1、BSI BS*EN850090- 2 96 E Lb2idbb9 0569204 698 m BRITISH STANDARD Customer premises cabling for information technology Part 2.2048 kbitls ISDN primary access and leased line network interface * * Vi The European Standard EN 500982 : 1996 has the status of a British Standard ICs 33.080 NO COPYING WITHO
2、UT ES1 PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 50098-2 : 1996 ElSI BS*EN*5009B- 2 96 Lb24669 0569205 524 Amd. No. Date BS EN 60098-2 : 1996 Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Conunittee TCT/
3、7, Telecommunications - hstakiion requirements, upon which the following bodies were represented BR Telecommunications Ltd British Approvals Board for Telecommunications British Telecommunications pic Department of Ii-ade and Industry (Telecommunications and Posts Division) Electrical Contractors As
4、sociation Electricity Association Energis Communications Ltd. Federation of the Electronics Industry Mercury Communications Limited National Communications Union OFTEL (Mce of Telecommunications) Telecommunications Industsy Association This British Standard, having been prepared under the direction
5、of the Telecommunications Assembly, was published under the authority of the Standards Board and comes into effect on 15 November 1996 O BSI 1996 The following BSI references relate to the work on this standard Committee reference TCT/7 Draft for comment 94630206 DC ISBN O 680 26412 2 BSI BS*EN*5009
6、- 2 96 Lb24bb9 0513928b 4ibO BS EN 509-2 : 1996 Contents page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 500982 3 O BSI 1996 i BS EN 60098-2 : 1996 National foreword This British Standard has been prepared by Technical Committee “CTR and is the English angua
7、ge version of EN 500982 : 1996 Customerpmnises cabiing for information technology Part 2.2049 KbiVs ISDNprimayl mess and leaseal line networlc intqfiie, published by the European Committee for Electrokchnical Standardization (CENELEC). Cross-references Publication referred to Corresponding British S
8、tandard BS EN 50098 CusW premises cabling for information technology BS EN 500981 : 1994 ISDN b - cabling requirements for the installation of new cabling; - criteria for the use of existing cabling; - implementation of ISDN primary access on generic cabling systems according to EN 501 73. This stan
9、dard applies to the customer premises cabling for the transmission of ISDN primary access signals as defined by ETS 300 O1 1, The requirements in this standard also apply to the cabling between Open Network Provision 2048 kbitls network interfaces and terminal equipment conforming to ETS 300 248. 2
10、Normative references This European Standard 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 revision
11、s of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 50098-1 Customer premises cabling for information technology - Part 1: ISDN basic access EN 50173
12、 Information technology - Generic cabling systems EN 55022 Limits and methods of measurement of radio interference characteristics of information technology equipment (IECICISPR 21 993) EN 60603-7 Connectors for frequencies below 3 MHz for use with printed boards - Part 7: Detail specification for c
13、onnectors, 8 way, including fixed and free connectors with common mating features (IEC 603-7:1990) Integrated Sevices Digital Network (ISDN) - Primary rate user-network interface - Layer 1 specification and test principles Rectangular connectors for frequencies below 3 MHr - Part 8: Detail specifcat
14、ion for connectors, four-signal contacts and earthing contacts for cable screen ETS 300 O1 1 IEC 807-8 3 Definitions For the purposes of this standard the definitions of EN 50098-1 and EN 50173 apply, of which the following are repeated below. 3.1 cable unit: A single assembly of one or more cable e
15、lements usually of the same type or category. The cable unit may have a screen. 3.1.8 of EN 50173:1995 3.2 channel: The end to end transmission path connecting any two pieces of application-specific equipment. Equipment cables and work area cables are included in the channel. 3.1.13 of EN 50173:1995
16、 NOTE: A binder group is an example of a cable unit. Page 5 EN 50098-2 : 1996 4 Abbreviations and symbols 4.1 BD CD DC EMC FD GC ISDN NEXT NT PBX TE Abbreviations Building distributor Campus disibutor Direct current Electromagetic compatibility Floor distributor Generic cabling Integrated setvices d
17、igital network Near-end crosstalk 108s Network termination Private branch exchange Terminal equipment 4.2 Symbols cable * UJ * Ll Dedicated cabling socket * Dedicated cabling plug Generic cabling socket (.e. telecommunications outlet) - Generic cabling plug Page 6 EN 50098-2 1996 5 Design requiremen
18、ts 5.1 General Signals passing between the NTlINT2 and TE or signals passing between the NTl and NT2 are subject to attenuation, distortion and induced noise. These signals may also cause electromagnetic radiation. Cabling components (including extension cords, adapters, cross connect components, so
