1、EN 300 462-1 =I 1.1.1 (1998-05) European Standard (Telecommunications series) Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 1 -I : Definitions and terminology for synchronization networks 2 EN 300 462-1-1 V1.l.l (1998-05) Reference RENiTM-03017-1-1 (4a09
2、9ico.PDF) Keywords Transmission, synchronization, network, SDH, vocabulary ETSI Postai address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Siret N“ 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre a la Sous-P
3、refecture de Grasse (06) No 7803/88 Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Internet secretariata etci.fr http:/www.etsi .fr http:/www. etsi .org Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to
4、reproduction in all media. O European Telecommunications Standards Institute 1998. Ali rights reserved. ETSI STDmETSI EN 300 4b2-1-L-ENGL 1998 3400855 0337673 LTL 3 EN 300 462-1-1 V1.l.l (1998-05) Contents Intellectual Property Rights 4 Foreword 4 1 Scope 6 2 References 6 3 3.1 3.1.1 3.1.2 3.1.3 3.1
5、.4 3.1.5 3.1.6 3.2 Definitions and abbreviations 7 Definitions . . 7 General definitions . 7 Definitions related to clock equipments . 8 Definitions related to synchronization networks . 8 Definitions related to clock modes of operation (applicable to slave clocks) 9 Definitions related to clock cha
6、racterization . 9 Synchronous Digital Hierarchy (SDH) specific definitions 11 Abbreviations . 11 4 Measurement configurations 12 4.1 Synchronized clock measurement configuration 12 4.2 Independent clock measurement configuration 13 Annex A (normative): Mathematical models of timing signals . 15 A.l
7、A.2 A.3 Total instantaneous phase model of an ideal timing signal . 15 Total instantaneous phase model of actual timing signals . 15 Time error model . 15 Annex B (informative): Definitions and properties of frequency and time stability quantities . 16 B.l Allan deviation (ADEV) 16 B.2 Modified Aila
8、n deviation (MDEV) . 18 B.3 Time deviation (TDEV) . 19 B.4 Root mean square Time Interval Error (TIErms) . 20 B.5 Maximum Time Interval Error (MTIE) . 21 Annex C (informative): Bibliography . 23 History 24 4 EN 300 462-1-1 V1.l.l (1998-05) Intellectual Property Rights IPRs essential or potentially e
9、ssential to the present document may have been declared to ETSI. The information pertaining to these essential PRs, if any, is publicly available for ETSI members and non-members , and can be found in ETR 3 14: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified
10、to ETSI in respect of ETSI standards“, which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/www.etsi.fr/ipr or http:/www.etsi.org/ipr). Pursuant to the ETSI Interim PR Policy, no investigation, including iPR searches, has been carrie
11、d out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This European Standard (Telecommunications series) has been produced by the Tr
12、ansmission and Multiplexing (TM) Technical Committee. The present document has been produced to provide requirements for synchronization networks that are compatible with the performance requirements of digital networks. It is one of a family of documents covering various aspects of synchronization
13、networks : Part 1-1: Part 2-1: “Synchronization network architecture“; Part 3-1: Part 4-1: “Definitions and terminology for synchronization networks“; “The control of jitter and wander within synchronization networks“; “Timing characteristics of slave clocks suitable for synchronization supply to Sy
14、nchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment“; “Timing characteristics of slave clocks suitable for synchronization supply to Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment Implementation Conformance (ICs) Statement“
15、; Part 4-2: Part 5-1: “Timing characteristics of slave clocks suitable for operation in Synchronous Digital Hierarchy (SDH) equipment“; “Timing characteristics of primary reference clocks“; “Timing characteristics of primary reference clocks Implementation Conformance (ICs) Statement I; Part 6-1: Pa
16、rt 6-21 Pat 7-1: “Timing characteristics of slave clocks suitable for synchronization supply to equipment in local node applications“. Parts 1-1, 2-1, 3-1 and 5-1 have previously been published as ETS 300 462 Parts 1,2, 3 and 5, respectively. Additionally, parts 4-1 and 6-1 completed the Voting phas
17、e of the Two Step Approval procedure as ETS 300 462 Parts 4 and 6, respectively. It was decided to prepare ICs proformas for several of the parts and this necessitated a re-numbering of the individual document parts. It was also decided to create a new part 7-1. This in turn led to a need to re-publ
