5i' FASCICLE III.4 Recommendations G.700 to G.795 GENERAL ASPECTS OF DIGITAL TRANSMISSION SYSTEMS; TERMINAL EQUIPMENTS Blanc MONTAGE: PAGE 2 = PAGE BLANCHE SECTION 7 GENERAL ASPECTS OF DIGITAL TRANSMISSION SYSTEMS; TERMINAL EQUIPMENTS 7.0 General Recommendation G.700 FRAMEWORK OF THE SERIES G.700, G.800 AND G.900 RECOMMENDATIONS (former Recommendation G.701 of Volume III of the Yellow Book) SECTION 7 - General aspects of digital transmission sys- tems; terminal equipments 7.0 General G.700 Framework of the series G.700, G.800 and G.900 Recom- mendations G.701 Vocabulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms G.702 Digital hierarchy bit rates G.703 Physical/electrical characteristics of hierarchical digital interfaces G.704 Functional characteristics of interfaces associated with network nodes G.705 Characteristics required to terminate digital links on a digital exchange G.706 Frame alignement and cyclic redundancy check (CRC) procedures relating to basic frame structures defined in Recommendation G.704 G.707 Synchronous digital hierarcy bit rates G.708 Network node interface for the synchronous digital hierarchy G.709 Synchronous multiplexing structure 7.1 Coding of analogue signals by pulse code modulation G.711 Pulse code modulation (PCM) of voice frequencies G.712 Performance characteristics of PCM channels between 4-wire interfaces at voice frequencies G.713 Performance characteristics of PCM channels between 2-wire interfaces at voice frequencies G.714 Separate performance characteristics for the encoding and decoding sides of PCM channels applicable to 4-wire voice-frequency interfaces G.715 Separate performance characteristics for the encoding and decoding side of PCM channels applicable to 2-wire interfaces 7.2 Coding of analogue signals by methods other than PCM G.721 32 kbit/s adaptive differential pulse code modulation (ADPCM) G.722 7 kHz audio-coding within 64 kbit/s G.723 Extensions of Recommendation G.721 ADPCM to 24 and 40 kbit/s for DCME application G.724 Characteristics of a 48-channel low bit rate encoding primary multiplex operating at 1544 kbit/s G.725 System aspects for the use of the 7 kHz audio codec within 64 kbit/s 7.3 Principal characteristics of primary multiplex equipment G.731 Primary PCM multiplex equipment for voice frequencies G.732 Characteristics of primary PCM multiplex equipment operating at 2048 kbit/s G.733 Characteristics of primary PCM multiplex equipment operating at 1544 kbit/s G.734 Characteristics of synchronous digital multiplex equipment operating at 1544 kbit/s G.735 Characteristics of primary PCM multiplex equipment operating at 2048 kbit/s and offering synchronous digital access at 384 kbit/s and/or 64 kbit/s G.736 Characteristics of a synchronous digital multiplex equipment operating at 2048 kbit/s G.737 Characteristics of an external access equipment operating at 2048 kbit/s offering synchronous digital access at 384 kbit/s and/or 64 kbit/s G.738 Characteristics of primary PCM multiplex equipment operating at 2048 kbit/s and offering synchronous digital access at 320 kbit/s and/or 64 kbit/s G.739 Characteristics of an external access equipment operating at 2048 kbit/s offering synchronous digital access at 320 kbit/s and/or 64 kbit/s 7.4 Principal characteristics of second order multiplex equipments G.741 General considerations on second order multiplex equipments G.742 Second order digital multiplex equipment operating at 8448 kbit/s and using positive justification G.743 Second order digital multiplex equipment operating at 6312 kbit/s and using positive justification G.744 Second order PCM multiplex equipment operating at 8448 kbit/s G.745 Second order digital multiplex equipment operating at 8448 kbit/s and using positive/zero/negative justification G.746 Characteristics of second order PCM multiplex equip- ment operating at 6312 kbit/s G.747 Second order digital multiplex equipment operating at 6312 kbit/s and multiplexing three tributaries at 2048 kbit/s 7.5 Principal characteristics of higher order multiplex equipments G.751 Digital multiplex equipments operating at the third order bit rate of 34 | 68 kbit/s and the fourth order bit rate of 139 | 64 kbit/s and using positive justification G.752 Characteristics of digital multiplex equipments based on a second order bit rate of 6312 kbit/s and using positive jus- tification G.753 Third order digital multiplex equipment operating at 34 | 68 kbit/s and using positive/zero/negative justification G.754 Fourth order digital multiplex equipment operating at 139 | 64 kbit/s and using positive/zero/negative justification G.755 Digital multiplex equipment operating at 139 | 64 kbit/s and multiplexing three tributaries at 44736 kbit/s 7.6 Principal characteristics of transcoder and digital circuit multiplication equipments G.761 General characteristics of a 60-channel transcoder equipment G.762 General characteristics of a 48-channel transcoder equipment G.763 Digital circuit multiplication equipment using 32 kbit/s ADPCM and digital speech interpolation 7.7 Operations administration and maintenance features of transmission equipments G.771 Q-interfaces and associated protocols for transmis- sion equipment in the telecommunications management network (TMN) G.772 Digital protocol monitoring points 7.9 Other terminal equipments G.791 General considerations on transmultiplexing equip- ments G.792 Characteristics common to all transmultiplexing equipments G.793 Characteristics of 60-channel transmultiplexing equipments G.794 Characteristics of 24-channel transmultiplexing equipments G.795 Characteristics of codecs for FDM assemblies SECTION 8 - Digital networks 8.0 General aspects of digital networks G.801 Digital transmission models G.802 Interconnection between networks based on different digital hierarchies and speech encoding laws 8.1 Design objectives for digital networks G.810 Considerations on timing and synchronization issues G.811 Timing requirements at the outputs of primary refer- ence clocks suitable for plesiochronous operation of international digital links G.812 Timing requirements at the outputs of slave clocks suitable for plesiochronous operation of international digital links 8.2 Quality and availability targets G.821 Error performance of an international digital connec- tion forming part of an integrated services digital network G.822 Controlled slip rate objectives on an international digital connection G.823 The control of jitter and wander within digital net- works which are based on the 2048 kbit/s hierarchy G.824 The control of jitter and wander within digital net- works which are based on the 1544 kbit/s hierarchy SECTION 9 - Digital sections and digital line systems 9.0 General G.901 General considerations on digital sections and digi- tal line systems 9.1 Digital line sections at hierarchical bit rates based on a rate of 1544 kbit/s Recommendations G.911 to G.915 have been deleted 9.2 Digital sections at hierarchical bit rates based on a primary bit rate of 2048 kbit/s G.921 Digital sections based on the 2048 kbit/s hierarchy 9.3 Digital line transmission systems on cable at non-hierarchical bit rates G.931 Digital line sections at 3152 kbit/s 9.4 Digital line systems provided by FDM transmission bearers G.941 Digital line systems provided by FDM transmission bearers 9.5 Digital line systems G.950 General considerations on digital line systems G.951 Digital line systems based on the 1544 kbit/s hierar- chy on symmetric pair cables G.952 Digital line systems based on the 2048 kbit/s hierar- chy on symmetric pair cables G.953 Digital line systems based on the 1544 kbit/s hierar- chy on coaxial pair cables G.954 Digital line systems based on the 2048 kbit/s hierar- chy on coaxial pair cables G.955 Digital line systems based on the 1544 kbit/s hierar- chy on optical fibre cables G.956 Digital line systems based on the 2048 kbit/s hierar- chy on optical fibre cables 9.6 Digital section and digital transmission systems for ISDN customer access G.960 Digital section for ISDN basic rate access G.961 Digital transmission system on metallic local lines for ISDN basic rate access (H.T.=OUI) TAB.??? FICHIER: H.T. = (34.TA.341.E) (SANS FORMULES) Tableaux: 2 - Tabulateurs: 1 d) Formules: 0 - Tabulateurs: 0 TEXTE (tabulateurs) E: D. 2 NF01/006 = OPM: 02 Primary group A D. 2 NF01/039 = OPM: 02 - D. 2 NF01/039 = OPM: 02 hetero D. 3 NF01/004 = OPM: 03 (cs,1) Disk 2 NF01/054 (OPM = 02) (BT10) Disk 2 NF01/028 (OPM = 02) (BT20) Disk 2 NF01/051 (OPM = 02) (34.TE.01.E) (A1.23e) / [26e] FOLIOS: 7 - 44 (DO PRC.COSY.2) MEP [PA1] : OK= [1] Saisie diskette 17.11.89 YB ID + Verif. + diskette MAJ + laser 19.12.89 KJ Corr. LASER (1re epreuve) = 3eme Espaces reserves + Transfert + Impr. AJOUTER (PA1) (CL1,0,0,0) pour MEP MEP + LASER 20.02.90 GH/PC Corr. MEP Insertion des tableaux (tabulateurs .) BAT 5.04.90 PM MAJ s/disquettes Recommendation G.701 VOCABULARY OF DIGITAL TRANSMISSION AND MULTIPLEXING, AND PULSE CODE MODULATION (PCM) TERMS 1 Introduction This Recommendation provides a vocabulary of terms and defini- tions that are appropriate to digital and pulse code modulation multiplexing and transmission systems. A small number of the terms in the Recommendation are dupli- cated in Recommendation I.112. References to these definitions are given in parenthesis as an aid to ensuring consistency between the two Recommendations in the event of future amendments. According to the conventions applied in this Recommendation any term in common usage, but whose use is deprecated in the sense defined, is shown after the recommended term as in the following example: "2026 controlled slip [slip]". Where a truncated term is widely used in an understood context the complete term is quoted following the colloquial form, for example: "1007 circuit, telecommunication circuit". Furthermore, any term which is in general use in addition to the principal term is shown after the principal term as in the fol- lowing example: "6002 timing recovery (timing extraction)". In the interest of standardization in the drafting of docu- ments the following abbreviations are recommended: kbit/s, Mbit/s, Gbit/s. To avoid misinterpretation of the use of the point (.) and the comma (,) in different languages to separate the whole and decimal parts, it is recommended that the use of decimals should be avoided wherever possible. For example, "2048 kbit/s" is preferred to "2.048 Mbit/s" or "2,048 Mbit/s. Annex A to this Recommendation contains an alphabetical list of all of the terms defined in this Recommendation. 