ITU-T G 992 1 ANX H-2000 Asymmetric Digital Subscriber Line (ADSL) Tranceivers Annex H Specific Requirements for a Sychronized Symmetrical DSL (SSDSL) System Operating in the Same 1 A.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TE LEC0 MM UN I CATI0 N STANDARDIZATION SECTOR OF ITU G.992.1 Annex H (1 0/2000) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system - Access networks Asymmetric digital subscriber line (ADSL) tra

2、nsceivers Annex H: Specific requirements for a synchronized symmetrical DSL (SSDSL) system operating in the same cable binder as ISDN as defined in ITU-T G.961 Appendix 111 ITU-T Recommendation G.992.1 - Annex H (Formerly CCITT Recommendation) ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND

3、MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS TRANSMISSION SYSTEMS INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE METALLIC LINES COORDINATION OF RADIOTELEPHONY A

4、ND LINE TELEPHONY TESTING EQUIPMENTS TRANSMISSION MEDIA CHARACTERISTICS DIGITAL TERMINAL EQUIPMENTS DIGITAL NETWORKS DIGITAL SECTIONS AND DIGITAL LINE SYSTEM GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER- SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH General Parameters

5、for optical fibre cable systems Digital sections at hierarchical bit rates based on a bit rate of 2048 kbit/s Digital line transmission systems on cable at non-hierarchical bit rates Digital line systems provided by FDM transmission bearers Digital line systems Digital section and digital transmissi

6、on systems for customer access to ISDN Optical fibre submarine cable systems Optical line systems for local and access networks G.lOO-G.199 G.200-G.299 G.300-G.399 G.400-G.449 G.450-G.499 G.500-G.599 G.600-G.699 G.700-G.799 G. 800-6.899 G.900-G.999 G.900-G.909 G.9 10-G.9 19 G.920-G.929 G.930-G.939 G

7、. 940-G. 949 G.950-G.959 G.960-G.969 G.970-G.979 For further details, please refer to the list of ITU-T Recommendations. ITU-T Recommendation G.992.1 Asymmetric digital subscriber line (ADSL) transceivers ANNEX H Specific requirements for a synchronized symmetrical DSL (SSDSL) system operating in th

8、e same cable binder as ISDN as defined in ITU-T G.961 Appendix III Summary This annex describes those specifications that are unique to Synchronized Symmetrical Digital Subscriber Line (SSDLS) transceivers for use in the same cable binder as TCM-ISDN defined in ITU-T G.961 Appendix III. The SSDSL tr

9、ansmission method allows symmetric data rates in the range of 192 kbit/s to 1.6 Mbit/s with 32 kbit/s granularity using a scheme synchronized with TCM-ISDN. Source Annex H to ITU-T Recommendation G.992.1 was prepared by ITU-T Study Group 15 (1997-2000) and approved by the World Telecommunication Sta

10、ndardization Assembly (Montreal, 27 September - 6 October 2000). ITU-T G.992.UAnnex H 10/2000) i FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permane

11、nt 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 years, establishe

12、s 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 necessary standard

13、s are prepared on a collaborative basis with IS0 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 the possibility th

14、at 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 of the Recommenda

15、tion 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 information and are

16、therefore strongly urged to consult the TSB patent database. O ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. ITU-T G.992.UAnn

17、ex H (10/2000) 11 CONTENTS Page 1 H . 1 H.2 H.3 H.4 H.5 H.6 H.7 H.8 Scope Definitions Reference Models . H.3.1 System reference model H.3.2 H.3.3 H.3.4 Transport capacity (supplements clause 6) . H.4.1 H.4.2 ATU-C transmitter reference model (replaces figures in 5.1) . ATU-R transmitter reference mo

18、del (replaces figures in 5.2) . ATU-C/R transmitter timing model (replacement for 5.3) . Transport of STM data (supplements 6.1) Transport of ATM data (supplements 6.2) ATU-C functional characteristics (supplements clause 7) . STM transmission protocol specific functionality (pertains to 7.1) ATM tr

19、ansmission protocol specific functionalities (pertains to 7.2) . H.5.1 H.5.2 H.5.3 H.5.4 H.5.5 H.5.6 Framing (pertains to 7.4) . Bitmapping and rate conversion (replaces 7.15) . Modulation (pertains to 7.1 1) ATU-C downstream transmit spectral mask (replaces 7.14) ATU-R functional characteristics (s

20、upplements clause 8) . STM transmission protocols specific functionalities (pertains to 8 . 1) ATM transmission protocols specific functionalities (pertains to 8.2) . Bitmapping and rate conversion (replaces 8.15) . ATU-R upstream transmit spectral mask (supplements 8.14) EOC operations and maintena

