1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T G.996.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(03/2003) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Access networks Test procedures for digital subscriber line (DSL) t
2、ransceivers Amendment 1: New Annex B ITU-T Recommendation G.996.1 (2001) Amendment 1ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISS
3、ION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEP
4、HONY AND LINE TELEPHONY G.450G.499 TESTING EQUIPMENTS G.500G.599 TRANSMISSION MEDIA CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 General G.900G.909 Parameters for optical fibre cable systems G.910G.9
5、19 Digital sections at hierarchical bit rates based on a bit rate of 2048 kbit/s G.920G.929 Digital line transmission systems on cable at non-hierarchical bit rates G.930G.939 Digital line systems provided by FDM transmission bearers G.940G.949 Digital line systems G.950G.959 Digital section and dig
6、ital transmission systems for customer access to ISDN G.960G.969 Optical fibre submarine cable systems G.970G.979 Optical line systems for local and access networks G.980G.989 Access networks G.990G.999 QUALITY OF SERVICE AND PERFORMANCE G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 D
7、IGITAL TERMINAL EQUIPMENTS G.7000G.7999 DIGITAL NETWORKS G.8000G.8999 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) i ITU-T Recommendation G.996.1 Test procedures for digital subscriber line (DSL) transceivers Amendment 1 New Annex
8、B Summary The amendment adds a new Annex B to ITU-T Rec. G.996.1 that contains primary constants and disturbers for test loops for use in ADSL+ in an environment coexisting with TCM-ISDN DSL. Source Amendment 1 to ITU-T Recommendation G.996.1 (2001) was prepared by ITU-T Study Group 15 (2001-2004) a
9、nd approved under the WTSA Resolution 1 procedure on 16 March 2003. ii ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU
10、-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four y
11、ears, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the ne
12、cessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to th
13、e possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside o
14、f the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest info
15、rmation and are therefore strongly urged to consult the TSB patent database. ITU 2003 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) 1 ITU-T Recommendation G.996.1 Tes
16、t procedures for digital subscriber line (DSL) transceivers Amendment 1 New Annex B 1) New Annex B Add the following Annex B to ITU-T Rec. G.996.1: Annex B Test loops and crosstalk disturbers of ADSL transceivers with extended bandwidth for environment coexisting with TCM-ISDN DSL as defined in ITU-
17、T Rec. G.961 Appendix III B.1 Test loops B.1.1 Loop configurations To test the performance of ADSL transceivers with extended bandwidth, the test loops in Figure 11 and the associate loop lengths in Table 10 shall be used. B.1.2 Primary line constants The primary line constants are R, L, C, and G. T
18、he equations below give the values of R in ohm/m, L in H/m, G in mho/m, C in F/m, and f (frequency) in Hz. The equation of G only is modified to that defined in 6.1.3. The coefficient values are shown in Table B.1. The values of the exponent “ge“ contained in the equation of G are added in Table B.1
19、, and the other coefficient values are the same as those shown in Table 11. ()RnsRnRiR += 2 ohm/m LnsLnLiLaL += 2 H/m iCC =F/m= tan2 CfGgemho/m ()()=1022Re1JJrRiii; skin effect ()()=012Re1JJdRnii; intra-pair eddy current effect ()()=012Re41JJdRnsii; intra-quad eddy current effect =iirdLa ln20; exter
20、nal inductance 2 ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) ()()=101Re2 JJLii; skin effect ()()=0220Re2 JJdrLnii; intra-pair eddy current effect ()()=0220Re42 JJdrLnsii; intra-quad eddy current effect where: 210, JJJ: zero-, first-, and second-order Bessel functions Re : real part in ()iirj+ 1 ir : r
