1、ETS 300 246 October 1993 Source: ETSI TC-BT Reference: DEBT-0201 8 UDC: 621.39 Key words: ONP, leased lines, 0204811 Business Telecommunications (BT); Open Network Provision (ONP) technical requirements; 2 048 kbit/s digital unstructured leased line (D2048U) Network interface presentation ETS I Euro
2、pean Telecommunications Standards Institute ETSI Secretariat Postal address: 06921 Sophia Antipolis Cedex - FRANCE Office address: Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE Tel.: + 33 92 94 42 O0 - Fax: + 33 93 65 47 16 European Telecommunications Standards Institute 1 993. All right
3、s reserved. No part may be reproduced except as authorised by written permission. The Copyright and the foregoing restriction on reproduction extend to all media in which the information may be embodied. Page 2 ETS 300 246:1993 Whilst every care has been taken in the preparation and publication of t
4、his 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. I 3404583 0085673 T55 = Page 3 ETS 300 246:1993 Contents Foreword . 5 Introduction
5、 5 1 Scope . 7 2 Normative references 7 3 Definitions . 7 4 Symbols and abbreviations . 8 5.2.2 5 Requirements . 9 5.1 Physical characteristics . 9 5.1.2 Hardwired connection 10 5.2 Electrical characteristics 10 5.2.1 Output port 10 5.2.1.1 Signal coding . 10 5.2.1.2 Waveform shape 10 5.2.1 -3 Outpu
6、t timing under failure conditions . 11 5.2.1.4 Impedance towards ground 11 5.2.1.5 Output return loss 11 5.2.1.6 Output signal balance . 12 input port . 12 5.2.2.1 Signai coding . 12 5.2.2.2 Input return loss . 12 5.2.2.3 input loss tolerance 12 5.2.2.4 Immunity against reflections 12 5.2.2.5 Tolera
7、ble l0ngitUdinal voltages . 13 5.2.2.6 Impedance towards ground 13 5.2.2.7 5.1.1 Connector specification 9 Input timing and jitter tolerance 13 5.3 Safety 13 5.3.1 General requirements . 13 5.3.2 Touch current . 13 5.4 Overvoltage protection 13 5.4.1 Surge simulation, common mode . 14 5.4.2 Surge si
8、mulation, transverse mode between transmit and receive pairs 14 5.4.3 Mains simulation, common mode . 14 5.4.4 Mains simulation, transverse mode 14 5.4.5 impulse transfer from mains, common mode . 14 5.4.6 Impulse transfer from mains, transverse mode . 14 5.4.7 Conversion of common mode to transvers
9、e mode 15 5.5 Electro-magnetic compatibility 15 Annex A (normative): Test methods 16 A.l General . 16 A . 1 “1 A . 1 . 2 Additional information to support the test 16 Equipment connection . 16 A.2 Test methods . 16 Signal Coding at output port 16 A.2.1 B 3404583 0085674 771 Page 4 ETS 300 246:1993 A
10、.2.2 A.2.3 A.2.4 A.2.5 A.2.6 A.2.7 Waveform shape at output port 17 Return loss at input port 18 Input loss tolerance and immunity against reflections . 18 Tolerable longitudinai voltage and HDB3 input coding 19 Output timing under failure conditions . 21 Impedance towards ground 20 Annex B (normati
11、ve): Definition of HDB3 code . 22 B.l General 22 B.2 Definition . 22 Annex C (informative): Bibliography 23 History . 24 IC3 3404583 0085b5 828 Page 5 ETS 300 246:1993 Foreword This European Telecommunication Standard (ETSI has been produced by the Business Telecommunications (BT) Technical Committe
12、e of the European Telecommunications Standards Institute (ETSI). This ETC 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 stand
13、ards directly related to this ETC: ETS 300 247: “Open Network Provision (ONP) technical requirements; 2 048 kbit/s digital unstructured leased line (D2048U), Connection characteristics“; ETS 300 248: “Open Network Provision (ONP) technical requirements; 2 048 kbit/s digital unstructured leased line
14、(D2048U), Terminal equipment interface“. 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), conce
15、rns 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 Community (EEC) of a minimum set of leased lines with harmonised technical characteristics. The consequence of the Dir
16、ective is that Telecornmunications Organisations within the EEC 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
17、leased lines will be required to fulfil certain essential requirements. ETC 300 166 and CCITT Recommendation G.703 are used as the basis for the interface presentation requirements. I 3404583 0085b76 764 = Page 7 ETS 300 246:1993 1 Scope This ETS specifies the technical requirements and test princip
18、les for the network interface presentations of ONP 2 048 kbit/s digital unstructured leased lines using 120 R interfaces. A connection is presented via interfaces at Network Termination Points (NTP). This ETS defines the network interface presented by the leased line provider and should be used in c
19、onjunction with the companion standard, ETC 300 247 specifying the connection characteristics between the NTPs of the leased line. Together, these documents describe the service offered. This ETS is applicable to leased lines, including part time leased lines, for which the establishment or release
20、do not require any protocol exchange or other intervention at the NTP. 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
21、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 c
22、oncerning testing. There is no requirement for each leased line to be tested in accordance with this ETS before it is brought into, or returned into, service. 2 Normative references This ETS incorporates by dated or undated reference, provisions from other publications. These normative references ar
23、e 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
24、publication referred to applies. i1 1 21 i31 i41 i51 i 61 NOTE: CCITT Recommendation G.703 (1 991 i: “Physical/electrical characteristics of hierarchical digital interfaces“. CCITT Recommendation O. 1 51 (1 988): “Error performance measuring equipment for digital systems at the primary rate and abov
25、e“. EN 60950 (1 992): “Safety of information technology equipment including electrical business equipment“. ETS 300 046-4 (1 992): “Integrated Services Digital Network (ISDN); Primary rate access - safety and protection, Part 4: Interface ib - safety“. ETC 300 046-5 (1 992): “Integrated Services Dig
