SIST ETS 300 452:1999
(Main)Business TeleCommunications (BTC); Special quality voice bandwidth 4-wire analogue leased line (A4S); Connection characteristics and network interface presentation
Business TeleCommunications (BTC); Special quality voice bandwidth 4-wire analogue leased line (A4S); Connection characteristics and network interface presentation
Specification of the public network side of the interface and the performance of the leased line service, including test procedures for compliance
Poslovne telekomunikacije (BTC) - Analogni 4-žični zakupljeni vodi z govorno pasovno širino in posebno kakovostjo (A4S) - Prenosne značilnosti in omrežni vmesnik
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-1999
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SDVRYQRãLULQRLQSRVHEQRNDNRYRVWMR $6 3UHQRVQH]QDþLOQRVWLLQRPUHåQL
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Business TeleCommunications (BTC); Special quality voice bandwidth 4-wire analogue
leased line (A4S); Connection characteristics and network interface presentation
Ta slovenski standard je istoveten z: ETS 300 452 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN ETS 300 452
TELECOMMUNICATION February 1996
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02033
ICS: 33.020
ONP, leased line, A4S
Key words:
Business TeleCommunications (BTC);
Special quality voice bandwidth
4-wire analogue leased line (A4S);
Connection characteristics and network interface presentation
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
*
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1996. All rights reserved.
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ETS 300 452: February 1996
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
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ETS 300 452: February 1996
Contents
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .8
3.1 Definitions .8
3.2 Abbreviations .9
4 Requirements and tests .9
4.1 Connection characteristics.9
4.1.1 Tabulation of connection characteristics .9
4.1.2 Overall loss.10
4.1.3 Loss/frequency distortion .10
4.1.4 Transmission signals.11
4.1.4.1 Maximum mean input power .11
4.1.4.2 Maximum instantaneous power.11
4.1.4.3 Maximum signal power at 10 Hz bandwidth .12
4.1.4.4 Maximum input power outside the voice band .12
4.1.5 Transmission delay .12
4.1.6 Group-delay distortion .12
4.1.7 Variation of overall loss with time .13
4.1.7.1 Amplitude hits .13
4.1.7.2 Other variations .14
4.1.8 Random circuit noise.14
4.1.9 Impulsive noise.14
4.1.10 Phase jitter .14
4.1.11 Distortion .14
4.1.11.1 Quantizing distortion .14
4.1.11.2 Total distortion .14
4.1.12 Single tone interference .15
4.1.13 Frequency error.15
4.1.14 Harmonic distortion .15
4.2 Interface presentation .15
4.2.1 Connector specification.15
4.2.2 Hardwired presentation .16
4.2.3 Return loss .16
4.2.4 Power feeding .16
4.3 Safety.17
4.4 Overvoltage protection.17
4.5 ElectroMagnetic Compatibility (EMC) .17
4.6 Availability .17
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ETS 300 452: February 1996
Annex A (normative): Test methods. 18
A.1 General. 18
A.1.1 Equipment connection. 18
A.1.2 Reference impedance. 18
A.1.3 Measurement frequency . 18
A.2 Test Methods. 18
A.2.1 Overall loss. 18
A.2.2 Loss/frequency distortion and maximum mean input power. 19
A.2.3 Transmission delay . 20
A.2.4 Group delay distortion . 21
A.2.5 Amplitude hits. 21
A.2.6 Random circuit noise. 22
A.2.7 Impulsive noise. 23
A.2.8 Phase jitter . 23
A.2.9 Total distortion. 24
A.2.10 Single tone interference . 25
A.2.11 Frequency error. 25
A.2.12 Harmonic distortion . 26
A.2.13 Maximum instantaneous power . 26
A.2.14 Return loss . 27
A.2.15 Power feeding . 28
Annex B (informative): Weighted return loss measurements. 29
B.1 Introduction. 29
B.2 Weighting function. 29
B.2.1 Calculation (trapezoidal rule). 29
B.2.2 Calculation (tabulated data) . 30
Annex C (informative): Overall loss and quantizing distortion . 31
C.1 Introduction. 31
C.2 Overall loss. 32
C.3 Quantizing distortion . 32
Annex D (informative): Availability . 34
D.1 General. 34
D.1.1 Unavailability . 34
D.1.2 Availability. 34
D.2 Definition of unavailability periods. 34
D.3 Availability figures . 36
Annex E (informative): Bibliography . 37
History. 38
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ETS 300 452: February 1996
Foreword
This European Telecommunication Standard (ETS) has been produced by the Business
TeleCommunications (BTC) Technical Committee of the European Telecommunications Standards
Institute (ETSI).
