SIST ETS 300 290 E1:2004

• Abstract:

  Specification of the terminal equipment side of the interface and test procedures for compliance.

• Status: Published
• Publication Date: 30-Sep-2004
• ICS: 33.040.50 - Lines, connections and circuits
• Technical Committee: BTC - Business telecommunications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-2004
• Due Date: 01-Oct-2004
• Completion Date: 01-Oct-2004
• Mandate: T-147-2
• Ref Project: ETSI ETS 300 290 ed.1 (1994-01) - Business TeleCommunications (BTC); 64 kbit/s digital unrestricted leased line with octet integrity (D64U); Terminal equipment interface

SIST ETS 300 290 E1:2004 is the Slovenian adoption of ETS 300 290 Edition 1 from ETSI. It specifies the terminal equipment interface for Business TeleCommunications (BTC) 64 kbit/s digital unrestricted leased lines with octet integrity (D64U), including the physical and electrical interface characteristics and the test principles used to verify them.

It is intended for terminal equipment that connects to ONP leased lines, so designers and test labs can check whether a device will interwork with the network termination point (NTP).

What does SIST ETS 300 290 E1:2004 specify?

SIST ETS 300 290 E1:2004 specifies the terminal equipment side of the interface for ONP 64 kbit/s digital unrestricted leased lines with octet integrity. It covers the interface itself and the tests used to demonstrate compliance.

The scope is limited to the terminal equipment interface and excludes customer premises wiring and installation between the terminal equipment and the NTP. The document also notes that other ETSs may apply to equipment that carries a particular service, complex apparatus, or apparatus in private networks.

The standard is organized into clauses on scope, normative references, definitions, symbols and abbreviations, and requirements. It also includes three annexes:

Annex	What it covers
Annex A	Normative test methods
Annex B	Normative code conversion rules
Annex C	Informative bibliography

What are the key requirements of SIST ETS 300 290 E1:2004?

SIST ETS 300 290 E1:2004 defines the connector, signal coding, timing, jitter, electrical protection and safety behavior that terminal equipment must meet to be compatible with the leased line. These are the points that matter most in design, integration and conformance testing.

Physical interface and coding

• Clause 5.1 requires an 8-contact plug of the type specified in ISO/IEC 10173, with the receive pair on contacts 1 and 2, the transmit pair on 4 and 5, shield reference on 3 and 6, and contacts 7 and 8 unused. In practice, this fixes the pinout that a supplier or installer must use.
• Clause 5.2.1.1 and Annex B define the code conversion rules for the codirectional 64 kbit/s interface. This tells implementers how each bit is represented on the line and how octet timing is marked.
• Clause 5.2.1.2 requires the output waveform to match the G.703 pulse masks at a 120 Ω load. This is what a test lab checks when it measures pulse shape, amplitude and symmetry.

Timing, jitter and line behavior

• Clause 5.2.1.3 requires the terminal equipment to synchronize output timing either to received timing or to an external reference. That matters when the equipment must follow the network clock or operate plesiochronously.
• Clause 5.2.1.4 limits output jitter, with different limits depending on the measurement filter bandwidth. This is important for equipment that regenerates or passes timing, because excessive jitter can disturb downstream devices.
• Clause 5.2.2.2 to 5.2.2.6 require the input port to work over 64 kbit/s ± 100 ppm, tolerate the specified input jitter, accept the stated return loss, loss tolerance and reflections, and decode the coded signal without errors. In practice, these clauses describe the line conditions under which the equipment must still operate correctly.

Grounding, safety and protection

• Clauses 5.2.1.6, 5.2.1.7, 5.2.2.7 and 5.2.2.8 set limits for impedance towards ground and longitudinal conversion loss when the equipment has a ground. These requirements help control transformerless implementations and reduce unwanted coupling from longitudinal disturbance into the signal path.
• Clause 5.3 requires the interface to comply with accessible parts of a Safety Extra-Low Voltage (SELV) circuit, and clause 5.3.2 limits touch current across the interface to 0.25 mA where mains supply is present. This is the basic user-safety part of the standard.
• Clause 5.4 sets overvoltage protection behavior for common-mode and transverse-mode surges, mains-simulation tests, impulse transfer from mains, and conversion of common mode to transverse mode. The compliance criteria require the equipment to keep working within the specification after the tests without reset, hardware replacement, or reloading protected data.
• Clause 5.5 states that there are no EMC requirements under this ETS. EMC obligations are handled elsewhere.

