ETSI TBR 013 ed.1 (1996-01)

SLOVENSKI STANDARD
SIST TBR 013 E1:2004
01-oktober-2004

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

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Whilst every care has been taken in the preparation and publication of this document, errors in content,

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"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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....................................................................................10

4.1.2 Alternative means of connection ...................................................................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 jitter ..........................................................................12

4.2.1.5 Output structure...................................................................13

4.2.2 Input port .......................................................................................................14

4.3 Safety.................................................................................................................................14

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

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

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

4.4.3 Conversion of common mode to transverse mode .......................................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 output port .........................................................................................18

A.2.3 Clock accuracy at the output port ......................................................................................19

A.2.4 Output jitter ........................................................................................................................19

A.2.5 Frame structure .................................................................................................................21

Annex B (normative): Definition of HDB3 code .....................................................................................22

B.1 General..............................................................................................................................................22

B.2 Definition ...........................................................................................................................................22

Annex C (normative): Definition of frame structure ...............................................................................23

C.1 Frame structure ................................................................................................................................ 23

C.2 CRC-4............................................................................................................................................... 23

C.2.1 CRC-4 generation ............................................................................................................. 24

Annex D (normative): TBR Requirements Table (TBR-RT) ................................................................. 25

Annex E (informative): Bibliography ....................................................................................................... 26

History......................................................................................................................................................... 27

This Technical Basis for Regulation (TBR) has been produced by the Business Telecommunications

(BTC) Technical Committee of the European Telecommunications Standards Institute (ETSI).

This TBR results from a mandate from the Commission of the European Community (CEC) to provide

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

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 on public telecommunications networks, and the availability throughout the European Union (EU)

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

available a set of leased lines between points in these countries with specified connection characteristics

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 Technical Basis for Regulations (TBRs) give the

essential requirements under the Second Phase Directive (91/263/EEC) for attachment to the leased

CCITT Recommendations G.703, G.704 and G.706, as qualified by ETS 300 166, are used as the basis

This TBR specifies the attachment requirements and corresponding test principles for a terminal

equipment interface for connection to the Network Termination Points (NTPs) of ONP 2 048 kbit/s digital

structured leased lines (D2048S) using 120 õ interfaces with an information rate of 1 984 kbit/s without

restriction on binary content. A terminal equipment interface that conforms to this TBR will also conform

The term "attachment requirements" in the context of this TBR describes the essential requirements for

access which have to be fulfilled under the Second Phase Directive (91/263/EEC). Conformance to these

This TBR is applicable to all interfaces designed for connection to the ONP 2 048 kbit/s structured leased

line. It covers the essential requirements for the physical and electrical characteristics of the terminal

Customer premises wiring and installation between the terminal equipment and the NTP are outside the

This TBR incorporates by dated and undated reference, provisions from other publications. These

normative references are cited at the appropriate places in the text and the publications are listed

hereafter. For dated references, subsequent amendments to or revisions of any of these publications

apply to this TBR only when incorporated into it by amendment or revision. For undated references the

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

errored Sub-MultiFrame: A Sub-MultiFrame (SMF) where the calculated Cyclic Redundancy Check-4 bit

(CRC-4)1 does not correspond with the CRC-4 contained within the next SMF (see subclause C.2.2).

frame: A sequence of 256 bits of which the first 8 bits define the frame structure (see annex C).

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

multiframe: A sequence of two SMFs containing the multiframe alignment word (see annex C).

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): Pseudo Random Bit Sequence (PRBS) (as defined in subclause 2.1 of CCITT

S bits: Bits 4 to 8 (bits S to S ) in frames not containing the frame alignment signal (see annex C).

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

Sub-Multiframe (SMF): A sequence of 8 frames, each of 256 bits, over which the CRC-4 is calculated

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

The terminal equipment interface is for use with 2 048 kbit/s structured leased lines which provide bi-

directional, point-to-point digital connections with an information transfer rate of 1 984 kbit/s without

restriction on binary content. Any structuring of the data within the transparent 1 984 kbit/s part of the

Justification: Without a connection method defined, it is impossible for the terminal equipment to connect

to the network, therefore this is required for the terminal equipment to interwork with the network

Currently no standardised connector is readily available. Consequently, the only method of connection that

can be specified in this TBR is the use of solid conductors of 0,4 mm to 0,6 mm. This TBR requires the

terminal equipment to be capable of presenting either a point for the attachment of unterminated solid

conductors, or solid conductors themselves (see subclause 4.1.1). It is a requirement that such a

connection method be available to be provided for use with the terminal equipment if necessary.

