ETSI ETS 300 418 ed.1 (1995-11)

SLOVENSKI STANDARD
SIST ETS 300 418:1999
01-november-1999

Poslovne telekomunikacije (BTC) - Digitalni zakupljeni vodi za prenosno hitrost 2

Business TeleCommunications (BTC); 2 048 kbit/s digital unstructured and structured

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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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 Physical characteristics........................................................................................................9

4.1.1 Hardwired connection......................................................................................9

4.1.2 Socket specification.........................................................................................9

4.1.3 Shield connection point .................................................................................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 under failure conditions .................................11

4.2.1.4 Impedance towards ground .................................................12

4.2.1.5 Output return loss ................................................................12

4.2.1.6 Output signal balance..........................................................12

4.2.1.7 Output timing and jitter ........................................................12

4.2.2 Input port .......................................................................................................12

4.2.2.1 Signal coding .......................................................................12

4.2.2.2 Input return loss...................................................................12

4.2.2.3 Input loss tolerance..............................................................12

4.2.2.4 Immunity against reflections ................................................13

4.2.2.5 Tolerable longitudinal voltages ............................................13

4.2.2.6 Impedance towards ground .................................................13

4.2.2.7 Input timing and jitter tolerance ...........................................13

4.3 Safety.................................................................................................................................13

4.3.1 General requirements....................................................................................13

4.3.2 Touch current ................................................................................................14

4.4 Overvoltage protection.......................................................................................................14

4.4.1 Surge simulation, common mode..................................................................14

4.4.2 Surge simulation, transverse mode between transmit and receive pairs......14

4.4.3 Mains simulation, common mode..................................................................14

4.4.4 Mains simulation, transverse mode...............................................................14

4.4.5 Impulse transfer from mains, common mode ...............................................15

4.4.6 Impulse transfer from mains, transverse mode ............................................15

4.4.7 Conversion of common mode to transverse mode .......................................15

4.4.8 Impulse transfer from auxiliary interface .......................................................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.................................................................................................................................... 16

A.2.1 Signal coding at output port............................................................................................... 16

A.2.2 Waveform shape at output port......................................................................................... 17

A.2.3 Return loss at input port .................................................................................................... 18

A.2.4 Input loss tolerance and immunity against reflections....................................................... 19

A.2.5 Tolerable longitudinal voltage and HDB3 input coding...................................................... 20

A.2.6 Impedance towards ground............................................................................................... 21

A.2.7 Output timing under failure conditions............................................................................... 22

Annex B (normative): Definition of HDB3 code..................................................................................... 23

B.1 General............................................................................................................................................. 23

B.2 Definition........................................................................................................................................... 23

Annex C (informative): Bibliography ....................................................................................................... 24

History......................................................................................................................................................... 25

TeleCommunications (BTC) Technical Committee of the European Telecommunications Standards

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

In the case of the unstructured leased line, this ETS is intended to supersede ETS 300 246.

- ETS 300 247: "Open Network Provision (ONP) technical requirements; 2 048 kbit/s digital

- ETS 300 248: "Open Network Provision (ONP) technical requirements; 2 048 kbit/s digital

- ETS 300 419: "Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased line

- ETS 300 420: "Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased line

This ETS is based on information from ITU-T Recommendations and ETSI publications and the relevant

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

The consequence of the Directive is that telecommunications organizations within the EU shall make

available a set of leased lines 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.

ETS 300 166 and CCITT Recommendation G.703 are used as the basis for the network interface

This ETS specifies the technical requirements and test principles for the network interface presentations

- the 2 048 kbit/s digital structured leased line with an information transfer rate of 1 984 kbit/s without

A connection is presented via interfaces at Network Termination Points (NTP). This ETS defines the

network interface as presented by the leased line provider and should be used in conjunction with the

appropriate companion standard, ETS 300 247 or ETS 300 419, specifying the connection characteristics

between the NTPs of the leased line. This ETS and the appropriate connection characteristics standard

This ETS is applicable to leased lines, including part time leased lines, for which the establishment or

This ETS covers the physical, mechanical and electrical characteristics of the network interface and

specifies the conformance tests for equipment of the kind that provides the interface presentation. 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. There is no requirement for each leased line to be tested in accordance

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

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

leased lines: The telecommunications facilities provided by a public telecommunications network that

provide defined transmission characteristics between NTPs and that do not include switching functions

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

PRBS(2 -1): A Pseudo Random Bit Sequence (PRBS) (as defined in subclause 2.1 of CCITT

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

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

RX RX is a signal input (at either the leased line interface or the test equipment, see

TX TX is a signal output (at either the leased line interface or the test equipment,

- the 2 048 kbit/s digital unstructured leased line (D2048U) which provides a bidirectional

point-to-point digital connection with a usable bit rate of 2 048 kbit/s where timing is not provided

from the network. The provision of circuit timing is the responsibility of the user. No structuring of

the data is provided, or shall be required, by the network and any structuring is the responsibility of