This ETS resulted from a mandate from the Commission of the European Community (CEC) to provide
harmonized standards for support of the Directive on Open Network Provision (ONP) of leased lines
(92/44/EEC).
There is another standard directly related to this ETS:
ETS 300 453: "Business TeleCommunications (BTC); Ordinary and Special quality voice
bandwidth 4-wire analogue leased lines (A4O and A4S); Terminal equipment
interface".
This ETS is based on information from ITU-T Recommendations and ETSI publications and the relevant
documents are quoted where appropriate.
Transposition dates
Date of adoption of this ETS: 2 February 1996
Date of latest announcement of this ETS (doa): 31 May 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 November 1996
Date of withdrawal of any conflicting National Standard (dow): 30 November 1996
Introduction
The Council Directive on the application of ONP to used lines (92/44/EEC), concerns the harmonization of
conditions for open and efficient access to, and use of, the leased lines provided over public
telecommunications networks and the availability throughout the European Union (EU) of a minimum set
of leased lines with harmonized technical characteristics.
The consequence of the Directive is that telecommunications oganizations within the EU shall make
available a set of leased lines within and between points in these countries with specified connection
characteristics and specified interfaces. Under the Second Phase Directive (91/263/EEC) terminal
equipment for connection to these leased lines will be required to fulfil certain essential requirements.
CCITT Recommendation M.1020 (1988) is used as the basis for the connection characteristics.
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ETS 300 452: February 1996
Blank page
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ETS 300 452: February 1996
1 Scope
This European Telecommunication Standard (ETS) specifies the technical requirements and test
principles for the connection characteristics and the physical and electrical characteristics of the network
interface presentation of special quality, voice bandwidth, 4-wire, analogue leased lines, provided as part
of the minimum set under the Council Directive on the application of Open Network Provision (ONP) to
leased lines (92/94/EEC).
A connection is presented via interfaces at Network Termination Points (NTPs) and includes any
equipment that may provide the NTP. Signals between terminal equipments are subject to impairments
during their transfer over the connection. The limits to these impairments are stated in this ETS although
in practice the overall performance may be considerably better.
The leased line provides access to the voice bandwidth (300 Hz to 3 400 Hz) with no restrictions on the
use of the frequencies. The requirements of this standard have been chosen primarily for the transmission
of data between terminal equipments without equalizers although there is no restriction on the use of the
leased line for other types of traffic.
This ETS is applicable for leased lines, including part time leased lines, for which the establishment or
release does not require any protocol exchange or other intervention at the NTP.
The tests specified in this ETS cannot be carried out, nor can performance be monitored by the leased
line provider, while the leased line is in service, i.e. carrying user's traffic. Thus the tests are designed for
bringing into and returning into service although there is no obligation to perform these tests each time the
leased line is brought into or returned into service.
This ETS covers the physical, mechanical and electrical characteristics of the network interface and
specifies the conformance tests for the connection characteristics and network interface. Some of the
tests described in this ETS are not designed to be applied to the interface of an installed leased line; such
tests may be applied to equipment of the kind used to provide the interface.
This ETS does not include details concerning the implementation of the tests nor does it include
information on any regulations concerning testing.
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] CCITT Recommendation O.71 (1988): "Impulsive noise measuring equipment
for telephone-type circuits".
[2] CCITT Recommendation O.81 (1988): "Group-delay measuring equipment for
telephone-type circuits".
