ETSI EN 300 462-1-1 V1.1.1 (1998-05)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 1-1: Definitions and terminology for synchronization networks33.040.20Prenosni sistemTransmission systems01.040.33Telekomunikacije. Avdio in video tehnika (Slovarji)Telecommunications. Audio and video engineering (Vocabularies)ICS:Ta slovenski standard je istoveten z:EN 300 462-1-1 Version 1.1.1SIST EN 300 462-1-1 V1.1.1:2003en01-december-2003SIST EN 300 462-1-1 V1.1.1:2003SLOVENSKI
STANDARD



SIST EN 300 462-1-1 V1.1.1:2003



EN 300 462-1-1 V1.1.1 (1998-05)European Standard (Telecommunications series)Transmission and Multiplexing (TM);Generic requirements for synchronization networks;Part 1-1: Definitions and terminologyfor synchronization networksSIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)2ReferenceREN/TM-03017-1-1 (4a099ico.PDF)KeywordsTransmission, synchronization, network, SDH,vocabularyETSIPostal addressF-06921 Sophia Antipolis Cedex - FRANCEOffice address650 Route des Lucioles - Sophia AntipolisValbonne - FRANCETel.: +33 4 92 94 42 00
Fax: +33 4 93 65 47 16Siret N° 348 623 562 00017 - NAF 742 CAssociation à but non lucratif enregistrée à laSous-Préfecture de Grasse (06) N° 7803/88Internetsecretariat@etsi.frhttp://www.etsi.frhttp://www.etsi.orgCopyright NotificationNo part may be reproduced except as authorized by written permission.The copyright and the foregoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1998.All rights reserved.SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)3ContentsIntellectual Property Rights.4Foreword.41Scope.62References.63Definitions and abbreviations.73.1Definitions.73.1.1General definitions.73.1.2Definitions related to clock equipments.83.1.3Definitions related to synchronization networks.83.1.4Definitions related to clock modes of operation (applicable to slave clocks).93.1.5Definitions related to clock characterization.93.1.6Synchronous Digital Hierarchy (SDH) specific definitions.113.2Abbreviations.114Measurement configurations.124.1Synchronized clock measurement configuration.124.2Independent clock measurement configuration.13Annex A (normative):Mathematical models of timing signals.15A.1Total instantaneous phase model of an ideal timing signal.15A.2Total instantaneous phase model of actual timing signals.15A.3Time error model.15Annex B (informative):Definitions and properties of frequency and time stability quantities.16B.1Allan deviation (ADEV).16B.2Modified Allan deviation (MDEV).18B.3Time deviation (TDEV).19B.4Root mean square Time Interval Error (TIErms).20B.5Maximum Time Interval Error (MTIE).21Annex C (informative):Bibliography.23History.24SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)4Intellectual Property RightsIPRs essential or potentially essential to the present document may have been declared to ETSI. The informationpertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be foundin ETR 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect ofETSI standards", which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSIWeb server (http://www.etsi.fr/ipr or http://www.etsi.org/ipr).Pursuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. Noguarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on the ETSI Webserver) which are, or may be, or may become, essential to the present document.ForewordThis European Standard (Telecommunications series) has been produced by the Transmission and Multiplexing (TM)Technical Committee.The present document has been produced to provide requirements for synchronization networks that are compatible withthe performance requirements of digital networks. It is one of a family of documents covering various aspects ofsynchronization networks:Part 1-1:"Definitions and terminology for synchronization networks";Part 2-1:"Synchronization network architecture";Part 3-1:"The control of jitter and wander within synchronization networks";Part 4-1:"Timing characteristics of slave clocks suitable for synchronization supply to Synchronous DigitalHierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment";Part 4-2:"Timing characteristics of slave clocks suitable for synchronization supply to Synchronous DigitalHierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment ImplementationConformance (ICS) Statement";Part 5-1:"Timing characteristics of slave clocks suitable for operation in Synchronous Digital Hierarchy(SDH) equipment";Part 6-1:"Timing characteristics of primary reference clocks";Part 6-2:"Timing characteristics of primary reference clocks Implementation Conformance (ICS)Statement";Part 7-1:"Timing characteristics of slave clocks suitable for synchronization supply to equipment in localnode 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 phase of the Two Step Approval procedure as ETS 300 462 Parts4 and 6, respectively.It was decided to prepare ICS proformas for several of the parts and this necessitated a re-numbering of the individualdocument parts. It was also decided to create a new part 7-1.This in turn led to a need to re-publish new versions of all six parts of the original ETS. At the same time, theopportunity 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 editorialerrors which appeared in ETS 300 462-5.SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)5Transposition datesDate of adoption:4 April 1997Date of latest announcement of this ETS (doa):31 July 1997Date of latest publication of new National Standardor endorsement of this ETS (dop/e):31 January 1998Date of withdrawal of any conflicting National Standard (dow):31 January 1998NOTE:The above transposition table is the original table from ETS 300 462-1 (April 1997, see History).SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)61ScopeThe present document specifies the definitions and abbreviations, used in the other parts of EN 300 462.2ReferencesThe following documents contain provisions which, through reference in this text, constitute provisions of the presentdocument.