18、ish new versions of all six parts of the original ETS. At the same time, the opportunity was taken to convert the document type to EN. This has involved no technical change to any of the documents. However part 5-1 has been modified, due to editorial errors which appeared in ETS 300 462-5. ETSI STD-
19、ETSI EN 300 462-3-3-ENGL 3798 3400855 0337675 T74 5 EN 300 462-1-1 Vl.l.1 (1998-05) Transposition dates Date of adoption: Date of latest announcement of this ETS (doa): 4 April 1997 31 July 1997 Date of latest publication of new National Standard or endorsement of this ETS (dop/e): 31 January 1998 I
20、 Date of withdrawal of any conflicting National Standard (dow): 31 January 1998 NOTE: The above transposition table is the original table from ETS 300 462-1 (April 1997, see History). ETSI 6 EN 300 462-1-1 V1.l .i (1998-05) 1 Scope The present document specifies the definitions and abbreviations, us
21、ed in the other parts of EN 300 462. 2 Ref e rences The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date of publication, edition number, version number, etc.) or non-specifi
22、c. For a specific reference, subsequent revisions do not apply. For a non-specific reference, subsequent revisions do apply. A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. u1 Pl ITU-R Recommendation 686 (1990): “Standard fre
23、quencies and time signals -Glossary“. ETS 300 147 (1996): “Transmission and Multiplexing (TM); Synchronous Digital Hierarchy (SDH) Multiplexing Structure“. EN 300 462-4-1 : “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 4-1: Timing characteristics of sla
24、ve clocks suitable for synchronization supply to Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment“. EN 300 462-5-1 : “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 5-1: Timing Characteristics of slave clocks suitab
25、le for operation in Synchronous Digital Hierarchy (SDH) equipment“. EN 300 462-6-1 : “Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 6-1 : Timing characteristics of primary reference clocks“. ITU-T Recommendation G.70 1 (1993): “Vocabulary of digital tran
26、smission and multiplexing, and pulse code modulation (PCM) terms“. ITU-T Recommendation G.704 (1995): “Synchronous frame structures used at 1 544,6 3 12, 2 048,8 488 and 44 736 kbit/s hierarchical levels“. 3 1 41 5 1 61 71 81 ITU-T Recommendation G.832 (1995): “Transport of SDH elements on PDH netwo
27、rks: Frame and multiplexing structures“. ETS I STD-ETSI EN 300 462-L-L-ENGL 3978 m 3400855 0337697 847 7 EN 300 462-1-1 V1.l.l (1998-05) 3 3.1 Definitions and abbreviations Def i n it ions For the purposes of the present document, the following definitions apply: 3.1 .I General definitions bilateral
28、: A synchronization link where the corrective action to maintain locking is active at both ends of the link, jitter: Short term variations of the significant instants of a digital signal from their reference positions in time. network synchronization: A generic concept that depicts the way of distri
29、buting a common time and/or frequency to all elements in a network. single ended synchronization: A method of synchronizing a specified synchronization node with respect to another synchronization node in which synchronization information at the specified node is derived from the phase difference be
30、tween the local clock and the incoming digital signal from the other node. slip: The repetition or deletion of a block of bits in a synchronous or plesiochronous bit stream due to a discrepancy in the read and write rates at a buffer. synchronization chain: An active interconnection of synchronizati
31、on nodes and links synchronization reference chain: A specific synchronization chain defined in the present multi-part document to form the basis for simulations of jitter and wander in the synchronization network. synchronization status message: A coding of the reference level of the timing source
32、as specified in ETS 300 147 21 for STM-N, iTU-T Recommendation G.704 7 for 2 048 kbitls, IT-T Recommendation G.832 8 for synchronous 34 Mbit/s and 140 Mbitts. time: Is used to specify an instant (time of the day) or as a measure of time interval. NOTE 1: The words time or timing, when used to descri
33、be synchronization networks, usually refer to the frequency signals used for synchronization or measurement. time scale: A system of unambiguous ordering of events. NOTE 2: This could be a succession of equal time intervals, with accurate references of the limits of these time intervals, which follo
34、w each other without any interruption since a well defined origin. A time scale allows to date any event. For example, calendars are time scales. A frequency signal is not a time scale (every period is not marked and dated). For this reason “Universal Time Coordinated (LJTC) frequency“ should be use
