1、 STD-ETSI PRETS 300 462-4-ENGL 1778 3400855 0275303 TO2 m I EUROPEAN T I ELECOMMUNICATION STANDARD FINAL DRAFT pr ETS 300 462-4 March 1998 Source: TM Reference: DE/TM-03017-4 ICs: 33.020 Key words: Synchronization, transmission, SDH, PDH Transmission and Multiplexing (TM); Generic requirements for s
2、ynchron izat ion networks; Part 4: Timing characteristics of slave clocks suitable for synchronization supply to Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment ETSI European Telecommunications Standards Institute ETSI Secretariat Postai address: F-O6921 Soph
3、ia Antipolis CEDEX - FRANCE Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat Qetsi.fr Tel .: +33 4 92 94 42 O0 - Fax: +33 4 93 65 47 16 Copyright Notification: No part may be reproduced except as authori
4、zed by written permission. The copyright and the foregoing restriction extend to reproduction in all media. O European Telecommunications Standards Institute 1998. All rights resewed. COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling ServicesSTD=ETSI PRETS 300
5、 462-4-ENGL 1998 m 3iJnO55 0275304 949 m Page 2 Final draft prETS 300 462-4: March 1998 Whilst every care has been taken in the preparation and publication of this document, errors in content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETSI
6、Editing and Committee Support Dept.“ at the address shown on the title page. COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling Services . STD.ETS1 PRETS 300 462-4-ENGL 1998 3400855 0275305 85 Page 3 Final draft prETS 300 462-4: March 1998 Contents Foreword 5 1
7、 2 3 4 5 6 7 8 9 10 Scope . 7 Normative references 7 Definitions. abbreviations and symbols 8 3.1 Definitions _ . 8 3.2 Abbreviations . 8 3.3 Symbols 8 Frequency accuracy. -8 Pull-in and pull-out ranges 8 Noise generation . 9 6.1 Wander in locked mode 9 6.2 Non-locked wander . 1D 6.3 Jitter 10 Outpu
8、t jitter at a 2 048 kHz and 2 048 kbit/s interface 11 Output jitter at a Synchronous Transport Module N (STM-N) interface 11 6.3.1 6.3.2 Noise tolerance . 11 7.1 Jitter tolerance . 12 7.2 Wander tolerance 12 Transfer characteristic . 14 Transient response and holdover performance 15 9.1 Phase respon
9、se during input reference switching . 15 9.2 Phase response during hold-over operation 16 9.3 Phase response to input signal interruptions . 17 9.4 Phase discontinuity 17 Interfaces 18 Annex A (informative): Annex B (informative): B.1 Functional model of TDEV noise generator . 23 Annex C (informativ
10、e): Bibliography . 24 History . 25 Information on the SSU noise model 19 Measurement method for combined noise transfer and noise generation . 22 COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling ServicesSTD.ETS1 PRETS 300 4b2-4-ENGL 2778 0 3406855 0275306 711
11、 0 Page 5 Final draft prETS 300 462-4: March 1998 Foreword This final draft European Telecommunication Standard (ETS) has been produced by the Transmission and Multiplexing (TM) Technical Committee of the European Telecommunications Standards institute (ETSI), and is now submitted for the Voting pha
12、se of the ETSI standards approval procedure. This ETS provides requirements for synchronization networks that are compatible with the performance requirements of digital networks. This ETS consists of 6 parts as follows: Part 1: “Definitions and terminology for synchronization networks“ Part 2: “Syn
13、chronization network architecture“ Part 3: “The control of jitter and wander within synchronization networks“ Part 4: “Timing characteristics of slave clocks suitable for synchronization supply to Synchronous Digltal Hierarchy (SDH) and Piesiochronous Digital Hierarchy (PDH) equipment“. Part 5: “Tim
14、ing characteristics of slave clocks suitable for operation in Synchronous Digital Hierarchy (SDH) equipment“. Part 6: “Timing characteristics of primary reference clocks“. Proposed transposition dates Date of latest announcement of this ETS (doa): 3 months after ETSI publication Date of latest publi
15、cation of new National Standard or endorsement of this ETS (doph): 6 months after doa I Date of withdrawal of any conflicting National Standard (dow): 6 months after doa Previous page is blank COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling ServicesSTD-ETSI
16、PRETS 300 462-4-ENGL 1778 W 3400855 0275307 b5 Page 7 Final draft prETS 300 462-4: March 1998 1 Scope This European Telecommunication Standard (ETS) outlines requirements for timing devices called Synchronization Supply Units (SSUs) used in synchronizing network equipment in the Synchronous Digital
17、Hierarchy (SDH) transport network and the Public Switched Telephone Network (PSTN) network. NOTE 1: The requirements in this ETS apply under environmental conditions according to one of the environmental classes defined in ETS 300 O19 l, unless stated otherwise. The manufacturer will need to specify
18、 to which specific environmental class an equipment belongs. A description of the Synchronization Supply Unit (SSU) logical function is given in figure 1 in ETS 300 462-2 131. In general, the SSU will have multiple timing reference inputs and in the event that all timing references fail, the SSU sho
