EN 60835-2-9:1995

Methods of measurement for equipment used in digital microwave radio transmission systems - Part 2: Measurements on terrestrial radio-relay systems - Section 9: Service channels

Deals with measurements pertaining to the service channels used in digital microwave radio-relay systems. Two basic methods are commonly used for the transmission of service channel signals (that is voice, supervisory and control signals).

Meßverfahren für Geräte in digitalen Mikrowellen - Funkübertragungssystemen - Teil 2: Messungen an terrestrischen Richtfunksystemen - Hauptabschnitt 9: Dienstkanäle

Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission numérique en hyperfréquence - Partie 2: Mesures applicables aux faisceaux hertziens terrestres - Section 9: Voies de service

Il existe deux mesures se rapportant aux voies de service utilisées dans les faisceaux hertziens numériques. Il existe deux méthodes communément employées pour la transmission des signaux de voie de service (signaux vocaux, signaux de surveillance et de commande).

Methods of measurement for equipment used in digital microwave radio transmission systems - Part 2: Measurements on terrestrial radio-relay systems - Section 9: Service channels (IEC 60835-2-9:1995)

General Information

• Status: Withdrawn
• Publication Date: 10-Dec-1995
• Withdrawal Date: 31-Aug-1996
• ICS: 33.060.30 - Radio relay and fixed satellite communications systems
• Technical Committee: CLC/SR 102 - Equipment used in radio communications for mobile services and satellite communication systems
• Drafting Committee: IEC/TC 102 - IEC_TC_102
• Parallel Committee: IEC/TC 102 - IEC_TC_102
• Ref Project: SIST EN 60835-2-9:2002 - Methods of measurement for equipment used in digital microwave radio transmission systems -- Part 2: Measurements on terrestrial radio-relay systems -- Section 9: Service channels

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2002
Methods of measurement for equipment used in digital microwave radio
transmission systems - Part 2: Measurements on terrestrial radio-relay systems -
Section 9: Service channels (IEC 60835-2-9:1995)
Methods of measurement for equipment used in digital microwave radio transmission
systems -- Part 2: Measurements on terrestrial radio-relay systems -- Section 9: Service
channels
Meßverfahren für Geräte in digitalen Mikrowellen - Funkübertragungssystemen -- Teil 2:
Messungen an terrestrischen Richtfunksystemen -- Hauptabschnitt 9: Dienstkanäle
Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission
numérique en hyperfréquence -- Partie 2: Mesures applicables aux faisceaux hertziens
terrestres -- Section 9: Voies de service
Ta slovenski standard je istoveten z: EN 60835-2-9:1995
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
60835-2-9
INTERNATIONAL
Première édition
STAN DARD
First edition
1995-11
Méthodes de mesure applicables au matériel
utilisé pour les systèmes de transmission
numérique en hyperfréquence
Partie 2:
Mesures applicables aux faisceaux hertziens
terrestres
Section 9: Voies de service
Methods of measurement for equipment used in
digital microwave radio transmission systems
Part 2:
Measurements on terrestrial radio-relay systems
Section 9: Service channels
© IEC 1995 Droits
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835-2-9 © IEC:1995 - 3 -
CONTENTS
Page
FOREWORD 5
Clause
1 General 7
1.1 Scope 7
1.2 Normative references 9
2 Analogue inte rface of serv
ice channels transmitted by analogue techniques 9
2.1 Return loss 9
2.2 Input deviation sensitivity 9
2.3 Output deviation sensitivity 11
2.4 Transmit-receive section parameters 13
3 Analogue inte rface of se rvice channels transmitted by digital techniques 17
3.1 Return loss 17
3.2 Amplitude-frequency characteristic 17
3.3 PCM coder overload point 17
3.4 Idle channel noise 19
3.5 Total distortion including quantizing distortion 19
4 Digital inte rf 21
ace of se rvice channels transmitted by digital techniques
4.1 21
Return loss, terminal balance ratio
4.2 Acceptability of the signal at the input of the transmit code converter 21
4.3 Level and shape of the signal at the output of the receive code converter
4.4 Effect of jitter 23
Figures
1 Method of service channel transmission over a digital radio-relay system 25
2 Measurement of peak-to-peak deviation in case of sinusoidal modulation using
a spectrum analyzer 27
3 Back-to-back connection of transmit-side and receive-side multiplex equipment 29
4 Test arrangement for measuring the signal-to-total distortion ratio 31
5 Test arrangement for measuring the acceptability of the signal at the input of
the transmit code converter 31
6 Test arrangement for measuring the level and shape of the signal at the output
of the receive code converter 33
Annex A - Bibliography 35
835-2-9 © IEC:1995 - 5 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT FOR EQUIPMENT
USED IN DIGITAL MICROWAVE RADIO TRANSMISSION SYSTEMS -
Part 2: Measurements on terrestrial radio-relay systems -
Section 9: Service channels
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 835-2-9 has been prepared by sub-committee 12E: Radio-relay
and fixed satellite communication systems, of IEC technical committee 12: Radio-
communications.
The text of this standard is based on the following documents:
DIS Report on voting
12E/246/DIS 12E/260/RVD
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.
Annex A is for information only.

