SIST TBR 025 E1:2004

SLOVENSKI STANDARD
SIST TBR 025 E1:2004
01-oktober-2004
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Business TeleCommunications (BTC); 140 Mbit/s digital unstructured and structured
leased lines (D140U and D140S); Attachment requirements for terminal equipment
interface
Ta slovenski standard je istoveten z: TBR 025 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
SIST TBR 025 E1:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST TBR 025 E1:2004

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TECHNICAL TBR 25
BASIS for July 1997
REGULATION
Source: ETSI TC-BTC Reference: DTBR/BTC-02060
ICS: 33.040.40
Key words: Access, digital, interface, leased line, ONP, terminal, testing, type approval
Business TeleCommunications (BTC);
140 Mbit/s digital unstructured and structured leased lines
(D140U and D140S);
Attachment requirements for 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 1997. All rights reserved.

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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 .7
3.1 Definitions .7
3.2 Abbreviations .8
4 Requirements.9
4.1 Mechanical characteristics.9
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 .12
4.2.1.4 Output jitter .13
4.2.1.5 Output frame structure.14
4.2.2 Input port .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 Equipment connection .16
A.1.2 Test environment .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 .17
A.2.3 Output timing.18
A.2.4 Output jitter .19
A.2.5 Frame structure .20
Annex B (normative): Definition of CMI code .21
B.1 General.21
B.2 Definition .21
Annex C (normative): Definition of frame structure .22
C.1 Frame structure at 139 264 kbit/s .22
Annex D (normative): TBR Requirements Table (TBR-RT) .23
Annex E (informative): Bibliography.24
History.25

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Foreword
This Technical Basis for Regulation (TBR) has been produced by the Business TeleCommunications
(BTC) Technical Committee, in conjunction with the Terminal Equipment (TE) and Transmission and
Multiplexing (TM) Technical Committees, of the European Telecommunications Standards Institute
(ETSI).
This TBR resulted from a mandate from the Commission of the European Community (CEC) to provide
harmonized standards for the support of the Second Phase Directive (91/263/EEC).
This TBR 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 Open Network Provision (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.
At the date of publication of this TBR, the 140 Mbit/s unstructured and structured leased lines are not part
of the minimum set of leased lines under the Leased Line Directive and it is not planned that they will be
added to the minimum set.
Two classes of standard will be used for the interfaces of terminal equipment designed for connection to
the ONP leased lines. European Telecommunications Standards (ETSs), which are voluntary, give the full
technical specifications for these interfaces, whereas TBRs give the essential requirements under the
Second Phase Directive (91/263/EEC) for attachment to the leased lines. This TBR is a subset of the
corresponding ETS 300 690.
ETS 300 166 and ITU-T Recommendations G.703 are used as the basis for the terminal equipment
interface.

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1 Scope
This TBR specifies the attachment requirements and the corresponding conformance tests for a terminal
equipment interface for:
- connection to the Network Termination Points (NTPs) of 139 264 kbit/s digital unstructured leased
lines (D140U); and
- connection to the NTPs of 139 264 kbit/s digital structured leased lines (D140S) with an information
transfer rate of 138 240 kbit/s without restriction on binary content.
These leased lines are defined in ETS 300 686 and ETS 300 688.
The term "attachment requirements" in the context of this TBR refers to the essential requirements for
access that apply under articles 4d and 4f of the Second Phase Directive (91/263/EEC). Conformance to
these requirements does not guarantee end-to-end interoperability. Essential requirements under articles
4c and 4e are not applicable to this TBR.
This TBR is applicable to all interfaces intended for connection to the D140U or D140S leased line. It
covers the essential requirements for the mechanical and electrical characteristics of the terminal
equipment interface. Interfaces intended only for connection to the D140U leased lines which do not
comply with the specified requirements on output structure, do not satisfy the attachment requirements for
connection to the D140S structured leased line.
Customer premises wiring and installation between the terminal equipment and the NTP are outside the
scope of this TBR.
2 Normative references
This TBR 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 TBR only when incorporated into it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
[1] ITU-T Recommendation G.703 (1991): "Physical/electrical characteristics of
hierarchical digital interfaces".
[2] ITU-T Recommendation O.151 (1992): "Error performance measuring
equipment for digital systems at the primary rate and above".
[3] ITU-T Recommendation O.171 (1992): "Timing jitter measuring equipment for
digital systems".
NOTE: This TBR 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.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this TBR, the following definitions apply:
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.