19、ckets, junction boxes etc.) and cable all contribute to these effects. 5.2 Insertion loss The insertion loss is measured from the NT1 to the TE, or from NT1 to NT2 at 1,024 MHz with 120 R non- reactive source and load impedances. The maximum insertion loss shall not exceed 6 dB. 5.3 Power feeding In
20、 some cases power can be supplied via the cabling from the TE to the NT1 or from the NT2 to the NT1. In these cases a separate pair dedicated for power feeding is required. 5.4 Electromagnetic environment The performance of the ISDN primary access may be degraded by interference from external source
21、s of electromagnetic radiation (such as motors), and from electrical signals from other applications carried under the same cable sheath. These effects can be minimised by employing good installation practice. The impulsive noise generated by circuits carrying, for instance, analogue telephone signa
22、ls or some unbalanced data transmission, can cause interference with signals carried on the ISDN cabling. Interference by crosstalk can be limited by putting pairs or quads for ISDN primary access in separate cables or cable units in the same cable. EMC, emission and immunity to interference from th
23、e environment, also has to be considered. EMC can be improved by screening, balancing of equipment, balance of cabling, filtering or a combination of ihese. Standards giving more specific advice on these matters will be developed. However, all equipment and systems shall meet the requirements of EMC
24、 standards. The current relevant standard for emission is EN 55022, for immunity EN 551 05 is under preparation. 5.5 Spurs There shall be no spurs in the ISDN primary access cabling. 5.6 Nearsnd crosstalk loss The NEXT of the cabling shall be greater than 38 dB at 1 ,O MHr, which provides an operati
25、ng margin over the 25 dB minimum theoretical system requirement at 1 ,O MHz (see ETS 300 O1 1). Page 7 EN 50098-2 : 1996 NT2 * L 6 Point-to-point configuration The point-to-point configuration is illustrated in figure 1. I NT1 i NT1 or M2 TE t 6 I NT1 M2 or - d, maximum distance between the NT1 and
26、the point of connection of the customers terminal equipment. d, also applies for the distance between NTl and NT2. Figure 1 : Point-to-point configuration Figure 1 is also relevant for the connection of an NT1 to an NT2. The TE can be connected to the cabling in one of three ways: - via a plug at th
27、e end of a cord connected to the TE; - hardwired e.g. by the use of insulation displacement connectors incorporated in the TE; - via a socket within the TE. The insertion loss is measured over the distance dl in figure 1 and shall not be greater than specified in 5.2. Maximum distances achievable wi
28、th common cables used in Europe can be found in Annex B. Two pairs shall be available for the transmit and receive circuits. It is recommended that the polarity of each wire be maintained throughout the length of the cabling to facilitate testing and more effective cable management. 7 Component requ
29、irements within dedicated ISDN cabling 7.1 General Cabling specifically designed to support ISDN primary rate services shall comprise components which meet the requirements of 7.2, 7.3 and 7.4. The implementation of ISDN primary rate applications over generic cabling in accordance with EN 50173 is d
30、efined in clause 8. BSP BS*EN*50098- 2 96 D 1624667 05695135 473 Page 8 EN 60098-2 : 1996 7.2 Cables 7.2.1 General Balanced cables (twisted pair or star quads) shall be used. The cable or cable elements may be screened or unscreened (see 5.4). 7.2.2 Characteristic impedance The characteristic impeda
31、nce of the cable shall be (120 f 12) R at 1 ,O MHz. The insertion los of the cabling (see 5.2) shall be measured with a source and load impedance of 120 R, regardless of the characteristic impedance of the cable used. 7.2.3 Attenuation The attenuation of the cable shall ensure that the requirements
32、of 5.2 are met. 7.2.4 Near-end crosstalk loss The NEXT of the cable shall be greater than 40 dB at 1 ,O MHz for a 1 O0 m cable length. 7.2.5 Insulation resistance The insulation resistance of the cable shall be greater than 50 M-km when measured at 20 C and 500 V DC A measurement of the insulation r
33、esistance of existing cabling at 50 V DC can be used to indicate the likely presence of cable defects (see 9.5). 7.3 Connectors The socket used to connect the termirla1 equipment to the cabling shall be in accordance with the connecting hardware recommended within ETS 300 O1 1. Alternatively, hard-w
34、iring may be used. NOTE: The connector plug recommended in ETC 300 O1 1 A992 is not readily available. Subclause 8.2 provides information on connections to generic cabling which may also be used for dedicated cabling. 7.4 Cords All cords used in the connection shall be balanced cable (twisted pairs