[3] CCITT Recommendation O.91 (1988): "Phase jitter measuring equipment for
telephone-type circuits".
[4] CCITT Recommendation O.95 (1988): "Phase and amplitude hit counters for
telephone-type circuits".
[5] CCITT Recommendation O.132 (1988): "Quantizing distortion measuring
equipment using a sinusoidal test signal".
[6] EN 28877 (1989): "Information processing systems - Interface connector and
contact assignments for ISDN basic access interface located at reference points
S and T".
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ETS 300 452: February 1996
[7] EN 60950 (1992): "Safety of information technology equipment including
electrical business equipment".
[8] ITU-T Recommendation O.41 (1993): "Psophometer for use on telephone-type
circuits".
NOTE: This ETS also contains a number of informative references which have been included
to indicate the sources from which material has been derived, hence they do not have
an associated normative reference number. Details of these publications are given in
annex E. In some cases the same publication may have been referenced in both a
normative and an informative manner.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
group delay: A measure of the propagation time through the leased line. For a given frequency it is equal
to the first derivative of the phase shift through the leased line, measured in radians, with respect to the
angular frequency measured in radians per second.
group delay distortion: The difference between group delay at a given frequency and minimum group
delay, in the frequency band of interest.
leased lines: The telecommunications facilities provided by a public telecommunication network that
provide defined transmission characteristics between network termination points and that do not include
switching functions that the user can control, (e.g. on-demand switching).
Network Termination Point (NTP): All physical connections and their technical access specifications
which form part of the public telecommunications network and are necessary for access to and efficient
communication through that public network.
reference impedance Z : This is 600 Ω. See also subclause A.1.2.
R
terminal equipment: Equipment intended to be connected to the public telecommunication network; i.e.:
- to be connected directly to the termination of a public telecommunication network; or
- to interwork with a public telecommunication network being connected directly or indirectly to the
termination of a public telecommunication network,
in order to send, process, or receive information.
voice bandwidth: The band of frequencies over the range 300 Hz to 3 400 Hz.
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ETS 300 452: February 1996
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
a Return loss in dB
af() Return loss at frequency f in dB
a Weighted return loss in dB
w
Af() Return loss at frequency f expressed as a ratio
A4S Special quality voice bandwidth 4-wire analogue leased line
ADPCM Adaptive Differential Pulse Coded Modulation
EMC ElectroMagnetic Compatibility
f frequency
NTP Network Termination Point
ONP Open Network Provision
qdu quantizing distortion unit
rms root mean square
RX Receive is a signal input at either the leased line interface or the test equipment
TNV Telecommunication Network Voltage (see EN 60950 [7], subclause 3.4.)
TX Transmit is a signal output at either the leased line interface or the test
equipment
Z Reference impedance
R
4 Requirements and tests
4.1 Connection characteristics
The special quality voice bandwidth 4-wire analogue leased line is a bidirectional line, configured point-to-
point, nominally covering the voice bandwidth. The connection is, in general, symmetrical, i.e. each
direction of transmission has the same nominal characteristics, although the actual values are
independent.
4.1.1 Tabulation of connection characteristics
The parameters defining the characteristics of the connection are given in table 1. These characteristics
define the service offered.