2 Vocabulary of digital transmission and multiplexing and pulse code modulation terms (PCM) CONTENTS 2.1 General 2.2 Digital signals 2.3 Digital transmission 2.4 Digital multiplexing 2.5 Frame alignment 2.6 Timing 2.7 Synchronization 2.8 Pulse code modulation 2.9 Codes Annex A - Alphabetical List 2.1 General 1001 signal [102] F: signal S: se~al A physical phenomenon one or more of whose characteristics may vary to represent information. 1002 analogue signal [103] F: signal analogique S: se~al analogica A signal one of whose characteristic quantities follows con- tinuously the variations of another physical quantity representing information. 1003 discretely-timed signal [104] F: signal (temporel) discret S: se~al discretamente temporizada A signal composed of successive elements in time, each element having one or more characteristics which can convey information, for example, its duration, its waveform and its amplitude. 1004 transmission [106] F: transmission S: transmision The action of conveying signals from one point to one or more other points. Note 1 - Transmission can be effected directly or indirectly, with or without intermediate storage. Note 2 - The use of the English word "transmission" in the sense of "emission" is deprecated. 1005 channel, transmission channel [108] F: voie, voie de transmission S: canal, canal de transmision A means of unidirectional transmission of signals between two points. Note 1 - Several channels may share a common path; for exam- ple each channel may be allocated a particular frequency band or a particular time slot. Note 2 - The term may be qualified by the nature of the transmitted signals, by the bandwidth, by the digit rate, or by an arbitrary designation. Note 3 - See also Recommendation I.112, Term 414, access channel. 1006 telecommunication [110] F: telecommunication S: telecomunicacion Any transmission and/or emission and reception of signals representing signs, writing, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic sys- tems. 1007 circuit, telecommunication circuit [111] F: circuit, circuit de telecommunications S: circuito, circuito de telecomunicacion A combination of two transmission channels permitting bidirec- tional transmission of signals between two points, to support a single communication. Note 1 - If the telecommunication is by nature unidirectional (for example: long distance television transmission), the term "circuit" is sometimes used to designate the single channel provid- ing the facility. Note 2 - In a telecommunication network, the use of the term "circuit" is generally limited to a telecommunication circuit directly connecting two switching devices or exchanges, together with associated terminating equipment. Note 3 - A telecommunication circuit may permit transmission in both directions simultaneously (duplex), or not simultaneously (simplex). Note 4 - A telecommunication circuit that is used for transmission in one direction only is sometimes referred to as a unidirectional telecommunication circuit. A telecommunication cir- cuit that is used for transmission in both directions (whether simultaneously or not) is sometimes referred to as a bidirectional telecommunication circuit. 1008 interface [408] F: jonction (interface) S: interfaz The common boundary between two associated systems. 2.2 Digital signals 2001 digit F: element numerique S: digito A member selected from a finite set. Note 1 - In digital transmission, a digit may be represented by a signal element, being characterized by the dynamic nature, discrete condition and discrete timing of the element, for example it may be represented as a pulse of specified amplitude and dura- tion. Note 2 - In equipment used in digital transmission, a digit may be represented by a stored condition being characterized by a specified physical condition, for example it may be represented as a binary magnetic condition of a ferrite core. Note 3 - The context of the use of the term should be such as to indicate the radix of notation. (The meaning of "digit" in Notes 1, 2 and 3 translates into French as "element numerique".) Note 4 - In telephone subscriber numbering, a digit is any of the numbers 1, 2, 3 . | | 9 or 0 forming the elements of a tele- phone number (Recommendation Q.10 [1]). (This meaning of "digit" translates into French as "chiffre".) 2002 binary figure F: chiffre binaire S: cifra binaria One of the two figures (that is, 0 or 1) used in the represen- tation of numbers in binary notation. 2003 binary digit (bit) F: element binaire S: digito binario (bit) A member selected from a binary set. Note 1 - Bit is an abbreviation for binary digit. Note 2 - In the interest of clarity, it is recommended that the term "bit" should not be used in two-condition start-stop modu- lation instead of "unit element". 2004 octet F: octet S: octeto A group of eight binary digits or eight signal elements representing binary digits operated upon as an entity. 2005 code word [character signal] F: mot de code [signal de caractere] S: palabra de codigo [se~al de caracter] A set of signal elements representing the quantized value of a sample in PCM. Note - In PCM, the term "PCM word" may be used in this sense. 2006 digital signal [105] F: signal numerique S: se~al digital A discretely timed signal in which information is represented by a number of well-defined discrete values that one of its charac- teristic quantities may take in time. Note - The term may be qualified to indicate the digit rate, for example: "140 Mbit/s digital signal". 2007 signal element F: element de signal S: elemento de se~al A part of a digital signal, characterized by its discrete tim- ing and its discrete value, and used to represent a digit. 2008 digit position F: position d'un element de signal; position d'un element numerique S: posicion de digito The position in time or space into which a representation of a digit may be placed. 2009 n-ary digital signal F: signal numerique n-aire S: se~al digital n-aria A digital signal in which each signal element has one of n permitted discrete values. 2010 redundant digital signal F: signal numerique redondant S: se~al digital redundante The signal that is produced by encoding a given signal in accordance with a redundant line code. 2011 redundant n-ary signal F: signal n-aire redondant S: se~al n-aria redundante A digital signal whose elements can assume n | iscrete states where the average equivalent binary content per signal element is less than log2n . Note - The relative redundancy R , of an n -ary digital sig- nal, is given by: R = 1 - fIr d fR x log 2fIn ___________________ = | |1 -fIr d fR x log 2fIn ___________________| | x 100% where rdis the symbol rate of the n -ary signal and reis the equivalent bit rate. This may also be expressed in terms of the number of binary digits which can be transmitted by an element of a particular line code. Examples are: AMI (37% redundant), 1 binary digit per element; 4B3T (16% redundant), 1.33 binary digit per element. 2012 pseudo n-ary signal F: signal pseudo n-aire S: se~al seudo n-aria A redundant n -ary digital signal that is derived from a m -ary digital signal without change of the line digit rate. Note - An alternate mark inversion signal is an example of a pseudo-ternary signal, i.e. n = 3, m = 2. 2013 digit rate F : debit numerique S: velocidad digital The number of digits per unit time. Note 1 - An appropriate adjective may precede the word "digit", for example, binary digit rate. Note 2 - In the interests of clarity it is recommended that this term should not be used to express the symbol rate on the line. 2014 line digit rate [symbol rate] F: debit numerique en ligne [debit de symboles] S: velocidad digital de linea [velocidad de simbolos] The number of signal elements of the line signal transmitted per unit time. Note 1 - The baud is usually used to quantify this, one baud being equal to one single element per second. Note 2 - Modulation rate is the term used in telegraphy and data communication; it is the reciprocal of the duration of the unit interval. 2015 equivalent binary content F: contenu binaire equivalent S: contenido binario equivalente The number of binary digits strictly necessary to convey the same information as a defined number of signal elements in a given digital signal. 2016 equivalent bit rate F: debit binaire equivalent S: velocidad binaria equivalente The value of the bit rate strictly necessary to convey the same information in the same time as a given digital signal at a given digit rate. 2017 significant instant, significant instant of a digital signal F: instant significatif, instant significatif d'un signal numerique S: instante significativo, instante significativo de una se~al digital The instant at which a signal element commences in a discretely-timed signal. 2018 unit interval F: intervalle unitaire S: intervalo unitario (o intervalo unidad) The nominal difference in time between consecutive significant instants of an isochronous signal. 2019 decision instant, decision instant of a digital signal F: instant de decision, instant de decision d'un sig- nal numerique S: instante de decision instante de decision de una se~al digital The instant at which a decision is taken as to the probable value of signal element of a received digital signal. 2020 decision circuit F: circuit de decision S: circuito de decision A circuit that decides the probable value of a signal element of a received digital signal. 2021 regeneration F: regeneration S: regeneracion The process of receiving and reconstructing a digital signal so that the amplitudes, waveforms and timing of its signal elements are constrained within specified limits. 