What terms does SIST ETS 300 290 E1:2004 define?

• Leased lines - telecommunications facilities on a public network that provide defined transmission characteristics between NTPs without user-controlled switching.
• Network Termination Point (NTP) - the physical connections and access specifications that form part of the public network and provide access to it.
• Terminal Equipment (TE) - equipment intended to connect to the public telecommunications network to send, process or receive information.
• Safety Extra-Low Voltage (SELV) circuit - a secondary circuit designed so accessible voltages stay within a safe value under normal and single-fault conditions.
• D64U - the 64 kbit/s digital unrestricted ONP leased line with octet integrity that this interface serves.
• Pseudo Random Bit Sequence (PRBS(2 -1)) - a test pattern used in Annex A to exercise coding, reflections and jitter behavior.
• Unit Interval (UI) - one bit-time interval, used to express jitter and pulse timing.

Who uses SIST ETS 300 290 E1:2004?

SIST ETS 300 290 E1:2004 is used by terminal equipment manufacturers, interface designers, test laboratories, and conformity assessment teams. It is also useful to quality managers and buyers who need to specify a compatible 64 kbit/s leased-line interface.

In practice, they use it to choose the connector, design the transmit and receive port behavior, set up compliance testing, and check safety and surge performance. Network and service engineers use it when connecting equipment to ONP leased lines or when verifying that a product can interoperate with the leased-line interface.

Which standards are used with SIST ETS 300 290 E1:2004?

Standard	What it contributes
CCITT Recommendation G.703	Physical and electrical characteristics for the digital interface, including pulse shape and return loss basis
CCITT Recommendation O.152	PRBS definition and error-performance context for 64 kbit/s paths
EN 60950	Safety requirements for information technology equipment
ETS 300 046-2	Test method basis for touch current
ETS 300 046-3	Test methods for overvoltage protection and surge behavior
ISO/IEC 10173	8-contact connector type used at the interface
ETS 300 288	Related BTC standard for network interface presentation
ETS 300 289	Related BTC standard for connection characteristics
TBR 14	Regulatory subset covering essential requirements for attachment under the Second Phase Directive
ETS 300 166	Basis for the terminal interface and related physical/electrical characteristics

What does the SIST ETS 300 290 E1:2004 document contain?

The document contains the full requirement set for the interface, plus test methods and code conversion rules. Annex A gives the test setups and procedures for signal coding, waveform shape, input coding, loss tolerance, immunity against reflections, return loss, jitter, longitudinal conversion loss and impedance towards ground.

The main clauses include tables and figures for contact assignment, output pulse masks, jitter limits, return loss limits, surge and mains-simulation behavior, and longitudinal conversion loss limits. Annex B provides the step-by-step bit-to-line coding rule and a figure showing how octet timing is marked.

SLOVENSKI STANDARD
01-oktober-2004
Poslovne telekomunikacije (BTC) - Digitalni zakupljeni vodi za prenosno hitrost 64
kbit/s brez omejitev za prenašane signale in z ohranjanjem oktetov (D64U) -
Vmesnik terminalske opreme
Business TeleCommunications (BTC); 64 kbit/s digital unrestricted leased line with octet
integrity (D64U); Terminal equipment interface
Ta slovenski standard je istoveten z: ETS 300 290 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 300 290
TELECOMMUNICATION January 1994
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02026
ICS: 33.020, 33.040.40
ONP, leased line
Key words:
Business TeleCommunications (BTC);
64 kbit/s digital unrestricted leased line with octet integrity
(D64U)
Terminal equipment interface
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 - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
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 1994. All rights reserved.
New presentation - see History box

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ETS 300 290: January 1994
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 Standards Approval Dept." at the address shown on the title page.