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ETS 300 452: February 1996
Table 1: Network performance characteristics
Description Nature Reference
subclause
Overall loss 4.1.2
0 ≤ overall loss ≤ 13 dB
Loss/frequency distortion Table 2, figure 1 4.1.3
Transmission signals 4.1.4
- maximum mean input power -13 dBm 4.1.4.1
- maximum instantaneous power 0 dBm 4.1.4.2
- signal power in a 10 Hz bandwidth no requirement 4.1.4.3
- maximum input power outside voice band no requirement 4.1.4.4
Transmission delay 4.1.5
- terrestrial (for distance G in kilometres) < (15 + 0,01 G) ms
- via satellite
< 350 ms
Group delay distortion Table 3, figure 2 4.1.6
Variation of overall loss with time 4.1.7
- amplitude hits 4.1.7.1
≤ 10 in a 15 minute period
- other variations 4.1.7.2
± 4 dB of that at 1 020 Hz
Random circuit noise < -41 dBm0p (see note) 4.1.8
Impulsive noise ≤ 18 peaks ≥ -21 dBm0 in a 4.1.9
15 minute period (see note)
Phase jitter ≤ 10° peak to peak 4.1.10
Total distortion 4.1.11
- quantizing distortion 4.1.11.1
≤ 3 qdu; no ADPCM
- total distortion 4.1.11.2
> 28 dB signal to distortion ratio
Single tone interference 4.1.12
≤ -44 dBm0 (see note)
Frequency error 4.1.13
≤ ± 5 Hz
Harmonic distortion 4.1.14
≥ 25 dB below fundamental
NOTE: Where the output relative level is not defined, an alternative value is specified in the reference
subclause.
4.1.2 Overall loss
Requirement: The overall loss, including long term variations, presented to a signal frequency of
1 020 Hz sent at a power level of -13 dBm in each direction of transmission with the line terminated in 600
Ω at each end shall be in the range:
0 ≤ overall loss ≤ 13 dB.
NOTE: The overall loss in each direction can be different.
Test: The test shall be conducted according to subclause A.2.1.
4.1.3 Loss/frequency distortion
Requirement: The overall loss relative to that defined in subclause 4.1.2 above for the connection,
presented to a signal sent at a power level of -13 dBm with the line terminated in 600 Ω at each end shall
lie between the limits given in table 2 and figure 1.
Below 300 Hz and above 3 600 Hz the relative loss shall not be less than -2 dB and 0 dB respectively, but
is otherwise unspecified.
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ETS 300 452: February 1996
Table 2: Limits for loss of the circuit relative to that at 1 020 Hz
Upper limit Lower limit
Point Frequency Hz Relative loss dB Point Frequency Hz Relative loss dB
(see fig. 1) (see fig. 1)
A 300 6 G 500 -2
B 500 6 H 500 -1
C 500 3 I 2 800 -1
D 2 800 3 J 2 800 -2
E 2 800 6 K 3 600 -2
F 3 000 6 L 3 600 0
Relative loss dB
6 F
AB
E
CD
L
H
I
-1
G K
J
-2
Frequency Hz
300 500 1020 3600
Figure 1: Limits for overall loss of the circuit relative to that at 1 020 Hz
Test: The test shall be conducted according to subclause A.2.2.
4.1.4 Transmission signals
4.1.4.1 Maximum mean input power
Requirement: The leased line shall be capable of carrying any signal presented at the input with a one
minute mean power level of -13 dBm within a voice bandwidth of 300 Hz to 3 400 Hz with the line
terminated in 600 Ω at each end.
Test: The test shall be conducted according to subclause A.2.2.
4.1.4.2 Maximum instantaneous power
Requirement: The leased line shall be capable of carrying a signal at the input having a maximum value
equal to an instantaneous power which is 13 dB above the mean value of -13 dBm (i.e. 0 dBm).
NOTE: This value is based upon a provisional ITU-T value. See CCITT Recommendation V.2.
Test: The test shall be conducted according to subclause A.2.13.
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ETS 300 452: February 1996
4.1.4.3 Maximum signal power at 10 Hz bandwidth
There is no requirement for maximum power in a 10 Hz bandwidth.
NOTE: However, there is a corresponding requirement on the terminal equipment specified in
ETS 300 453.
4.1.4.4 Maximum input power outside the voice band
NOTE: The leased line interface is not suitable for the handling of signals below 300 Hz and
above 3 400 Hz. Out of band signals from the terminal equipment are limited to avoid
trouble in the network (see terminal equipment interface requirement in ETS 300 453).
