Tài liệu Cabling Standard - TSB-155 - IEEE 802.3an for Cat 6A 10GBase-T System - Draft 4.0 pdf

PN-3-0134 to be published as TSB-155 DRAFT 4.0 May 1, 2006 GUIDELINES FOR THE ASSESSMENT AND MITIGATION OF INSTALLED CATEGORY CABLING TO SUPPORT 10GBASE-T NOTICE OF DISCLAIMER AND LIMITATION OF LIABILITY 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 The document to which this Notice is affixed (the “Document”) has been prepared by one or more Engineering Committees or Formulating Groups of the Telecommunications Industry Association (“TIA”) TIA is not the author of the Document contents, but publishes and claims copyright to the Document pursuant to licenses and permission granted by the authors of the contents TIA Engineering Committees and Formulating Groups are expected to conduct their affairs in accordance with the TIA Engineering Manual (“Manual”), the current and predecessor versions of TIA’s which are available at http://www.tiaonline.org/standards/sfg/engineering_manual.cfm function is to 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REGULATION, OR THE SAFETY OR HEALTH EFFECTS OF THE CONTENTS OR ANY PRODUCT OR SERVICE REFERRED TO IN THE DOCUMENT OR PRODUCED OR RENDERED TO COMPLY WITH THE CONTENTS TIA SHALL NOT BE LIABLE FOR ANY AND ALL DAMAGES, DIRECT OR INDIRECT, ARISING FROM OR RELATING TO ANY USE OF THE CONTENTS CONTAINED HEREIN, INCLUDING WITHOUT LIMITATION ANY AND ALL INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF BUSINESS, LOSS OF PROFITS, LITIGATION, OR THE LIKE), WHETHER BASED UPON BREACH OF CONTRACT, BREACH OF Draft 4.0 i PN-3-0134 to be published as TSB-155 10 WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCT LIABILITY OR OTHERWISE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES THE FOREGOING NEGATION OF DAMAGES IS A FUNDAMENTAL ELEMENT OF THE USE OF THE CONTENTS HEREOF, AND THESE CONTENTS WOULD NOT BE PUBLISHED BY TIA WITHOUT SUCH LIMITATIONS 11 INTRODUCTION 12 PURPOSE AND SCOPE 13 REFERENCES .1 14 DEFINITIONS, ACRONYMS & ABBREVIATIONS .1 15 4.1 Definitions .1 16 4.2 Acronyms and abbreviations 17 TEST CONFIGURATIONS .2 18 19 20 21 22 5.1 5.3 Channel test configuration Figure – Schematic representation of a channel test configuration Permanent test configuration Figure – Schematic representation of a permanent link test configuration Alien Crosstalk test configurations 23 Alien crosstalk channel coupling parameters 24 6.1 ANEXT loss 25 6.1.1 Pair-to-pair ANEXT loss 26 6.1.2 27 6.1.2.1 Channel power sum ANEXT loss 28 6.1.2.2 Channel average power sum ANEXT loss 29 6.1.2.3 Power sum ANEXT loss adjustment 30 6.1.2.3.1 Power sum ANEXT constant 31 6.2 AFEXT loss and AELFEXT .7 32 6.2.1 Pair-to-pair AELFEXT 33 6.2.2 Power sum AELFEXT 34 6.2.2.1 Channel power sum AELFEXT 35 6.2.2.2 Channel average power sum AELFEXT 36 6.2.2.3 Power sum AELFEXT adjustment 37 6.2.2.3.1 Power sum AELFEXT constant 38 Category channel transmission parameters extended to 500 MHz 10 39 7.1 GUIDELINES FOR THE ASSESSMENT AND MITIGATION OF INSTALLED CATEGORY CABLING TO SUPPORT 10GBASE-T TABLE OF CONTENTS 5.2 Insertion loss .10 7.1.1 40 ii Power sum ANEXT loss Channel insertion loss 10 Draft 4.0 PN-3-0134 to be published as TSB-155 7.2 NEXT loss .11 7.2.1 Channel pair-to-pair NEXT loss 11 7.2.2 7.2.2.1 Channel power sum NEXT loss 12 7.3 Power sum NEXT loss 12 ELFEXT and FEXT loss 13 7.3.1 Channel pair-to-pair ELFEXT 13 7.3.2 7.3.2.1 Channel power sum ELFEXT 14 10 11 7.4 Return loss 15 7.4.1 7.5 Power sum ELFEXT 14 Channel return loss 15 Propagation delay/delay skew 16 12 7.5.1 Cabling propagation delay 16 13 7.5.2 Cabling propagation delay skew 16 14 Category permanent link transmission parameters extended to 500 MHz 16 15 8.1 Permanent link Insertion loss 16 16 8.2 Permanent link pair-to-pair NEXT loss 17 17 8.2.1 Permanent link power sum NEXT loss 18 18 8.3 Permanent link pair-to-pair ELFEXT .19 19 8.3.2 Permanent link power sum ELFEXT 20 20 8.4 Permanent link return loss .20 21 Annex A Cabling (field) measurement procedures 22 22 A.1 General 22 23 