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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 [2]).
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).
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 TBR, the following abbreviations apply:
ac alternating current
BNC Bayonet Nut Connector
CMI Coded Mark Inversion
D140S 140 Mbit/s digital structured leased line
D140U 140 Mbit/s digital unstructured leased line
dc direct current
EMC ElectroMagnetic Compatibility
FA1 Frame Alignment byte 1
FA2 Frame Alignment byte 2
LSB Least Significant Bit
MSB Most Significant Bit
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)
SELV Safety Extra-Low Voltage
TBR-RT TBR-Requirements Table
TX TX is a signal output (at either the terminal equipment or the test equipment,
see figure 1)
UI Unit Interval

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4 Requirements
The terminal equipment is for use with D140U or D140S leased lines.
The D140U 139 264 kbit/s unstructured leased line provides a bi-directional point-to-point digital
connection with an information transfer rate of 139 264 kbit/s without restriction on binary content. Any
structuring of the data is the responsibility of the user.
The D140S 139 264 kbit/s structured leased line provides a bi-directional point-to-point digital connection
with an information transfer rate of 138 240 kbit/s without restriction on binary content. Any structuring of
the data within the transparent 138 240 kbit/s part of the frame is the responsibility of the user.
For both D140U and D140S 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
Justification: Without a means of connection, it is impossible for the terminal equipment to connect to the
network, therefore this is included in order for the terminal equipment to interwork with the network
(article 4f).
Requirement: The terminal equipment interface shall provide two coaxial 75 Ω connectors, one each for
transmit and receive.
There is no requirement under this TBR for a particular plug or socket to be provided on the terminal
equipment.
NOTE 1: ETS 300 690 specifies that the terminal equipment shall provide either:
- two coaxial sockets, one each for transmit and receive; these sockets being
either 75 Ω sockets complying with IEC 169-13 or 75 Ω Bayonet Nut Connector
(BNC) sockets; IEC 9-1 or
- two coaxial plugs at the end of a cord (or cords), one each for transmit and
receive; these plugs being either 75 Ω plugs complying with IEC 169-13 or 75 Ω
BNC plugs IEC 9-1.
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 TBR, 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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OUTPUT INPUT
TX RX
TERMINAL
NETWORK
EQUIPMENT
INTERFACE
INTERFACE
RX TX
INPUT OUTPUT
Figure 1
Test: There shall be a visual inspection that two 75 Ω connectors are provided.
4.2 Electrical characteristics
4.2.1 Output port
4.2.1.1 Signal coding
Justification: The correct signal coding is necessary for the output signals from the terminal equipment to
be recognized correctly at the input to the NTP. Failure to provide the correct coding may cause error
reports within the network. A requirement on signal coding is therefore included in order to prevent harm
to the network (article 4d).
Requirement: The signal transmitted at the output port shall comply with the Coded Mark Inversion (CMI)
encoding rules (see annex B).
Test: The test shall be conducted according to subclause A.2.1.
4.2.1.2 Waveform shape
Justification: The correct waveform shape both limits the voltages to line and ensures correct recognition
of the pulses. Incorrect recognition of pulses may cause error reports within the network. A requirement on
waveform shape is therefore included in order to prevent harm to the network (article 4d).
Requirement: The pulse at the output port shall comply with the requirements given in figures 2 and 3
and table 1; based on ITU-T Recommendation G.703.