4.1.5 Transmission delay
Requirement: The requirement depends upon whether satellite transmission is involved in the connection
or not:
a) for connections where satellite transmission is not involved the one way end-to-end delay
shall be less than (15 + 0,01 G) ms, where G is the geographical distance in kilometres, as
shown in figure 2; or
Delay (ms)
0 3000 6000 9000
Geographical distance (km)
Figure 2: Upper limit of delay
b) for connections where satellite transmission is involved the one way end-to-end delay shall
be less than 350 ms.
NOTE: Requirements a) and b) are based on subclauses 2.2 and 2.3 of
ITU-T Recommendation G.114, with suitable adjustment to requirement a) to allow for
the possible use of loaded cable.
Test: The test shall be conducted according to subclause A.2.3.
4.1.6 Group-delay distortion
Requirement: The connection shall conform to the limits for group delay distortion given in table 3 and
figure 3 in which the limiting values over the frequency band are expressed as values relative to the
minimum measured group delay in the 500 Hz to 2 800 Hz frequency band.
NOTE: Figure 3 is based on figure 2 of CCITT Recommendation M.1020.
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ETS 300 452: February 1996
Table 3: Limits for group delay relative to the minimum measured group delay
in the 500 Hz to 2 800 Hz band
Upper limit
Point Frequency Hz Group delay distortion ms
(see fig. 3)
A 500 3,0
B 600 3,0
C 600 1,5
D 1 000 1,5
E 1 000 0,5
F 2 600 0,5
G 2 600 3,0
H 2 800 3,0
Group delay distortion ms
3 H
AB
G
CD
EF
300 500 1000 2600
600 2800
Frequency Hz
Figure 3: Limits for group delay relative to the minimum measured group delay
in the 500 Hz to 2 800 Hz band
Test: The test shall be conducted according to subclause A.2.4.
4.1.7 Variation of overall loss with time
4.1.7.1 Amplitude hits
Requirement: When measurements are made using an instrument complying with
CCITT Recommendation O.95 [4] with the send level set at -13 dBm at a frequency of 1 020 Hz, the
number of amplitude hits greater than ± 2 dB shall not exceed 10 in any 15 minute measuring period.
NOTE: Phase or amplitude hits are defined as sudden positive or negative changes in phase
or amplitude of an observed test signal which exceed a specified threshold and persist
for a period of time greater than a specified duration.
Test: The test shall be conducted according to subclause A.2.5.
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ETS 300 452: February 1996
4.1.7.2 Other variations
Requirement: For a particular implementation variations with time of the overall loss at 1 020 Hz
(including daily and seasonal variations but excluding amplitude hits) shall not exceed ± 4 dB variation
from the value established by the test for overall loss, see subclause 4.1.2. Any such variation shall not
result in an overall loss greater than the maximum specified in subclause 4.1.2.
Test: There is no test for this but the record of the results of successive tests of overall loss may be used
to check compliance. The test shall be conducted according to subclause A.2.1.
4.1.8 Random circuit noise
Requirement: The level of the psophometric noise power at the output of the leased line shall be less
than -41 dBm0p. In order that this parameter can be tested, the leased line provider should declare the
planned value of the output relative level of the leased line.
Where the output relative level either is not, or cannot be, declared by the leased line provider, the
psophometrically weighted random circuit noise level shall be 28 dB below a received test signal which is
sent at a level of -13 dBm at a frequency of 1 020 Hz into the far end of the leased line.
Test: The test shall be conducted according to subclause A.2.6.
4.1.9 Impulsive noise
Requirement: With an input signal level of -13 dBm applied at a frequency of 1 020 Hz to the input of the
leased line, there shall not be more than 18 impulsive noise peaks exceeding a threshold level of
-21 dBm0 within a period of 15 minutes. In order that this parameter can be tested, the leased line
provider should declare the planned value of the output relative level of the leased line.
Where the output relative level either is not, or cannot be, declared by the leased line provider, the
threshold level shall be 8 dB below the received signal level. Thus, if a signal level of -13 dBm is applied at
the input and the line loss is 13 dB then the received signal level will be -26 dBm and the threshold for
impulsive noise peaks will be -34 dBm.
Test: The test shall be conducted according to subclause A.2.7.
