SIST ETS 300 689 E1:2005

SLOVENSKI STANDARD
SIST ETS 300 689 E1:2005
01-februar-2005
Poslovne telekomunikacije (BTC) - Digitalni zakupljeni vodi za prenosno hitrost 34
Mbit/s (D34U, D34S) - Vmesnik terminalske opreme
Business TeleCommunications (BTC); 34 Mbit/s digital leased lines (D34U and D34S);
Terminal equipment interface
Ta slovenski standard je istoveten z: ETS 300 689 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
SIST ETS 300 689 E1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 689 E1:2005

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SIST ETS 300 689 E1:2005
EUROPEAN ETS 300 689
TELECOMMUNICATION December 1996
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02057
ICS: 33.040.40
Key words: Access, digital, interface, leased line, ONP, terminal
Business TeleCommunications (BTC);
34 Mbit/s digital leased lines (D34U and D34S);
Terminal equipment interface
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 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 300 689: December 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 Mechanical characteristics.9
4.1.1 Sockets.10
4.1.2 Plugs .10
4.2 Electrical characteristics .10
4.2.1 Output port .10
4.2.1.1 Signal coding .10
4.2.1.2 Waveform shape .10
4.2.1.3 Output timing .11
4.2.1.4 Output return loss .12
4.2.1.5 Output jitter .12
4.2.1.6 Output frame structure.12
4.2.2 Input port .13
4.2.2.1 Signal coding .13
4.2.2.2 Input return loss.13
4.2.2.3 Input loss tolerance.13
4.2.2.4 Immunity against reflections .13
4.2.2.5 Input jitter tolerance .13
4.2.2.6 Input clock tolerance.14
4.2.2.7 Input frame structure .14
4.2.2.8 Frame alignment procedure .14
4.3 Safety.15
4.4 Overvoltage protection.15
4.5 ElectroMagnetic Compatibility (EMC) .15
Annex A (normative): Test methods.16
A.1 General.16
A.1.1 Additional information to support the test .16
A.1.2 Equipment connection .16
A.2 Test methods .17
A.2.1 Signal coding at the output port .17
A.2.2 Waveform shape at the output port .18
A.2.3 Output timing.19
A.2.4 Input signal coding, loss tolerance and immunity against reflections .20
A.2.5 Input return loss .22
A.2.6 Output return loss .23
A.2.7 Input and output jitter .24
A.2.8 Frame structure .26
A.2.9 Frame alignment procedure.27
Annex B (normative): Definition of HDB3 code .28

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ETS 300 689: December 1996
B.1 General. 28
B.2 Definition. 28
Annex C (normative): Definition of frame structure. 29
C.1 Frame structure at 34 368 kbit/s. 29
C.1.1 Trail access point identifier format . 30
C.1.1.1 CRC-7 calculation - multiplication and division process . 31
C.1.1.2 CRC-7 calculation - encoding procedure. 31
C.1.1.3 CRC-7 calculation - decoding procedure. 31
Annex D (normative): ETS Requirements Table (ETS-RT). 32
Annex E (informative): Bibliography . 33
History. 34

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ETS 300 689: December 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 the support of the Directive on Open Network Provision (ONP) of leased lines
(92/44/EEC).
There are two other standards directly related to this ETS:
- ETS 300 686: "Business TeleCommunications (BTC); 34 Mbit/s and 140 Mbit/s digital leased lines
(D34U, D34S, D140U and D140S); Network interface presentation";
- ETS 300 687: "Business TeleCommunications (BTC); 34 Mbit/s digital leased lines (D34U and
D34S); Connection characteristics".
Transposition dates
Date of adoption 6 December 1996
Date of latest announcement of this ETS (doa): 31 March 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 September 1997
Date of withdrawal of any conflicting National Standard (dow): 30 September 1997
This ETS is based on information from ITU-T Recommendations and ETSI publications and the relevant
documents are quoted where appropriate.
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 of a minimum set of
leased lines with harmonized technical characteristics.
The 34 Mbit/s unstructured and structured leased lines are not part of the minimum set of leased lines
under the leased line Directive, however these standards are being written with the intention that where
34 Mbit/s leased lines are offered, they will be in accordance with these harmonized standards.
Two classes of standard will be used for the interfaces of terminal equipment designed for connection to
the ONP leased lines. European Telecommunication Standards (ETSs), which are voluntary, give the full
technical specifications for these interfaces, whereas Technical Basis for Regulations (TBRs) give the
essential requirements under the Second Phase Directive (91/263/EEC) for attachment to the leased
lines. The TBR (TBR 24) will be a subset of the corresponding ETS. This standard, which is an ETS,
belongs to the first category.
ETS 300 166 and ITU-T Recommendation G.703 are used as the basis for the terminal equipment
interface.

