1、 International Telecommunication Union ITU-T G.825TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(05/2008) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital networks Quality and availability targets The control of jitter and wander within digital networks whi
2、ch are based on the synchronous digital hierarchy (SDH) Amendment 1 Recommendation ITU-T G.825 (2000) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO
3、ALL ANALOGUE CARRIER-TRANSMISSION 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.
4、449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 General aspects G.800G.809 Design objectives for digital networks G.810G.819 Quality and availability
5、targets G.820G.829 Network capabilities and functions G.830G.839 SDH network characteristics G.840G.849 Management of transport network G.850G.859 SDH radio and satellite systems integration G.860G.869 Optical transport networks G.870G.879 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 QUALITY
6、OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Reco
7、mmendations. Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) i Recommendation ITU-T G.825 The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH) Amendment 1 Summary Amendment 1 to Recommendation ITU-T G.825 contains the STM-256 rate jitter paramet
8、ers and specifications. Source Amendment 1 to Recommendation ITU-T G.825 (2000) was approved on 22 May 2008 by ITU-T Study Group 15 (2005-2008) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) FOREWORD The International Telecommunication Union (ITU) is the United
9、Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendati
10、ons on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approva
11、l 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 standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration
12、 is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance wi
13、th the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is requir
14、ed of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the 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 Intellectu
15、al Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. Howe
16、ver, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the pr
17、ior written permission of ITU. Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) iii CONTENTS Page 1 Scope 1 2 Changes to Recommendation ITU-T G.825. 1 2.1 Modifications to clause 2 1 2.2 Modifications to clause 5.1, network limits for jitter . 1 2.3 Modifications to clause 6.1.2.4, STM-64 jitter tolerance. 2
18、 2.4 New clause 6.1.2.5, STM-256 jitter tolerance 2 Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) 1 Recommendation ITU-T G.825 The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH) Amendment 1 1 Scope This amendment contains material to be adde
19、d to Recommendation ITU-T G.825 in terms of STM-256, 40 Gbit/s rate signals. 2 Changes to Recommendation ITU-T G.825 The following clauses contain changes to be made to Recommendation ITU-T G.825. 2.1 Modifications to clause 2 Add the two following references to clause 2: Recommendation ITU-T G.693
20、2006), Optical interfaces for intra-office systems. Recommendation ITU-T G.959.1 (2006), Optical transport network physical layer interfaces. 2.2 Modifications to clause 5.1, network limits for jitter Add the STM-256 values to Table 1, and delete the obsolete note concerning STM-64, as follows: Tab
21、le 1 Maximum permissible jitter at network interfaces Interface Measurement bandwidth, 3 dB frequencies (Hz) Peak-to-peak amplitude (UIpp) 500 to 1.3 M 1.5 STM-1e (Notes 1, 2) 65 k to 1.3 M 0.075 500 to 1.3 M 1.5 STM-1 (Note 3) 65 k to 1.3 M 0.15 1 k to 5 M 1.5 STM-4 (Note 3) 250 k to 5 M 0.15 5 k t
22、o 20 M 1.5 STM-16 (Note 3) 1 M to 20 M 0.15 20 k to 80 M 1.5 STM-64 (Note 3) 4 M to 80 M 0.15 (Note 3) 2 Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) Table 1 Maximum permissible jitter at network interfaces Interface Measurement bandwidth, 3 dB frequencies (Hz) Peak-to-peak amplitude (UIpp) 80 k to 320 M
23、 1.5 STM-256 (Note 3) 16 M to 320 M 0.18 NOTE 1 Electrical format CMI-encoded, according to G.703. NOTE 2 For networks deployed with G.813 Option II clocks or G.812 Type II, III or IV clocks, STM-1 requirements apply to STM-1e. NOTE 3 The effect of dispersion and non-linearities on the eye opening a
24、nd on the choice of this value is for further study. NOTE 3 STM-1 1 UI = 6.43 ns STM-4 1 UI = 1.61 ns STM-16 1 UI = 0.402 ns STM-64 1 UI = 0.100 ns STM-256 1 UI = 0.025 ns 2.3 Modifications to clause 6.1.2.4, STM-64 jitter tolerance In clause 6.1.2.4, delete the following text: For the purposes of p
25、ractical conformance testing, the characteristics of the transmit eye mask need to be carefully considered. This is for further study. 2.4 New clause 6.1.2.5, STM-256 jitter tolerance Insert a new clause 6.1.2.5 as follows: 6.1.2.5 STM-256 jitter tolerance The level of jitter that must be accommodat
26、ed by STM-256 SDH interfaces is specified in Table 8 and illustrated in Figure 6. Table 8 STM-256 input jitter and wander tolerance limit Frequency f (Hz) Requirement (Peak-Peak) 2048 kbit/s networks 1544 kbit/s networks 10 f 1184 17760 f1UI 1184 f 8 k 15 UI 10 f 12.1 9953 UI (0.25 s) 12.1 f 8 k 1.2
27、 x 105f1UI 8 k f 80 k 1.2 x 105f1UI 80 k f 1.92 M 1.5 UI 1.92 M f 16 M 2.88 x 106f1UI 16 M f 320 M 0.18 UI Rec. ITU-T G.825 (2000)/Amd.1 (05/2008) 3 NOTE The dashed curve is the requirement for 1544 kbit/s networks for frequencies less than 2 kHz. Figure 6 STM-256 jitter tolerance Printed in Switzer
28、land Geneva, 2009 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems a
29、nd media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, install
30、ation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone t
31、ransmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