A.2 Frequency range 22 24 A.3 Test parameters 22 25 26 27 A.4 Test configurations 22 Figure A.1 – Schematic representation of a channel alien crosstalk test configuration 23 A.5 Channel Alien Crosstalk Field Testing 23 28 A.6 Measurement floor of the test device and patch/test cord power sum ANEXT loss 23 29 30 31 32 A.6.1.Measurement floor of the test device for the channel test configuration 23 Figure A.2 - Schematic diagram for testing the measurement floor of the channel test configuration 24 A.7 Alien Crosstalk measurements 24 33 34 35 36 37 A.7.1 Measuring power sum ANEXT loss in the channel configuration 24 Figure A.3 - Schematic diagram to measure channel power sum ANEXT loss 24 A.7.2 Measuring power sum AFEXT loss in the channel configuration .25 Figure A.4 - AFEXT loss measurement test configuration 25 A.8 General test strategies for alien crosstalk field testing 25 38 A.9 39 A.9.1 Significance condition testing .26 Processing measurement data 26 Draft 4.0 iii PN-3-0134 to be published as TSB-155 A.9.2 Computing the power sum ANEXT loss and power sum AELFEXT 26 A.9.3 Applying the correction for the measurement floor (optional) 27 Annex B Alien Crosstalk Mitigation 28 Annex B.1 Alien Crosstalk mitigation procedures 28 Annex C Alien Crosstalk Margin Computation .29 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 LIST OF FIGURES Figure – Schematic representation of a channel test configuration Figure – Schematic representation of a permanent link test configuration Figure A.1 – Schematic representation of a channel alien crosstalk test configuration 23 Figure A.2 - Schematic diagram for testing the measurement floor of the channel test configuration 24 Figure A.3 - Schematic diagram to measure channel power sum ANEXT loss 24 Figure A.4 - AFEXT loss measurement test configuration 25 LIST OF TABLES Table 1– Calculated power sum ANEXT constants Table 2– Calculated average power sum ANEXT constants Table 3– Calculated power sum AELFEXT constants Table 4– Calculated average power sum AELFEXT constants Table 5– Channel insertion loss 11 Table 6– Channel NEXT loss, worst pair-to-pair 12 Table 7– Channel power sum NEXT loss 13 Table 8– Channel ELFEXT, worst pair-to-pair 14 Table 9– Channel power sum ELFEXT 15 Table 10– Channel return loss equations 15 Table 11– Channel return loss 16 Table 12– Permanent link insertion loss 17 Table 13– Permanent link NEXT loss, worst pair-to pair 18 Table 14– Permanent link power sum NEXT loss 19 Table 15– Permanent link ELFEXT, worst pair-to-pair 19 Table 16– Permanent link power sum ELFEXT 20 Table 17– Permanent link return loss equations 20 Table 18– Permanent link return loss 21 Table 19 – Minimum Power Backoff 29 iv Draft 4.0 PN-3-0134 to be published as TSB-155 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FOREWORD (This foreword is not part of the Telecommunications Systems Bulletin) At the request of the Institute of Electrical and Electronics Engineers (IEEE) 802.3 Working Group, TIA agreed to create additional guidelines for 4-pair 100 Ω Category Cabling for 10GBASE-T Applications The project was assigned to TR-42.7 under Engineering Committee TR-42 TIA standards documents are developed within the Technical Committees of the TIA and the standards coordinating committees of the TIA standards board Members of the committees serve voluntarily and without commission The companies that they represent are not necessarily members of the TIA The standards developed within the TIA represent a consensus of the broad expertise on the subject This expertise comes from within the TIA as well as those outside of the TIA that have an expressed interest The viewpoint expressed at the time that this standard was approved was from the contributors’ experience and the state of the art at that time Users are encouraged to verify that they have the latest revision of the standard This telecommunications bulletin has been prepared by the TR-42.7 Subcommittee and approved by the Technical Committee TR-42 There are three annexes in this