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、PUBLISHED DOCUMENTPD CLC/TR 50173-99-1: 2007Cabling guidelines in support of 10 GBASE-TICS 35.110g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58PD

2、CLC/TR 50173-99-1:2007This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 January 2008 BSI 2008ISBN 978 0 580 61549 8National forewordThis Published Document is the UK implementation of CLC/TR 50173-99-1:2007.The UK participation in its prep

3、aration 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 contract. Users are respon

4、sible for its correct application.Amendments/corrigenda issued since publicationDate CommentsTECHNICAL REPORT CLC/TR 50173-99-1 RAPPORT TECHNIQUE TECHNISCHER BERICHT December 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisc

5、hes Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 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 suppor

6、t of 10 GBASE-T Guide de cblage pour supporter le 10 GBASE-T Verkabelungsleitfaden zur Untersttzung von 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, Denm

7、ark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword This Technical Report was prepared by the Techni

8、cal 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 requirem

9、ents 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 501

10、73-1:2007, 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 ba

11、sis, 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 an

12、d installer 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 Whil

13、e IEEE 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 bal

14、anced 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 t

15、he 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.

16、In 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 (C

17、lass 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 50173-99-1:2007Contents Introduction 5 1 Scope 7 2 Normative references . 7 3 Definitions and abbreviations 7 3.1 Definitions 7 3.2 Abb

18、reviations 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 Attenuation to crosstalk loss ratio far-end (ACR-F).14 4.7 Alien (exogenous) crosstalk.16 4.8 Propagatio

19、n 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 met 22 5.3 Mitigation techniques in case external parameters of the channel (alien noise) from 4

20、.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 mitigation .31 Tables Table 1 Changes and additions to definitions in EN 50173-1:2007. 6 Table 2 Equat

21、ions 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 channel at key frequencies 11 Table 6 Equations for NEXT limits for a channel .11 Table 7 NEXT l

22、imits 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 frequencies13 Table 11 PSACR-N limits for a channel at key frequencies .14 Table 12 Equation for ACR-F

23、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 50173-99-1:2007Table 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

24、 a channel at key frequencies.17 Table 18 Equations for PSAACR-F limits for a channel.19 Table 19 PSAACR-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 P

25、ropagation delay limits for a channel at key frequencies.21 Table 23 Delay skew limits for a channel 21 Table 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

26、 link .25 Table A.6 PSACR-F for permanent link 25 Table B.1 Power backoff schedule from main body IEEE 802.3 10 GBASE-T .26 4 CLC/TR 50173-99-1:2007Introduction 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

27、 50173, 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

28、 defines 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

29、 have 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 assur

30、ed (see 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

31、 between 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 inc

32、reased 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 sou

33、rces cannot 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 back

34、ground 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

35、 NEXT 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

36、 either 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

37、length 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 distu

38、rbed channel; 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 with

39、in the disturbed channel. 5 CLC/TR 50173-99-1:2007If 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 50173-1:2007 Term used in EN 50173-1:2007 Term used in this Technical Report Definition Requirement A

40、CR 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 50173-99-1:20071 Scope This Technical Report a) specifies the transmission performance for channels to support 10 GBASE-T as specif

41、ied in IEEE 802.3an, b) specifies the methods to assess whether installed Class E and Class F channels meet 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 perfo

42、rmance specified in this TR is derived from IEEE 802.3an. NOTE 2 IEEE 802.3an specifies requirements beyond 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 n

43、ot re-specify the requirements for Class E and Class F channels of EN 50173-1:2007. 2 Normative references The 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 th

44、e referenced document (including any amendments) applies. EN 50173-1:2007, Information technology Generic cabling systems Part 1: General requirements EN 50346, Information technology Cabling installation Testing of installed cabling ISO/IEC 8802-3:2000/A1 1), Information technology - Telecommunicat

45、ions and information exchange between systems - Local and metropolitan area networks - Specific requirements 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 manageme

46、nt parameters for 10 Gb/s operation 3 Definitions and abbreviations 3.1 Definitions For the purposes of this 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 ano

47、ther 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 a

48、 channel and a disturbed pair of another channel, measured at the near-end 1)Under preparation. 7 CLC/TR 50173-99-1:20073.1.4 attenuation to alien (exogenous) crosstalk ratio at the far-end (AACR-F) the difference, in dB, between the alien far-end crosstalk loss from a disturbing pair of a channel a

49、nd the insertion loss of a disturbed pair in another channel 3.1.5 attenuation to alien (exogenous) crosstalk ratio at the near-end (AACR-N) the difference, in dB, between the alien near-end crosstalk loss from a disturbing pair of a channel and the insertion loss of a disturbed pair in another channel 3.1.6 attenuation to crosstalk ratio at the far-end (ACR-F) the difference, in dB, between the far-end crosstalk loss from a disturbing pair of a channel and the insertion lo