network . 51
I.5 Maximum traffic estimation for TETRA and TETRAPOL PMR cellular network contribution . 52
Annex J (informative) WiFi measurements. 55
J.1 General . 55
J.2 Integration time for reproducible measurements . 55
J.3 Channel occupation . 56
J.4 Some considerations . 56
J.5 Scalability by channel occupation . 57
J.6 Influence of the application layers . 57
Annex K (informative) Examples of implementation of this standard in the context of Council
Recommendation 1999/519/EC . 58
K.1 Purpose . 58
K.2 General considerations . 58
K.3 Evaluation of broadband results . 58
K.4 Evaluation of frequency selective results . 59
Bibliography . 60

– 5 – EN 50492:2008
Figures
Figure 1 – Alternative routes to determine in-situ the electromagnetic field for human exposure
assessm ent . 11
Figure 2 – Location of measurement points for spatial averaging. 17
Figure D.1 – Spectral occupancy for GMSK. 29
Figure D.2 – Spectral occupancy for WCDMA . 30
Figure F.1 – Channel allocation . 35
Figure F.2 – Decoder power range versus antenna factor and cable losses for satisfying selective
measurement requirements . 37
Figure G.1 – Simulation arrangement . 40
Figure G.2 – Body influence . 41
Figure G.3 – Simulation arrangement . 42
Figure H.1 – Physical model of small-scale fading variations . 43
Figure H.2 – Example of field strength variations in line of sight of an antenna operating at 2,2 GHz . 43
Figure H.3 – Error at 95 % on average power estimation . 45
Figure H.4 – 343 measurement positions building a cube (centre) and different templates consisting of a
different number of positions . 46
Figure H.5 – Moving a template (Line 3) through the CUBE . 47
Figure H.6 – Standard deviations for GSM 900, DCS 1 800 and UMTS . 48
Figure I.1 – Time variation over 24 h of the exposure induced by GSM 1 800 MHz (left) and FM (right) . 52
Figure J.1 – Example of WiFi frames . 55
Figure J.2 – Channel occupation versus the integration time . 55
Figure J.3 – Channel occupation versus nominal throughput rate . 56
Figure J.4 – WiFi spectrum trace snapshot . 56

Tables
Table 1 – Quantities to measure at different distances from radio-stations . 13
Table 2 – Broadband measurement system requirements . 15
Table 3 – Frequency selective measurement systems requirements . 15
Table 4 – Uncertainty assessment in controlled environment . 20
Table 5 – Uncertainty assessment in-situ . 21
Table A.1 – Main services . 23
Table D.1 – Example of spectrum analyser settings for an integration per service . 31
Table F.1 – WCDMA decoder requirements . 36
Table F.2 – Signals configuration . 37
Table F 3 – WCDMA generator setting for power linearity . 38
Table F.4 – WCDMA generator setting for decoder calibration. 38
Table F.5 – WCDMA generator setting for reflection coefficient measurement . 39
Table G.1 – Maximum simulated error due to the influence of a human body on the measurement
values of an omni-directional probe . 41
Table G.2 – Measured influence of a human body on omni-directional probe measurements . 42
Table H.1 – Uncertainty a 95 % for different fading models . 45
Table H.2 – Correlation coefficients for GSM 900 and DCS 1 800 . 47
Table H.3 – Variations of the standard deviations for the GSM 900, DCS 1 800 and UMTS frequency
band . 48
Table H.4 – Examples of total uncertainty calculation . 49
Table K.1 – Example of a results table for broadband measurements of the electric field strength at one
measurement point including an evaluation of compliance with exposure limits . 59
Table K.2 – Example of a results table for frequency selective measurements of the electric field
strength at one measurement point including an evaluation of compliance with exposure
limits . 59