2022 regenerator F: regenerateur S: regenerador A device that performs regeneration. 2023 regenerative repeater F: repeteur regenerateur S: repetidor regenerativo A repeater that regenerates digital signals. Note 1 - A regenerative repeater may operate in one or both directions of transmission, and the term may be qualified by "uni- directional" or "bidirectional" as appropriate. Note 2 - Repeater is defined in Recommendation G.601. 2024 jitter F: gigue S: fluctuacion de fase Short-term non-cumulative variations of the significant instants of a digital signal from their ideal positions in time. 2025 wander F: derapage S: fluctuacion lenta de fase Long term non-cumulative variations of the significant instants of a digital signal from their ideal positions in time. 2026 controlled slip [slip] F: glissement commande [saut] S: deslizamiento controlado [deslizamiento] The irretrievable loss or gain of a set of consecutive digit positions in a digital signal, in which both the magnitude and instant of that loss or gain are controlled, to enable the signal to accord with a rate different from its own. Note - Where appropriate the term may be qualified, for exam- ple: controlled octet slip, controlled frame slip. 2027 uncontrolled slip F: glissement non commande S: deslizamiento incontrolado The loss or gain of a digit position or a set of consecutive digit positions in a digital signal resulting from an aberration of the timing processes associated with transmission or switching of a digital signal, and in which either the magnitude or the instant of that loss or gain is not controlled. 2028 scrambler F: embrouilleur S: aleatorizador A device that converts a digital signal into a pseudo-random digital signal having the same meaning and the same digit rate. 2029 descrambler F: desembrouilleur S: desaleatorizador A device that performs the complementary operation to that of a scrambler. 2030 error, digital error F: erreur, erreur numerique S: error, error digital An inconsistency between a digit in a transmitted digital sig- nal and the corresponding digit in the received digital signal. 2031 error ratio [error rate] F: taux d'erreur [rapport d'erreur] S: tasa de errores [proporcion de errores] The ratio of the number of digital errors received in a speci- fied period to the total number of digits received in the same period. Note 1 - Numerical values of error ratio should be expressed in the form n | (mu | 0DlF261 p where p is a positive integer. Note 2 - Error ratio may be qualified, for example by the term "bit" or "block". 2032 error multiplication F: multiplication d'erreurs S: multiplicacion de errores The property of an apparatus whereby a single digital error in the input signal presented to it results in more than one digital error in the output signal. Note - Line code converters and descramblers are examples of apparatus that may cause error multiplication. 2033 error multiplication factor F: facteur de multiplication d'erreurs S: factor de multiplicacion de errores The ratio of the number of digital errors in the output signal to the number of digital errors in the input signal. Note - The error multiplication factor may be expressed as either an average or maximum value. 2034 error spread F: etalement d'erreurs [repartition des erreurs] S: dispersion de errores The number of consecutive digits of the output signal over which digital errors are distributed when a single digital error in the input signal causes error multiplication. 2.3 Digital transmission 3001 digital transmission [107] F: transmission numerique S: transmision digital The transmission of digital signals by means of a channel or channels that may assume in time any one of a defined set of discrete states. 3002 digital channel, digital transmission channel [109] F: voie numerique, voie de transmission numerique S: canal digital, canal de transmision digital The means of unidirectional digital transmission of digital signals between two points. 3003 digital circuit, digital telecommunication circuit [112] F: circuit numerique, circuit numerique de telecommunications S: circuito digital, circuito de telecomunicacion digital A combination of two digital transmission channels permitting bidirectional digital transmission in both directions between two points, to support a single communication. Note 1 - If the telecommunication is by nature unidirectional (for example, long-distance television transmission), the term "digital circuit" is sometimes used to designate the single digital channel providing the facility. Note 2 - In a telecommunication network, use of the term "digital circuit" is generally limited to a digital telecommunica- tion circuit directly connecting two switching devices or exchanges, together with associated terminating equipment. Note 3 - A digital telecommunication circuit may permit transmission in both directions simultaneously (duplex), or not simultaneously (simplex). Note 4 - A digital telecommunication circuit that is used for transmission in one direction only is sometimes referred to as a unidirectional digital telecommunication circuit. A digital telecommunication circuit that is used for transmission in both directions (whether simultaneously or not) is sometimes referred to as a bidirectional digital telecommunication circuit. 3004 digital connection [310] F: connexion numerique S: conexion digital A concatenation of digital transmission channels or digital telecommunication circuits, switching and other functional units set up to provide for the transfer of digital signals between two or more points in a telecommunication network, to support a single communication. 3005 digital link, digital transmission link [digital path] [302] F: liaison numerique, liaison de transmission numerique [conduit numerique] S: enlace digital, enlace de transmision digital [trayecto digital] The whole of the means of digital transmission of a digital signal of specified rate between two digital distribution frames (or equivalent). Note 1 - A digital link comprises one or more digital sec- tions and may include multiplexing and/or demultiplexing, but not switching. Note 2 - The term may be qualified to indicate the transmis- sion medium used, for example, "digital satellite link". Note 3 - The term always applies to the combination of "go" and "return" directions of transmission, unless stated otherwise. Note 4 - The term "digital path" is sometimes used to describe one or more digital links connected in tandem, especially between equipments at which the signals of the specified rate ori- ginate and terminate. 3006 digital distribution frame F: repartiteur numerique S: repartidor digital A structure that provides flexibility of semipermanent inter- connection of digital channels or digital circuits. Note - Digital sections and digital links normally terminate at digital distribution frames. Figure 1/G.701 gives examples of digital sections, digital links, digital line sections, etc. 3007 digital section F: section numerique S: seccion digital The whole of the means of digital transmission of a digital signal of specified rate between two consecutive digital distribu- tion frames or equivalent. Note 1 - A digital section forms either a part or the whole of a digital link, and includes terminating equipments at both ends, but excludes multiplexers. Note 2 - Where appropriate, the digital rate or multiplex order should qualify the title. Note 3 - The definition applies to the combination of "go" and "return" directions of transmission, unless stated otherwise. 3008 section termination F: extremite de section S: extremo de seccion A connectional interface selected to be the boundary between a physical transmission medium and its associated equipment. Note - This point will usually be the connectors at the input and output of an equipment. 3009 elementary cable section [repeater section] F: section elementaire de c | ble [section (elementaire) d'amplification] S: seccion elemental de cable [seccion con amplificacion] The whole of the physical transmission medium between the sec- tion termination at the output of one equipment and the section termination at the input of the following equipment. Note 1 - An elementary cable section usually consists of several factory lengths of cable connected together and any associ- ated accessories (such as flexible cables) necessary to connect it to the section terminals. Note 2 - Examples of the physical transmission media are a coaxial or symmetric pair, and optical fibre. 3010 elementary repeater section F: section elementaire amplifiee S: seccion elemental de repeticion In a given direction of transmission, an elementary cable sec- tion together with the immediately following analogue repeater. 3011 elementary regenerator section [regenerator section] F: section elementaire regeneree [section de regeneration] S: seccion elemental de regeneracion [seccion de regeneracion] In a given direction of transmission, an elementary cable sec- tion together with the immediately following regenerative repeater. 3012 digital line section F: section de ligne numerique S: seccion de linea digital A digital section implemented on a single type of manufactured transmission medium, such as symmetric pair, coaxial pair, or opti- cal fibre. Note - A digital line section includes line terminating equipments at both ends, and regenerative repeaters if needed, but excludes multiplexers. 3013 digital line link [digital line path] F: liaison de ligne numerique [conduit de ligne numerique] S: enlace de linea digital [trayecto de linea digital] A digital link that comprises a digital line section or a number of tandem-connected digital line sections. 3014 digital transmission system F: systeme de transmission numerique S: sistema de transmision digital A specific means of providing a digital section. 3015 digital line system F: systeme de ligne numerique S: sistema de linea digital A digital transmission system that provides a digital line section. 