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1 Scope
This ETS specifies the full mechanical and electrical characteristics, the necessary functional
characteristics and the corresponding conformance tests for a terminal equipment interface for:
- connection to the network termination points of 34 368 kbit/s digital unstructured leased lines
(D34U); and
- connection to the network termination points of 34 368 kbit/s digital structured leased lines (D34S)
which support an unstructured 33 920 kbit/s information transfer rate.
These leased lines are defined in ETS 300 686 and ETS 300 687.
This ETS is not written for regulatory purposes.
This ETS is written only to ensure that the interface of the terminal equipment is compatible with the
34 Mbit/s digital unstructured or structured leased line. This ETS is applicable to all interfaces designed for
connection to the leased line, however in the cases of apparatus that carries a particular service, of
complex apparatus and of apparatus in private networks, other ETSs may apply in addition to this ETS.
Customer premises wiring and installation between the terminal equipment and the Network Termination
Point (NTP) are outside the scope of this ETS.
2 Normative references
This ETS incorporates by dated or 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 into it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
[1] EN 60950 (1992): "Safety of information technology equipment including
electrical business equipment".
[2] IEC 169-8 (1978): "Radio frequency connectors; Part 8: R.F coaxial connectors
with inner diameters of outer conductor 6,5 mm (0,256 in) with bayonet lock -
Characteristic impedance 50 ohms (Type BNC)".
[3] IEC 169-13 (1976): "Radio frequency connectors; Part 13: R.F. coaxial
connectors with inner diameter of outer conductor 5,6 mm (0,22 in) -
Characteristic impedance 75 ohms (Type 1,6/5,6) - Characteristic impedance
50 ohms (Type 1,8/5,6) with similar mating dimensions".
[4] ISO/IEC 10173 (1991): "Information technology - Integrated Services Digital
Network (ISDN) primary access connector at reference points S and T".
[5] ITU-T Recommendation G.703 (1991): "Physical/electrical characteristics of
hierarchical digital interfaces".
[6] ITU-T Recommendation O.151 (1992): "Error performance measuring
equipment for digital systems at the primary rate and above".
[7] ITU-T Recommendation O.171 (1992): "Timing jitter measuring equipment for
digital systems".
NOTE: This ETS also contains a number of informative references which have been included
to indicate the sources from which various 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.