TSB Alien crosstalk field testing procedures and alien crosstalk mitigation guidelines are addressed in annex A and annex B respectively and an alien crosstalk margin computation is provided in annex C Draft 4.0 v PN-3-0134 to be published as TSB-155 1 The guidelines of this Telecommunications Systems Bulletin (TSB) contain additional recommendations to further characterize existing category cabling plant as specified in TIA568B.2-1 for 10GBASE-T applications This TSB includes field test procedures and field tester guidelines that can be used for this assessment INTRODUCTION NOTE - The terms “guidelines” and “recommendations” are used interchangeably within this Telecommunications Systems Bulletin PURPOSE AND SCOPE 10 11 12 13 14 15 16 17 18 19 This TSB describes additional guidelines to support the IEEE 802.3an 10GBASE-T standard for using 100 Ω, 4-pair category cabling meeting the requirements of TIA/EIA-568-B.2-1 This TSB characterizes the crosstalk coupling between 4- pair category cabling in close proximity referred to as alien crosstalk and provides additional guidelines for field test equipment and field test methods and alien crosstalk mitigation These guidelines provide additional information on the extended frequency transmission performance expected of category cabling extended from 250 MHz to 500 MHz The transmission parameter recommendations included herein provide a means to assess installations of category cabling, as specified in TIA/EIA-568-B.2-1 and corresponding addenda, up to the extended frequencies and for the additional parameters necessary to support 10GBASE-T This TSB does not specify any requirements for category cabling systems or components, beyond those already given in TIA-568B.2-1 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 The following standards are referenced in this text At the time of publication, the editions indicated were valid All standards are subject to revision; parties to agreements based on this TSB are encouraged to investigate the possibility of applying the most recent editions of the standards indicated ANSI and TIA maintain registers of currently valid national standards published by them ANSI/TIA/EIA-568-B.2-10, Transmission Performance Specifications for Pair 100 Ohm Augmented Category Cabling 38 39 4.1 Definitions 40 41 42 43 44 45 46 47 48 49 50 The generic definitions in this section have been formulated for use by the entire family of telecommunications infrastructure standards As such, the definitions not contain mandatory requirements of the Standard Specific requirements are found in the normative sections of this Standard REFERENCES ANSI/TIA/EIA-568-B.1, Commercial Building Telecommunications Cabling Standard Part 1: General Requirements ANSI/TIA/EIA-568-B.2, Commercial Building Telecommunications Cabling Standard Part 2: 100 Ohm Balanced Twisted-pair Cabling Standard ANSI/TIA/EIA-568-B.2-1, Transmission Performance Specifications for Pair 100 Ohm Category Cabling DEFINITIONS, ACRONYMS & ABBREVIATIONS Alien crosstalk: A measure of the unwanted signal coupling between cabling or components in close proximity Alien near-end crosstalk loss: A measure of the unwanted signal coupling between pairs in cabling in close proximity from transmit signals at the near-end into a pair measured at the nearend Draft 4.0 PN-3-0134 to be published as TSB-155 10 11 12 13 14 15 16 17 18 19 20 Power sum alien near-end crosstalk loss: A computation of the unwanted signal coupling between pairs in cabling in close proximity from multiple transmit signals at the near-end into a pair measured at the near-end Alien far-end crosstalk loss: A measure of the unwanted signal coupling between pairs in cabling in close proximity from transmit signals at the near-end into a pair measured at the far-end Power sum alien far-end crosstalk loss: A computation of the unwanted signal coupling between pairs in cabling in close proximity from multiple transmit signals at the near-end into another pair measured at the far-end Power sum alien