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ETS 300 290: January 1994
Contents
Foreword.5
Introduction .5
1 Scope .7
2 Normative references .7
3 Definitions. 7
4 Symbols and abbreviations.8
5 Requirements.8
5.1 Physical characteristics .9
5.2 Electrical characteristics .9
5.2.1 Output port. 9
5.2.1.1 Signal coding.9
5.2.1.2 Waveform shape . 10
5.2.1.3 Output timing. 11
5.2.1.4 Output jitter. 11
5.2.1.5 Output return loss. 12
5.2.1.6 Impedance towards ground. 12
5.2.1.7 Longitudinal conversion loss. 12
5.2.2 Input port. 13
5.2.2.1 Signal coding. 13
5.2.2.2 Input clock tolerance. 13
5.2.2.3 Input jitter tolerance . 13
5.2.2.4 Input return loss. 14
5.2.2.5 Input loss tolerance. 14
5.2.2.6 Immunity against reflections. 14
5.2.2.7 Impedance towards ground. 15
5.2.2.8 Longitudinal conversion loss. 15
5.3 Safety. 15
5.3.1 General requirements . 15
5.3.2 Touch current. 15
5.4 Overvoltage protection . 16
5.4.1 Surge simulation, common mode . 16
5.4.2 Surge simulation, transverse mode between transmit and receive pairs. 16
5.4.3 Mains simulation, common mode . 16
5.4.4 Mains simulation, transverse mode . 16
5.4.5 Impulse transfer from mains, common mode . 16
5.4.6 Impulse transfer from mains, transverse mode . 17
5.4.7 Conversion of common mode to transverse mode. 17
5.5 Electro-magnetic compatibility. 17
Annex A (normative): Test methods . 18
A.1 General . 18
A.1.1 Additional information to support the test. 18
A.1.2 Equipment connection. 18
A.2 Test methods. 19
A.2.1 Signal coding at output port. 19
A.2.2 Waveform shape at output port . 19

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ETS 300 290: January 1994
A.2.3 Input coding, loss tolerance and immunity against reflections .20
A.2.4 Return loss at input port.21
A.2.5 Input and output jitter. 21
A.2.6 Longitudinal conversion loss .23
A.2.7 Impedance towards ground. 24
Annex B (normative): Code conversion rules . 25
Annex C (informative): Bibliography.26
History .27

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ETS 300 290: January 1994
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 results from a mandate from the Commission of the European Community (CEC) to provide
harmonised 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 300 288: "Business TeleCommunications (BTC); 64 kbit/s digital unrestricted leased line with
octet integrity (D64U), Network interface presentation";
ETS 300 289: "Business TeleCommunications (BTC); 64 kbit/s digital unrestricted leased line with
octet integrity (D64U), Connection characteristics".
This ETS is based on information from CCITT 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 harmonisation of conditions for open and efficient access to, and use of, the leased lines
provided over public telecommunications networks and the availability throughout the Community (EEC) of
a minimum set of leased lines with harmonised technical characteristics.
The consequence of the Directive is that Telecommunications Organisations within the EEC shall make
available a set of leased lines between points in these countries with specified connection characteristics
and specified interfaces.
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.
This standard, which is an ETS, belongs to the first category. The TBR (TBR 14) is a subset of this
corresponding ETS.
ETS 300 166 and CCITT Recommendation G.703 are used as the basis for the terminal interface.