- the 2 048 kbit/s digital structured leased line (D2048S) which provides a bidirectional point-to-point

digital connection with an information transfer rate of 1 984 kbit/s without restriction on binary

content. The frame structure in the 2 048 kbit/s bit stream is defined in ETS 300 419. Any

structuring of the data within the transparent 1 984 kbit/s part of the frame is the responsibility of the

NOTE 2: If equipment providing the interface requires a mains supply, the leased line provider

should bring this to the attention of the user so that the user can provide mains supply

The connection arrangements provided by the leased line interface shall be suitable for hardwired

connection (see subclause 4.1.1); however, with the agreement of the user, an alternative means of

The transmit pair is the output from the network interface. The receive pair is the input to the network

interface, as shown in figure 1. Where the terms "output" and "input" are used without qualification in this

The use on the terminal equipment side of the interface of shielded cables may be necessary to meet

radiation and immunity requirements defined in ElectroMagnetic Compatibility (EMC) standards. Therefore

the NTP is required to provide a point for connection of the shield (see subclause 4.1.3).

Requirement: Where the leased line is being presented as a hardwired connection, the leased line

interface shall provide a means of terminating wire with solid conductors having diameters in the range 0,4

mm to 0,6 mm. The leased line provider shall provide information on the configuration of the means of

Test: There is no test. All subsequent tests are carried out via the specified connection method.

NOTE: The intention is to specify the same socket as is specified for Integrated Services

Digital Network (ISDN) primary rate access; however this approach is not practicable

requirement to use the ISDN primary rate socket may be added to this ETS when such

Requirement: The NTP shall provide a point, or points, to which the shield, or shields, of the cable on the

NOTE: The purpose of these points is to provide a path from the shield to a common

Test: There shall be a visual inspection that a point, or points, for connection of the shield, or shields, is

Requirement: The signal transmitted at the output port shall comply with the High Density Bipolar code of

Requirement: The pulse at the output port shall comply with the requirements given in table 1 and

Requirement: When there is a failure within the network and if a signal is presented at the interface

output (e.g. an Alarm Indication Signal (AIS)), the output timing shall be 2 048 kbit/s ± 50 parts per million

NOTE: AIS is encoded as a continuous stream of binary ONEs. It is used to indicate a loss of

Requirement: The impedance towards ground of the output port shall be greater than 1 000 Ω for

frequencies in the range 10 Hz to 1 MHz when measured with a sinusoidal test voltage of 2 V root mean

square (rms). Ground (in this context) shall be the shield connection point defined in subclause 4.1.3.

NOTE: A requirement for output return loss may be added to this ETS when appropriate

NOTE: The effects of the output signal imbalance are covered under the EMC Directive

NOTE: Output timing requirements and jitter limits for the leased line are specified in the

Requirement: The input port shall correctly decode HDB3 encoded signals without error in accordance

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 2, which is taken from subclause 6.3.3 of CCITT Recommendation G.703.

Requirement: The input port shall correctly decode without errors a 2 048 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

- attenuation that follows a √f law with values throughout the range 0 to 6 dB at 1 024 kHz; and

- characteristic impedance of 120 Ω with a tolerance of ± 20% in the frequency range from 200 kHz

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 6 dB at 1 MHz, no errors

The normal signal shall be a signal encoded according to HDB3, shaped according to the mask of figure 2

The interfering signal shall be the same as the normal signal except that the level shall be attenuated by

18 dB, the bit rate shall be within 2 048 kbit/s ± 50 ppm and the timing shall not be synchronized to the

Requirement: The receiver shall operate without errors with any input signal in the presence of a

longitudinal voltage of magnitude 2 V rms over the frequency range 10 Hz to 30 MHz.

Requirement: The impedance towards ground of the input port shall be greater than 1 000 Ω for

frequencies in the range 10 Hz to 1 MHz when measured with a sinusoidal test voltage of 2 V rms. Ground

(in this context) shall be the shield connection point defined in subclause 4.1.3.

NOTE: Input timing and jitter tolerance of the leased line are specified in the appropriate

The tests associated with the requirements in this subclause are not suitable for use on installed leased

lines. Such tests may be applied to equipment of the kind used to provide the interface.

Requirement: The leased line interface shall comply with the requirements for accessible parts of a

NOTE: Designers should take into account the minimum impedance towards ground specified

This requirement recognizes the fact that the equipment providing the NTP may have a mains electricity

supply interface. If the equipment providing the NTP does not have a mains supply, this requirement is not

For the purpose of the following requirement, the term referred to as I in ETS 300 046-4 [4] shall be

Requirement: The touch current measured across the leased line interface shall not exceed 0,25 mA.

Overvoltage protection shall be tested in accordance with the methods described in ETS 300 046-5 [5] as

detailed below. The tests associated with these requirements are not suitable for use on installed leased

lines. The compliance criteria for the overvoltage protection tests of subclauses 4.4.1 to 4.4.7 shall be:

The leased line interface shall operate properly within the limits of this specification after the test

- reloading of data other than data of a type declared in the operating instructions to be