ETSI ETS 300 449 ed.1 (1996-02)

SLOVENSKI STANDARD
SIST ETS 300 449:1999
01-november-1999
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Business TeleCommunications (BTC); Special quality voice bandwidth 2-wire analogue
leased line (A2S); Connection characteristics and network interface presentation
Ta slovenski standard je istoveten z: ETS 300 449 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
SIST ETS 300 449:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 449:1999

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SIST ETS 300 449:1999
EUROPEAN ETS 300 449
TELECOMMUNICATION February 1996
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02029
ICS: 33.020
ONP, leased line, A2S
Key words:
Business TeleCommunications (BTC);
Special quality voice bandwidth
2-wire analogue leased line (A2S);
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 300 449: 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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Contents
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .8
3.1 Definitions .8
3.2 Abbreviations .8
4 Requirements.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 power in a 10 Hz bandwidth.11
4.1.4.4 Maximum input power outside the voice band .11
4.1.5 Transmission delay .11
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 .13
4.1.8 Random circuit noise.13
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 .14
4.1.13 Frequency error.15
4.1.14 Harmonic distortion .15
4.1.15 Echo and stability .15
4.1.15.1 Echo.15
4.1.15.1.1 Echo control devices.15
4.1.15.1.2 Talker echo.15
4.1.15.1.3 Listener echo .15
4.1.15.2 Stability .15
4.2 Interface presentation .15
4.2.1 Connector specification.16
4.2.2 Hardwired presentation .16
4.2.3 Return loss .16
4.2.4 Power feeding .17
4.3 Safety.17
4.4 Overvoltage protection.17
4.5 ElectroMagnetic Compatibility (EMC) .17
4.6 Availability .17

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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 Non-reactive line termination. 18
A.1.4 Measurement frequency . 19
A.2 Test methods. 19
A.2.1 Overall loss. 19
A.2.2 Loss/frequency distortion and maximum mean input power. 19
A.2.3 Maximum instantaneous power . 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. 22
A.2.8 Phase jitter . 23
A.2.9 Total distortion. 23
A.2.10 Single tone interference . 24
A.2.11 Frequency error. 25
A.2.12 Harmonic distortion . 25
A.2.13 Stability. 26
A.2.14 Return loss . 26
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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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 300 450: "Business TeleCommunications (BTC); Ordinary and Special quality voice
bandwidth 2-wire analogue leased lines (A2O and A2S); 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 leased 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 organizations 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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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, 2-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 (92/44/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 to 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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[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 a complex impedance made up of a resistance of 270 Ω in series with
R
a parallel combination of 750 Ω and 150 nF. See also subclause A.1.2.
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.
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
A2S Special quality voice bandwidth 2-wire analogue leased line
ADPCM Adaptive Differential Pulse Coded Modulation
EMC ElectroMagnetic Compatibility
f frequency
NTP Network Termination Point
ONP Open Network Provision

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qdu quantizing distortion unit
rms root mean square
TNV Telecommunication Network Voltage (see subclause 3.4 of EN 60950 [7])
Z Reference impedance
R
4 Requirements
4.1 Connection characteristics
The special quality voice bandwidth 2-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.
Table 1: Network performance characteristics
Description Nature Reference
subclause
Overall loss 0 ≤ overall loss ≤ 17 dB 4.1.2
Loss/frequency distortion Table 2, figure 1 4.1.3
Transmission signals 4.1.4
- maximum mean input power -9 dBm 4.1.4.1
- maximum instantaneous power +4 dBm 4.1.4.2
- maximum 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 3 4.1.6
Variation of overall loss with time 4.1.7
- amplitude hits ≤ 10 in a 15 minute period 4.1.7.1
- 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 4.1.9
≤ 18 peaks ≥ -21 dBm0 in a
15 minute period (see note)
Phase jitter 4.1.10
≤ 10° peak to peak
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 ≤ -44 dBm0 (see note) 4.1.12
Frequency error 4.1.13
≤ ± 5 Hz
Harmonic distortion 4.1.14
≥ 25 dB below fundamental
Echo and stability 4.1.15
- Echo control devices no echo control 4.1.15.1.1
- Talker echo > 10 dB 4.1.15.1.2
- Listener echo > 20 dB 4.1.15.1.3
- Stability 0 to 4 kHz 4.1.15.2
NOTE: Where the output relative level is not defined, an alternative value is specified in the
reference subclause.

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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 -9 dBm in each direction of transmission with the line terminated in 600
Ω at each end shall be in the range:
0 ≤ overall loss ≤ 17 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 -9 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.
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
3
CD
L
0
H
I
-1
G K
J
-2
Frequency Hz
300 500 1020 3600
2800
3000
Figure 1: Limits for loss of the circuit relative to that at 1 020 Hz
Test: The test shall be conducted according to subclause A.2.2.

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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 at a one
minute mean power level of -9 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 -9 dBm (i.e. +4 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.2.3.
4.1.4.3 Maximum power in a 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 300 450.
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 300 450).
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
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.

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Delay (ms)
100
15
10
0
0 3000 6000 9000
Geographical distance (km)
Figure 2: Upper limit of delay
Test: There is no test. This requirement shall be checked by calculation using information from the
network plans.
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.
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

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Group delay distortion ms
5
4
3 H
AB
G
2
CD
1
EF
0
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 -9 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.
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 success
...