– 7 – EN 50492:2008
1 Scope
This European Standard specifies in the vicinity of base station as defined in 3.2 the measurement methods,
the measurement systems and the post processing that shall be used to determine in-situ the
electromagnetic field for human exposure assessment in the frequency range 100 kHz to 300 GHz.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 50383, Basic standard for the calculation and measurement of electromagnetic field strength and SAR
related to human exposure from radio base stations and fixed terminal stations for wireless
telecommunication systems (110 MHz - 40 GHz)
EN 50400, Basic standard to demonstrate the compliance of fixed equipment for radio transmission
(110 MHz – 40 GHz) intended for use in wireless telecommunication networks with the basic restrictions or
the reference levels related to general public exposure to radio frequency electromagnetic fields, when put
into service
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
antenna
device that serves as a transducer between a guided wave (e.g. coaxial cable) and a free space wave, or
vice versa. In the present standard, if not mentioned, the term antenna is used only for emitting antenna(s)
3.2
base station (BS)
fixed equipment for radio transmission intended for use in wireless telecommunications networks, such as
those used in cellular communication, Wireless Local Area Networks, point-to-point communication and
point-to-multipoint communication according to ITU-R Recommendation F.592-3. Point to point and point to
multi point communication equipment listed in “The European table of frequency allocations and utilisations
covering the frequency range 9 kHz to 275 GHz” (ERC report 25) (see example in Annex A) are considered.
For the purpose of this standard, the term “base station” includes the radio station and the antenna
3.3
average (temporal) power (P )
avg
the time-averaged rate of energy transfer defined by:
t
__
P = P(t)dt
avg
∫
t − t
2 1
t
where t and t are the start and stop time of the measurement. The period t - t is the exposure duration
1 2 2 1
time
3.4
averaging time (t )
avg
appropriate time over which exposure is averaged for purposes of determining compliance with the limits

3.5
electric field strength (E)
magnitude of a field vector at a point that represents the force (F) on a small test charge (q) divided by the
charge
r
r
F
E =
q
The electric field strength is expressed in units of volt per metre (V/m)
3.6
intrinsic impedance
ratio of the electric field strength to the magnetic field strength of a propagating electromagnetic wave. The
intrinsic impedance of a plane wave in free space is 377 ohm
3.7
hemispherical isotropy
maximum deviation of the field strength when rotating the probe around its major axis with the probe
exposed to a reference wave, having varying incidence angles relative to the axis of the probe, incident from
the half space in front of the probe
3.8
probe isotropy
degree to which the response of an electric field or magnetic field probe is independent of the polarization
and direction of propagation of the incident wave
3.9
axial isotropy
maximum deviation of the field strength when rotating around the major axis of the probe housing while the
probe is exposed to a reference wave impinging from a direction along the probe major axis
3.10
linearity
maximum deviation over the measurement range of the measured quantity from the closest linear reference
curve defined over a given interval
3.11
magnetic flux density (B)
vector field quantity B which exerts on any charged particle having velocity v a force F equal to the product of
r
r
the vector product and the electric charge q of the particle:
v × B
r r
r
F = qv × B
where
r
F
is the vector force acting on the particle in newtons
q is the charge on the particle in coulombs
r
v
is the velocity of the particle in metres per second
r
B
is the magnetic flux density in teslas

– 9 – EN 50492:2008
3.12
magnetic field strength (H)
vector quantity obtained at a given point by subtracting the magnetization M from the magnetic flux density B
divided by the magnetic constant (permeability) µ:
r
r r
B
H = − M
µ
where
r
H
is the magnetic field in amperes per metre
r
B
is the magnetic flux density in teslas
µ is the magnetic constant (permeability) of the vacuum in henries per metre
r
M
is the magnetization in amperes per metre
r
NOTE For the purposes of this standard, M = 0 at all points.
3.13
multi-band
multi-band equipment is operating in more than one frequency band, e.g., GSM 900 and GSM 1 800
3.14
permeability (µ)
magnetic permeability of a material is defined by the magnetic flux density B divided by the magnetic field
strength H:
r
B
µ = r
H
where µ is the permeability of the medium expressed in Henry per metre (H/m)
3.15
permittivity (ε)
property of a dielectric material (e.g., biological tissue). In case of an isotropic material, it is defined by the
electrical flux density D divided by the electrical field strength E
r
D
ε =
r
E
The permittivity is expressed in units of farads per metre (F/m)
3.16
root-mean-square (r.m.s.)
effective value or r.m.s. value obtained by taking the square root of the average of the square of the value of
the periodic function taken throughout one period
3.17
power density (S)
radiant power incident perpendicular to a surface, divided by the area of the surface. The power density is
expressed in units of watt per square metre (W/m²)
3.18
transmitter
device to generate radio frequency electrical power to be connected to an antenna for communication purpose

4 Physical quantities, units and constants
4.1 Quantities
The internationally accepted SI-units are used throughout the standard.
Quantity Symbol Unit Dimensions
Current density J ampere per square metre A/m²

