BS PD CLC TR 50173-99-1-2007 Cabling guidelines in support of 10 GBASE-T《支持10 GBASE-T电缆铺设指南》.pdf

1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58I

2、CS 35.110Cabling guidelines in support of 10 GBASE-TPUBLISHED DOCUMENTPD CLC/TR 50173-99-1: 2007PD CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIThis Published Document was published under the authority of the Standards Polic

3、y and Strategy Committee on 31 January 2008 BSI 2008ISBN 978 0 580 61549 8Amendments/corrigenda issued since publicationDate Commentscontract. Users are responsible for its correct application.National forewordThis Published Document is the UK implementation of CLC/TR 50173-99-1:2007.The UK particip

4、ation in its preparation was entrusted to Technical Committee TCT/7, Telecommunications Installation requirements.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a TECHNICAL

5、 REPORT CLC/TR 50173-99-1 RAPPORT TECHNIQUE TECHNISCHER BERICHT December 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 20

6、07 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. CLC/TR 50173-99-1:2007 E ICS 35.110 English version Cabling guidelines in support of 10 GBASE-T Guide de cblage pour supporter le 10 GBASE-T Verkabelungsleitfaden zur Untersttzung vo

7、n 10 GBASE-T This Technical Report was approved by CENELEC on 2007-11-02. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, L

8、uxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIForeword This Technical Report was prepared by the Technical

9、 Committee CENELEC TC 215, Electrotechnical aspects of telecommunication equipment. The text of the draft was submitted to vote and was approved by CENELEC as CLC/TR 50173-99-1 on 2007-11-02. This Technical Report provides guidance whether an installed generic cabling channel meeting the requirement

10、s of EN 50173-1:2007, Class E, will support 10 GBASE-T as specified by IEEE 802.3an. The Technical Report also provides mitigation procedures to improve the performance of Class E channels to the point where the application is supported. Generic cabling channels meeting the requirements of EN 50173-

11、1:2007, Class F, will support IEEE 802.3an up to 100 m without mitigation. The support of IEEE 802.3an includes additional parameters and an extended frequency range beyond Class E. Conformance of installed cabling beyond the original cabling specifications must be determined on a case-by-case basis

12、, and is primarily needed due to new external noise requirements. Whether these requirements are met by a specific channel is influenced by the components and installation practices used. As IEEE 802.3an uses frequencies above those specified for Class E of EN 50173-1:2007, input from supplier and i

13、nstaller may be helpful to evaluate the performance of installed Class E channels. This Technical Report takes into account the design goals for IEEE 802.3an (10 GBASE-T) equipment such as: a) frequency signal range up to 500 MHz; b) meet EMC limits specified for EN 55022:2006, Class A; NOTE While I

14、EEE 802.3an specifies an application to meet Class A on unshielded cabling, meeting Class B may require application specific equipment and/or cabling that exceeds the requirements of this TR respectively. c) support a bit error rate of 1012; d) support operation over four-connector, four-pair balanc

15、ed cabling. It is expected that IEEE 802.3an will be supported by the following cabling channels specified in EN 50173-1:2007: Class F channels will support IEEE 802.3an to distances of at least 100 m; Class E channels using screened Category 6 components and assessed and mitigated according to the

16、guidelines in this Technical Report will support IEEE 802.3an over distances up to 100 m; Class E channels assessed and mitigated according to the guidelines in this Technical Report are expected to support IEEE 802.3an over distances from 55 m up to 100 m using unscreened Category 6 components. In

17、order to provide normative cabling specifications in explicit support of IEEE 802.3an, an amendment to EN 50173-1:2007 is under consideration. This amendment will provide new channel specifications that will include all characteristics needed to meet and/or exceed the IEEE 802.3an requirements (Clas

18、s EAand Class FA). This Technical Report is derived from ISO/IEC TR 24750, which has been developed by ISO/IEC JTC 1/SC 25 as a Technical Report Type 2. 2 CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIContents Introduction 5