4.1.10 Phase jitter
Requirement: The phase jitter shall be less than or equal to 10° peak-to-peak when measured at a
frequency of 1 020 Hz.
Test: The test shall be conducted according to subclause A.2.8.
4.1.11 Distortion
4.1.11.1 Quantizing distortion
Requirement: The quantizing distortion shall not exceed 3 quantizing distortion unit (qdu). Moreover,
Adaptive Differential Pulse Coded Modulation (ADPCM) systems shall not be used.
NOTE: In some cases (e.g. international leased lines spanning several transit countries,
particular network configurations), an allocation of 4 qdu may be needed.
Test: There is no test. This requirement shall be checked by calculation using information from the
network plans.
4.1.11.2 Total distortion
Requirement: With a power level of -13 dBm applied at a frequency of 1 020 Hz to the input of the leased
line, the signal to total distortion ratio shall be greater than 28 dB.
Test: The test shall be conducted according to subclause A.2.9.
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ETS 300 452: February 1996
4.1.12 Single tone interference
Requirement: The power level of single tone interference in the band 300 Hz to 3 400 Hz shall not
exceed -44 dBm0, that is 3 dB less than the permitted noise power level (see subclause 4.1.8). In order
that this parameter can be tested, the leased line provider should declare the planned value of the output
relative level of the leased line.
Where the output relative level either is not, or cannot be, declared by the leased line provider, the power
level of any single tone shall be 31 dB below a received test signal which is sent at a level of -13 dBm at a
frequency of 1 020 Hz into the far end of the leased line.
Test: The test shall be conducted according to subclause A.2.10.
4.1.13 Frequency error
Requirement: The frequency error introduced by the connection shall be less than or equal to ± 5 Hz
when measured at a frequency of 1 020 Hz.
Test: The test shall be conducted according to subclause A.2.11.
4.1.14 Harmonic distortion
Requirement: When a 700 Hz test frequency of -13 dBm is injected at the input of the leased line, the
level of any individual harmonic frequency at the output shall be at least 25 dB below the received level of
the fundamental frequency.
Test: The test shall be conducted according to subclause A.2.12.
4.2 Interface presentation
The physical connection arrangements shall normally be by a socket as specified in subclause 4.2.1;
however at the specific request of the user the connection arrangements specified in subclause 4.2.2 shall
be provided.
4.2.1 Connector specification
Requirement: The network interface shall provide an 8-contact socket of the type specified in
EN 28877 [6] and with contact assignments as specified in table 4.
Table 4: Contact assignment
Contact Network interface
1 Unused
2 Unused
3 & 6 Receive pair
4 & 5 Transmit pair
7 Unused
8 Unused
NOTE: The transmit pair is the output from the network interface. The receive pair is the input to
the network interface as shown in figure 4. Where the terms "output" and "input" are used
without qualification in this ETS, they refer to the network interface.
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ETS 300 452: February 1996
OUTPUT
INPUT
TX
RX
TERMINAL
NETWORK
EQUIPMENT
INTERFACE
INTERFACE
RX TX
INPUT
OUTPUT
Figure 4: Leased line configuration conventions
Test: There shall be a visual inspection that the socket is of the correct type. The contact assignments are
tested indirectly through the tests in annex A.
4.2.2 Hardwired presentation
Requirement: The network interface shall provide a set of connection contacts (e.g. an insulation
displacement connector or a screw terminal block) to which solid conductors with wire diameters in the
range 0,4 to 0,6 mm may be connected. The leased line provider shall provide information on the
configuration of the connection contacts used for each leased line interface.
Test: There shall be a visual inspection that both the connection method provided suitable for taking solid
conductors as defined in the requirement and that information on the configuration is provided.
NOTE: All subsequent tests are carried out via the appropriate connection method.