26、ital Network (ISDN); Primary rate access - safety and protection, Part 5: Interface lb - p rot ec t i on “ . ISOAEC 1 O1 73 (1 991 1: “Information technology - Integrated Services Digital Network (ISDN) primary access connector at reference points S and T“. This ETC also contains a number of informa
27、tive 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 no
28、rmative 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 Previous page is blank I 3.33 0085677 bTO Page 8 ETS 300 246: 1993 that provide defined tran
29、smission 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 telecommuni
30、cations 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, or betw
31、een one accessible part and the equipment protective earthing terminal for a class I equipment, does not exceed a safe value (subclause 1.2.8.5 of EN 60950 131). Terminal Equipment (TE): equipment intended to be connected to the public telecommunications network, .e.: a) to be connected directly to
32、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
33、purposes of this ETS, the following abbreviations apply: AIS Alarm Indication Signal D2048U 2 048 kbit/s digital unstructured ONP leased line DC Direct Current EMC Electro-Magnetic Compatibility HDB3 High Density Bipolar code of order 3 (see Annex BI ONP Open Network Provision NTP Network Terminatio
34、n Point PPm parts per million PRBS(215-1) Pseudo Random Bit Sequence (as defined in 5 2.1 of CCITT Recommendation O. 1 5 1 21) rms root mean square RX Receive (a signal input at either the leased line interface or the test equipment) SELV Safety Extra-Low Voltage TE TX Terminal Equipment Transmit (a
35、 signal output at either the leased line interface or the test equipment) E3 3q04583 0085678 537 I Contact Page 9 ETS 300 246:1993 Network interface 5 Requirements . The 2 048 kbit/s unstructured leased line provides a bidirectional point-to-point digital leased line with a usable bit rate of 2 048
36、kbitls 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 by the network and anv structuring is the responsibility of the user. The interface is not designed to provide power feeding capabilities to
37、 the attached terminal equiument. NOTE: 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 back-up facilities, if required. 5.1 Physical characteristics The physical connectio
38、n arrangements shall be by a socket; however at the request of the user, and with agreement of the leased line provider, an alternative means of connection may be provided, which shall consist of a hardwired connection using insulation displacement connectors. The use on the terminal equipment side
39、of the interface of shielded cables may be necessary to meet radiation and immunity requirements defined in Electro-Magnetic Compatibility (EMC) standards. Therefore, the NTP shall provide a point, or points, to which the shield, or shields, of the cable on the terminal side of the interface can be
40、connected. NOTE: The purpose of these points is to provide a path from shield to a common reference. The common reference point does not necessarily have to be earthed. 5.1 .I Connector specification Requirement: Where a connector is specified as the means of termination of the leased line, the netw
41、ork interface shall provide an 8-contact socket of the type specified in ISO/IEC 10173 i61 and with contact assignments as specified in table 1. 1 where O = space and 1 = mark input to the HDB3 encoder (see NOTE). The output bit stream for a test period of sufficient time to allow transmission of 10
42、0 occurrences of the above patterns plus the latency period of the error detection mechanism. There shall be no errors in the HDB3 encoding. A pseudo random bit stream, e.g. PRBS(215-1). will be acceptable if the bit patterns of the above subclause are included in the bit stream. A.2.2 Waveform shap
43、e at output port Purpose: To verify the output waveform. Test configuration: Figure A.2. Leased Line Interface TX NTP T = TERMINATING RESISTOR 120 Q f 0,25 % Figure A.2: Waveform shape at output port Interface state: Powered. Stimulus: Undefined. Monitor: Marks and spaces transmitted from the NTP, m
44、easuring the amplitude and shape of positive and negative pulses (measured at the centre of the pulse interval) and the time duration of positive and negative pulses (measured at the nominal half of the pulse amplitude, .e. 1,5 V). The overall measurement accuracy shall be better than 90 mV. All the
45、 measurements shall be performed using measuring equipment capable of I 3404583 0065687 54T = Page 18 ETS 300 246:1993 Results: recording Direct Current (DC). A bandwidth of 200 MHz or greater shall be used to ensure the capture of over or undershoot of the pulse. Both positive and negative pulses s
46、hall be within the mask of figure 2, where V = 100 % shall be 3 V, The bit interval corresponding to a space shall not present voltages higher than f 0,3 V. The ratio between the amplitude of positive and negative pulses shall be contained in the range from 0,95 to 1,05. The ratio between the pulse
47、widths of positive and negative pulses shall be in the range from 0,95 to 1,05. A.2.3 Purpose: Test configuration: Figure A.3. Return loss at input port To measure the return loss of the receive pair of the leased line interface. Leased Line Interface Interface state: Stimulus: Monitor: Results: NOT
48、E: T T = TERMINATING RESISTOR 120 Q k 0,25 % NTP Figure A.3: Return loss at input port Powered. Sinusoidal signal of 3 V peak at the input to the network interface with a frequency variable between 51 kHz and 3 072 kHz. Voltage measured across the bridge, representing a terminating resistor of 120 R
49、, using a selective voltmeter with a bandwidth of less than 1 kHz. The measured return loss shall be greater than or equal to the values specified in subclause 5.2.2.2 of this ETS. The characteristics of the generator and of the voltmeter may be different depending on the implementation of the bridge however the total error of the test Set-up should be less than 0,5 dB in the range between 10 dB and 20 dB. When connected to a 120 R k 0,25 % resistor the measured return loss of the bridge should be 20 dB higher than the limits specified for the interface. A.2.4 Input loss tolerance an