19、1 Scope 7 2 Normative references . 7 3 Definitions and abbreviations 7 3.1 Definitions 7 3.2 Abbreviations 9 4 Channel requirements 9 4.1 General 9 4.2 Return loss10 4.3 Insertion loss .10 4.4 Near-end crosstalk loss (NEXT).11 4.5 Attenuation to crosstalk loss ratio near-end (ACR-N) .13 4.6 Attenuat

20、ion to crosstalk loss ratio far-end (ACR-F).14 4.7 Alien (exogenous) crosstalk.16 4.8 Propagation delay21 4.9 Delay skew21 5 Guidance for mitigation.21 5.1 Planning certification, measurement and documentation21 5.2 Mitigation techniques if in-channel parameters of the channel from Clause 4 are not

21、met 22 5.3 Mitigation techniques in case external parameters of the channel (alien noise) from 4.7 are not met.22 Annex A (informative) Permanent link performance guidelines24 Annex B (normative) Alien crosstalk margin computation26 Annex C (informative) Analytical approach to alien crosstalk mitiga

22、tion .31 Tables Table 1 Changes and additions to definitions in EN 50173-1:2007. 6 Table 2 Equations for return loss limits for a channel 10 Table 3 Return loss limits for a channel at key frequencies .10 Table 4 Equation for insertion loss limits for a channel11 Table 5 Insertion loss limits for a

23、channel at key frequencies 11 Table 6 Equations for NEXT limits for a channel .11 Table 7 NEXT limits for a channel at key frequencies .11 Table 8 Equations for PSNEXT limits for a channel.12 Table 9 PSNEXT limits for a channel at key frequencies.12 Table 10 ACR-N limits for a channel at key frequen

24、cies13 Table 11 PSACR-N limits for a channel at key frequencies .14 Table 12 Equation for ACR-F limits for a channel15 Table 13 ACR-F limits for a channel at key frequencies 15 Table 14 Equation for PSACR-F limits for a channel.15 3 CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA S

25、TANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSITable 15 PSACR-F limits for a channel at key frequencies16 Table 16 Equations for PSANEXT limits for a channel 17 Table 17 PSANEXT limits for a channel at key frequencies.17 Table 18 Equations for PSAACR-F limits for a channel.19 Table 19 PSAACR-

26、F limits for a channel at key frequencies and lengths 20 Table 20 Examples of implementations at key insertion loss .20 Table 21 Equations for propagation delay limits for a channel.21 Table 22 Propagation delay limits for a channel at key frequencies.21 Table 23 Delay skew limits for a channel 21 T

27、able A.1 Return loss for permanent link 24 Table A.2 Insertion loss for permanent link .24 Table A.3 NEXT for permanent link 25 Table A.4 PSNEXT for permanent link25 Table A.5 ACR-F for permanent link .25 Table A.6 PSACR-F for permanent link 25 Table B.1 Power backoff schedule from main body IEEE 80

28、2.3 10 GBASE-T .26 4 CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIIntroduction In order to support IEEE 802.3 10 GBASE-T (ISO/IEC 8802-3:2000/A1, at present draft) over a generic cabling systems as defined in series EN 50173

29、, several new parameters are required to specify the electrical transmission properties of the channel. EN 50173-1 defines ACR and ELFEXT as: The S/N ratio of the noise in the disturbed pair to the signal in the disturbing pair. The definition in EN 50173-1 is correct for cabling. IEEE 802.3an defin

30、es these parameters slightly different: The S/N ratio of the noise in the disturbed pair to the signal in the disturbed pair. This is of course the definition of importance for electrical systems. For equally long channels the values of both definitions are nearly the same, but if the channels have

31、different length the values based on IEEE 802.3an and EN 50173-1:2007 are different. To align with IEEE 802.3an it was decided in February 2006 to change the naming and definition in their cabling standard of some noise related items. The limits stay the same so backward compatibility is assured (se

32、e Table 1 for summary). Crosstalk and power sum crosstalk are well defined in EN 50173-1:2007. As cables are laid in trays, ducts and/or are bundled together, the noise from one cable can couple into other cables. This can happen between telecommunications cables of the same category, but also betwe

33、en cables with different categories or even between signal or power line cables and telecommunications cables. This type of noise is well known in telephony and existing versions of Ethernet over balanced cabling. It has not been a major issue for the systems in use up to now. However, the increased

