.rs .\" Troff code generated by TPS Convert from ITU Original Files .\" Not Copyright ( c) 1991 .\" .\" Assumes tbl, eqn, MS macros, and lots of luck. .TA 1c 2c 3c 4c 5c 6c 7c 8c .ds CH .ds CF .EQ delim @@ .EN .nr LL 40.5P .nr ll 40.5P .nr HM 3P .nr FM 6P .nr PO 4P .nr PD 9p .po 4P .rs \v | 5i' .sp 1P .ce 1000 \v'12P' \s12FASCICLE\ III.4 \v'4P' .RT .ce 0 .sp 1P .ce 1000 \fBRecommendations\ G.700\ to\ G.795\fR \v'2P' .EF '% \ \ \ ^'' .OF ''' \ \ \ ^ %' .ce 0 .sp 1P .ce 1000 \fBGENERAL\ ASPECTS\ OF\ DIGITAL\ TRANSMISSION\ SYSTEMS;\fR .ce 0 .sp 1P .ce 1000 \fBTERMINAL\ EQUIPMENTS\fR .ce 0 .sp 1P .LP .rs .sp 28P .ad r Blanc .EF '% \ \ \ ^'' .OF ''' \ \ \ ^ %' .ad b .RT .LP .bp .LP \fBMONTAGE:\fR \ PAGE 2 = PAGE BLANCHE .sp 1P .RT .LP .bp .sp 1P .ce 1000 \v'3P' SECTION\ 7 .ce 0 .sp 1P .ce 1000 \fBGENERAL\ ASPECTS\ OF\ DIGITAL\ TRANSMISSION\ SYSTEMS;\fR .ce 0 .sp 1P .ce 1000 \fBTERMINAL\ EQUIPMENTS\fR .ce 0 .sp 1P .IP \fB7.0\ General\fR \v'6p' .sp 1P .RT .sp 2P .LP \fBRecommendation\ G.700\fR \v'1P' .RT .sp 2P .sp 1P .ce 1000 \fBFRAMEWORK\ OF\ THE\ SERIES\ G.700,\ G.800\ AND\ G.900\ RECOMMENDATIONS\fR .EF '% Fascicle\ III.4\ \(em\ Rec.\ G.700'' .OF '''Fascicle\ III.4\ \(em\ Rec.\ G.700 %' .ce 0 .sp 1P .ce 1000 \fI(former Recommendation G.701 of Volume III of the Yellow Book)\fR .sp 9p .RT .ce 0 .sp 1P .LP SECTION\ 7\ \(em \fIGeneral aspects of digital transmission systems; terminal\fR \fIequipments\fR .sp 1P .RT .sp 2P .LP \fB7.0\fR \fBGeneral\fR .sp 1P .RT .sp 1P .LP G.700 Framework of the series G.700, G.800 and G.900 Recommendations .sp 9p .RT .LP G.701 Vocabulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms .LP G.702 Digital hierarchy bit rates .LP G.703 Physical/electrical characteristics of hierarchical digital interfaces .LP G.704 Functional characteristics of interfaces associated with network nodes .LP G.705 Characteristics required to terminate digital links on a digital exchange .LP G.706 Frame alignement and cyclic redundancy check (CRC) procedures relating to basic frame structures defined in Recommendation\ G.704 .LP G.707 Synchronous digital hierarcy bit rates .LP G.708 Network node interface for the synchronous digital hierarchy .LP G.709 Synchronous multiplexing structure \v'3p' .sp 2P .LP \fB7.1\fR \fBCoding of analogue signals by pulse code modulation\fR .sp 1P .RT .sp 1P .LP G.711 Pulse code modulation (PCM) of voice frequencies .sp 9p .RT .LP G.712 Performance characteristics of PCM channels between 4\(hywire interfaces at voice frequencies .LP G.713 Performance characteristics of PCM channels between 2\(hywire interfaces at voice frequencies .bp .LP G.714 Separate performance characteristics for the encoding and decoding sides of PCM channels applicable to 4\(hywire voice\(hyfrequency interfaces .LP G.715 Separate performance characteristics for the encoding and decoding side of PCM channels applicable to 2\(hywire interfaces \v'3p' .sp 2P .LP \fB7.2\fR \fBCoding of analogue signals by methods other than PCM\fR .sp 1P .RT .sp 1P .LP G.721 32 kbit/s adaptive differential pulse code modulation (ADPCM) .sp 9p .RT .LP G.722 7 kHz audio\(hycoding within 64 kbit/s .LP G.723 Extensions of Recommendation G.721 ADPCM to 24 and 40 kbit/s for DCME application .LP G.724 Characteristics of a 48\(hychannel low bit rate encoding primary multiplex operating at 1544\ kbit/s .LP G.725 System aspects for the use of the 7 kHz audio codec within 64\ kbit/s \v'3p' .sp 2P .LP \fB7.3 \fBPrincipal characteristics of primary multiplex equipment\fR .sp 1P .RT .sp 1P .LP G.731 Primary PCM multiplex equipment for voice frequencies .sp 9p .RT .LP G.732 Characteristics of primary PCM multiplex equipment operating at 2048\ kbit/s .LP G.733 Characteristics of primary PCM multiplex equipment operating at 1544\ kbit/s .LP G.734 