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T = 7,18 ns
V
0,60
(see note 1) (see note 1)
0,55
0,50
1 ns
1,795 ns 1,795 ns
0,45
Nominal
1 ns 1 ns
0,40 pulse
0,1 ns
0,1 ns
0,35 ns 0,1 ns
0,1 ns
0,35 ns
0,05
Nominal
zero level
-0,05
1 ns 1 ns
1 ns
-0,40
1,795 ns 1,795 ns
-0,45
-0,50
-0,55 (see note 1)
(see note 1)
-0,60
Negative
transitions Positive transition
at mid-unit interval
NOTE 1: The maximum "steady state" amplitude shall not exceed the 0,55 V limit. Overshoots and other
transients are permitted to fall into the dotted area, bounded by the amplitude levels 0,55 V and
0,60 V, provided they do not exceed the steady state level by more than 0,05 V.
NOTE 2: The rise time and decay time shall be measured between -0,4 V and 0,4 V and shall not
exceed 2 ns.
Figure 2: Mask of a pulse corresponding to a binary 0

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T = 7,18 ns
V
0,60
(see note 1)
(see note 1)
0,55
0,50
1 ns
0,45
1 ns
0,40
0,1 ns 0,1 ns
0,5 ns 0,5 ns
0,05
Nominal
zero level
-0,05
3,59 ns 3,59 ns
1,35 ns 1,35 ns
1 ns 1 ns
-0,40
1,795 ns 1,795 ns
-0,45
-0,50
-0,55
(see note 1)
-0,60
Negative
Positive
transition
transition
NOTE 1: The maximum "steady state" amplitude shall not exceed the 0,55 V limit. Overshoots and other
transients are permitted to fall into the dotted area, bounded by the amplitude levels 0,55 V and
0,60 V, provided they do not exceed the steady state level by more than 0,05 V.
NOTE 2: The inverse pulse shall have the same characteristics, noting that the timing tolerance at the
level of the negative and positive transitions are ± 0,1 ns and ± 0,5 ns respectively.
NOTE 3: The rise time and decay time shall be measured between -0,4 V and 0,4 V and shall not
exceed 2 ns.
Figure 3: Mask of a pulse corresponding to a binary 1
Table 1: Waveform shape at output port
Pulse shape Nominally rectangular and conforming with the masks shown
in figures 2 and 3.
Test load impedance 75 Ω non-reactive
Peak to peak voltage 1,0 ± 0,1 V
Rise time between 10 %and ≤ 2 ns
90 %amplitudes of the measured steady
state amplitude
Transition timing tolerance (referred to Negative transitions: ± 0,1 ns
the mean value of the 50 %amplitude Positive transitions at unit interval boundaries: ± 0,5 ns
points of the negative transition) Positive transitions at mid-interval: ± 0,35 ns
Test: The test shall be conducted according to subclause A.2.2.
4.2.1.3 Output timing
Justification: Pulses at the wrong bit rate may not be properly recognized and may cause error reports
within the network. A requirement on output timing is therefore included in order to prevent harm to the
network (article 4d).

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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 139 264 kbit/s ± 15 parts per million (ppm), when any relevant external reference
signal, including the received signal at the input port, is within its stated tolerance.
Test: The test shall be conducted according to subclause A.2.3.
4.2.1.4 Output jitter
Justification: A high level of jitter causes error reports within some networks, therefore this requirement
is included to prevent harm to the network (article 4d).
Requirement: The peak-to-peak output jitter shall not exceed the limits of table 2 when measured with a
band pass filter 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 4 and
table 3.
Table 2: 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)
200 Hz 3 500 kHz 0,4
10 kHz 3 500 kHz 0,075