21、nce (pertains to clause 9) H.6.1 H.6.2 H.6.3 H.6.4 H.6.5 H.6.6 Framing (pertains to 8.4) . Modulation (pertains to 8.1 1) H.7.1 ADSL line related primitives (supplements 9.3.1) H.7.2 Test Parameters (supplements 9.5) Initialization H.8.1 Initialization with hyperframe (replaces 1 O . 1.5) . H . 8.2

22、H . 8.3 H.8.4 H . 8.5 H.8.6 H.8.7 H . 8.8 H . 8.9 Handshake - ATU-C (supplements 10.2) . Handshake - ATU-R (supplements 10.3) . Transceiver training - ATU-C (supplements 10.4) . Transceiver training - ATU-R (supplements 10.5). Channel analysis (ATU-C) (supplements 10.6) Channel analysis (ATU-R) (sup

23、plements 10.7) Exchange - ATU-C (supplements 1 O . 8) . Exchange - ATU-R (supplements 10.9). . 1 2 2 3 5 7 9 9 9 9 10 11 11 16 17 18 18 19 19 19 23 24 24 24 24 25 25 25 29 29 30 31 31 32 33 33 . ITU-T G.992.UAnnex H (10/2000) 111 Page 37 H.9 AOC on-line adaptation and reconfiguration (pertains to cl

24、ause 11) . H.9.1 Bit swap acknowledge (supplements 11.2.5) 37 H. 1 O Electrical characteristic (new) 37 L1 -to-L2 capacitance (new) H. 1 O. 1 37 iv ITU-T G.992.UAnnex H (10/2000) ITU-T Recommendation G.992.1 Asymmetrical digital subscriber line (ADSL) transceivers ANNEX H Specific requirements for a

25、 synchronized symmetrical DSL (SSDSL) system operating in the same cable binder as ISDN as defined in ITU-T G.961 Appendix III H.l Scope This annex describes those specifications that are unique to Synchronized Symmetrical Digital Subscriber Line (SSDSL) transceivers for use in the same cable binder

26、 as TCM-ISDN defined in ITU-T G.961 Appendix III. This SSDSL transmission method allows symmetric data rates in the range of 192 kbit/s to 1.6 Mbit/s with 32 kbit/s granularity using a scheme synchronized with TCM-ISDN. 1.544 Mbit/s STM data transport capability is optionally supported. SSDSL transc

27、eivers can provide digital data service on the same twisted pair with voiceband services (including POTS and voiceband data services). The SSDSL transmission scheme occupies a frequency band above the voiceband, and may be separated from it by filtering. Optionally when POTS service and filtering ar

28、e not utilized, frequencies below 26 kHz including the voiceband may be used in the EFT mode. The clauses in this annex provide supplementary and replacement material to the clauses in the main body. The nature of the material is parenthetically indicated in the clause heading. H.2 Definitions This

29、annex defines the following terms: H.2.1 SSDSL: Synchronized Symmetrical DSL. H.2.2 and above for data transmission. H.2.3 tones #1 to #5 for data transmission. H.2.4 TTR: TCM-ISDN Timing Reference. H.2.5 H.2.6 H.2.7 H.2.8 Bitmap- .! SPFM v:- .! i Hyperframe = 345 symbols (85 ms) 4 Superframe (SPF#O

30、) = 69 symbils (17 ms) i SPF#1 i SPF#2 n n II i_ n u 1 symbol = 264 ps (544 samples) w 1-I o El i Sliding window Inverse synch symbol Symbol using Bitmap-H, (FEXT, duration bitmap) NEXT, symbol FEXT, Synch symbol Figure H.lO/G.992.1 - Hyperframe structure for downstream TI 535490-00 ITU-T G.992.UAnn

31、ex H (10/2000) 13 TTRc - O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Figure H.lUG.9 u r i 1 I Inverse synch symbol FEXT, Synch symbol FEXT, symbol NEXT, symbol TI 535500-00 192.1 - Symbol pattern in a hyperframe with cyclic prefix - Downstre am 14 ITU-

32、T G.992.UAnnex H (10/2000) H.5.3.3 Subframe structure (replaces 7.4.1.4) A subframe is 10 consecutive DMT symbols (except for those noted in Table H.l). The 34 subframes form a hyperframe. Table H.UG.992.1 - S Subframe No. DMT symbol No. ibframe (downstream) No te I O I 0-9 I 1 I 10-19 I 2 I 20-29 I