Electric field strength E volt per metre V/m
Electric flux density D coulomb per square metre C/m²
Frequency f hertz Hz
Magnetic field strength H ampere per metre A/m
Magnetic flux density B tesla (Vs/m²) T
µ
Permeability henry per metre H/m
Permittivity ε farad per metre F/m
Wavelength metre m
λ
4.2 Constants
Physical constant Magnitude
Speed of light in a vacuum c 2,997 x 10 m/s
-12
Permittivity of free space ε
0 8,854 x 10 F/m
-7
Permeability of free space µ
0 4π x 10 H/m
Impedance of free space 377 ohm (approx 120π Ω)
η
5 General process
This clause describes the process that shall be followed to determine the methods, the measurement
systems and the post processing that shall be used to estimate in-situ the electromagnetic field for human
1)
exposure assessment .
Depending on the objectives (see Clause 6), the in-situ measurement shall be performed in compliance with
the following flowchart:
1)
This European Standard takes into account the CEPT-ECC Recommendation (02)04.

– 11 – EN 50492:2008
In-Situ measurement
Site analysis
(Clause 6)
Source determination
(Subclause 6.2)
Measurement quantity
determination (Clause 7)
Case
determination
(Subclause 6.3)
Case A :
Case B :
Global exposure assessment Comprehensive exposure assessment
(broad band)
(narrow band)
Measurement system
selection
(Clauses 6-8)
Measurements
(Clause 9)
Measurements
(Clause 9)
No
Extrapolation
required?
(Clause 6)
Power density
Yes
S ≤ threshold ?
(Clause 6)
No
Extrapolation post-
processing (Clause 10)
Yes
Measurement uncertainty
determination (Clause 11)
Measurement report
preparation (Clause 12)
Figure 1 – Alternative routes to determine in-situ the electromagnetic field
for human exposure assessment
6 Site analysis and case determination
6.1 Introduction
This clause describes how to analyse the site and determine which type of measurement shall be performed
depending on the objective.
6.2 RF sources to be considered
Reasonable endeavours shall be applied to identify all RF emissions between 100 kHz and 300 GHz.
Such sources can be identified e.g. through visual inspection, consulting databases as defined in
EN 50400 and using frequency selective measurements. If sources are identified, then measurements shall
be performed according to applicable standards. If the location to be evaluated is not in the main beam of
antennas operating at frequencies above 6 GHz, then the fields produced by such sources can be generally
ignored since in most cases they are not significant for human exposure assessment.
All fixed permanently installed identified RF sources operating between 100 kHz and 6 GHz shall be
considered.
6.3 Case determination
6.3.1 Overview
The first decision is to choose between evaluation approaches (Cases A and B). Case A provides a single
result covering all sources and frequencies. Case B provides a set of field values for sources, frequencies or
frequency sub-bands.
If the objective of the in-situ measurement is a comprehensive exposure assessment, i.e. investigating every
contribution from RF sources using a frequency selective analysis, then Case B is applicable.
If the objective of the in-situ measurement is a global exposure assessment, i.e. combining the contributions
of all RF sources then the assessment shall be done either using Case B through a combination of all the
measured contribution (i.e. Total Exposure Ratio defined in EN 50400) or Case A.
6.3.2 Case A
Case A corresponds to the situation where one wants to perform global exposure assessment using
broadband equipment in compliance with Clause 8.
Broadband measurement may be used to indicate if it is necessary to perform a comprehensive exposure
assessment (Case B). Evaluation of power density levels above a threshold of 10 mW/m² shall be completed
according to Case B. However, if there are pre-existing national requirements, a different threshold between
5 mW/m² and 100 mW/m² may be used.
Broadband measurement may be used to give real-time environmental field-strength information "as
observed".
Broadband measurement shall not be used for extrapolation (Clause 10). Without the ability to discriminate
frequency, such extrapolation will result in a large overestimation of the maximum exposure.
6.3.3 Case B
Case B corresponds to the situation where one wants to perform a comprehensive exposure assessment
including if needed an extrapolation to estimate the field at maximum traffic.
To perform this comprehensive exposure assessment the operator shall use frequency selective
measurement equipment in compliance with Clause 8.