· References are either specific (identified by date of publication, edition number, version number, etc.) ornon-specific.· 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 samenumber.[1]ITU-R Recommendation 686 (1990): "Standard frequencies and time signals -Glossary".[2]ETS 300 147 (1996): "Transmission and Multiplexing (TM); Synchronous Digital Hierarchy(SDH) Multiplexing Structure".[3]EN 300 462-4-1: "Transmission and Multiplexing (TM); Generic requirements for synchronizationnetworks; Part 4-1: Timing characteristics of slave clocks suitable for synchronization supply toSynchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) equipment".[4]EN 300 462-5-1: "Transmission and Multiplexing (TM); Generic requirements for synchronizationnetworks; Part 5-1: Timing characteristics of slave clocks suitable for operation in SynchronousDigital Hierarchy (SDH) equipment".[5]EN 300 462-6-1: "Transmission and Multiplexing (TM); Generic requirements for synchronizationnetworks; Part 6-1: Timing characteristics of primary reference clocks".[6]ITU-T Recommendation G.701 (1993): "Vocabulary of digital transmission and multiplexing, andpulse code modulation (PCM) terms".[7]ITU-T Recommendation G.704 (1995): "Synchronous frame structures used at 1 544, 6 312,2 048, 8 488 and 44 736 kbit/s hierarchical levels".[8]ITU-T Recommendation G.832 (1995): "Transport of SDH elements on PDH networks: Frame andmultiplexing structures".SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)73Definitions and abbreviations3.1DefinitionsFor the purposes of the present document, the following definitions apply:3.1.1General definitionsbilateral: 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 distributing a common time and/or frequency toall elements in a network.single ended synchronization: A method of synchronizing a specified synchronization node with respect to anothersynchronization node in which synchronization information at the specified node is derived from the phase differencebetween 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 inthe read and write rates at a buffer.synchronization chain: An active interconnection of synchronization nodes and links.synchronization reference chain: A specific synchronization chain defined in the present multi-part document to formthe basis for simulations of jitter and wander in the synchronization network.synchronization status message: A coding of the reference level of the timing source as specified in ETS 300 147 [2]for STM-N, ITU-T Recommendation G.704 [7] for 2 048 kbit/s, ITU-T Recommendation G.832 [8] for synchronous34 Mbit/s and 140 Mbit/s.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 describe synchronization networks, usually refer to the frequencysignals 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 timeintervals, which follow each other without any interruption since a well defined origin. A time scale allowsto date any event. For example, calendars are time scales. A frequency signal is not a time scale (everyperiod is not marked and dated). For this reason "Universal Time Coordinated (UTC) frequency" shouldbe used 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(BIPM) and the International Earth Rotation Service (IERS), which forms the basis of a coordinated dissemination ofstandard frequencies and time signal.NOTE 3:The reference frequency for network synchronization is the frequency which generates the UTC timescale. It is therefore preferable to use the words "UTC frequency" instead of "UTC".wander: The long term variations of the significant instances of a digital signal from their ideal positions in time (wherelong 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 integratedfrequency departure.SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)83.1.2Definitions related to clock equipmentsclock: A device which provides a reference timing signal.frequency standard: A generator, the output of which is used as a measurement 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 within a node.Primary Reference Clock (PRC): A reference clock that provides a reference timing signal compliant withEN 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 its reference timing signals and goes holdover, it can be considered as being amaster clock under these conditions.NOTE 2:In locked mode, the slave clock is synchronized to a reference timing signal. The output frequency of theclock is the same as the frequency of the reference timing signal over the long term, and the phasedifference 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 reference timing signal selection, processing anddistribution, 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 withcustomer equipment.3.1.3Definitions related to synchronization networksasynchronous 