equal level far-end crosstalk: A computation of the unwanted signal coupling between pairs in cabling in close proximity from multiple transmit signals at the near-end into another pair measured at the far-end, and relative to the received signal level Note: The definitions of equal level far-end crosstalk (ELFEXT) and power sum equal level farend crosstalk (PSELFEXT) as used in this standard are defined in ASTM D 4566 as attenuation to crosstalk ratio far end (ACR-F) and power sum attenuation to crosstalk ratio, far end (PSACRF) respectively 21 4.2 Acronyms and abbreviations 22 23 24 25 26 ANEXT PSANEXT AFEXT PSAFEXT PSAELFEXT 27 28 29 The following guidelines are for the assessment of the channel and permanent link transmission parameters over the frequency range of MHz to 500 MHz 30 5.1 Channel test configuration 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 The channel test configuration is used by system designers and users of telecommunications systems to verify the performance of the overall channel The channel includes up to 90 m (295 ft) of horizontal cable, a work area equipment cord, a telecommunications outlet/connector, an optional consolidation point connector, two connections in the telecommunications room, and an equipment cord The total length of equipment cords, patch cords or jumpers and work area cords does not exceed 10 m (32.8 ft) The channel configuration excludes the connections to the equipment at each end of the channel The channel definition does not apply to those cases where the horizontal cabling is cross-connected to the backbone cabling A schematic representation of the channel test configuration is illustrated in figure Alien near-end crosstalk Power sum alien near-end crosstalk Alien far-end Crosstalk Power sum alien far-end crosstalk Power sum alien equal level far-end crosstalk TEST CONFIGURATIONS Draft 4.0 PN-3-0134 to be published as TSB-155 Channel under test Work area equipment A B WA D C C1 CP E Equipment in TR C2 Legend Cables and cords Work area cord A Optional transition cabling B Horizontal cabling C Patch cord or jumper cable .D Telecommunications room equipment cord E Connecting hardware Telecommunications outlet/ connector WA optional consolidation point connector CP Horizontal cross-connect or interconnect C1, C2 Maximum length B + C 90 m (295 ft) A + D + E .10 m (32.8 ft) Figure – Schematic representation of a channel test configuration 10 11 12 13 14 15 5.2 Permanent test configuration The permanent link test configuration is used by installers and users of data telecommunications systems to verify the performance of permanently installed cabling The permanent link consists of up to 90 m (295 ft) of horizontal cabling and one connection at each end and may also include an optional transition/consolidation point connection The permanent link configuration excludes both the cable portion of the test equipment cord and the connection to the test instrument A schematic representation of the permanent link test configuration is illustrated in Figure Draft 4.0 PN-3-0134 to be published as TSB-155 Permanent link under test Test instrument F B C F Test instrument C1 Legend Cables and cords Connecting hardware Test equipment cord F Telecommunications outlet/ Optional transition cabling B connector……………………… WA Horizontal cabling C Consolidation point connector……… CP Horizontal cross-connect or Interconnect…………………… C1 WA CP Maximum length B + C 90 m (295 ft) Figure – Schematic representation of a permanent link test configuration 5.3 Alien Crosstalk test configurations 10 11 12 13 14 15 The alien crosstalk test configurations are used to assess the alien crosstalk performance between the disturbed pair and disturbing pairs of category channels 16 17 6.1 ANEXT loss 18 19 20 21 22 ANEXT loss is a measure of the unwanted signal coupling between pairs in cabling in close proximity from transmit signals at the near-end into a pair measured at the near-end AlNEXT loss is expressed in dB relative to the transmit signal level Since