35、or quads), and meet the requirements of 7.2. 8 Implementation over generic cabling systems 8.1 General The point-to-point configuration of clause 6 may need to be constructed over generic cabling systems which meet the requirements of EN 50173. In generic cabling it is not intended to change the fix
36、ed parts of the cabling (e.g. sockets, cables). The terminal cords should not be hardwired to the generic cabling system. Methods for connecting terminal equipment to generic cabling shall be in accordance with 8.2. Figure 2 shows the typical hierarchical structure of generic cabling systems. When t
37、he NT is located within the generic cabling it shall be located at the campus distributor, building distributor or floor distributor. The copper cable types supported by EN 50173 comprise 100 R. 120 R and 150 2 balanced cables. Where the cables used do not comply with the requirements of clause 7 it
38、 is recommended that system performance is ensured by the following means: a) equipment manufacturers specification (recommended); b) impedance matching components (preferred alternative); c) observation over representative cabling. The use of bit error rate testing is recommended. * * m BSI BS*EN*5
39、0098- 2 9b M LL24bb9 0569216 30T Page 9 EN 50098-2 : 1996 The requirements of 5.2 to 5.6 shall be fulfilled for the complete primary access connections, including ISDN primary access connections generic cabling adapter, independent of the cable types used. h / CD Campus Distributor ing Detributor FD
40、 Floor Distributor ;ition Point Telecommunications outlets NOTE: Dotted lines denote optional connections, dotted circles denote optional elements. Figure 2: NT location in a generic cabling system 8.2 Figure 3a) shows a TE plugged directly into the generic cabling. Figure 3b) shows the use of a cor
41、d with different plugs on each end to make the connection. Figure 3c) shows the use of generic cabling adapters to provide ISON primary access. Such an adapter consists of: Connection of ISDN primary access to generic cabling - a plug which matches the telecommunications outlet of the generic cablin
42、g; - an optional cord conforming to 8.3; - an optional socket or plug conforming to 7.3: - an optional impedance matching device, The requirements in 5.2 to 5.6 shall be fulfilled for the complete primary access connection including the ISDN primary access generic cabling adapter. This shall be fulf
43、illed even if cables with impedance other than 120 f2 are used (note the additional attenuation of the reflection points). For the cable types supported by EN 501 73, the pin assignments of table 1 shall be used. Page 10 EN 50098-2 : 1996 Item I work area Cable type 100 R. 120 R I i50 R I a) hard wi
44、red i ! Connecting hardware Receive pair (input to TE) Transmit pair (output from TE) Power feeding negative (optional) Power feeding positive (optional) i b) socket I I : EN 60603-7) IEC 801-8) Pins 1 and 2 Pins 5 and 4 Pins G and R Pins B and O Pin 7 - Pin 8 c) plug ended GCadaptor i Generic cabli
45、ng (GC) n GC Odet (.e. telecommunications ouet) Figure 3: Means of connection of ISDN primary access to generic cabling Table 1: Pin allocation of connecting hardware 8.3 The cord shall conform to the requirements for cables in 7.2. The maximum length of the cord shall be 5 m. Terminating resistors
46、shall not be present in adapters for primary access. The socket of the ISDN primary access adapter shall conform to the requirements in 7.3. Requirements for ISDN primary access generic cabling adapters 9 Cabling qualification 9.1 Gen e rat The following should be verified either by design or by dir
47、ect or indirect measurement to ensure the good operation of a primary access channel: - absence of spurs; - continuity and cabling polarity: BSI BS*EN*50078- 2 76 E Lb2idbb7 0567218 382 Page 11 EN 50098-2 1996 - DC loop resistance: - insulation resistance; - screen continuity where applicable; - ins
48、ertion loss; - characteristic impedance; - near end crosstalk. The tests which have to be applied depend to a large extent on the knowledge of the present installation. For this reason the tests applied to new or recent installations may be restricted to simple continuity check whereas an unknown ex
49、isting installation will require more comprehensive testing. In these cases or where functional problems are encountered, the relevant tests from 9.2 to 9.7 should be applied. 9.2 spurs The presence and position of spurs can be determined by visual means and if this is not possible by the use of either a time domain reflectometer or a pulse echo meter. Ail spurs shall be removed, see 5.5. 9.3 Cabling integrity The cabling shall be checked for correct pin and pair assignment at all interfaces. 9.4 DC loop resistance OC loop resistance may be used as a measur