3016 digital radio section F: section radioelectrique numerique S: seccion radiodigital A digital section implemented on a radio-relay system. 3017 digital radio link [digital radio path] F: liaison radioelectrique numerique [conduit radioelectrique numerique] S: enlace radiodigital, [trayecto radiodigital] A digital link that comprises a digital radio section or a number of tandem-connected digital radio sections. 3018 digital radio system F: systeme radioelectrique numerique S: sistema radiodigital A digital transmission system that provides a digital radio section. 3019 bit sequence independence F: independance de la sequence des bits S: independencia de la secuencia de bits The property of a binary transmission channel, telecommunica- tion circuit or connection, that permits all sequences of binary signal elements to be conveyed over it at its specified bit rate, without change to the value of any signal elements. Note - Practical transmission systems that are not completely bit sequence independent may be described as quasi bit sequence independent. In such cases the limitations should be clearly stated. 3020 digit sequence integrity F: integrite de la suite des elements numeriques S: integridad de la secuencia de digitos The property of a digital transmission channel, telecommunica- tion circuit or connection, that permits a digital signal to be conveyed over it without change to the order of any signal ele- ments. 3021 octet sequence integrity F: integrite de la suite des octets S: integridad de la secuencia de octetos The property of a digital transmission channel, telecommunica- tion circuit or connection that permits a digital signal to be con- veyed over it without change to the order of any octets. 3022 transparency, digital transparency F: transparence, transparence numerique S: transparencia, transparencia digital The property of a digital transmission channel, telecommunica- tion circuit or connection, that permits any digital signal to be conveyed over it without change to the value or order of any signal elements. Note - The digital transmission channel, telecommunication circuit or connection concerned may introduce delay, and may con- tain reversible code conversion functions. 3023 alarm indication signal (AIS) F: signal d'indication d'alarme (SIA) S: se~al de indicacion de alarma (SIA) A signal that replaces the normal traffic signal when a maintenance alarm indication has been activated. 3024 upstream failure indication F: indication de defaillance en amont S: indicacion de fallo atras An indication provided by a digital multiplexer, line section or a radio section, that a signal applied at its input port is out- side its prescribed maintenance limit. 3025 service digits [housekeeping digits] F: elements numeriques de service S: digitos de servicio Digits that are added, to a digital signal at the sending end of a digital link, normally at regular intervals and removed at the receiving end of that link and used to provide ancillary facili- ties. Figure 1/G.701, p. 2.4 Digital multiplexing 4001 highway (American: bus) F: bus (jonction multiplex interne) [canal] S: arteria (bus) A common path within an apparatus or station over which pass signals from a number of channels identified by time division. 4002 channel gate F: porte de canal S: puerta de canal A device for connecting a channel to a highway, or a highway to a channel, at specified times. 4003 digital multiplex hierarchy F: hierarchie de multiplexage numerique S: jerarquia de los mulitplex digitales A series of digital multiplexers graded according to capabil- ity so that multiplexing at one level combines a defined number of digital signals, each having the digit rate prescribed for a lower order, into a digital signal having a prescribed digit rate which is then available for further combination with other digital sig- nals of the same rate in a digital multiplexer of the next higher order. 4004 primary digital group F: groupe numerique primaire S: grupo digital primario An assembly, by digital multiplexing, of digital signals occu- pying a specified number of channel time-slots to form a composite signal having a digit rate of 2048 kbit/s or 1544 kbit/s. Note - Normally each channel time-slot has eight digit time-slots and an effective digit rate of 64 kbit/s. 4005 primary PCM group [primary block] (American: digroup) F: groupe primaire MIC [bloc primaire] S: grupo primario MIC [bloque primario] An assembly, by digital multiplexing, of PCM signals occupying a specified number of channel time-slots to form a composite signal having a digit rate of 1544 kbit/s or 2048 kbit/s, in both direc- tions of transmission. Note - The following conventions could be useful: Primary group u - a basic group of PCM signals derived from 1544-kbit/s PCM multiplex equipment. Primary group A - a basic group of PCM signals derived from 2048-kbit/s PCM multiplex equipment. 4006 n-ary digital group F: groupe numerique n-aire S: grupo digital n-ario A number of primary digital or pcm groups assembled by digital multiplexing to form a composite signal of specified digit rate, in both directions of transmission. Note 1 - A secondary digital group may comprise four primary digital or pcm groups to form a composite signal having a digit rate of 8448 or 6312 kbit/s. Note 2 - A tertiary digital group may comprise four 8448 kbit/s secondary digital groups or five or seven 6312 kbit/s secon- dary digital groups to form a composite signal having a digit rate of 34368, 32064 or 44736 kbit/s. Note 3 - A quaternary digital group may comprise four 34368 kbit/s tertiary digital groups to form a composite signal having a digit rate of 139264 kbit/s. 4007 frame F: trame S: trama A cyclic set of consecutive time slots in which the relative position of each time slot can be identified. 4008 multiframe F: multitrame S: multitrama A cyclic set of consecutive frames in which the relative posi- tion of each frame can be identified. 4009 subframe F: sous-trame, secteur de trame S: subtrama A sequence of noncontiguous time-slots within a frame, each occurring at n times the frame repetition rate where n is an integer >1. 4010 parallel to serial converter (American: serializer) [dynamicizer] F: convertisseur parallele/serie S: convertidor paralelo/serie A device that converts a group of signal elements, all of which are presented simultaneously, into a corresponding sequence of consecutive signal elements. 4011 serial to parallel converter (American: deserializer) [staticizer] F: convertisseur serie/parallele S: convertidor serie/paralelo A device that converts a sequence of consecutive signal ele- ments into a corresponding group of signal elements all of which are presented simultaneously. 4012 time-division multiplexing F: multiplexage temporel [multiplexage par repartition dans le temps] S: multiplexacion por division en el tiempo Multiplexing in which several signals are interleaved in time for transmission over a common channel. 4013 digital multiplexing F: multiplexage numerique S: multiplexacion digital A form of time division multiplexing applied to digital chan- nels which convey digital signals. 4014 digital multiplexer F: multiplexeur numerique S: multiplexor digital Equipment that combines by time-division multiplexing several digital signals into a single composite digital signal. 4015 digital demultiplexing F: demultiplexage numerique S: demultiplexacion digital The separation of a composite digital signal into its com- ponent digital signals. 4016 digital demultiplexer F: demultiplexeur numerique S: demultiplexor digital Equipment that separates a composite digital signal into its component digital signals. 4017 digital multiplex equipment F: equipement de multiplexage numerique S: equipo multiplex digital The combination of a digital multiplexer and a digital demul- tiplexer at the same location, operating in opposite directions of transmission. 4018 PCM multiplex equipment F: equipement de multiplexage MIC S: equipo multiplex MIC Equipment that derives a single digital signal at a defined digit rate from several voice frequency channels by a combination of pulse code modulation and time division multiplexing, and that also carries out the complementary functions in the opposite direc- tion of transmission. 4019 digital block F: bloc numerique S: bloque digital The combination of a digital link and associated digital mul- tiplex equipments. Note - The bit rate of the digital link should form part of the title. 4020 transmultiplexer F: transmultiplexeur S: transmultiplexor An equipment that transforms a frequency-division multiplexed signal (such as group or supergroup) into a corresponding time-division multiplexed signal that has the same structure as if it had been derived from PCM multiplex equipment, and that also carries out the complementary function in the opposite direction of transmission. 4021 digital filling [digital padding] F: remplissage numerique S: relleno digital [complementacion digital] The addition of signal elements at regular intervals to a digital signal to change the digit rate from its original value to a predetermined higher value. Note - The added digits are not normally used to transmit information. 4022 justification [stuffing, pulse stuffing] F: justification S: justificacion [relleno de impulsos] The process of changing the digit rate of a digital signal in a controlled manner so that it can accord with a digit rate dif- ferent from its own inherent rate, usually without loss of information. 4023 positive justification [positive stuffing, positive pulse stuffing] F: justification positive S: justificacion positiva [relleno positivo de impul- sos] A method of justification in which the digit time-slots used to convey a digital signal have a digit rate that is always higher than the digit rate of that original signal. Note 1 - Positive justification is usually achieved by the provision of a fixed number of digit time-slots (justifiable digit time-slots) per frame in the resultant signal which may be used to transmit either information from the original signal, or no infor- mation, according to the relative digit rates of the resultant sig- nal and the original signal. Note 2 - Information which indicates whether the justifiable digit time-slots contain information digits or justifying digits is conveyed by means of the justification service digits. 