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ETS 300 290: January 1994
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ETS 300 290: January 1994
1 Scope
This ETS specifies the full physical and electrical characteristics and corresponding test principles for a
terminal equipment interface for connection to the network termination points of ONP 64 kbit/s digital
unrestricted leased lines with octet integrity.
This ETS is not written for regulatory purposes. A separate TBR (TBR 14) covers the essential
requirements for attachment under the Second Phase Directive (91/263/EEC).
This ETS is to ensure that the interface of the terminal equipment is compatible with the ONP 64 kbit/s
digital unrestricted leased line with octet integrity. It 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 in it by amendment or revision. For undated references the latest edition of the
publication referred to applies.
[1] CCITT Recommendation G.703 (1991): "Physical/electrical characteristics of
hierarchical digital interfaces".
[2] CCITT Recommendation O.152 (1988): "Error performance measuring
equipment for 64 kbit/s paths".
[3] EN 60950 (1992): "Safety of information technology equipment including
electrical business equipment".
[4] ETS 300 046-2 (1992): "Integrated Services Digital Network (ISDN); Primary
rate access - safety and protection, Part 2: Interface Ia - safety".
[5] ETS 300 046-3 (1992): "Integrated Services Digital Network (ISDN); Primary
rate access - safety and protection, Part 3: Interface Ia - protection".
[6] ISO/IEC 10173 (1991): "Information technology - Integrated Services Digital
Network (ISDN) primary access connector at reference points S and T".
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 C. In some cases the same publication may have been referenced in both a
normative and an informative manner.
3 Definitions
For the purposes of this ETS, the following definitions apply:
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).

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ETS 300 290: January 1994
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.
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 [3]).
Terminal Equipment (TE): equipment intended to be connected to the public telecommunications network,
i.e.:
a) to be connected directly to the termination of a public telecommunication network; or,
b) 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.
4 Symbols and abbreviations
For the purposes of this ETS, the following abbreviations apply:
D64U 64 kbit/s digital unrestricted ONP leased line with octet integrity
dc direct current
EMC Electro-Magnetic Compatibility
NTP Network Termination Point
ONP Open Network Provision
ppm parts per million
PRBS(2 -1) Pseudo Random Bit Sequence (as defined in § 2.1 of CCITT Recommendation
O.152 [2])
rms root mean square
RX Receive (a signal input at either the leased line interface or the test equipment,
see figure 1)
SELV Safety Extra-Low Voltage
TE Terminal Equipment
TX Transmit (a signal output at either the leased line interface or the test equipment,
see figure 1)
UI Unit Interval
5 Requirements
The terminal equipment interface is for use with 64 kbit/s unrestricted leased lines with octet integrity,
which provide bidirectional, point-to-point digital connections with a usable bit rate of 64 kbit/s where the
leased line output timing is provided from the network. The interface timing arrangements are codirectional.

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ETS 300 290: January 1994
5.1 Physical characteristics
Requirement: The terminal equipment shall provide an 8-contact plug of the type specified in
ISO/IEC 10173 [6] with contact assignments as specified in table 1. In addition, the terminal equipment
may provide an alternative method of connection.
NOTE 1: The use of a shielded cord or cable may be necessary to meet radiation and immunity
requirements defined in Electro-Magnetic Compatibility (EMC) standards. The common
reference point does not necessarily need to be earth.
NOTE 2: The alternative connection method is primarily for the purpose of permitting hardwired
presentations of the leased line using insulation displacement terminals and wire with
solid conductors having diameters in the range from 0,4 to 0,6 mm.
Table 1: Contact assignment
Contact Terminal interface
1 & 2 Receive pair
3 Shield reference point (if provided)
4 & 5 Transmit pair
6 Shield reference point (if provided)
7 Unused
8 Unused
NOTE 1: 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 2: For connection of the shield, or shields, to the common reference point at the NTP contacts
3 and 6 shall be used.
�˝˝˝˝˝˝˝˝˝˝˝˝» OUTPUT        INPUT �˝˝˝˝˝˝˝˝˝˝˝˝»
”     TX ˙˜˜˜˜˜˜˜˜˜˜˜˜˜>˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶ RX     ”
” NETWORK  ˙˜˜˜˜˜˜˜˜˜˜˜˜˜>˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶ TERMINAL ”
” INTERFACE ”              ” EQUIPMENT ”
”      ˙˜˜˜˜˜˜˜˜˜˜˜˜˜<˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶      ”
”     RX ˙˜˜˜˜˜˜˜˜˜˜˜˜˜<˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶ TX     ”
¨˝˝˝˝˝˝˝˝˝˝˝˝… INPUT        OUTPUT ¨˝˝˝˝˝˝˝˝˝˝˝˝…
Figure 1
Test: There shall be a visual inspection that the plug is of the correct type. The contact assignments are
tested indirectly through the tests in Annex A.
5.2 Electrical characteristics
5.2.1 Output port
5.2.1.1 Signal coding
Requirement: The signal transmitted at the output port shall comply with the encoding rules given in
Annex B.
Test: The test shall be conducted according to Annex A, subclause A.2.1.