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3 Definitions and abbreviations
For the purposes of this ETS, the following definitions apply:
3.1 Definitions
frame: A repetitive set of consecutive bits in which the position of each bit can be identified by reference
to a frame alignment signal.
frame alignment signal: The distinctive signal inserted in every frame always occupying the same
relative position within the frame and used to establish and maintain frame alignment.
leased lines: The telecommunications facilities provided by a public telecommunications 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.
23-1
PRBS(2 ): A Pseudo Random Bit Sequence (PRBS) (as defined in subclause 2.2 of ITU-T
Recommendation O.151 [6]).
Safety Extra-Low Voltage (SELV) circuit: A secondary circuit which is so designed and protected that
under normal and single fault conditions, the voltage between any two accessible parts and, for class 1
equipment, between any accessible part and the equipment protective earthing terminal does not exceed
a safe value (subclause 1.2.8.5 of EN 60950 [1]).
terminal equipment: Equipment intended to be connected to the public telecommunications network, i.e.:
- to be connected directly to the termination of a public telecommunication network; or
- to interwork with a public telecommunications network being connected directly or indirectly to the
termination of a public telecommunications network;
in order to send, process, or receive information.
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AIS Alarm indication Signal
AMI Alternate Mark Inversion
ASCII American Standard Code for Information Interchange
ATM Asynchronous Transfer Mode
BIP-8 Bit Interleaved Parity (8 bit)
BNC Bayonet Nut Connector
CRC-7 Cyclic Redundancy Check (7 bit)
dc direct current
D34S 34 Mbit/s digital structured leased line
D34U 34 Mbit/s digital unstructured leased line
EM Error Monitoring
EMC ElectroMagnetic Compatibility
ETS-RT ETS Requirements Table
FA1 Frame Alignment byte 1
FA2 Frame Alignment byte 2
FAS Frame Alignment Signal
GC General purpose Communications channel
HDB3 High Density Bipolar code 3
LOF Loss Of Frame
LOS Loss Of Signal
LSB Least Significant Bit

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ETS 300 689: December 1996
MA Maintenance and Adaptation
MSB Most Significant Bit
NR Network operator byte
NTP Network Termination Point
ONP Open Network Provision
ppm parts per million
PRBS Pseudo Random Bit Sequence
RDI Remote Defect Indication
REI Remote Error Indication
RX RX is a signal input (at either the terminal equipment or the test equipment, see
figure 1)
SDH Synchronous Digital Hierarchy
SELV Safety Extra-Low Voltage
TM Timing Marker
TU Tributary Unit
TR TRail trace
TTI Trail Trace Identifier
TX TX is a signal output (at either the terminal equipment or the test equipment, see
figure 1)
UI Unit Interval
4 Requirements
The D34U 34 368 kbit/s unstructured leased line provides a bi-directional point-to-point digital leased line
for the support of an unstructured 34 368 kbit/s information transfer rate. Any structuring of the data is the
responsibility of the user.
The D34S 34 368 kbit/s structured leased line provides a bi-directional point-to-point digital leased line for
the support of an unstructured 33 920 kbit/s information transfer rate. Any structuring of the data within the
transparent 33 920 kbit/s part of the frame is the responsibility of the user.
For both D34U and D34S the provision of timing is the responsibility of the user; however, in certain
installations the leased line provider may be able to offer a leased line that is synchronized to the network.
4.1 Mechanical characteristics
The terminal equipment shall provide at least one of the methods of connection given in subclauses 4.1.1
and 4.1.2.
NOTE 1: When connecting the terminal equipment to the NTP, any difference in ground
potential between the two equipments may produce a voltage across the signal ground
connection and may cause damage. See DEN/EE-02004 for details of earthing
requirements within the customer's premises.
NOTE 2: The transmit pair is the output from the terminal equipment interface. The receive pair
is the input to the terminal equipment interface, as shown in figure 1. Where the terms
"output" and "input" are used without qualification in this ETS, they refer to the terminal
equipment interface.
NOTE 3: Normal practice is for the outer conductors of the input and output connectors to be
connected via a dc path to the signal ground and thence to ground. This connection is
to reduce EMC emissions. If there is a difference in ground potential between the
terminal equipment and the NTP, this arrangement may result in high currents in the
outer conductors and cause damage.
To prevent this problem, dc isolation may be introduced between the terminal
equipment and the NTP, for example by introducing dc isolation between the outer
conductor and the signal ground in the terminal equipment. Careful attention should be
given to the requirements of standards on installation earthing practice.