4024 negative justification [negative stuffing, negative pulse stuffing] F: justification negative S: justificacion negativa [relleno negativo, relleno negativo de impulsos] A method of justification in which the digit time-slots used to convey a digital signal have a digit rate that is always lower than the digit rate of that original signal. Note 1 - The deleted digits are conveyed by separate means. Note 2 - Information which facilitates the recovery of the deleted digits is conveyed by means of the justification service digits. 4025 positive/zero/negative justification [positive/zero/negative stuffing, positive/zero/negative pulse stuffing] F: justification positive/nulle/negative S: justification positiva/nula/negativa [relleno positivo/nulo/negativo de impulsos] A method of justification in which the digit time-slots used to convey a digital signal have a digit rate that may be higher than, the same as, or lower than the digit rate of the original signal. Note 1 - Justifiable digit time-slots are provided in accor- dance with Note 1 of 4023 above. Note 2 - Separate means of transmitting deleted digits are provided in accordance with Note 2 of 4024 above. Note 3 - Information which facilitates the recovery of the original digits, which are conveyed by means of the justification service digits. Note 4 - Usually the digit time-slots used to convey a digi- tal signal have the same nominal digit rate as the original signal. 4026 justifiable digit time-slot [stuffable digit time-slot] F: creneau temporel elementaire justifiable S: intervalo de tiempo de digito justificable [intervalo de tiempo de digito rellenable] A digit time-slot that is provided for the purpose of justifi- cation and which may contain either an information digit or a jus- tifying digit. 4027 justifying digit [stuffing digit] F: element numerique de justification S: digito de justificacion [digito de relleno] A digit inserted in a justifiable digit time-slot when that time slot is not required for an information digit. 4028 justification service digit [stuffing service digit] F: element numerique de service de justification S: digito de servicio de justificacion [digito de ser- vicio de relleno] A digit that transmits information concerning the status of a justifiable digit time-slot. 4029 justification rate [stuffing rate] F: debit de justification S: velocidad de justificacion [velocidad de relleno] The rate at which justifying digits are inserted, or at which information digits are transmitted by other means. 4030 nominal justification rate [nominal stuffing rate] F: debit nominal de justification S: velocidad nominal de justificacion [velocidad nomi- nal de relleno] The justification rate that occurs when the digit rates of both the original signal and the justified signal are at their nom- inal values. 4031 maximum justification rate [maximum stuffing rate] F: debit maximal de justification S: velocidad maxima de justificacion [velocidad maxima de relleno] The maximum possible justification rate that can be accommo- dated by a justification process. Note - In practice the tolerance limits of the original sig- nal and of the system used to convey the justified signal might be such that the maximum justification rate is never realized. 4032 justification ratio [stuffing ratio] F: taux de justification S: relacion de justificacion [relacion de relleno] The ratio of the actual justification rate to the maximum jus- tification rate. 4033 nominal justification ratio [nominal stuffing ratio] F: taux nominal de justification S: relacion nominal de justificacion [relacion nominal de relleno] The ratio of the nominal justification rate to the maximum justification rate. 2.5 Frame alignment Similar definitions are applicable to multiframe alignment. 5001 frame alignment F: verrouillage de trame S: alineacion de trama The state in which the frame of the receiving equipment is synchronized with that of the received signal. 5002 frame alignment signal F: signal de verrouillage de trame S: se~al de alineacion de trama The distinctive signal inserted in every frame or once in every n frames, always occupying the same relative position within the frame, and used to establish and maintain frame alignment. 5003 bunched frame alignment signal F: signal de verrouillage de trame concentre S: se~al de alineacion de trama concentrada A frame alignment signal whose signal elements occupy consecu- tive digit time slots. 5004 distributed frame alignment signal F: signal de verrouillage de trame reparti [signal de verrouillage de trame distribue] S: se~al de alineacion de trama distribuida A frame alignment signal whose signal elements occupy non-consecutive digit time slots. 5005 frame alignment recovery time F: temps de reprise du verrouillage de trame S: tiempo de recuperacion de la alineacion de trama The time that elapses between a valid frame alignment signal being available at the receive terminal equipment and frame align- ment being established. Note - The frame alignment recovery time includes the time required for replicated verification of the validity of the frame alignment signal. 5006 out-of-frame alignment time F: duree de perte du verrouillage de trame S: duracion de la perdida de la alineacion de trama The time during which frame alignment is effectively lost. Note - That time includes the time to detect loss of frame alignment and the frame alignment recovery time. 2.6 Timing 6001 timing signal F: signal de rythme S: se~al de temporizacion A cyclic signal used to control the timing of operations. 6002 timing recovery [timing extraction] F: recuperation du rythme S: recuperacion de la temporizacion [extraccion de la temporizacion] The derivation of a timing signal from a received signal. 6003 retiming F: reajustement du rythme S: reajuste de la temporizacion Adjustment of the intervals between the significant instants of a digital signal, by reference to a timing signal. 6004 time-slot F: creneau temporel [intervalle de temps] S: intervalo de tiempo [sector de tiempo, celda de tiempo] Any cyclic time interval that can be recognized and defined uniquely. 6005 digit time-slot F: creneau temporel elementaire [intervalle de temps elementaire] S: intervalo de tiempo de digito A time slot allocated to a single digit. 6006 channel time-slot F: creneau temporel de voie S: intervalo de tiempo de canal A time slot occupying a specific position in a frame and allo- cated to a particular time-derived channel. Note 1 - Where appropriate a description may be added, for example "telephone channel time slot". Note 2 - In addition to its main function of transmitting a character signal, a channel time slot may also be used for in-slot signalling or for transmitting other information. 6007 signalling time-slot F: creneau temporel de signalisation S: intervalo de tiempo de se~alizacion A time slot occupying a specific position in a frame and allo- cated to the transmission of signalling. 6008 frame alignment time-slot F: creneau temporel de verrouillage de trame S: intervalo de tiempo de alineacion de trama A time slot occupying the same relative position in every frame and used to transmit the frame alignment signal. 6009 clock F: horloge S: reloj Equipment that provides a timing signal. Note - Where replicated sources are used for security rea- sons, the assembly of these is regarded as single clock. 6010 reference clock F: horloge de reference S: reloj de referencia A clock of very high stability and accuracy that may be com- pletely autonomous and whose frequency serves as a basis of com- parison for the frequency of other clocks. 6011 master clock F: horloge ma | tresse S: reloj maestro A clock that is used to control the frequency of other clocks. 6012 time interval error F: derive temporelle S: error de intervalo de tiempo The total difference over a specified interval of time in the significant instants of a digital signal from their ideal positions in time. 6013 relative time interval error F: derive temporelle relative S: error de intervalo de tiempo relativo The total difference over a specified interval of time in the corresponding significant instants of two digital signals. 6014 isochronous F: isochrone S: isocrono The essential characteristic of a time-scale or a signal such that the time intervals between consecutive significant instants either have the same duration or durations that are integral multi- ples of the shortest duration. Note - In practice, variations in the time intervals are con- strained within specified limits. 6015 anisochronous F: anisochrone S: anisocrono The essential characteristic of a time-scale or a signal such that the time intervals between consecutive significant instants do not necessarily have the same duration or durations that are integral multiples of the shortest duration. 6016 synchronous [mesochronous] F: synchrone [mesochrone] S: sincrono [mesocrono] The essential characteristic of time-scales or signals such that their corresponding significant instants occur at precisely the same average rate. Note - The timing relationship between corresponding signifi- cant instants usually varies between specified limits. 6017 homochronous F: homochrone S: homocrono The essential characteristic of time-scales or signals such that their corresponding significant instants have a constant, but uncontrolled, time relationship with each other. 6018 non-synchronous [asynchronous/heterochronous] F: nonsynchrone [asynchrone/heterochrone] S: no-sincrono [asicrono/heterocrono] The essential characteristic of time-scales or signals such that their corresponding significant instants do not necessarily occur at the same average rate. 6019 plesiochronous F: plesiochrone S: plesiochrono The essential characteristic of time-scales or signals such that their corresponding significant instants occur at nominally the same rate, any variation in rate being constrained within specified limits. Note 1 - Two signals having the same nominal digit rate, but not stemming from the same clock or homochronous clocks, are usu- ally plesiochronous. Note 2 - There is no limit to the time relationship between corresponding significant instants. 