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ETS 300 290: January 1994
5.2.1.2 Waveform shape
Requirement: The pulse at the output port shall comply with the requirements given in table 2 and
figures 2 and 3, taken from CCITT Recommendation G.703 [1].
Table 2: Waveform shape at output port
Pulse shape All pulses of a valid signal shall conform
(nominally rectangular) with the masks (see figures 2 and 3)
irrespective of the polarity.
Test load impedance 120 Ω non-reactive
Nominal peak voltage V of a mark (pulse) 1 V
Peak voltage of a space (no pulse) 0 ± 0,1 V
Nominal pulse width 3,9 μs for a single pulse
7,8 μs for a double pulse
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 0,95 to 1,05
pulses at the nominal half amplitude
Figure 2: Pulse mask for single pulse

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ETS 300 290: January 1994
Figure 3: Pulse mask for double pulse
Test: The test shall be according to Annex A, subclause A.2.2.
5.2.1.3 Output timing
Requirement: The terminal equipment shall be capable of:
a) synchronizing the output timing to the timing received at the receive side of the interface; or
b) synchronizing the output timing to an external reference (plesiochronous working).
Test: The test for the synchronisation of the output timing is covered by the test of Annex A,
subclause A.2.5.
5.2.1.4 Output jitter
This requirement applies when the terminal equipment is producing the timing from an internal clock source
or when the terminal equipment is deriving the output timing from an external source (including derivation
from the input signal).
1)
Requirement: The peak-to-peak output jitter shall not exceed the limits of table 3 when measured with
first order linear filters with the defined cut-off frequencies. For the purpose of testing, any signal input

1)
This requirement differs from that in ETR 005 which defines maximum output jitter in terms of intrinsic jitter and a jitter transfer
characteristic. Intrinsic jitter is limited to 0,05 UI from 20 Hz to 20 kHz. The jitter transfer characteristic is limited to 0,5 dB from
20 Hz to 3 kHz, decreasing to -16 dB at 20 kHz.

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ETS 300 290: January 1994
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 5.
Table 3: Maximum output jitter
Measurement filter bandwidth Output jitter
Lower cut-off Upper cut-off UI peak-to-peak
(high pass) (low pass) (maximum)
20 Hz 20 kHz 0,25 UI
3 kHz 20 kHz 0,05 UI
Test: The test shall be conducted according to Annex A, subclause A.2.5.
5.2.1.5 Output return loss
There are no requirements for output return loss under this ETS.
NOTE: A requirement for output return loss may be added to this ETS when appropriate
specifications become available.
5.2.1.6 Impedance towards ground
Requirement: Where the terminal equipment has a ground, the impedance towards ground of the output
port shall be greater than 1 000 Ω for frequencies in the range from 10 Hz to 1 MHz when measured with a
sinusoidal test voltage of 2 V rms. For the purpose of this requirement, ground shall be the terminal
equipment common reference point or test reference point.
NOTE: This requirement is included to allow transformerless implementations.
Test: The test shall be according to Annex A, subclause A.2.7.
5.2.1.7 Longitudinal conversion loss
Requirement: Where the terminal equipment has a ground, the longitudinal conversion loss of the terminal
output port shall be greater than or equal to the figures given in table 4. For the purpose of this
requirement, ground shall be the terminal equipment common reference point or test reference point.
NOTE: This requirement is included to allow transformerless implementations.
Table 4: Output port longitudinal conversion loss
Frequency Longitudinal conversion loss
3,4 kHz 40 dB
3,4 kHz to 34 kHz decreasing 20 dB/decade from 40 dB to 20 dB
34 kHz to 256 kHz 20 dB
Test: The test shall be conducted according to Annex A, subclause A.2.6.