35、d instead of “UTC“. unilateral: A synchronization link where the corrective action to maintain locking is only active at one end of the link. Universal Time Coordinated (UTC): The time scale, maintained by the Bureau International des Poids et Mesures (BPM) and the International Earth Rotation Servi
36、ce (ERS), which forms the basis of a coordinated dissemination of standard frequencies and time signal. NOTE 3: The reference frequency for network synchronization is the frequency which generates the UTC time scale. It is therefore preferable to use the words “UTC frequency“ instead of “UTC“. wande
37、r: The long term variations of the significant instances of a digital signal from their ideal positions in time (where long term implies that these variations are of frequencies less than 10 Hz). NOTE 4: For the purposes of the present multi-part document, this definition of wander does not include
38、integrated frequency departure. ETSI STD-ETSI EN 300 4b2-II-1-ENGL II998 34r10855 CI317b98 783 8 EN 300 462-1-1 Vl.l.1 (1998-05) 3.1.2 Definitions related to clock equipments clock: A device which provides a reference timing signal. frequency standard: A generator, the output of which is used as a m
39、easurement reference timing signal. local node: A synchronous network node which interfaces directly with customer equipment. master clock: A clock providing a reference timing signal to other clocks, behaving as slave clocks. node clock: Clock distributing synchronization reference timing signals w
40、ithin a node. Primary Reference Clock (PRC): A reference clock that provides a reference timing signal compliant with EN 300 462-6-1 5, in order to synchronize all or a large part of a network. slave clock: A clock which is locked to a reference timing signal. NOTE 1: When a slave clock loses all it
41、s reference timing signals and goes holdover, it can be considered as being a master clock under these conditions. NOTE 2: In locked mode, the slave clock is synchronized to a reference timing signal. The output frequency of the clock is the same as the frequency of the reference timing signal over
42、the long term, and the phase difference between the input and the output is bounded. Stand Alone Synchronization Equipment (SASE): The stand alone implementation of the logical SSU function, which incorporates its own management function. Synchronization Supply Unit (SSU): A logical function for ref
43、erence timing signal selection, processing and distribution, having the frequency characteristics given in EN 300 462-4-1 3. transit node: A synchronous network node which interfaces with other nodes and does not directly interface with customer equipment. 3.1.3 Definitions related to synchronizatio
44、n networks asynchronous mode: A mode where clocks are intended to operate in free running mode. NOTE: This definition applies to clocks. However a more general definition applying to data network is in iTU-T Recommendation (3.701 6. master slave mode: A mode where a designated master clock provides
45、reference timing signals which are disseminated to all other clocks which are slaved to the master clock. mutually synchronized mode: A mode where all clocks exert a degree of control of each other. plesiochronous mode: A mode where the essential characteristic of time scales or signals such that th
46、eir corresponding significant instants occur at nominally the same rate, any variation in rate being constrained within specified limits. pseudo-synchronous mode: A mode where all clocks have a long term frequency accuracy compliant with a primary reference clock as specified in EN 300 462-6-1 5 und
47、er normal operating conditions. Not all clocks in the network will have timing traceable to the same PRC. synchronization link: A link between two synchronization nodes over which a reference timing signal is transmitted synchronization network : A network to provide reference timing signals. In gen
48、eral, the structure of a synchronization network comprises synchronization nodes connected by synchronization links. synchronization trail: The logical representation of one or several synchronization links. synchronous network: Where all clocks have the same long term accuracy under normal operatin
49、g conditions. ETSI 9 EN 300 462-1-1 V1.l.l (1998-05) 3.1.4 Definitions related to clock modes of operation (applicable to slave clocks) free running mode: An operating condition of a clock, the output signal of which is strongly influenced by the oscillating element and not controlled by servo phase-locking techniques. In this mode, the clock has never had a network reference input, or the clock has lost external reference and has no access to stored data, that could be acquired from a previously connected external reference. Free-run begins when