6020 heterochronous F: heterochrone S: heterocrono The essential characteristic of time-scales or signals such that their corresponding significant instants occur at different nominal rates. Note 1 - Two signals having different nominal digit rates, and not stemming from the same clock or from homochronous clocks are usually heterochronous. Note 2 - Terms 6015 to 6020 are based on the following Greek roots: iso = equal homo = same plesio = near hetero = different 6021 codirectional interface F: interface codirectionnelle S: interfaz codireccional An interface across which the signals to be transferred and their associated timing signals are transmitted in the same direc- tion. 6022 centralized-clock interface F: interface a horloge centralisee S: interfaz de reloj centralizado An interface across which, for both directions of transmission of the signals to be transferred, the associated timing signals of both the exchange terminal on the line side and the exchange termi- nal on the service side are supplied from a centralized clock. Note - The timing of the centralized clock may be derived from a nominated incoming line signal. 6023 contradirectional interface F: interface contradirectionnelle S: interfaz contradireccional An interface across which the timing signals associated with both directions of transmission of the signals to be transferred, are directed towards the same side of the interface. 2.7 Synchronization 7001 synchronization F: synchronisation S: sincronizacion The process of adjusting the corresponding significant instants of signals to make them synchronous. 7002 timing information F: information de rythme S: informacion de temporizacion Information contained in a signal relating to the timing of another signal. 7003 synchronization information F: information de synchronisation S: informacion de sincronizacion Information that indicates the relationship between the timing of two or more signals. 7004 clock control signal F: signal de commande d'horloge S: se~al de control de reloj A signal that directly controls the phase or frequency of a clock. 7005 synchronization node F: noeud de synchronisation S: nodo de sincronizacion A point in a synchronized network at which synchronization information is derived, sent or received. 7006 synchronization link F: liaison de synchronisation S: enlace de sincronizacion A link between two synchronization nodes over which synchroni- zation information is transmitted. 7007 synchronization network F: reseau de synchronisation S: red de sincronizacion An arrangement of synchronization nodes and synchronization links provided in order to synchronize the clocks at, or connected to, those nodes. 7008 single-ended synchronization F: synchronisation locale [synchronisation unilaterale] S: sincronizacion uniterminal A method of synchronizing a specified synchronization node with respect to another synchronization node in which synchroniza- tion information at the specified node is derived from the phase difference between the local clock and the incoming digital signal from the other node. 7009 double-ended synchronization F: synchronisation locale et distante [synchronisation bilaterale] S: sincronizacion biterminal A method of synchronizing a specified synchronization node with respect to another synchronization node in which synchroniza- tion information at the specified node is derived by comparing the phase difference between the local clock and the incoming digital signal from the other node, with the phase difference at the other node between its local clock and the digital signal incoming from the specified node. 7010 unilateral control F: synchronisation unilaterale [commande unilaterale] S: control unilateral Control between two synchronization nodes such that the fre- quency of the clock of only one of these nodes is influenced by timing information derived from the clock of the other node. 7011 bilateral control F: synchronisation bilaterale [commande bilaterale] S: control bilateral Control between two synchronization nodes such that the fre- quency of the clock of each of these nodes is influenced by timing information derived from the clock of the other node. 7012 analogue control F: synchronisation analogique [mode analogique] S: control analogico A method of controlling clocks in which the clock control sig- nal is a continuous (monotonic) function of the phase difference between clocks, at least over a limited range. 7013 linear analogue control F: synchronisation analogique lineaire [mode analogique lineaire] S: control analogico lineal Analogue control in which the clock control signal is propor- tional to the phase difference between clocks, at least over a lim- ited range. 7014 amplitude quantized control F: synchronisation quantifiee [mode a quantification d'amplitude] S: control por cuantificacion de amplitud A method of controlling clocks in which the clock control sig- nal is a quantized function of the phase difference between clocks. Note - In practice this implies that the working range of phase errors is divided into a finite number of subranges and that a unique signal is derived for each subrange whenever the error falls within a subrange. 7015 time quantized control F: synchronisation echantillonnee [mode a quantification temporelle] S: control por cuantificacion temporal A method of controlling clocks in which each clock control signal is derived or utilized only at a number of discrete instants, which may or may not be equally separated in time. 7016 synchronized network [synchronous network] F: reseau synchronise [reseau synchrone] S: red sincronizada [red sincrona] A network in which the corresponding significant instants of nominated signals are adjusted to make them synchronous. 7017 non-synchronized network F: reseau non synchronise S: red no sincronizada A network in which signals need not be synchronous. 7018 mutually synchronized network F: reseau a synchronisation mutuelle S: red mutuamente sincronizada A synchronized network in which each clock exerts a degree of control on all others. 7019 democratic network, democratic mutually synchronized network F: reseau democratique, reseau a synchronisation mutuelle democratique S: red democratica, red democratica mutuamente sincron- izada A mutually synchronized network in which all clocks are of equal status and exert equal amounts of control on the others; the network operating frequency (digit rate) being the mean of the natural (uncontrolled) frequencies of all the clocks. 7020 hierarchic network, hierarchic synchronized network F: reseau hierarchise, reseau a synchronisation hierarchisee S: red jerarquica, red con sincronizacion jerarquica A synchronized network in which each clock is assigned a par- ticular status which determines the degree of control it exerts over the other clocks. 7021 hierarchic mutually synchronized network F: reseau hierarchise a synchronisation mutuelle S: red jerarquica mutuamente sincronizada A mutually synchronized network in which each clock is assigned a particular status which determines the degree of control it exerts over other clocks; the network operating frequency being a weighted mean of the natural frequencies of all the clocks. 7022 monarchic network, monarchic synchronized network [despotic network, despotic synchronized network] F: reseau despotique, reseau a synchronisation despotique S: red despotica, red con sincronizacion despotica [red monarquica, red con sincronizacion monarquica] A synchronized network in which a single clock exerts control over all the other clocks. 7023 oligarchic network, oligarchic synchronized network F: reseau oligarchique, reseau a synchronisation oligar- chique S: red oligarquica, red con sincronizacion oligarquica A synchronized network in which a few selected clocks are mutually synchronized and exert control over all the other clocks. 2.8 Pulse Code Modulation 8001 pulse code modulation (PCM) F: modulation par impulsions et codage (MIC) S: modulacion por impulsos codificados (MIC) A process in which a signal is sampled, and each sample is quantized independently of other samples and converted by encoding to a digital signal. 8002 differential pulse code modulation (DPCM) F: modulation par impulsions et codage differentiel (MICD) S: modulacion por impulsos codificados diferencial (MICD) A process in which a signal is sampled, and the difference between each sample of this signal and its estimated value is quan- tized and converted by encoding to a digital signal. Note - The estimated values of the signal are calculated by a predictor from the quantized difference signal. 8003 delta modulation F: modulation delta S: modulacion delta A form of differential pulse code modulation in which only the sign of the difference between each sample and its predicted value is detected and encoded by a single bit. 8004 adaptive differential pulse code modulation (ADPCM) F: modulation par impulsions et codage differentiel adap- tatif (MICDA) S: modulacion por impulsos y codigo diferencial adaptativo (MICDA) A form of differential pulse code modulation that uses adap- tive quantizing. Note 1 - The predictor may be either fixed (time invariant) or variable. Note 2 - When the predictor is adaptive, the adaption of its coefficients is made from the quantized difference signal. 8005 predictor F: predicteur S: predictor A device that provides an estimated value of a sampled signal derived from previous samples of the same signal or from a quan- tized version of those samples. 8006 adaptive predictor F: predicteur adaptatif S: predictor adaptativo A predictor whose estimating function is made variable accord- ing to the short term spectral characteristics of the sampled sig- nal. 8007 sample F: echantillon S: muestra A representative value of a signal at a chosen instant, derived from a portion of that signal. 