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ETS 300 290: January 1994
5.2.2 Input port
5.2.2.1 Signal coding
Requirement: The input port shall decode without errors signals encoded in accordance with encoding
rules of Annex B.
NOTE: When there is no input signal or octet timing is not present at the leased line distant
input or when there is a failure in the leased line connection, the octet timing at the
leased line output will not be meaningful.
Test: The test shall be according to Annex A, subclause A.2.3.
5.2.2.2 Input clock tolerance
Requirement: The terminal equipment shall operate without errors with signals encoded as in Annex B
over the frequency range 64 kbit/s ± 100 ppm.
Test: By declaration.
5.2.2.3 Input jitter tolerance
2)
Requirement : The terminal equipment shall function as specified without errors with the maximum
sinusoidal input jitter as shown in figure 4 and table 5.
peak-to-peak jitterpeak-to-peak jitter
A1A1
A2A2
f1f1 f2f2 f3f3 f4f4
jitter frequencyjitter frequency
Figure 4: Input jitter tolerance

2)
This requirement differs from that in ETR 005 which specifies an input jitter tolerance below 20 Hz (i.e. wander tolerance). The
-5
requirement is for 1,15 UI at 1,2 x 10 Hz, decreasing to 0,25 UI at 20 Hz.

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ETS 300 290: January 1994
Table 5: Input jitter tolerance
Peak-to-peak amplitude (UI) Frequency (Hz)
A1 A2 f1 f2 f3 f4
0,25 0,05 20 600 3 000 20 000
NOTE: 0,25 UI = 3,9 μs; 0,05 UI = 0,78 μs.
Test: The test shall be according to Annex A, subclause A.2.5.
5.2.2.4 Input return loss
Requirement: The input return loss with respect to 120 Ω at the interface shall be greater than or equal to
the values given in table 6 taken from CCITT Recommendation G.703 [1].
Table 6: Input port minimum return loss
Frequency range Return loss
4 kHz to 13 kHz 12 dB
13 kHz to 256 kHz 18 dB
256 kHz to 384 kHz 14 dB
Test: The test shall be according to Annex A, subclause A.2.4.
5.2.2.5 Input loss tolerance
Requirement: The input port shall correctly interpret a 64 kbit/s signal as defined in subclauses 5.2.1.1
and 5.2.1.2 above but modified by an intervening pair with the following characteristics:
a) attenuation that follows a ´f law with values throughout the range from 0 dB to 3 dB at 128 kHz; and
b) characteristic impedance of 120 Ω with a tolerance of ± 20 % in the frequency range from 200 kHz
to 1 MHz, and ± 10 % at 1 MHz.
Test: The test shall be according to Annex A, subclause A.2.3.
5.2.2.6 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 from 0 dB to 3 dB at 128 kHz, no
errors shall result due to the interfering signal.
The normal signal shall be a signal encoded according to Annex B, shaped according to the masks of
figures 2 and 3, with a binary content in accordance with a Pseudo Random Bit Sequence as defined in
§ 2.1 of CCITT Recommendation O.152 [2] (PRBS(211-1)).
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 64 kbit/s ± 100 ppm, and the timing shall not be synchronised to the
normal signal.
Test: The test shall be according to Annex A, subclause A.2.3.

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ETS 300 290: January 1994
5.2.2.7 Impedance towards ground
Requirement: Where the terminal equipment has a ground, the impedance towards ground of the input
port shall be greater than 1 000 Ω for frequencies in the range from 10 Hz to 1 MHz when measured with a
sinusoidal test voltage of 2 V rms. For the purpose of this requirement, ground shall be the terminal
equipment common r
...