21、adius of conductor m iii=2: skin depth m i : conductivity of copper (conductor) mho/m 0 : permeability of vacuum H/m i : permeability of copper (conductor) H/m; 0=rr : relative permeability of copper (conductor) : angular frequency rad/m id : distance between wire (conductor) centers of a pair m : (
22、)iiiCOrd += 22 iCO : thickness of insulator for wire (conductor) m Table B.1/G.996.1 Coefficient values PaperPolyethyleneCoefficient 0.4 mm0.5 mm0.65 mm0.9 mm0.32 mm0.4 mm0.5 mm0.65 mm0.9 mmri m 0.2 103 0.25 103 0.325 103 0.45 103 0.16 103 0.2 103 0.25 103 0.325 103 0.45 103 COi m 0.09 103 0.11 103
23、0.17 103 0.24 103 0.05 103 0.13 103 0.15 103 0.20 103 0.27 103 ge 0.996 0.993 0.998 0.998 1.21 1.16 1.05 1.02 1.02 tan 2.5 1024.0 1045.0 104Ci F/m 50 1012i mho/m 5.8 1070 H/m 4 107r1 B.1.3 Line transfer function and test loop characteristics The line transfer function (of voltage) based on the propa
24、gation constant is given below. The transfer function assumes no impedance mismatch and perfect terminations by characteristic impedances at both ends, and is a simplified approximation. ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) 3 ()d= efH )( CjGLjR += where: d : loop length m : propagation constant
25、 The test loop characteristics for reference are presented in Tables B.2, B.3 and B.4 as results of calculation using the above line transfer function and the coefficient values. NOTE The insertion loss with a source impedance of R = 100 and a terminal impedance of R = 100 should be calculated by us
26、ing the loop ABCD parameters, and the result is loop length and composition dependent. Table B.2/G.996.1 Test loop image attenuation in dB for reference Frequency kHz Cable type Loop length 1 km 20 40 100 160 260 550 1100 2195 3750 0.4 mm 7.07 dB 8.82 11.0 12.6 15.3 22.7 33.9 50.4 69.0 0.5 mm 5.26 d
27、B 6.31 7.99 9.63 12.3 18.8 28.0 41.9 57.6 0.65 mm 3.55 dB 4.15 5.66 7.16 9.39 14.4 21.6 32.8 45.8 Paper 0.9 mm 2.14 dB 2.63 4.10 5.36 7.08 10.9 16.6 25.6 36.4 0.32 mm 9.23 dB 12.0 15.5 17.4 20.2 28.7 42.5 63.0 85.2 0.4 mm 6.89 dB 8.47 10.2 11.3 13.3 18.9 27.2 39.2 52.3 0.5 mm 5.09 dB 6.00 7.26 8.47
28、10.5 15.4 22.1 31.4 41.3 0.65 mm 3.42 dB 3.91 5.09 6.27 8.02 11.8 16.8 23.9 31.4 Polyethylene 0.9 mm 2.03 dB 2.42 3.61 4.60 5.92 8.68 12.4 17.6 23.1 Table B.3/G.996.1 Test loop group delay in s for reference Frequency kHz Cable type Loop length 1 km 20 40 100 160 260 550 1100 2195 3750 0.4 mm 5.53 s
29、 5.31 5.49 5.48 5.36 5.13 4.99 4.91 4.86 0.5 mm 5.32 s 5.38 5.47 5.35 5.19 5.01 4.91 4.85 4.81 0.65 mm 5.44 s 5.59 5.47 5.33 5.21 5.10 5.03 4.99 4.96 Paper 0.9 mm 5.60 s 5.56 5.30 5.20 5.13 5.06 5.01 4.98 4.96 0.32 mm 5.97 s 5.27 5.23 5.30 5.26 4.98 4.76 4.63 4.57 0.4 mm 5.70 s 5.52 5.74 5.75 5.66 5
30、.47 5.35 5.28 5.24 0.5 mm 5.48 s 5.57 5.69 5.60 5.47 5.30 5.22 5.16 5.13 0.65 mm 5.55 s 5.71 5.61 5.49 5.37 5.26 5.20 5.16 5.14 Polyethylene 0.9 mm 5.69 s 5.65 5.42 5.31 5.25 5.18 5.13 5.10 5.09 4 ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) Table B.4/G.996.1 Test loop characteristic impedance in for r
31、eference Frequency kHz Cable type 20 40 100 160 260 550 1100 2195 3750 0.4 mm 214 161 127 120 115 110 105 102 100 0.5 mm 176 140 120 116 112 106 103 100 98.7 0.65 mm 147 127 117 114 110 106 104 102 101 Paper 0.9 mm 128 119 113 110 107 104 102 101 100 0.32 mm 264 191 137 124 117 109 103 98.5 95.8 0.4
32、 mm 215 162 130 124 120 115 112 109 107 0.5 mm 177 142 123 119 116 111 108 106 105 0.65 mm 148 129 119 116 113 109 107 105 104 Polyethylene 0.9 mm 129 121 114 112 109 107 105 104 103 B.2 Crosstalk disturbers B.2.1 Disturber types Crosstalk margin measurements are performed with several types of dist
33、urbers, extended-bandwidth-ADSL self, TCM-ISDN DSL (Appendix III/G.961) and VDSL (ITU-T Rec. G.993.1). Two kinds of noise models are defined as follows. Noise A and Noise Bj(j = 1-3). Noise A only or Noise A + each Noise Bj (j = 1 or 2) shall be injected at each central office or customer premises s
34、ide end. Noise A + Noise B3 shall be injected at the only customer premises side end. The test should be performed several (3-4) times. A combination Noise Bjand Bk(jk) is not used for performance test. Also, simultaneous injection at both central office and customer premises side ends is not used.