4.2.3 Return loss
Requirement: The return loss presented by the network interface against the reference impedance, when
the far end interface of the connection is terminated by the reference impedance, shall either be:
a) greater than 6 dB over the frequency range 300 Hz to 3 400 Hz when measured with a voltage
equivalent to a signal power level at the input to the leased line of -13 dBm at 1 020 Hz; or
b) if the return loss is not greater than 6 dB at all frequencies, then the weighted return loss against the
reference impedance shall be greater than 6 dB over the frequency range 300 Hz to 3 400 Hz,
when measured with a voltage equivalent to a signal power at the input to the leased line of
-13 dBm at 1 020 Hz.
The weighted return loss a shall be given by:
w
Af()
a=−38,l5 10og df dB
w
∫
f
300
−af() 10
where Af()= 10
and af() is the measured return loss at frequency f expressed in dB.
Test: The test shall be conducted according to subclause A.2.14.
4.2.4 Power feeding
Requirement: The network interface shall not feed power to the terminal equipment interface and shall
not require power from the terminal equipment interface.
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ETS 300 452: February 1996
Test: The test for power output from the network interface shall be conducted according to subclause
A.2.15. The test for the requirement not to support power feeding from the terminal interface is tested
indirectly through the various tests of annex A since no power is supplied over the network interface from
the test equipment.
4.3 Safety
Requirement: The leased line interface presentation shall comply with the requirements for
Telecommunications Network Voltage (TNV) circuits and protection against electric shock given in
subclause 6.2 of EN 60950 [7].
Test: The test shall be conducted according to subclause 6.2 of EN 60950 [7].
NOTE: The tests associated with the requirements in this subclause are not suitable for use
on installed leased lines. Such tests may be applied to equipment of the kind used to
provide the interface.
4.4 Overvoltage protection
Requirement: The leased line provider shall provide primary protection in accordance with the general
practice adopted in the country in which the leased line is terminated.
NOTE: Secondary protection at the terminal equipment may be necessary to protect the
terminal equipment from damage caused by overvoltages.
Test: The test provisions of the applicable national requirements shall apply.
4.5 ElectroMagnetic Compatibility (EMC)
There are no EMC requirements under this ETS.
NOTE: EMC requirements are imposed under the EMC Directive (89/336/EEC). Requirements
for conducted emissions and immunity to continuous conducted signals may be added
to this ETS when appropriate specifications become available if these requirements
are not imposed under the EMC directive.
4.6 Availability
There is no requirement on availability under this ETS.
NOTE 1: Annex D provides information about availability values for analogue leased lines.
NOTE 2: At present some leased line providers include availability performance, defined on an
individual basis as a quality of service parameter, as part of the contracted supply
conditions for their leased line offerings.
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ETS 300 452: February 1996
Annex A (normative): Test methods
A.1 General
This annex describes the test principles to be used to determine the compliance of a leased line
connection and network interface presentation against the requirements of this ETS.
It is outside the scope of this annex to identify the specific details of the implementation of the tests.
Details of test equipment accuracy and the specification tolerance of the test devices are not included in
all cases. Where such details are provided, they shall be complied with, but the way they are expressed
shall not constrain the method of implementing the test.
NOTE: Attention is drawn to the issue of measurement uncertainty which may be addressed in
future documents. Not all the required test results make allowance for spurious events
during testing (e.g. errors due to EMC effects), which may make it necessary to repeat
a test.
The test configurations given do not imply a specific realization of the test equipment or test arrangement,
or the use of specific test devices. However any test configuration used shall provide those test conditions
specified under "interface state", "stimulus" and "monitor" for each individual test.
The test equipment shall be a device, or group of devices, that is capable of generating a stimulus signal
conforming to this ETS and capable of monitoring the receive signal from the network interface.
A.1.1 Equipment connection
The leased line interface may be supplied with either a socket or a set of contacts suitable for termination
of solid conductors. Testing shall be performed at the socket or contact points as this is the point at which
compliance with this ETS is required.
A.1.2 Reference impedance
Where the test defines the use of the reference impedance (Z ), this shall be a non-reactive resistance of
R
600 Ω ± 0,25 %.