In order to allow connection to be made using other methods (e.g. connectors), the terminal equipment is

permitted to be supplied with a connection method suitable for use with those methods (see

NOTE 1: The following are examples of arrangements that comply with the requirements. The

list below should not be regarded as an exhaustive list of all permitted arrangements:

f) the arrangement in c) or d) plus one or more cords suitable for connection to the

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

NOTE 2: The use of a shielded cord or cable may be necessary to meet radiation and immunity

a) a set of connection contacts (e.g. an insulation displacement connector or a screw terminal block)

to which solid wire conductors with diameters in the range 0,4 mm to 0,6 mm may be connected; or

b) a wiring arrangement connected by any means to the terminal equipment, with unterminated solid

wire conductors with diameters in the range 0,4 mm to 0,6 mm at the end distant from the terminal

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

Any alternative means of connection may be provided in addition to the connection arrangements under

Justification: The correct signal coding is necessary for the output signals from the terminal equipment to

be received correctly at the input to the NTP, otherwise the leased line will not achieve frame alignment

and possibly send Alarm Indication Signal (AIS) forward within the network; therefore a requirement on

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

Justification: The correct waveform shape serves to limit the voltages to line preventing harm to the

network (article 4d). It is also necessary for the output signals from the terminal equipment to be received

correctly at the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly

send AIS forward within the network; therefore a requirement on the waveform shape should be included

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

Justification: A certain level of timing accuracy is necessary for the bit stream to be received correctly at

the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly send AIS

forward within the network; therefore a requirement on output timing should be included for interworking

with the network (article 4f). An output clock accuracy of 2 048 kbit/s ± 50 parts per million (ppm) is

sufficient for the input signal to be received correctly although this may result in a number of slips.

Requirement: In the absence of any external reference signal timing, the output signal shall have a bit

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). It is necessary for the output signals from the

terminal equipment to be received correctly at the input to the NTP, otherwise the leased line will not

achieve frame alignment and possibly send AIS forward within the network; therefore a requirement on

Requirement: The peak-to-peak output jitter shall not exceed the limits of table 2 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 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

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

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 table 3 and

NOTE: A separate requirement for output jitter at frequencies below 40 Hz is not required

because the measurement filter with a first order lower cut-off will allow the jitter to

below 40 Hz. Where timing is taken from the leased line, the test uses input jitter

Justification: It is necessary for the output signals from the terminal equipment to be received correctly at

the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly send AIS

forward within the network; therefore a requirement on the output structure should be included for

The bit stream transmitted at the output of the terminal equipment shall be structured as

It is necessary for the CRC-4 from the terminal equipment to be correct at the output from

the terminal equipment, otherwise the occurrence of · 915 errored SMFs will cause the leased line to

believe that frame alignment is lost and possibly send AIS forward within the network; therefore a

requirement on the CRC-4 should be included for interworking with the network (article 4f).

The CRC-4 bits transmitted at the output of the terminal equipment shall be as defined in

tables C.1 and C.2 and subclause C.2.1 of annex C and shall correspond to the data transmitted at the

Justification: The E-bits received at the NTP indicate errors that have occurred in the bit stream from the

NTP to the terminal equipment. The connection standard for the D2048S leased line (ETS 300 419) does

not require the network to take any action as a result of receiving an indication of errors, therefore, there

should be no requirement on the E-bits at the output from the terminal equipment.

Justification: Although the connection standard for the D2048S leased line (ETS 300 419) does not

require the network to take any action as a result of receiving an alarm indication (A = 1), there are many

networks that will respond, either at the NTP or within the network, to an input signal indicating an alarm

indication. Therefore, to ensure no harm to the network (article 4d) and correct interworking, i.e. continued

transmission, (article 4f) the terminal equipment should ensure that the alarm indication is not sent when

NOTE: This requirement does not impose any essential requirement on the input port of the

terminal equipment, or any requirement to monitor the input bit stream for loss of

Requirement: When the input signal to the terminal equipment comprises continuous error free frames

and multiframes, structured according to annex C, with the calculated CRC-4 corresponding to the data in

the previous SMF, the A-bit at the output of the terminal equipment shall be set to binary ZERO.

Justification: Bits S to S are reserved for the use of the leased line operator and these are not

necessarily transmitted transparently across the connection. Therefore there is no harm to the network

(article 4d) or failure to interwork (article 4f) caused by any potential setting of these bits.

There are no requirements on the input port under this TBR beyond those imposed in subclauses 4.4.1 to

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 is protected against both

short circuit and open circuit. Therefore there are no requirements within the base st