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ETS 300 689: December 1996
OUTPUT INPUT
TX RX
TERMINAL
NETWORK
EQUIPMENT
INTERFACE
INTERFACE
RX TX
INPUT OUTPUT
Figure 1
4.1.1 Sockets
Requirement: The terminal equipment interface shall provide two coaxial 75 Ω sockets, one each for
transmit and receive; these sockets being either:
a) 75 Ω sockets (type 1,6/5,6) complying with IEC 169-13 [3]; or
b) 75 Ω BNC sockets complying with the general requirements of IEC 169-8 [2] with the mating
dimensions specified in annex B of ISO/IEC 10173 [4].
The outer conductor of the coaxial pair shall be connected to signal ground both at the input port and at
the output port.
Test: There shall be a visual inspection that the sockets are of the correct type.
4.1.2 Plugs
Requirement: The terminal equipment interface shall provide two coaxial 75 Ω plugs at the end of a cord
(or cords), one each for transmit and receive; these plugs being either:
a) 75 Ω plugs (type 1,6/5,6) complying with IEC 169-13 [3]; or
b) 75 Ω BNC plugs complying with the general requirements of IEC 169-8 [2] with the mating
dimensions specified in annex B of ISO/IEC 10173 [4].
The outer conductor of the coaxial pair shall be connected to signal ground both at the input port and at
the output port.
NOTE: There is no requirement on the method of connection of the cord (or cords) to the
terminal equipment.
Test: There shall be a visual inspection that the plugs are of the correct type.
4.2 Electrical characteristics
4.2.1 Output port
4.2.1.1 Signal coding
Requirement: The signal transmitted at the output port shall comply with the High Density Bipolar code 3
(HDB3) encoding rules (see annex B).
Test: The test shall be conducted according to subclause A.2.1.
4.2.1.2 Waveform shape
Requirement: The pulse at the output port shall comply with the requirements given in table 1 and
figure 2; based on ITU-T Recommendation G.703 [5].

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Table 1: Waveform shape at output port
Pulse shape (nominally rectangular) All marks of a valid signal shall conform with the
mask (see figure 2). The value V corresponds to the
nominal peak voltage of a mark.
Test load impedance
75 Ω non-reactive
Nominal peak voltage V of a mark 1,0 V
Peak voltage of a space 0 ± 0,1 V
Nominal pulse width 14,55 ns
Ratio of the amplitudes of positive and negative 0,95 to 1,05
pulses at the centre of the pulse interval
Ratio of the widths of positive and negative pulses 0,95 to 1,05
at the nominal half amplitude
17 ns
(14,55 + 2,45)
V
0,2
0,1
1,0
8,65 ns
0,1
(14,55 - 5,90)
0,2
Nominal
pulse
14,55 ns
0,5
12,1 ns
(14,55 - 2,45)
24,5
0,1 0,1
(14,55 + 9,95)
0
0,1
0,1
0,2
29,1 ns
(14,55 + 14,55)
Figure 2: Pulse mask for 34 Mbit/s pulse
Test: The test shall be conducted according to subclause A.2.2.
4.2.1.3 Output timing
The terminal equipment may derive its timing from:
a) an internal source (e.g. an internal clock);
b) an external reference signal input;
c) the received signal at the input port.
Requirement: For each of the timing arrangements intended for use, the bit rate at the output port shall
be within the limits of 34 368 kbit/s ± 20 parts per million (ppm), when any relevant external signal,
including the received signal at the input port, is within its stated tolerance.