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peak-to-peak jitter
A1
A2
f1 f2 f3 f4
jitter frequency
Figure 4: Input jitter tolerance
Table 3: Input jitter tolerance
Peak-to-peak amplitude (UI) Frequency
A1 A2 f1 f2 f3 f4
1,5 0,075 200 Hz 500 Hz 10 kHz 3 500 kHz
Test: The test shall be conducted according to subclause A.2.6.
4.2.1.5 Output frame structure
Justification: If the input bit stream to the structured leased line does not have the correct Frame
Alignment bytes 1 (FA1) and Frame Alignment bytes 2 (FA2), the leased line will not be able to achieve
frame alignment for the purposes of monitoring the line and may cause error reports. Therefore a
requirement on the frame alignment signals is included to prevent harm to the network (article 4d).
Requirement: For terminal equipments intended for connection to the D140S structured leased line,
the bit stream transmitted at the output of the terminal equipment shall be structured as defined in
annex C.
Test: The test shall be conducted according to subclause A.2.5.
4.2.2 Input port
There are no requirements on the input port under this TBR, except as specified in subclause 4.1.
Justification: The requirements imposed on the terminal equipment output port do not require the correct
receipt of data at the terminal equipment input port. The network output port should be protected against
both short circuit and open circuit. Therefore there are no requirements within the base standard
ETS 300 690 that can be considered as essential requirements.

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4.3 Safety
There are no safety requirements under this TBR.
NOTE: Safety requirements are imposed under the Low Voltage Directive (73/23/EEC) and
articles 4a and 4b of the Second Phase Directive (91/263/EEC). ETS 300 690
subclause 4.3 defines the terminal equipment interface as an Safety Extra-Low
Voltage (SELV) circuit. Detailed requirements for SELV circuits are given in EN 60950.
4.4 Overvoltage protection
There are no overvoltage protection requirements under this TBR.
NOTE: Requirements for overvoltage protection requirements on a 75 Ω interface are under
study. Requirements may be added to this TBR when appropriate specifications
become available.
4.5 ElectroMagnetic Compatibility (EMC)
There are no EMC requirements under this TBR.
NOTE: General EMC requirements are imposed under the EMC Directive (89/336/EEC).
Requirements for conducted emissions will be added to this TBR when appropriate
specifications become available if these requirements are not imposed under the EMC
Directive.

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Annex A (normative): Test methods
A.1 General
This annex describes the test principles to determine the compliance of a terminal equipment against the
requirements of this TBR.
It is outside the scope of this TBR to identify the specific details of the implementation of the tests.
A terminal equipment may be designed for through-connecting and may fulfil the electrical requirements
only if through-connected. In these cases the requirements of this TBR are valid and the tests are carried
out with the through-connection terminated as specified by the equipment supplier.
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 given test configurations 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 a group of devices, generating a stimulus signal conforming to
this annex and capable of monitoring the signal received from the interface.
The terminal equipment interface under test shall have the ability to transmit a bit pattern for test
23-1
purposes, e.g. a Pseudo Random Bit Sequence (PRBS(2 )) as defined in subclause 2.2 of ITU-T
Recommendation O.151 [2]. Where this cannot be provided, an alternative method of conducting the test
shall be provided.
A.1.1 Equipment connection
The tests shall be applied at the sockets or plugs supplied with the terminal equipment for connection to
the leased line interface. Connecting cable between the sockets and test equipment shall be kept to a
minimum, except where cable is specified as part of the test.
Where plugs are provided at the end of a cord, the tests specified in subclause A.2.2 may be performed at
the point of connection of the cord to the terminal equipment, since the requirements are based on ITU-T
Recommendation G.703 which makes no allowance for any plug and cord.
A.1.2 Test environment
All tests shall be performed at:
- an ambient temperature in the range +19 C to +25 C;
- a relative humidity in the range 5 % to 75 %.
For terminal equipment which is not designed to operate within the environmental range specified above,
all tests shall be performed in an environmental condition as specified by the supplier.
For terminal equipment which is directly powered (either wholly or partly) from the mains supply, all tests
shall be carried out with ± 5 % of the rated voltage of that supply. If the equipment is powered by other
means and those means are not suppl
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