Characteristics of synchronous digital multiplex equipment operating at 1544\ kbit/s .LP 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 .LP G.736 Characteristics of a synchronous digital multiplex equipment operating at 2048\ kbit/s .LP 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 .LP 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 .LP 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 \v'3p' .sp 2P .LP \fB7.4\fR \fBPrincipal characteristics of second order multiplex equipments\fR .sp 1P .RT .sp 1P .LP G.741 General considerations on second order multiplex equipments .sp 9p .RT .LP G.742 Second order digital multiplex equipment operating at 8448\ kbit/s and using positive justification .LP G.743 Second order digital multiplex equipment operating at 6312\ kbit/s and using positive justification .LP G.744 Second order PCM multiplex equipment operating at 8448\ kbit/s .LP G.745 Second order digital multiplex equipment operating at 8448\ kbit/s and using positive/zero/negative justification .LP G.746 Characteristics of second order PCM multiplex equipment operating at 6312\ kbit/s .LP G.747 Second order digital multiplex equipment operating at 6312\ kbit/s and multiplexing three tributaries at 2048 kbit/s .bp .sp 2P .LP \fB7.5\fR \fBPrincipal characteristics of higher order multiplex equipments\fR .sp 1P .RT .sp 1P .LP 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 .sp 9p .RT .LP G.752 Characteristics of digital multiplex equipments based on a second order bit rate of 6312\ kbit/s and using positive justification .LP G.753 Third order digital multiplex equipment operating at 34 | 68\ kbit/s and using positive/zero/negative justification .LP G.754 Fourth order digital multiplex equipment operating at 139 | 64\ kbit/s and using positive/zero/negative justification .LP G.755 Digital multiplex equipment operating at 139 | 64 kbit/s and multiplexing three tributaries at 44736\ kbit/s \v'3p' .sp 2P .LP \fB7.6\fR \fBPrincipal characteristics of transcoder and digital circuit multiplication equipments\fR .sp 1P .RT .sp 1P .LP G.761 General characteristics of a 60\(hychannel transcoder equipment .sp 9p .RT .LP G.762 General characteristics of a 48\(hychannel transcoder equipment .LP G.763 Digital circuit multiplication equipment using 32\ kbit/s ADPCM and digital speech interpolation \v'3p' .sp 2P .LP \fB7.7\fR \fBOperations administration and maintenance features of transmission\fR \fBequipments\fR .sp 1P .RT .sp 1P .LP G.771 Q\(hyinterfaces and associated protocols for transmission equipment in the telecommunications management network (TMN) .sp 9p .RT .LP G.772 Digital protocol monitoring points \v'3p' .sp 2P .LP \fB7.9\fR \fBOther terminal equipments\fR .sp 1P .RT .sp 1P .LP G.791 General considerations on transmultiplexing equipments .sp 9p .RT .LP G.792 Characteristics common to all transmultiplexing equipments .LP G.793 Characteristics of 60\(hychannel transmultiplexing equipments .LP G.794 Characteristics of 24\(hychannel transmultiplexing equipments .LP G.795 Characteristics of codecs for FDM assemblies .LP SECTION\ 8\ \(em \fIDigital networks\fR .sp 1P .RT .sp 2P .LP \fB8.0\fR \fBGeneral aspects of digital networks\fR .sp 1P .RT .sp 1P .LP G.801 Digital transmission models .sp 9p .RT .LP G.802 Interconnection between networks based on different digital hierarchies and speech encoding laws \v'3p' .sp 2P .LP \fB8.1\fR \fBDesign objectives for digital networks\fR .sp 1P .RT .sp 1P .LP G.810 Considerations on timing and synchronization issues .sp 9p .RT .LP G.811 Timing requirements at the outputs of primary reference clocks suitable for plesiochronous operation of international digital links .LP G.812 Timing requirements at the outputs of slave clocks suitable for plesiochronous operation of