33、 3 I 30-39 I 4 I 40-49 I 5 I 50-59 I 6 I 60-70 11 DMT symbols for this subframe I I 7 I 71-80 8 81-90 9 91-100 10 101-1 10 11 11 1-120 12 121-130 13 131-141 14 142-151 11 DMT symbols for this subframe I I 15 I 152-16 I I 16 I 162-171 I 17 I 172-181 I 18 I 182-19 I I 19 I 192-20 I I 20 I 202-212 #206

34、 is Synch Symbol I I 21 I 213-222 I 22 I 223-232 I 23 I 233-242 24 243-252 25 253-262 26 263-272 27 273-283 28 284-293 29 294-303 30 304-3 13 #275 is Inverse Synch Symbol I 31 I 314-323 I 32 I 324-333 I 33 I 334-344 11 DMT symbols for this subframe I ITU-T G.992.UAnnex H (10/2000) 15 H.5.3.4 A speci

35、al framing mode is optionally specified to support symmetric 1.544 Mbit/s STM data rate, which is not a multiple of 32 kbit/s, as below. This framing mode shall be selected during handshake process as specified in H.8.2 and H.8.3. See Table H.2. Framing for 1.544 Mbit/s STM data mode (new) (Fast buf

36、fer only) Fast byte format Table H.2/G.992.1- Overhead functions for framing modes for 1.544 Mbit/s STM data support (Interleaved buffer only) Sync byte format I 1.544 Mbit/s STM data Overhead mode 1 34 35 Frame Number IBO-7 IBO-7 IB8-15 IB8-15 IB 16-23 IB16-23 Remainder 8 kbit/s of LSO O I Fast CRC

37、 I Interleaved CRC Remainder 8 kbit/s of LSO 65 8n + 4, 8n + 5 with n = O .7, 64 Dummy byte Dummy byte 4n + 2,4n + 3 withn= 0.16, n # 8 8n, 8n + 1 EOC or sync (Note) EOC or sync (Note) AOC AOC with n = 1 .7 NOTE - In the reduced overhead mode, only the “no synchronization action“ code shall be used.

38、 H.5.4 H.5.4.1 Bitmapping (new) Data transmission is only allowed by FEXTR symbols using Bitmap-HR, which is synchronized with the sliding window pattern of NEXTR/FEXTR symbols. H.5.4.2 Rate converter (new) The rate converter buffering changes the data frame boundaries between the reference points B

39、 and C according to Bitmap-HR and the Sliding Window. The rate converter has to be prepared for each interleaved path and fast path independently. The relation of data amount at the reference points B and C shall be calculated with the following formulae. Bitmapping and rate conversion (replaces 7.1

40、5) For the interleaved path, tR is selected so that: - - - 1261 symbol 1.(/. -11- hyperframe symbol a) and (S + 271 O) subcarriers in the NEXT or FEXT bitmap, whichever results in the highest average gain. The sync symbol reference transmit PSD shall not be updated with used subcarrier gain changes

41、during SHOWTIME. Gain scaling in synchronization symbol (new) 2 2 2 H.6.6 ATU-R upstream transmit spectral mask (supplements 8.14) The upstream spectral mask is the same as the downstream transmit spectral mask in H.5.6. All PSD and power measurements shall be made using only the whole period of the

42、 FEXTc duration at the U-R interface. H.7 EOC operations and maintenance (pertains to clause 9) H.7.1 ADSL line related primitives (supplements 9.3.1) H.7.1.1 Two near-end defects are further defined: ADSL line related near-end defects (supplements 9.3.1.3) e Loss-ofsignal (LOS): The ADSL power shal

43、l be measured only in the FEXTc duration at Severely erroredframe (SEF): A SEF defect occurs when the content of two consecutively ATU-C, or only in the FEXTR duration at ATU-R. received ADSL synchronization symbols in the FEXTc duration at ATU-C, or in the FEXTR duration at ATU-R, does not correlat

44、e with the expected content over a subset of the tones. An SEF defect terminates when the content of two consecutively received ADSL synchronization symbols in the FEXTc duration at ATU-C, or in the FEXTR duration at ATU-R, correlate with the expected contents over the same subset. The correlation m

45、ethod, the selected subset of tones, and the threshold for declaring these defect conditions are implementation discretionary. e H.7.1.2 Loss-of-signal is further defined: ADSL line related far-end defects (supplements 9.3.1.4) e Loss-ofsignal (LOS): The ADSL power shall be measured only in the FEXTc duration at ATU-C, or only in the FEXTR duration at ATU-R. 24 ITU-T G.992.UAnnex H (10/2000)