1、TECHNICAL TBR 12 December 1993 Source: ETSI TC-BT Reference: DTBR/BT-020 36 UDC: 621.39 Key words: ONP, leased lines, D2048U Business Telecommunications (BT); Open Network Provision (ONP) technical requirements; 2 048 kbitls digital unstructured leased line (D2048U) Attachment requirements for termi
2、nal equipment interface ETSI European 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 Sta
3、ndards Institute 1 993. All rights 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. ETSI TBR*:L2 93 3400855 0083290 83T H Page 2 TBR 12:1993 ETSI T
4、BR*32 93 9 3400855 0083293 776 9 - 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
5、shown on the title page. ETSI TBR*L2 73 3400855 0083272 602 Page 3 TBR 12:1993 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 . 8 5.2 Electrical characteristics 9 5.2.1 output
6、 port 9 5.2.1.1 Signal coding . 9 5.2.1.2 Waveform shape . 9 5.2.1.3 Clock accuracy 10 5.2.1.4 Output jitter 11 5.2.2 Input port . 12 5.3 Safety 12 5.4 Overvoltage protection 12 Conversion of common mode to transverse mode 12 5.5 Electro-magnetic compatibility., 13 5.4.1 5.4.2 5.4.3 Impulse transfer
7、 from mains. common mode . 12 impulse transfer from mains, transverse mode . 12 Annex A (normative): Test methods 14 A.l General . 14 A . 1 . 2 Test environment 14 . A . 1 . 1 Equipment connection 14 . A.2 Test methods . 15 Signal coding at output port 15 Waveform shape at output port 15 Clock accur
8、acy at the output port . 16 A.2.4 Jitter 17 A.2.1 A.2.2 A.2.3 Annex B (normative): Definition of HDB3 code . 19 B.l General . 19 B.2 Definition . 19 Annex C (informative): Bibliography 20 History 21 - ETSI TBR*L2 93 3400855 0083293 549 m . Page 5 TBR 12:1993 Foreword This Technical Basis for Regulat
9、ion (TBR) has been produced by the Business Telecommunications (BT) Technical Committee of the European Telecommunications Standards Institute (ETSI) and was adopted after having passed through the ETSI standards approval procedure. This TBR results from a mandate from the Commission of the European
10、 Community (CEC) to provide harmonised standards for the support of the Second Phase Directive (91 /263/EEC). This TBR is based on information from CCITT Recommendations and ETSI publications and the relevant documents are quoted where appropriate. Introduction The Council Directive on the applicati
11、on 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 Community (EEC) of a minimum set of leased lines
12、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
13、 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 re
14、quirements under the Second Phase Directive (91 /263/EECi for attachment to the leased lines. This TBR is a subset of the corresponding ETC 300 248 (1 9931. CCITT Recommendation G.703 (1 991 1, as qualified by ETC 300 166 (1 9931, is used as the basis for the terminal interface. Previous page is bla
15、nk _ _ ETSI TBR* -,TX 5.1 Physical characteristics 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 (article 4f). Currently no standardized co
16、nnector 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 to 0,6 mm. This TBR requires the TE to be capable of presenting either a point for the attachment of unterminated solid conductors, or solid conductors th
17、emselves (see subclause 5.1.1). It is a requirement that such a connection method be available to be provided for use with the TE if necessaiy. In order to allow connection to be made using other methods (e.g. connectors), the TE is permitted to be supplied with a connection method suitable for use
18、with those methods (see subclause 5.1.2). 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: NOTE 1: RX TERMINAL EQUIP M E N - INTERFACE a cord, permanently connected to the terminal
19、 equipment at one end and unterminated at the other end, with wires that are solid conductors with diameters in the range 0,4 to 0,6 mm; a cord, connected via a plug and socket to the terminal equipment at one end and unterminated at the other end, with wires that are solid conductors with diameters