19、uld be capable of maintaining operation (holdover) within prescribed performance limits as detailed in this ETS. The requirements laid down in this ETS decribe the minimum performance of an SSU applied as a transit node clock. It is recognized that local node clock applications for SSUs exist, requi
20、ring different parameters. Those are for further study. NOTE 2: There can be situations in which more stringent requirements are applicable, for instance, in cases where an SSU has only one independent reference (e.g. due to limitations in the network topology). The SSU function can be implemented i
21、n a separate piece of equipment called a Stand-Alone Synchronization Equipment (SASE) or it can form a logical function of another equipment such as a telephony exchange or an SDH crossconnect. The requirements specified in this ETS refer to the design of new synchronization networks and consequentl
22、y they do not necessarily represent the performance of existing synchronization networks and equipment. A timing device within SDH equipment can also conform to ETS 300 462-5 5. 2 Normative references This ETS incorporates by dated or undated reference, provisions from other publications. These norm
23、ative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references subsequent amendments to, or revisions of, any of these publications apply to this ETS only when incorporated in it by amendments or revisions. For undated references the
24、latest edition of the publication referred to applies. 1 31 41 i51 ETS 300 O1 9: “Equipment Engineering (EE); Environmental conditions and environmental tests for telecommunications equipment“. ETC 300 462-1 : “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Pa
25、rt 1 : Definitions and terminology for synchronization networks“. ETS 300 462-2: “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 2: Synchronization network architecture“. ETS 300 462-3: “Transmission and Multiplexing (TM); Generic requirements for synchro
26、nization networks; Part 3: The control of jitter and wander within synchronization networks“. ETS 300 462-5: “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 5: Timing characteristics of slave clocks suitable for operation in Synchronous Digital Hierarchy
27、(SDH) equipment“. ETS 300 462-6: “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 6: Timing characteristics of primaly reference clocks“. Previous page is blank COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling Servi
28、cesSTD.ETS1 PRETS 300 4b2-4-ENGL 1778 0 3400855 0275308 594 m Page 8 Final draft prETS 300 462-4: March 1998 71 91 ETS 300 166: “Transmission and Multiplexing (TM); Physical and electrical characteristics of hierarchical digital interfaces for equipment using the 2 048 kbit/s-based pleisiochronous o
29、r synchronous digital hierarchies“. ITU-T Recommendation G.825: “The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH)“. ITU-T Recommendation G.823: “The control of jitter and wander within digital networks which are based on the 2 048 kb
30、it/s hierarchy“. 3 Definitions, abbreviations and symbols 3.1 Def i niti on c For the purposes of this ETC, the definitions given in ETS 300 462-1 2 apply. 3.2 Abbreviations For the purposes of this ETS, the following abbreviations apply: MTIE NE PDH P LL PPm P STN SASE SDH SEC ssu STM-N TDEV UI UlP
31、P VCO Maximum Time Interval Error Network Element Plesiochronous Digital Hierarchy Phase Locked Loop parts per million Public Switched Telephone Network Stand Alone Synchronization Equipment Synchronous Digital Hierarchy SDH Equipment Clock Synchronization Supply Unit Synchronous Transport Module-N
32、Time DEViation Unit Interval Unit Interval peak to peak Voltage Controlled Oscillator A full list of abbreviations used in timing and synchronization is listed in ETS 300 462-1 2. 3.3 S y m bo Is For the purposes of this ETS, the following symbols apply: K 5 Kelvin Ta u 4 Frequency accuracy The long
33、 term frequency accuracy normally applies when operating in long term free running conditions. Since the SSU is a slave clock, then the normal operating modes are either locked or holdover. The frequency accuracy specification in holdover mode is specified in clause 9. 5 Pull-in and pull-out ranges
34、The minimum pull-in range shall be Generic functional requirements for Synchronous Digital Hierarchy (SDH) equipment; Part 1-1 : Generic processes and performance“. - ITU-T Recommendation G.810: “Definitions and terminology for synchronization networks“ - ITU-T Recommendation G.811: “Timing requirem
35、ents at the outputs of primary reference clocks suitable for plesichronous operation of international digital links“. - ITU-T Recommendation G.812: Timing requirements at the outputs of slave clocks suitable for plesiochronous operation of international digital links“. - ITU-T Recommendation G.813:
36、“Timing characteristics of SDH equipment slave clocks (SEC)“ COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling ServicesPage 25 March 1998 Final draft prETS 300 462-4: March1998 Vote V 9820: 1998-03-1 7 to 1998-05-1 5 History Document history I January 1997 I Public Enquiry PE 9722: 1997-01-31 to 1997-05-30 COPYRIGHT European Telecommunications Standards InstituteLicensed by Information Handling Services