8008 sampling F: echantillonnage S: muestreo The process of taking samples of a signal, usually at equal time intervals. 8009 sampling rate F: frequence d'echantillonnage [taux d'echantillonnage] S: velocidad de muestreo [frecuencia de muestreo] The number of samples taken of a signal per unit time. 8010 working range F: plage de fonctionnement [gamme de fonctionnement] S: gama de funcionamiento The range of values of an input signal over which an equipment is designed to operate with a specified performance. (See Figure 2/G.701.) 8011 quantizing F: quantification S: cuantificacion A process in which a continuous range of values is divided into a number of adjacent intervals, and any value within a given interval is represented by a single predetermined value within the interval. (See Figure 2/G.701.) 8012 adaptive quantizing F: quantification adaptative S: cuantificacion adaptativa Quantizing in which some parameters are made variable accord- ing to the short term statistical characteristics of the quantized signal. 8013 uniform quantizing F: quantification uniforme S: cuantificacion uniforme Quantizing in which all the quantizing intervals lying entirely with the working range are equal. (See Figure 2/G.701.) 8014 non-uniform quantizing F: quantification non uniforme S: cuantificacion no uniforme Quantizing in which not all the quantizing intervals lying entirely with the working range are equal. (See Figure 2/G.701.) 8015 quantizing interval F: intervalle de quantification S: intervalo de cuantificacion One of the intervals used in quantizing. (See Figure 2/G.701.) 8016 decision value F: valeur de decision [amplitude de decision] S: valor de decision A value defining the boundary between adjacent quantizing intervals. (See Figures 2/G.701 and 4/G.701.) 8017 virtual decision value F: valeur virtuelle de decision [amplitude virtuelle de decision] S: valor virtual de decision Each of the two defined values, that provide conventional bounds for the working range in quantizing. (See Figure 2/G.701.) Note - These values are taken to represent hypothetical outer bounds for the two extreme quantizing intervals of the quantizing law. 8018 quantized value F: valeur quantifiee [amplitude quantifiee] S: valor cuantificado The single discrete value used to represent any value in a particular quantizing interval. (See Figure 2/G.701.) 8019 load capacity [overload point] F: capacite de charge [point de surcharge] S: capacidad de carga [punto de sobrecarga] The level of a sinusoidal signal whose positive and negative peaks coincide with the virtual decision values. 8020 peak limiting, peak limiting in quantizing F: ecr | tage S: limitacion de cresta (en cuantificacion) The effect whereby any value to be quantized lying outside the working range is replaced by the nearest quantized value. (See Figure 2/G.701.) 8021 quantizing distortion F: distorsion de quantification S: distorsion de cuantificacion The distortion resulting from the process of quantizing sam- ples within the working range. 8022 quantizing distortion power F: puissance de distorsion de quantification S: potencia de la distorsion de cuantificacion The power of the distortion component of the output signal resulting from the process of quantizing. 8023 encoding [coding, coding in PCM] F: codage S: codificacion [codificacion en MIC] The generation of a code word to represent a quantized value. 8024 encoder [coder] F: codeur S: codificador A device that performs encoding. 8025 uniform encoding F: codage uniforme S: codificacion uniforme The generation of code words to represent uniformly quantized values. 8026 non-uniform encoding F: codage non uniforme S: codificacion no uniforme The generation of code words to represent non-uniformly quan- tized values. (See Figure 3/G.701.) 8027 encoding law F: loi de quantification [loi de codage] S: ley de codificacion The law defining the relative values of the quantizing inter- vals used in quantizing and encoding. (See Figure 4/G.701.) 8028 segmented encoding law F: loi de quantification a segments [loi de codage a seg- ments] S: ley de codificacion por segmentos An encoding law in which an approximation to a smooth law is obtained by a number of linear segments. (See Figures 3a/G.701 and 3b/G.701.) 8029 decoding F: decodage S: decodificacion The generation of reconstructed samples. 8030 decoder F: decodeur S: decodificador A device that performs decoding. 8031 reconstructed sample F: echantillon reconstitue S: muestra reconstruida The signal generated at the output of a decoder when a speci- fied digital signal representing a quantized value is applied to its input. 8032 codec F: codec S: codec A combination of an encoder and a decoder operating in oppo- site directions of transmission in the same equipment. Note - When used to describe an equipment the function of the equipment should qualify the title, for example: supergroup codec, hypergroup codec. 8033 digilogue channel F: voie digilogue S: canal digi-analogico A channel in which information is represented by a digital signal at one end and the same information is represented by the corresponding analogue signal at the other end. Note - The term may be qualified by "A to D" or "D to A" to indicate whether encoding or decoding is being performed. 8034 digilogue circuit F: circuit digilogue S: circuito digi-analogico A circuit in which transmission is provided in one direction by an A to D digilogue channel and in the other direction by a D to A digilogue channel. Note - Because the digital interface is inherently 4-wire, the term may be qualified by "2-W" or "4-W" to indicate whether the analogue interface is 2-wire or 4-wire. Figure 2/G.701, p. Figure 3/G.701, p. Figure 4/G.701, p. 2.9 Codes 9001 pulse code F: code d'impulsions (code de modulation d'impulsions) S: codigo de impulsos A set of rules giving the equivalence between each quantized value and its corresponding code word. 9002 line code F: code en ligne S: codigo de linea, codigo en linea A code chosen to suit the characteristics of a channel, that defines the equivalence between sets of digits presented for transmission and the corresponding sequence of signal elements transmitted over that channel. 9003 redundant line code F: code en ligne redondant S: codigo de linea redundante A line code that uses more encoded signal elements than strictly necessary to represent groups of digits of the original signal. 9004 alternate mark inversion code (AMI code) F: code bipolaire [code bipolaire alternant, code bipo- laire strict] S: codigo de inversion de marcas alternada (codigo AMI) [codigo bipolar] A line code that employs a ternary signal to convey binary digits, in which successive binary ones are represented by signal elements that are normally of alternating, positive and negative polarity but equal in amplitude, and in which binary zeros are represented by signal elements that have zero amplitude. 9005 modified alternate mark inversion code F: code bipolaire alternant modifie S: codigo de inversion de marcas alternada modificado A line code that is based on an alternate mark inversion code, in which alternate mark inversion violations occur in accordance with a defined set of rules. 9006 alternate mark inversion signal [bipolar signal] F: signal bipolaire [signal bipolaire alternant] S: se~al de inversion de marcas alternada [se~al bipolar] The encoded signal produced by alternate mark inversion code. 9007 alternate mark inversion violation [bipolar violation] F: violation de bipolarite S: violacion de inversion de marcas alternada [violacion bipolar] A non-zero signal element in an alternate mark inversion sig- nal that has the same polarity as the previous non-zero signal ele- ment. 9008 disparity F: disparite S: disparidad The algebraic sum of the values of the departure from notional zero level of one or more consecutive signal elements forming a defined group. 9009 digital sum F: somme numerique S: suma digital The algebraic sum of the disparities of a sequence of consecu- tive defined groups of signal elements. 9010 digital sum variation F: variation de la somme numerique S: variacion de la suma digital The difference between the maximum possible digital sum and the minimum possible digital sum of a specified number of groups of signal elements. 9011 balanced code F: code a somme bornee S: codigo equilibrado A code that generates only groups of signal elements that have zero digital sum. 9012 paired-disparity code [alternate code, alternating code] F: code a disparite compensee S: codigo con disparidad compensada [codigo alternado, codigo alternante] A code in which some or all of the digits in the original sig- nal are represented by two assemblies of digits, of opposite disparity, which are used in a sequence to minimize the digital sum of a longer sequence of digits. Note - An alternate mark inversion signal is an example of a paired-disparity code. 9013 PCM binary code F: code binaire MIC S: codigo binario MIC A pulse code in which all the quantized values are identified by binary numbers taken in order. Note - This term should not be used for line transmission. 9014 symmetrical binary code F: code binaire symetrique S: codigo binario simetrico A pulse code in which the sign of the quantized value, is represented by one digit, and in which the remaining digit consti- tute a binary number representing the magnitude. Note 1 - In a particular symmetrical binary code, the order of the digits and the use made of the symbols 0 and 1 in the vari- ous digit positions must be specified. Note 2 - This term should not be used for line transmission. 