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NOTE: The tolerance of ± 20 ppm relates to the transmission capability of the leased line.
Tighter limits may be needed to ensure satisfactory end to end interworking with the
distant terminal equipment.
Test: The test shall be conducted according to subclause A.2.3.
4.2.1.4 Output return loss
Requirement: The output return loss at the terminal equipment interface, with respect to 75 Ω, shall be
greater than or equal to the values given in table 2, which is taken from annex 3 of ETS 300 166.
Table 2: Output port minimum return loss
Frequency range Return loss
860 kHz to 1 720 kHz 6 dB
1 720 kHz to 51 550 kHz 8 dB
Test: The test shall be conducted according to subclause A.2.6.
4.2.1.5 Output jitter
Requirement: The peak-to-peak output jitter shall not exceed the limits of table 3 when measured with a
bandpass filter with linear cut-off with the defined cut-off frequencies. At frequencies below the lower 3 dB
point, the attenuation of the high pass filter shall rise with a value greater than, or equal to, 20 dB per
decade. At frequencies above the upper 3 dB point, the attenuation of the low pass filtration shall rise with
a value greater than, or equal to, 60 dB per decade.
For the purpose of testing, any signal input from which the output timing is derived shall be provided with
the maximum tolerable input jitter, and with the maximum tolerable input frequency deviation, as specified
by the manufacturer.
Where the output timing of the terminal equipment is taken from the leased line, the input to the terminal
equipment shall be provided with components of sinusoidal jitter at points on the curve of figure 3 and
table 5.
Table 3: Maximum output jitter
Measurement filter bandwidth Output jitter
Lower cut-off Upper cut-off Unit Interval (UI) peak-
(high pass) (low pass) to-peak (maximum)
100 Hz 800 kHz 0,4
10 kHz 800 kHz 0,15
NOTE: These values are chosen to allow for jitter build-up in user
networks and may be different from ITU-T Recommendations.
Test: The test shall be conducted according to subclause A.2.7.
4.2.1.6 Output frame structure
The requirement of this subclause applies to terminal equipment for connection to the D34S leased line.
For terminal equipments for connection to the D34U leased line, there is no requirement on the structure
of the output bit stream.
Requirement: For terminal equipments for connection to the D34S leased line, the bit stream transmitted
at the output of the terminal equipment shall be structured as defined in annex C.
Bit 1 of byte Maintenance and Adaptation (MA), a Remote Defect Indication (RDI), shall be set to "1"
within 250 μs of the detection of loss of received frame alignment (see subclause 4.2.2.8), and set to "0"
within 250 μs on gaining frame alignment.
Test: The test shall be conducted according to subclause A.2.8 and A.2.9.

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4.2.2 Input port
4.2.2.1 Signal coding
Requirement: The input port shall decode without error HDB3 encoded signals in accordance with HDB3
encoding rules (see annex B).
Test: The test shall be conducted according to subclause A.2.4.
4.2.2.2 Input return loss
Requirement: The input return loss with respect to 75 Ω at the interface shall be greater than or equal to
the values given in table 4, which is taken from subclause 8.3.3 of ITU-T Recommendation G.703 [5].
Table 4: Input port minimum return loss
Frequency range Return loss
860 kHz to 1 720 kHz 12 dB
1 720 kHz to 34 368 kHz 18 dB
34 368 kHz to 51 550 kHz 14 dB
Test: The test shall be conducted according to subclause A.2.5.
4.2.2.3 Input loss tolerance
Requirement: The input port shall decode without errors a 34 368 kbit/s signal as defined in subclauses
4.2.1.1 and 4.2.1.2 above but modified by a cable or artificial cable with the following characteristics:
a) attenuation that follows a √f law with values throughout the range 0 dB to 12 dB at
17 184 kHz; and
b) characteristic impedance of 75 Ω with a tolerance of ± 20 % over the frequency range from
860 kHz to 51 550 kHz.
Test: The test shall be conducted according to subclause A.2.4.
4.2.2.4 Immunity against reflections
Requirement: When a signal comprising a combination of a normal signal and an interfering signal is
applied to the input port, via an artificial cable with a loss in the range 0 dB to 12 dB at 17 184 kHz, no
errors shall result due to the interfering signal. The normal signal shall be a signal encoded according to
23-1
HDB3, shaped according to the mask of figure 2, with a binary content in accordance with a PRBS(2 ).
The interfering signal shall be the same as the normal signal except that the level shall be attenuated by
20 dB, the bit rate shall be within 34 368 kbit/s ± 20 ppm and the timing shall not be synchronized to the
normal signal.
Test: The test shall be conducted according to subclause A.2.4.
4.2.2.5 Input jitter tolerance
Requirement: The terminal equipment shall tolerate at its input port the maximum input jitter as shown in
figure 3 and table 5 (taken from ITU-T Recommendation G.823).
NOTE: Terminal equipment with more than one input will normally need to be designed with a
wander buffer of at least 18 microseconds, however, to accommodate the wander that
may be produced by Synchronous Digital Hierarchy (SDH) networks, up to 40
microseconds may be needed.

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