35、Noise A = 140 dBm/Hz AWGN (Additive White Gaussian Noise) Noise B1= 24 extended-bandwidth-ADSL self NEXT and FEXT Noise B2= 24 TCM-ISDN DSL (Appendix III/G.961) alternate NEXT and FEXT (see ITU-T Rec. G.996.1 as for the disturber PSD) Noise B3= 9 VDSL (ITU-T Rec. G.993.1) NEXT and in-equal level cou
36、pled FEXT (see Annex F/G.993.1 as for the disturber PSD) TCM-ISDN DSL NEXT and FEXT appear alternately in the same frequency band, and are cyclostationary. Annex B adopts cyclostationary crosstalk injection of NEXT and FEXT as defined in 7.9.3. The loop length of VDSL disturbers shall be fixed at 15
37、0 m and shall not be adjustable, drawing upward to a central office side from a customer premises side end. Namely, an in-equal level coupling of FEXT from VDSL to extended-bandwidth-ADSL is considered, and the only 0.4 mm polyethylene-insulated cable is considered as the coupling path. The disturbe
38、r loop length of 150 m is determined as a typical length of the most significant interference. NOTE Extended-bandwidth-ADSL NEXT and VDSL NEXT injection is for testing input signal dynamic range of an extended-bandwidth-ADSL receiver. ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) 5 B.2.2 Power sum loss
39、of crosstalk NEXT and FEXT PSL values for 24 disturbers with 1% worst case are shown in Table 25, which are used for generating the simulated Noise B1and B2. NEXT and FEXT PSL values for 9 disturbers with 1% worst case are shown in Table B.5, which are used for generating the simulated Noise B3, whe
40、re only a polyethylene-insulated cable is considered because an in-equal level FEXT coupling from VDSL to ADSL arises mostly within intra- user-building cables and all of them are polyethylene-insulated. Table B.5/G.996.1 Power sum loss values for 9 disturbers with 1% worst case Insulation material
41、of pair conductor NEXT/FEXT power sum loss Polyethylene-insulated Condition NPSL9dB 49.5 dB At fNEXT= 160 103Hz FPSL9dB 51.5 dB At fFEXT= 160 103Hz At dFEXT= 1 103m B.2.3 Power spectral density of disturbers The single-sided power spectral density (PSD) functions in watts/Hz are abbreviated by PSDxD
42、SL-DS(f) and PSDxDSL-US(f) in watts/Hz below for downstream and upstream, respectively. PSDxDSL-DS(f) and PSDxDSL-US(f) for TCM-ISDN DSL disturber are defined in 7.9.3.1, and those for VDSL are defined in F.3.2.2.1/G.993.1. As for extended-bandwidth-ADSL, they are specified in the related ITU-T Reco
43、mmendations. B.2.4 Power spectral density of crosstalk XT (crosstalk) PSD for each xDSL disturber is given by multiplying the xDSL disturber PSD and the XT power coupling function. B.2.4.1 Crosstalk power coupling function XT (crosstalk) power coupling functions XT(f) are given below for cases of NE
44、XT and FEXT. NEXT power coupling function for use of Noise B1, B2and B3is as follows. ()231010=NEXTNPSLdisturberdisturbedNEXTffZZfXTnFEXT power coupling function for use of Noise B1and B2is as follows. The bridged taps (BTs) shall not be incorporated in the simulated FEXT disturber PSD as a part of
45、the FEXT coupling path. () 21022410=FEXTkFEXTkkFPSLdkdisturberdisturbedFEXTffdde ZZfXTkkFEXT power coupling function for use of Noise B3is as follows. The bridged taps (BTs) shall not be incorporated in the simulated FEXT disturber PSD as a part of the FEXT coupling path. ()=FEXTxFEXTFPSLddisturberd
46、isturbedFEXTddffeZZfXTxx2102910 6 ITU-T Rec. G.996.1 (2001)/Amd.1 (03/2003) where: f : frequency in Hz NPSLn : NEXT PSL value with n disturbers FPSL24k: FEXT PSL value with 24 disturbers for each segment k consisting test loop k : the propagation constant of each segment k consisting test loop dk :
47、length of each segment k consisting test loop in m fFEXT= 160 103Hz dFEXT= 1 103m Zdisturbed: termination impedance of disturbed extended-bandwidth-ADSL (= 100 ) disturber: termination impedance of disturbing xDSL 100 : for extended-bandwidth-ADSL and VDSL 110 : for TCM-ISDN x : the propagation cons
48、tant of the 0.4 mm polyethylene-insulated cable dx= 150 m FPSL9 : FEXT PSL value with 9 disturbers for the polyethylene-insulated cable NOTE 1 The NEXT power coupling function of XTNEXT(f) is a function of a coupling path length, to be exact, as expressed below. However, Annex B does not adopt the equation below so as to reduce test parameters. () ( )dNEXTNPSLdisturberdisturbedNEXTeffZZfXTn=43210110 NOTE 2 FEXT of Noise