A.1.3 Measurement frequency
Many of the requirements specify a test signal frequency of 1 020 Hz. Where this is the case, the specified
reference frequency tolerance shall be -7 Hz to +2 Hz (range 1 013 Hz to 1 022 Hz).
A.2 Test Methods
A.2.1 Overall loss
Requirement: Subclauses 4.1.2 and 4.1.7.2.
Purpose: To determine the overall loss of the leased line.
Test configuration: A test sender is connected to one interface of the leased line. A level meter is
connected to the far end interface of the leased line which is terminated in the
reference impedance. See figure A.1.
The test is repeated in the other direction.
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ETS 300 452: February 1996
Far end
Near end
TEST
LEVEL
RX TX
SENDER
METER
CONNECTION
Z Z
TX RX
R R
Figure A.1: Overall loss
Connection state: Available.
Stimulus: The test sender, with an impedance of 600 Ω, is set to send a signal frequency
of 1 020 Hz into a load impedance consisting of the reference impedance at a
power level of -13 dBm. The load impedance is then disconnected and the
signal applied to one interface of the leased line.
Monitor: The power level is measured at the far end of the leased line with a terminating
impedance of 600 Ω.
Result: The overall loss, which is the difference between -13 dBm and the measured
output power, shall be as defined in subclause 4.1.2.
NOTE: For the purposes of checking the requirement of subclause 4.1.7.2 the test result may
be recorded every time the test is performed during the lifetime of the leased line and
the record checked for deviation from the limits set in subclause 4.1.7.2.
A.2.2 Loss/frequency distortion and maximum mean input power
Requirement: Subclauses 4.1.3 and 4.1.4.1.
Purpose: To check the loss/frequency distortion of the leased line over the bandwidth
300 Hz to 3 600 Hz. This test also serves to check the requirement for
maximum mean input power handling capacity of the leased line interface over
the bandwidth 300 Hz to 3 400 Hz.
Test configuration: A test sender, with an impedance of 600 Ω, is connected to one interface of the
leased line. A level meter is connected to the far end interface of the leased line
which is terminated in 600 Ω. See figure A.2.
The test is repeated in the other direction.
Near end Far end
TEST
LEVEL
RX TX
SENDER
METER
CONNECTION
Z Z
TX RX
R R
Figure A.2: Loss/frequency distortion and maximum mean input power
Connection state: Available.
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ETS 300 452: February 1996
Stimulus: The test sender, with an impedance of 600 Ω, is set to send a signal at a
number of frequencies within the range 300 Hz to 3 600 Hz into a load
impedance of 600 Ω at a power level of -13 dBm. At each frequency in turn the
load impedance is disconnected and the signal applied to one interface of the
leased line.
Monitor: The power level is measured at the far end of the leased line with a terminating
impedance of 600 Ω.
Result: Relative to the received level measured in subclause A.2.1 the received levels at
other frequencies shall be within the limits defined by table 2 and figure 1.
A.2.3 Transmission delay
Requirement: Subclause 4.1.5.
Purpose: To check the transmission delay of the leased line.
NOTE: This test describes general principles only. Test equipment for the performance of the
test may not be readily available and therefore special implementations may be
needed.
Test configuration: See figure A.3.
TEST
TEST
RX TX
RECEIVER A
SENDER A
CONNECTION
TEST TEST
TX RX
RECEIVER B SENDER B
Figure A.3: Measurement of transmission delay
Connection state: Available.
Stimulus: Test sender A shall send a distinctive signal within the bandwidth of the leased
line. Test sender B shall commence transmission of a distinctive signal at a
known time after the receipt of the test signal from test sender A.
Monitor: The delay between test sender A commencing transmission of the signal
and the receipt of the signal returned to test receiver B.
Result: The transmission delay of the leased line calculated from the measurements
shall be less than the limits specified in subclause 4.1.5.
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ETS 300 452: February 1996
A.2.4 Group delay distortion
Requirement: Subclause 4.1.6.
Purpose: To check the group delay distortion of the leased line.
Test configuration: A measuring set, to the specification of CCITT Re
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