20、 in the range 0,4 to 0,6 mm; an insulation displacement connector, designed to accept wires with solid conductors with diameters in the range 0,4 to 0,6 mm, but with no cord; a screw connector, designed to accept wires with solid conductors with diameters in the range 0,4 to 0,6 mm, but with no cord
21、; the arrangement in b) plus one or more additional alternative cords with the same plug or socket arrangement at the terminal end and any plug or socket at the other end; the arrangement in c) or d) plus one or more cords suitable for connection to the terminal equipment at one end and any plug or
22、socket at the other end. 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 terminai equipme
23、nt interface. Figure 1 NOTE 2: The use of a shielded cord or cable may be necessary to meet radiation and immunity requirements defined in Electro-Magnetic Compatibility (EMC) standards. A 5. . Page 9 TBR 12:1993 1 Hardwired connection Requirement: The terminal equipment shall provide: a) a set of c
24、onnection contacts (e.g. an insulation displacement connector or a screw terminal block) to which solid wire conductors with diameters in the range 0,4 to 0,6 mm may be connected; or a wiring arrangement connected by any means to the terminal equipment, with unterminated solid wire conductors with d
25、iameters in the range 0,4 to 0,6 mm at the end distant from the terminal equipment. b) Test: There is no test. All subsequent tests are carried out via the specified connection method. 5.1.2 Alternative means of connection Any alternative means of connection may be provided in addition to the connec
26、tion arrangements under subclause 5.1.1. 5.2 Electrical characteristics 5.2.1 Output port 5.2.1.1 Signal coding Requirement: Coding of the digital signal transmitted at the output port shall be in accordance with High Density Bipolar code of order 3 IHDB3) encoding rules (see Annex BI. Test: The tes
27、t shall be conducted according to Annex A, subclause A.2.1, 5.2.1.2 Waveform shape Requirement: The pulse at the output port shall comply with the requirements given in table 2 and figure 2, based on CCITT Recommendation G.703. Test: The test shall be conducted according to Annex A, subclause A.2.2.
28、 ETSI TBR*L2 93 3400855 0083298 020 = Pulse shape (nominally rectangular) Page 10 TBR 12:1993 All marks of a valid signal must conform with the mask (see figure 2) irrespective of the polarity. The value V corresponds to the nominal peak voltage of a mark. Table 2: Waveform shape at output port Test
29、 load impedance Nominal peak voltage V of a mark 120 ohms non-reactive 3 volts Nominal pulse width Ratio of the amplitudes of positive and negative pulses at the centre of the pulse interval Ratio of the widths of positive and negative pulses at the nominal half amplitude Peak voltage of a space 244
30、 ns 0,95 to 1,05 0,95 to 1,05 I O f 0,3 volts I 269 ns I V=100% 50% 1 480 ns (244 t 244) pulse Figure 2: Pulse mask for 2 048 kbit/s pulse 5.2.1.3 Clock accuracy Requirement: Where a Terminal Equipment (TE) has an internal clock, in the absence of any external reference signal timing, the output por
31、t shall have a bit rate of 2 048 kbit/s * 50 ppm. Test: The test shall be conducted according to Annex A, subclause A.2.3. ETSI TBR*L2 93 m 3400855 0083299 Tb7 m 40 Hz 5.2.1.4 Requirernen 100 kHz 0,11 u1 Output jitter The peak-to-peak ou with first order linear filters with Page 11 TBR 12:1993 put j
32、itter shall not exceed the limits of table 3 when measured le defined cut-off frequencies. 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 spec
33、ified 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 3 and table 4. NOTE: A separate requirement for output jitter at fre
34、quencies in the range 4 Hz to 40 Hz is not required because this frequency band is covered sufficiently by the first order linear filter which produces 20 dB attenuation at 4 Hz. Table 3: Maximum output jitter Measurement filter bandwidth Output jitter Lower cut-off (high pass) Upper cut-off (low pa