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-TRecommendation G.701 [6].master slave mode: A mode where a designated master clock provides reference timing signals which are disseminatedto 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 their correspondingsignificant 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 primaryreference clock as specified in EN 300 462-6-1 [5] under normal operating conditions. Not all clocks in the network willhave 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 general, the structure of a synchronizationnetwork 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 operating conditions.SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)93.1.4Definitions related to clock modes of operation (applicable to slaveclocks)free running mode: An operating condition of a clock, the output signal of which is strongly influenced by theoscillating element and not controlled by servo phase-locking techniques. In this mode, the clock has never had anetwork reference input, or the clock has lost external reference and has no access to stored data, that could be acquiredfrom a previously connected external reference. Free-run begins when the clock output no longer reflects the influenceof a connected external reference, or transition from it. Free run terminates when the clock output has achieved lock toan external reference.holdover mode: An operating condition of a clock which has lost its controlling input and is using stored data, acquiredwhile in locked operation, to control its output. The stored data are used to control phase and frequency variations,allowing the locked condition to be reproduced within specifications. Holdover begins when the clock output no longerreflects the influence of a connected external reference, or transition from it. Holdover terminates when the output of theclock reverts to locked mode condition.locked mode: An operating condition of a clock in which the output signal is controlled by an external input reference.It is the expected mode of operation of a slave clock and the state in which each clock within a chain of clocks has thesame long term average frequency.3.1.5Definitions related to clock characterizationageing: The systematic change in frequency of an oscillator with time.NOTE 1:It is the frequency drift when factors external to the oscillator (environment, power supply, temperature,etc.) are kept constant. An ageing value should always be specified together with the correspondingduration.fractional frequency deviation: The difference between the actual frequency of a signal and a specified nominalfrequency, divided by the nominal frequency. Mathematically, the fractional frequency deviation y(t) can be expressedas:()ytvtvvnomnom()=-frequency accuracy: The maximum magnitude of the fractional frequency deviation for a specified time period.NOTE 2:The frequency accuracy includes the initial frequency offset and any ageing and environmental effect.frequency drift: The systematic change in frequency of an oscillator caused by ageing and external effects (radiation,pressure, temperature, humidity, power supply, load, etc.).NOTE 3:The external factors should always be clearly indicated.frequency stability: The spontaneous and/or environmentally caused frequency change within a given time interval.NOTE 4:It is generally distinguished between systematic effects such as frequency drift effects (caused byradiations, pressure, temperature, humidity, power supply, charge, ageing etc.) and stochastic frequencyfluctuations which are typically characterized in time domain (special variances have been developed forthe characterization of these fluctuations: Allan variance, modified Allan variance, Allan variance in time)and/or frequency domain (one sided spectral densities).Maximum Relative Time Interval Error (MRTIE): The maximum peak-to-peak delay variation of an output timingsignal with respect to a given input timing signal within an observation time (t = nt0) for all observation times of thatlength within the measurement period (T).Maximum Time Interval Error (MTIE): The maximum peak-to-peak delay variation of a given timing signal withrespect to an ideal timing signal within an observation time (t = nt0) for all observation times of that length within themeasurement period (T). It is estimated using the following formula:SIST EN 300 462-1-1 V1.1.1:2003



ETSIEN 300 462-1-1 V1.1.1 (1998-05)10()MTIE ,
nxxnNkNnkiknikiknit01121=-æèçöø÷=-££-££+££+maxmax()min(),,.,()measurement reference timing signal: A timing signal of specified performance used as a time base for clockcharacterization measurements. The basic assumption is that its performance must be significantly better than the clockunder test with respect to the parameter being tested, in order to prevent the test results being compromised. Theperformance parameters of the frequency standard must be stated with all test results.phase transient: Perturbations in phase of limited duration.pull in range: The largest offset between a slave clock’s reference frequency and a specified nominal frequency, withinwhich the slave clock will achieve locked mode.pull out range: The offset between a slave clock’s reference and a specified nominal frequency, within which the slaveclock stays in the locked mode and outside of which the
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