– 13 – EN 50492:2008
7 Determination of field quantity to measure in relation to the distance to source
antennas
The objective of this clause is to determine, from site analysis and contributors, the quantities that have to be
measured according to the distance from the source antennas (only electric and magnetic fields are covered
conforming to the scope of this standard).
For each contributor (or group of contributors) and according to the site analysis, we have to measure either
E or H, or both according to the Table 1.
Electromagnetic fields are composed of an electric field E (measured in V/m) and a magnetic field H
(measured in A/m). Far from the sources (region III) the E-field and the H-field are mathematically
interdependent, but closer to the sources (regions I and II) they might need to be measured separately.
Table 1 – Quantities to measure at different distances from radio-stations
Region Region I Region II Region III
Region edges,
measured from
       
antenna        
λ λ 5λ 5λ
       
where
       
0Lmax. D max. D Lmax. 5D max. 5D L∞
λ wavelength
       
2 2 2 2
D D 0,6D 0,6D
       
D largest
       
dimension of
 4λ  4λ  λ   λ 
the antenna
E ⊥ H No Effectively yes Yes
η = E / H
≠ η ≈ η = η
0 0 0
Component to be
E & H E or H E or H
measured
In region I, reactive power Antenna pattern according the
components are not negligible. specifications of the manufacturer Far field conditions
The power density oscillates and not yet valid.
depending on the measurement
Comment location, lower values might be
obtained closer to the antenna in
In regions II and III, it is acceptable to measure one field
contrast to higher values further
component E or H only.
away. In this region both E and H
have to be measured.
NOTE 1  These distance limits of the regions are applicable generally. Therefore, antennas might exist for which these limits are
conservative, e.g. for region I, λ might be sufficient even if D or D /(4λ) are larger. However, if resorting to these cases, they must be
supported by sustainable proof.
NOTE 2  Nevertheless, the distance limits of the regions in Table 1 are already smaller than those proposed in textbooks covering
exact descriptions of antennas. For exposure assessment, the original distance limits were reduced resulting in the values of Table 1,
whose precision is still better than the uncertainty of the exposure assessment. FCC OET Bulletin 65 proposes these small distance
limits and they have been confirmed by recent measurements and calculations.
8 Requirements of measurement systems
8.1 General
This clause describes the basic requirements applicable to measurement equipment that can be used to
perform the measurement in this standard.

The measurement system generally consists of the following components:
– the probe (composed of E or H field antenna(s)) able to evaluate the field strength isotropically;
– measurement equipment (e.g. Spectrum analyser or receiver in case of frequency selective
measurement);
– cable(s) or fibres(s) connecting the probe to the measurement equipment;
– tripod to hold and position the probe;
– either customised rotating system for the isotropic measurement using a single axis probe or switching
or combining device for the isotropic measurement using a tri-axial probe.
The size of the antenna/probe should be smaller or comparable to a wavelength at the highest frequency.
Directive antennas should only be used with the sweeping method (Annex B) or in cases where there is only
a direct path to the source antenna.
In addition to these components, supplementary equipment may be used e.g. laptop computer to automate,
control the measurement, to store and post-process the measurements.
Below 6 GHz, isotropic measurement shall be used to determine the field value used to assess the human
exposure. Directive antennas may be used to assess the spatial peak value of the different field components
(Annex B) but is not recommended for human exposure assessment.
To avoid spurious field pick up, ferrite beads are recommended on the coaxial cable connecting the probe to
the measurement equipment. For frequencies below 800 MHz it is mandatory.
If used, the tripod shall be made of low reflective material such as plastic or wood.
8.2 Technical requirements of measurement systems
8.2.1 Broadband measurement system requirements
8.2.1.1 General requirements
Equipment for broadband measurements of the electric or the magnetic field strength usually consists of a
broadband probe and a read-out unit (see Annex C). The measured level represents the total field strength
within the frequency range covered by the probe.
Broadband measurements shall be performed using an electric or a magnetic field isotropic probe. Several
probes may be used to cover the specified frequency range and the total field strength level shall then be
calculated according to Equation (1).
N
E = E
∑ i
i=1
N – number of probes (1)
N
H = H
∑ i
i=1
NOTE  The application of Equation (1) implies that the out of band response of the probe can be neglected, if this is not the case, then
the indicated field level is an overestimation.
8.2.1.2 Frequency range
The measurement system(s) shall cover the frequency range from 100 kHz to 6 GHz at least and up to
300 GHz if required by the site analysis.