35、ss) U1 peak-to-peak (maximum) peak-to-peak jitter Al A2 I I l I I I I- fl f2 f3 f4 jitter frequency Figure 3: Input jitter for output jitter measurement ETSI TBR*L2 93 3V00855 0083300 509 = Peak-to-peak amplitude (U11 Al A2 1,5 02 Page 12 TBR 12:1993 Frequency (Hz) fl f2 f3 f4 20 2 400 18 O00 100 O0
36、0 Table 4: Input jitter for output jitter measurement Test: The test shall be conducted according to Annex A, subclause A.2.4. 5.2.2 Input port There are no requirements on the input port under this TBR. 5.3 Safety There are no safety requirements under this TBR. NOTE: Safety requirements are impose
37、d under the Low Voltage Directive (73/23/EEC) and articles 4a and 4b of the Second Phase Directive (91/263/EEC). ETS 300 248 subclause 5.3 defines the terminal equipment interface as a Safety Extra-Low Voltage (SELV) circuit. Detailed requirements for SELV circuits are given in EN 60950. 5.4 Overvol
38、tage protection For the purpose of the following subclauses on protection, the term referred to as la in ETC 300 046-3 21 shall be deemed to be the point of test referred to in Annex A, subclause A. 1. I. 5.4.1 Impulse transfer from mains, common mode Requirement: If the terminal equipment is suppli
39、ed from the mains, it shall transfer less than 1 kV common mode voltage and less than 250 volts transverse voltage to the terminal equipment interface when a common mode surge of either polarity and of 2,5 kV (1 0/700 jls) is applied to the mains supply port. Test: The test shall be conducted accord
40、ing to subclause 5.7.1 of ETS 300 046-3 21. I 5.4.2 Impulse transfer from mains, transverse mode Requirement: If the terminal equipment is supplied from the mains, it shall transfer less than 1 kV common mode voltage and less than 250 volts transverse voltage to the terminal equipment interface when
41、 a transverse mode surge of either polarity and of 2,5 kV (10/700ps) is applied to the mains supply port. Test: The test shall be conducted according to subclause 5.7.1 of ETS 300 046-3 21. 5.4.3 Conversion of common mode to transverse mode Requirement: The transverse mode voltage shall not be more
42、than 250 volts peak when 2 common mode surges of 1 kV (1,2/50ps) (one of each polarity) are applied to the terminal equipment interface. Test: The test shall be conducted according to subclause 5.7.3 of ETS 300 046-3 21 - ETSI TR*l12 73 M 3YOD855 0083303 YY5 Page 13 TBR 121993 5.5 Electro-magnetic c
43、ompatibility 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
44、EMC Directive. ETSI TBR*L2 93 M 3Ll00855 0083302 381 Page 14 TBR 12:1993 Annex A (normative): Test methods A.l 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 th
45、e specific details of the implementation of the tests. A terminal equipment may be designed for through-connecting and may only fulfil the electrical requirements if through-connected. In these cases the requirements of this TBR are valid and the tests are carried out with the through-connection sui
46、tably terminated as defined 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 i
47、mplementing the test. NOTE: Attention is drawn to the issue of measurement uncertainty which may be addressed in future regulatory documents. The required test results do not make allowances for spurious events during testing (e.g. errors due to EMC effects). The test configurations given do not imp
48、ly a specific realisation of test equipment or arrangement or use of specific test devices for conformance testing. 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 b
49、e a device, or a group of devices, generating a stimulus signal conforming to this TBR and capable of monitoring the receive signal from the interface. The terminal equipment interface under test shall have the ability to transmit a bit pattern for test purposes, e.g. Pseudo Random Bit Sequence as defined in 2.1 of CCIlT Recommendation O. 1 51 1 (PRBS(215-1). Where this cannot be provided, an alternative method of conducting the test shall be provided. A. 1.1 Equipment connection 4 The tests in this TBR shall be carrie