34、 frequency range and sensitivity of the IEEE 802.3an transmission cannot neglect this external noise any more. Only the power sum of the noise is of importance and is specified because it is irrelevant from which external pairs or cables the noise is coming from and the noise from external sources c

35、annot be compensated for within the specific application addressed here. The power sum computation assumes that the noise is generated by other channels using the same protocol. Disturbances that are created by other protocols (like TV distribution) using the other channels are handled as background

36、 noise. To determine alien crosstalk noise, the transmitter must therefore be known. In a channel as specified in EN 50173-1, and measured in accordance with EN 50346, the near-end (where the measurement transmitter is) and the far-end (were the measurement receiver is) are known and the terms NEXT

37、and FEXT are easy to define. For alien crosstalk the term ANEXT or AFEXT can be ambiguous. Therefore new definitions for power sum alien crosstalk noise (near-end and far-end) are introduced (see definitions). It appears that the worst case situation is when a short channel runs in parallel at eithe

38、r end of a long channel. The short channel with high signals will disturb the long channel receiver where receiving signals have been attenuated due to the insertion loss of the long channel. For this case IEEE 802.3an introduced power backoff strategies. The idea is that a system detects the length

39、 of the channel by receiving signal amplitude and reduces the transmitter voltage to decrease alien noise. IEEE 802.3an defines two limits for each of ANEXT and AFEXT that have to be met concurrently (for values see 4.7.1): a) The first limit applies to every pair individually within the disturbed c

40、hannel; b) The second limit applies to the average of all four pairs within the disturbed channel. PSANEXT average limit is 2,25 dB more stringent than the PSANEXT limit for each pair within the disturbed channel; PSACR-F average is 4 dB more stringent than the PSACR-F limit for each pair within the

41、 disturbed channel. 5 CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSIIf these two limits are not met concurrently tradeoffs can be calculated as explained in Annex B. Table 1 Changes and additions to definitions in EN 50173-1:

42、2007 Term used in EN 50173-1:2007 Term used in this Technical Report Definition Requirement ACR ACR-N Revised No change PSACR PSACR-N Revised No changeELFEXT ACR-F Revised No change PSELFEXT PSACR-F Revised No change- PSANEXT New New - PSAACR-F New New 6 CLC/TR 50173-99-1:2007Licensed Copy: Wang Bin

43、, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 08:07, Uncontrolled Copy, (c) BSI1 Scope This Technical Report a) specifies the transmission performance for channels to support 10 GBASE-T as specified in IEEE 802.3an, b) specifies the methods to assess whether installed Class E and Class F channels meet

44、IEEE 802.3an requirements, c) provides mitigation techniques to improve the performance of an existing installation to meet the IEEE 802.3an requirements. NOTE 1 The channel transmission performance specified in this TR is derived from IEEE 802.3an. NOTE 2 IEEE 802.3an specifies requirements beyond

45、the frequency range specified for EN 50173-1:2007, Class E, and additional parameters to those specified for Class E and Class F cabling in EN 50173-1:2007. NOTE 3 This Technical Report does not re-specify the requirements for Class E and Class F channels of EN 50173-1:2007. 2 Normative references T

46、he following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 50173-1:2007, Information technology Generic ca

47、bling systems Part 1: General requirements EN 50346, Information technology Cabling installation Testing of installed cabling ISO/IEC 8802-3:2000/A1 1), Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Specific requirements

48、 Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications - Media Access Control (MAC) parameters, physical layers, and management parameters for 10 Gb/s operation 3 Definitions and abbreviations 3.1 Definitions For the purposes of this

49、 document the following terms and definitions apply in addition to those of EN 50173-1. 3.1.1 alien crosstalk the signal coupling from a disturbing pair of a channel to a disturbed pair of another channel 3.1.2 alien (exogenous) far-end crosstalk loss (AFEXT) the signal isolation between a disturbing pair of a channel and a disturbed pair of another channel, measured at the far-end 3.1.3 alien (exogenous) near-end crosstalk loss (ANEXT) the signal isolation between a disturbing pair of