9015 code conversion F: transcodage S: conversion de codigo The conversion of digital signals in one code to the corresponding signals in a different code. ANNEX A (to Recommendation G.701) Alphabetical list of terms defined in this Recommendation 8004 adaptive differential pulse code modulation (ADPCM) 8006 adaptive predictor 8012 adaptive quantizing 3023 alarm indication signal (AIS) 9012 [alternate code] 9004 alternate mark inversion code (AMI code) 9012 [alternating code] 9006 alternate mark inversion signal 9007 alternate mark inversion violation 7014 amplitude quantized control 7012 analogue control 1002 analogue signal 6015 anisochronous 6018 [asynchronous/heterochronous] 9011 balanced code 7011 bilateral control 2003 binary digit 2002 binary figure 9006 [bipolar signal] 9007 [bipolar violation] 3019 bit sequence independence 5003 bunched frame alignment signal 4001 (bus: American) 6022 centralized-clock interface 1005 channel, transmission channel 4002 channel gate 6006 channel time-slot 2005 [character signal] 1007 circuit, telecommunication circuit 6009 clock 7004 clock control signal 2005 code word 8032 codec 8024 [coder] 8023 [coding, coding in PCM] 6021 codirectional interface 6023 contradirectional interface 2026 controlled slip 2020 decision circuit 2019 decision instant, decision instant of a digital signal 8016 decision value 8030 decoder 8029 decoding 8003 delta modulation 7019 democratic network, democratic mutually synchronized network 2029 descrambler 4011 (deserializer: American) 7022 [despotic network, despotic synchronized network] 8002 differential pulse code modulation (DPCM) 8033 digilogue channel 8034 digilogue circuit 2001 digit 2008 digit position 2013 digit rate 3020 digit sequence integrity 6005 digit time-slot 4019 digital block 3002 digital channel, digital transmission channel 3003 digital circuit, digital telecommunication circuit 3004 digital connection 4016 digital demultiplexer 4015 digital demultiplexing 3006 digital distribution frame 2030 digital error 4021 digital filling 3013 digital line link 3013 [digital line path] 3012 digital line section 3015 digital line system 3005 digital link, digital transmission link 4014 digital multiplexer 4017 digital multiplex equipment 4003 digital multiplex hierarchy 4013 digital multiplexing 4021 [digital padding] 3005 [digital path] 3017 digital radio link 3017 [digital radio path] 3016 digital radio section 3018 digital radio system 3007 digital section 2006 digital signal 9009 digital sum 9010 digital sum variation 3003 digital telecommunication circuit 3001 digital transmission 3002 digital transmission channel 3005 digital transmission link 3014 digital transmission system 3022 digital transparency 4005 (digroup: American) 1003 discretely-timed signal 9008 disparity 5004 distributed frame alignment signal 7009 double-ended synchronization 4010 [dynamicizer] 3009 elementary cable section 3011 elementary regenerator section 3010 elementary repeater section 8024 encoder 8023 encoding 8027 encoding law 2015 equivalent binary content 2016 equivalent bit rate 2030 error, digital error 2032 error multiplication 2033 error multiplication factor 2031 [error rate] 2031 error ratio 2034 error spread 4007 frame 5001 frame alignment 5002 frame alignment signal 5005 frame alignment recovery time 6008 frame alignment time-slot 6020 heterochronous 7021 hierarchic mutually synchronized network 7020 hierarchic network, hierarchic synchronized network 4001 highway 6017 homochronous 3025 [housekeeping digits] 1008 interface 6014 isochronous 2024 jitter 4026 justifiable digit time-slot 4022 justification 4029 justification rate 4032 justification ratio 4028 justification service digit 4027 justifying digit 9002 line code 2014 line digit rate 7013 linear analogue control 8019 load capacity 6011 master clock 4031 maximum justification rate 4031 [maximum stuffing rate] 6016 [mesochronous] 9005 modified alternate mark inversion code 7022 monarchic network, monarchic synchronized network 4008 multiframe 7018 mutually synchronized network 4006 n-ary digital group 2009 n-ary digital signal 4024 negative justification 4024 [negative stuffing, negative pulse stuffing] 4030 nominal justification rate 4033 nominal justification ratio 4030 [nominal stuffing rate] 4033 [nominal stuffing ratio] 7017 non-synchronized network 6018 non-synchronous 8026 non-unifrom encoding 8014 non-uniform quantizing 2004 octet 3021 octet sequence integrity 7023 oligarchic network, oligarchic synchronized network 5006 out-of-frame alignment time 8019 [overload point] 9012 paired-disparity code 4010 parallel to serial converter 4018 PCM multiplex equipment 8020 peak limiting, peak limiting in quantizing 6019 plesiochronous 4023 positive justification 4023 [positive stuffing, positive pulse stuffing] 4025 positive/zero/negative justification 4025 [positive/zero/negative stuffing] 4025 positive/zero/negative pulse stuffing 8005 predictor 4005 [primary block] 4004 primary digital group 4005 primary PCM group 2012 psuedo n-ary signal 9001 pulse code 8001 pulse code modulation (PCM) 4022 [pulse stuffing] 8018 quantized value 8011 quantizing 8021 quantizing distortion 8022 quantizing distortion power 8015 quantizing interval 8031 reconstructed sample 2010 redundant digital signal 9003 redundant line code 2011 redundant n-ary signal 6010 reference clock 2021 regeneration 2023 regenerative repeater 2022 regenerator 3011 [regenerator section] 3009 [repeater section] 6013 relative time interval error 6003 retiming 8007 sample 8008 sampling 8009 sampling rate 2028 scrambler 3008 section termination 8028 segmented encoding law 4011 serial to parallel converter 4010 (serializer: American) 3025 service digits 1001 signal 2007 signal element 6007 signalling time-slot 2017 significant instant, significant instant of a digital signal 7008 single-ended synchronization 2026 [slip] 4011 [staticizer] 4026 [stuffable digit time-slot] 4022 [stuffing] 4027 [stuffing digit] 4029 [stuffing rate] 4032 [stuffing ratio] 4028 [stuffing service digit] 4009 subframe 2014 [symbol rate] 9014 symmetrical binary code 7001 synchronization 7003 synchronization information 7006 synchronization link 7005 synchronization node 7007 synchronization network 6016 synchronous 7016 synchronized network 7016 [synchronous network] 1006 telecommunication 1007 telecommunication circuit 4012 time-division multiplexing 6012 time interval error 7015 time quantized control 6004 time-slot 6002 [timing extraction] 7002 timing information 6001 timing signal 6002 timing recovery 1004 transmission 1005 tranmission channel 4020 transmultiplexer 3022 transparency, digital transparency 2027 uncontrolled slip 8025 uniform encoding 8013 uniform quantizing 7010 unilateral control 2018 unit interval 3024 upstream failure indication 8017 virtual decision value 2025 wander 8010 working range Reference [1] CCITT Recommendation Definitions relating to national and international numbering plans , Vol. VI, Rec. Q.10. Recommendation G.702 DIGITAL HIERARCHY BIT RATES (Malaga-Torremolinos, 1984; amended at Melbourne, 1988) The CCITT, considering (a) that digital hierarchy bit rates are those bit rates which are or will be used as the basis for higher digital hierarchy lev- els if such levels exist (see Recommendation G.701, defini- tion 4003); (b) that the specification of hierarchical bit rates is neces- sary to prevent the proliferation of interface standards used in digital networks; (c) that international interconnections of digital network components are preferably carried out at hierarchical bit rates; (d) that when determining hierarchical bit rates a number of factors relating to services, transmission media and networking need to be taken into account, for example: - characteristics of and suitable coding method for analogue source signals; - bit rates of digital source signals; - use of available transmission media; - compatibility with analogue multiplex systems; - modularity and flexibility in assembling and routing groups of source signals, recommends that the following bit rates should be used as hierarchical bit rates in digital networks: Table [T1.702], p. Figure 1/G.702 and Figure 2/G.702 show the recommended hierarchical bit rates only, including references to related Recom- mendations on network interfaces, multiplex equipments, digital sections/systems. Recommendations on the following may also exist, but are not identified in Figure 1/G.702 and Figure 2/G.702: - multiplex equipments operating between non-adjacent levels of the digital hierarchy; - network interfaces, multiplex equipments and digital sections/systems at non-hierarchical bit rates. Annex A to this Recommendation provides guidelines on usable bit rates available for services. Figure 1/G.702, p. Figure 2/G.702, p. ANNEX A (to Recommendation G.702) Usable bit rates available for services In the case of access to the ISDN for broadband services, bit rates up to the primary hierarchy level are specified in the I.200 series of Recommendations. In general, with regard to bit rates available for transport of service signals, the following guidelines apply: A.1 For the hierarchies based on the 1544 kbit/s primary rate, the principle has been established that some bits in the frame should be reserved, in particular to perform quality control of the digital paths when several digital sections in tandem are involved. Table A-1/G.702 provides the necessary information. Table A-1/G.702 [T2.702], p. A.2 In case of networks using 2048 kbit/s based hierarchy there is in principle no basic restriction on the use of full capa- city of the digital path. However, it is recognized that compati- bility with recommended frame structures at the various levels of the 2 Mbit/s hierarchy (e.g. the use of the same frame alignment pattern) could be a preferred solution since it offers the follow- ing advantages: - use of the same framing devices for switched and non-switched applications; - end-to-end quality control performed in a unique way by the network when the maintenance entity that terminates the service (e.g. the encoding device) does not belong to the network; - possibility of performing additional network management functions that could be required, depending on the applications. The preference for compatibility with recommended frame struc- tures could be reconsidered for the applications where significant restrictions on the efficient use of the digital path capability can be identified.