835-2-9 © IEC:1995 - 7 -
METHODS OF MEASUREMENT FOR EQUIPMENT
USED IN DIGITAL MICROWAVE RADIO TRANSMISSION SYSTEMS -
Part 2: Measurements on terrestrial radio-relay systems -
Section 9: Service channels
1 General
1.1
Scope
This section of IEC 835-2 deals with measurements pertaining to the service channels
used in digital microwave radio-relay systems.
In digital radio-relay systems, two basic methods are commonly used for the transmission
of service channel signals (that is voice, supervisory and control signals) (see annex A,
ref. [6]).
The first transmission method uses analogue transmission techniques where the i.f. or r.f.
carrier signal of the digital modulator is directly frequency-modulated by the analogue
service channel signal, which is then recovered at the receive end by an f.m. demodulator
(for example in the carrier recovery circuit of a coherent digital demodulator).
In the second method of transmission, digital transmission is used and the service channel
signal is transmitted in the form of separate bits inserted into the main bit stream by a
multiplexer (possibly together with a bit stream carrying additional information).
For digital transmission, the service channel signal may be either an analogue signal
which is digitally encoded for bit insertion or a digital signal,
in which case suitable code
conversion is normally applied in order to convert the line code into a code suitable for the
rvice
radio equipment. At the receive end, a demultiplexer is used to recover the se
channel bits and thus supply, after suitable decoding or code conversion, the se rvice
channel output signal.
Normally, more than one se ice channel is transmitted. Sometimes an additional bit
rv
stream (for example alarm control signals for protection switching and supervisory equip-
ment) may also be transmitted. Suitable multiplexing and demultiplexing equipment is then
used, such as frequency division multiplexing for analogue transmission, and time division
multiplexing for digital transmission. The use of time division multiplexing also allows the
simultaneous digital transmission of analogue and digital service channel signals.
Figure 1 shows the simultaneous application of all the above possible service channel
transmission systems. However, in a given radio-relay link, only one or two of these
systems is used at a time.
835-2-9 © IEC:1995 - 9 -
1.2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this section of IEC 835-2. At the time of publication, the
editions indicated were valid. All normative documents are subject to revision, and pa
rties
to agreements based on this section of IEC 835-2 are encouraged to investigate the possi-
bility of applying the most recent editions of the normative documents indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 835-1-2: 1992, Methods of measurement for equipment used in digital microwave
radio transmission systems - Part
1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 2: Basic characteristics
IEC 835-1-3: 1992, Methods of measurement for equipment used in digital microwave
radio transmission systems - Part 1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 3: Transmission characteristics
IEC 835-1-4: 1992, Methods of measurement for equipment used in digital microwave
radio transmission systems - Part 1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 4: Transmission performance
IEC 835-2-4: 1993,
Methods of measurement for equipment used in digital microwave
radio transmission systems - Pa rt 2: Measurements on terrestrial radio-relay systems -
Section 4: Transmitter/receiver including modulator/demodulator
2 Analogue interface of service channels transmitted by analogue techniques
2.1 Return loss
See IEC 835-1-2.
2.2
Input deviation sensitivity
2.2.1 Definition
The input deviation sensitivity, Sm , of a frequency modulator, for a sinusoidal signal with a
given frequency, is expressed as the ratio of the frequency deviation, M, to the baseband
Vb ,
voltage, at the input of the service channel, i.e.:
Of
Sm = / Vb [kHz/V]
Vb and Mf are both expressed in either peak or r.m.s. values. The deviation sensitivity of
the modulator is a function of the baseband frequency if a pre-emphasis network is
applied.
835-2-9 ©IEC:1995 - 11 -
2.2.2 Method of measurement
The se rvice channel input po rt is driven by a sinusoidal signal with an input level and
frequency producing the specified nominal deviation. The r.f. output po rt of the transmitter
is connected, via a suitable r.f. attenuator, to a down converter which converts the
frequency of the r.f. output signal to the i.f. range, and a deviation meter is connected to
the i.f. output of the down converter. The down converter and deviation meter are both
commercially available items of equipment.
The reading of the deviation meter is noted, and the deviation sensitivity is calculated as
the ratio of the deviation to the input level.
A simple alternative method can be applied if the modulation index is large enough, for
example if Af is 70 kHz and modulation frequency is 1 kHz. On a spectrum analyzer with
calibrated frequency axis, the f.m. spectrum around the centre frequency produced by a
sinusoidal drive signal is displayed using a measurement bandwidth around 1 % of the de-
viation to be measured. The peak-to-peak deviation can be read immediately as indicated
in figure 2.
In case the deviation meter or spectrum analyzer is not able to measure properly when the
carrier is modulated by the main bit stream, it may be necessary to carry out the measure-
ment in the absence of modulation.
2.2.3 Presentation of results
Input signal level and frequency, together with the measured deviation and the calculated
deviation sensitivity, are tabulated.
2.2.4 Details to be specified
The following items should be included, as required, in the detailed equipment specifi-
cation:
a) nominal input signal level and frequency;
b)
permitted deviation sensitivity range.
2.3 Output deviation sensitivity
2.3.1 Definition
The output deviation sensitivity, Sd, of a frequency demodulator for a sinusoidal signal
with a given frequency is expressed as the ratio of the baseband voltage, Vb, at the
se rvice channel output to the frequency deviation M, i.e.:
Sd = Vb / Of [V/kHz]
Vb and A! are both expressed as either peak or r.m.s. values. The deviation sensitivity of
the demodulator is a function of the baseband frequency if a de-emphasis network is
applied.
835-2-9 © IEC:1995 - 13 -
2.3.2 Method of measurement
The demodulator i.f. input port is disconnected from the receiver and driven by a signal
generator, tuned to the nominal intermediate frequency, and supplying an f.m. signal of
known deviation and modulation frequency. The service channel output port is connected
to a low frequency level meter presenting the correct load impedance, and the output level
is then measured. The deviation sensitivity is calculated as the ratio of the measured out-
put level to the applied signal generator deviation.
2.3.3 Presentation of results
The applied signal generator deviation, together with the measured output level and the
calculated deviation sensitivity, are tabulated.
2.3.4 Details to be specified
The following items should be included, as required, in the detaile
...