– 15 – EN 50492:2008
8.2.1.3 Frequency response, dynamic range, linearity and isotropy
The requirement for frequency response, dynamic range, linearity and isotropy shall be within the
requirements described in Table 2.
Table 2 – Broadband measurement system requirements
Frequency Minimum Dynamic Linearity Isotropy
response detection limit range
Below 900 MHz
± 3 dB
and above 3 GHz ≤ 2 mW/m² < 2 dB evaluated
for the complete
≥ 40 dB ± 1,5 dB
(i.e. 1 V/m or measurement
Between 900 MHz
0,003 A/m) system
± 1,5 dB
and 3 GHz
8.2.1.4 Calibration
The measurement equipment shall be calibrated as a complete system at the measurement frequencies in
compliance with EN 50383. For signals with high crest factors or combinations of several signals, additional
calibration may be necessary in order to assess uncertainty.
8.2.2 Frequency selective measurement systems requirements
8.2.2.1 General
The measurement system shall cover in the frequency band from 100 kHz to 6 GHz at least the sources
identified in site analysis 6.2.
If site analysis has identified emissions above 6 GHz to be evaluated, adequate measurement systems have
to be used.
This range can be covered by the use of one or several antennas and measurement systems.
8.2.2.2 Dynamic range, linearity and isotropy
The requirement of dynamic range, linearity and isotropy shall be performed in compliance with EN 50383
and shall be within the requirements described in Table 3.
Table 3 – Frequency selective measurement systems requirements
Frequency Minimum Dynamic Linearity Isotropy
response detection limit range
< 2,5 dB
Below 900 MHz
evaluated for the
± 3 dB
≤ 0,01 mW/m²
and above 3 GHz
complete
measurement
(i.e. 0,05 V/m)
system
≥ 66 dB ± 1,5 dB
In the case of the
Noise ratio of at
sweeping method,
Between 900 MHz
least 20 dB
± 1,5 dB
the isotropy may
and 3 GHz
not be required.
8.2.2.3 Calibration and setting
8.2.2.3.1 Equipment based on a spectrum analyser
The measurement equipment shall be calibrated in compliance with EN 50383.
When measuring using a spectrum analyser the equipment settings shall be defined with due regard to the
characteristics of the signal, especially bandwidth, time behaviour and crest factor. The instrument settings
for different communication standards have to be chosen individually for accurate measurement results. E.g.
the resolution bandwidth of the measurement system shall either be larger than the occupied bandwidth of
the signal or all the contribution in the occupied bandwidth of the signal shall be added to find the amplitude
value. Examples are provided in Annex D and also in Annex E for broadcasting signals.
8.2.2.3.2 Equipment based on a WCDMA receiver
The measurement equipment shall be calibrated on the code domain parameters of interest which are Ec,
the power of the common pilot CPICH, and Ec/Io, the signal to noise ratio (Io is the total measured power
over a 5 MHz bandwidth centred on the carrier frequency).
The first step is to calibrate the dynamic range. The receiver cable is connected to a WCDMA generator. The
linearity deviation shall be lower than ± 2 dB for an input power covering the dynamic range. The
measurements outside the linear range must not be considered.
The second step is to determine the confidence range for Ec/Io regarding the noise level. This procedure
determines the CPICH decoding range of the device. Typically, for an isolated single WCDMA emitter
delivering the maximum power (maximum traffic), the measured signal to noise ratio Ec/Io is approximately
- 10 dB (3GPP standards indication for typical setting of the pilot power ratio). However, this value can be
lower in the case of a multisource configuration. The measurement equipment shall be able to measure
(decode) a signal down to an Ec/Io of - 20 dB (UMTS cell limit). For this purpose, the output power of the
generator is fixed while the CPICH allocated power ratio (referred to the total emitted power) is varied from
- 3 dB to - 20 dB. The measured value shall be within ± 2 dB deviation.
For more information see Annex F.
9 Measurement procedures
9.1 General requirements
The measurement shall be performed using the measurement system selected in Clause 6 and Clause 7.
In case of comprehensive exposure assessment (Case B), the measurement of the amplitude shall be
considered as the total power of the transmitted signal (Clause 8, Annex D and Annex E).
In all cases the minimum distance between the measurement probe tip and the body of the "operator" as well
as any reflecting object shall be 1 m when measuring below 300 MHz and 0,5 m when measuring above
300 MHz (see Annex G).
9.2 Field strength assessment
9.2.1 General
Multi-path propagation means the signal at a given location is composed of different field components
inducing fast fading (Annex H). The EM fields vary in time and in space therefore, the field strength used to
assess the human exposure has to be evalu
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