each channel can be disturbed by more than one other channel in close proximity, power sum alien near-end crosstalk (PSANEXT) loss is provided 23 6.1.1 Pair-to-pair ANEXT loss 24 25 26 Pair-to-pair ANEXT measurements are used in the calculation of power sum ANEXT recommendations given in Clause 6.1.2 and for the determination of threshold values for mitigation of power sum ANEXT in annex B 27 6.1.2 28 29 30 Power sum alien near-end crosstalk loss takes into account the combined crosstalk (statistical) on a receive pair from near-end disturbers in channels in close proximity The power sum nearend crosstalk (PSANEXT) loss is determined by summing the power of the individual pair-to-pair The transmission performance of the channel test configurations consists of single channels and therefore does not address the alien crosstalk test configurations 10GBASE-T is expected to operate over channel lengths of at least 37 meters (TBD) of Category cabling Channel lengths between 37 (TBD) and 55 meters are expected to support 10GBASE-T depending on the alien crosstalk environment Channel lengths over 55 meters may require mitigation (see Annex B in order to support 10GBASE-T) Alien crosstalk field testing procedures and alien crosstalk mitigation guidelines are addressed in annex A and annex B respectively An alien crosstalk margin computation is provided in annex C Alien crosstalk channel coupling parameters Power sum ANEXT loss Draft 4.0 PN-3-0134 to be published as TSB-155 differential ANEXT loss values over the frequency range MHz to 500 MHz as follows in equation (1): − ANEXT( f ) i, j , N m PSANEXTN ( f ) = −10 log ∑∑i =110 10 (dB) (1) j =1 10 11 12 13 Where: − ANEXT ( f ) i , j , N is the measured ANEXT of the individual pair combination (1 to 4) of the disturbing link (1 to m) for each disturbed pair N The alien crosstalk margin computation detailed in annex C may be applied in the event that the power sum ANEXT limits specified in 6.1.2.1 equation (2) or 6.1.2.2 equation (4) are not met The alien crosstalk margin computation further characterizes the alien crosstalk coupling "between" channels by evaluating the total combined power sum AFEXT and power sum ANEXT 14 6.1.2.1 Channel power sum ANEXT loss 15 16 17 18 19 The power sum ANEXT loss between a disturbed channel and the disturbing channels in cabling in close proximity should meet the values determined using equation (2) for each disturbed pair 20 f X − 10 log( ) dB ≤ f ≤ 100 100 PSANEXT ≥ f X − 15 log( ) dB 100 < f ≤ 500 100 (2) 21 22 23 24 25 26 27 28 29 The power sum ANEXT loss determined using equation (2) utilizes the power sum ANEXT constant determined using equation (5) The power sum ANEXT constant and the insertion loss at 250 MHz determined using equation (6), for channel lengths of 100 m and 55 m, are listed in table 30 Table 1– Calculated power sum ANEXT constants where: f is the frequency in MHz and X1 is the power sum ANEXT constant defined in 6.1.2.3.1 The calculated power sum ANEXT loss values greater that 67 dB are for information only 31 Channel Length 100 m 55 m PSANEXT constant (X1) (dB) 62 47 Insertion Loss at 250 MHz (dB) 35.9 20.3 32 33 6.1.2.2 Channel average power sum ANEXT loss 34 35 36 37 38 The average power sum ANEXT is calculated by averaging the individual power sum ANEXT loss values in dB for all four pairs in the disturbed channel at each frequency point as shown in equation (3) Draft 4.0 ... IEEE 802.3an 10GBASE-T standard for using 100 Ω, 4-pair category cabling meeting the requirements of TIA/EIA-568-B. 2-1 This TSB characterizes the crosstalk coupling between 4- pair category cabling. .. Telecommunications Cabling Standard Part 1: General Requirements ANSI/TIA/EIA-568-B.2, Commercial Building Telecommunications Cabling Standard Part 2: 100 Ohm Balanced Twisted-pair Cabling Standard. .. equation (5): Draft 4.0 PN- 3-0 134 to be published as TSB-155 10 11 12 PSANEXTcons tan t = 62 − (Cat _ IL _ 250MHZ − MCat _ IL _ 250MHZ ) ⋅ 15 dB 15.6 (5) where: - Cat _ IL _ 250MHZ is the Category