international digital links .bp .sp 2P .LP \fB8.2\fR \fBQuality and availability targets\fR .sp 1P .RT .sp 1P .LP G.821 Error performance of an international digital connection forming part of an integrated services digital network .sp 9p .RT .LP G.822 Controlled slip rate objectives on an international digital connection .LP G.823 The control of jitter and wander within digital networks which are based on the 2048\ kbit/s hierarchy .LP G.824 The control of jitter and wander within digital networks which are based on the 1544\ kbit/s hierarchy .LP SECTION\ 9\ \(em \fIDigital sections and digital line systems\fR .sp 1P .RT .sp 2P .LP \fB9.0\fR \fBGeneral\fR .sp 1P .RT .sp 1P .LP G.901 General considerations on digital sections and digital line systems .sp 9p .RT .sp 2P .LP \fB9.1\fR \fBDigital line sections at hierarchical bit rates based on a\fR \fBrate of 1544\ kbit/s\fR .sp 1P .RT .LP Recommendations G.911 to G.915 have been deleted \v'3p' .sp 2P .LP \fB9.2\fR \fBDigital sections at hierarchical bit rates based on a\fR \fBprimary bit rate of 2048\ kbit/s\fR .sp 1P .RT .sp 1P .LP G.921 Digital sections based on the 2048\ kbit/s hierarchy \v'3p' .sp 9p .RT .sp 2P .LP \fB9.3\fR \fBDigital line transmission systems on cable at\fR \fBnon\(hyhierarchical bit rates\fR .sp 1P .RT .sp 1P .LP G.931 Digital line sections at 3152\ kbit/s \v'3p' .sp 9p .RT .sp 2P .LP \fB9.4\fR \fBDigital line systems provided by FDM transmission bearers\fR .sp 1P .RT .sp 1P .LP G.941 Digital line systems provided by FDM transmission bearers \v'3p' .sp 9p .RT .sp 2P .LP \fB9.5\fR \fBDigital line systems .sp 1P .RT .sp 1P .LP G.950 General considerations on digital line systems .sp 9p .RT .LP G.951 Digital line systems based on the 1544\ kbit/s hierarchy on symmetric pair cables .LP G.952 Digital line systems based on the 2048\ kbit/s hierarchy on symmetric pair cables .LP G.953 Digital line systems based on the 1544\ kbit/s hierarchy on coaxial pair cables .LP G.954 Digital line systems based on the 2048\ kbit/s hierarchy on coaxial pair cables .LP G.955 Digital line systems based on the 1544\ kbit/s hierarchy on optical fibre cables .LP G.956 Digital line systems based on the 2048\ kbit/s hierarchy on optical fibre cables \v'3p' .sp 2P .LP \fB9.6\fR \fBDigital section and digital transmission systems for ISDN customer\fR \fBaccess\fR .sp 1P .RT .sp 1P .LP G.960 Digital section for ISDN basic rate access .sp 9p .RT .LP G.961 Digital transmission system on metallic local lines for ISDN basic rate access .bp .LP (H.T.=OUI) \fBTAB.???\fR FICHIER: H.T. = \fB(34.TA.341.E)\fR .ad r (SANS FORMULES) .ad b .RT .LP Tableaux: 2 \(em Tabulateurs: 1 .LP \ud\d\u)\d\ .sp 1P .LP Formules: 0 \(em Tabulateurs: 0 .sp 9p .RT .LP .sp 1P .LP TEXTE (tabulateurs) .sp 9p .RT .LP \fIE:\fR \ D. 2 NF01/006 = OPM: 02 .LP Primary\ group\ A\ D. 2 NF01/039 = OPM: 02 .LP \(em\ D. 2 NF01/039 = OPM: 02 .LP hetero\ D. 3 NF01/004 = OPM: 03 .LP .LP (cs,1) \ Disk 2 \ NF01/054 \ (OPM = 02) .LP .sp 1 (BT10) \ Disk 2 \ NF01/028 \ (OPM = 02) .LP (BT20) \ Disk 2 \ NF01/051 \ (OPM = 02) .LP .sp 2 \fB(34.TE.01.E)\fR .LP .sp 2 (A1.23e) / [26e] \ \ \ \fBFOLIOS:\ 7 \(em 44 \ \ \ \fB(DO PRC.COSY.2)\fR .LP .sp 2 .EF '% Fascicle\ III.4\ \(em\ Rec.\ G.701'' .OF '''Fascicle\ III.4\ \(em\ Rec.\ G.701 %' .LP MEP \fB[PA1]\fR : OK= [1] .LP .sp 2 .LP Saisie diskette 17.11.89 \ YB .LP ID + V\*'erif. + diskette MAJ + laser 19.12.89 \ KJ .LP Corr. LASER (1re \*'epreuve) = 3eme ........ \ .. .LP Espaces r\*'eserv\*'es + Transfert + Impr. ........ \ .. .LP .sp 1 \fBAJOUTER (PA1) (CL1,0,0,0) pour MEP\fR .LP .sp 1 MEP + LASER 20.02.90 GH/PC .LP Corr. MEP ........ .. .LP Insertion des tableaux (tabulateurs .) ........ .. .LP BAT 5.04.90 PM .LP MAJ s/disquettes ........ .. .LP .bp .sp 2P .LP \fBRecommendation\ G.701\fR .RT .sp 2P .ce 1000 \fBVOCABULARY\ OF\ DIGITAL\ TRANSMISSION\ AND\ MULTIPLEXING,\fR .EF '% Fascicle\ III.4\ \(em\ Rec.\ G.701'' .OF '''Fascicle\ III.4\ \(em\ Rec.\ G.701 %' .ce 0 .sp 1P .ce 1000 \fBAND\ PULSE\ CODE\ MODULATION\ (PCM)\ TERMS\fR .ce 0 .sp 1P .sp 2P .LP \fB1\fR \fBIntroduction\fR .sp 1P .RT .PP This Recommendation provides a vocabulary of terms and definitions that are appropriate to digital and pulse code modulation multiplexing and transmission systems. .PP A small number of the terms in the Recommendation are duplicated 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. .PP 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: \*Q2026 controlled slip [slip]\*U. .PP Where a truncated term is widely used in an understood context the complete term is quoted following the colloquial form, for example: \*Q1007 circuit, telecommunication circuit\*U. .PP Furthermore, any term which is in general use in addition to the principal term is shown after the principal term as in the following example: \*Q6002 timing recovery (timing extraction)\*U. .PP In the interest of standardization in the drafting of documents the following abbreviations are recommended: .RT .LP kbit/s, .LP Mbit/s, .LP Gbit/s. .PP 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, \*Q2048\ kbit/s\*U is preferred to \*Q2.048\ Mbit/s\*U or \*Q2,048\ Mbit/s. .PP Annex A to this Recommendation contains an alphabetical list of all of the terms defined in this Recommendation. .RT .sp 2P .LP \fB2\fR \fBVocabulary of digital transmission and multiplexing and pulse\fR \fBcode modulation terms (PCM)\fR .sp 1P .RT .LP .sp 1P .ce 1000 CONTENTS .ce 0 .sp 1P .sp 2P .LP 2.1 General .sp 1P .RT .LP 2.2 Digital signals .LP 2.3 Digital transmission .LP 2.4 Digital multiplexing .LP 2.5 Frame alignment .LP 2.6 Timing .LP 2.7 Synchronization .LP 2.8 Pulse code modulation .LP 2.9 Codes \v'3p' .LP Annex\ A\ \(em\ Alphabetical List .sp 2P .LP 2.1 \fIGeneral\fR .sp 1P .RT .sp 1P .LP 1001 \fBsignal\fR [102] .sp 9p .RT .LP \fIF:\fR \fIsignal\fR .LP \fIS:\fR \fIse\o"n~"al\fR .PP A physical phenomenon one or more of whose characteristics may vary to represent information. .bp .RT .sp 1P .LP 1002 \fBanalogue signal\fR [103] .sp 9p .RT .LP \fIF:\fR \fIsignal analogique\fR .LP \fIS:\fR \fIse\o"n~"al anal\*'ogica\fR .PP A signal one of whose characteristic quantities follows continuously the variations of another physical quantity representing information. .RT .sp 1P .LP 1003 \fBdiscretely\(hytimed signal\fR [104] .sp 9p .RT .LP \fIF:\fR \fIsignal (temporel) discret\fR .LP \fIS:\fR \fIse\o"n~"al discretamente temporizada\fR .PP 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. .RT .sp 1P .LP 1004 \fBtransmission\fR [106] .sp 9p .RT .LP \fIF:\fR \fItransmission\fR .LP \fIS:\fR \fItransmisi\*'on\fR .PP The action of conveying signals from one point to one or more other points. .PP \fINote\ 1\fR \ \(em\ Transmission can be effected directly or indirectly, with or without intermediate storage. .PP \fINote\ 2\fR \ \(em\ The use of the English word \*Qtransmission\*U in the sense of \*Qemission\*U is deprecated. .RT .sp 1P .LP 1005 \fBchannel, transmission channel\fR [108] .sp 9p .RT .LP \fIF:\fR \fIvoie, voie de transmission\fR .LP \fIS:\fR \fIcanal, canal de transmisi\*'on\fR .PP A means of unidirectional transmission of signals between two points. .PP \fINote\ 1\fR \ \(em\ Several channels may share a common path; for example each channel may be allocated a particular frequency band or a particular time slot. .PP \fINote\ 2\fR \ \(em\ The term may be qualified by the nature of the transmitted signals, by the bandwidth, by the digit rate, or by an arbitrary designation. .PP \fINote\ 3\fR \ \(em\ See also Recommendation I.112, Term 414, access channel. .RT .sp 1P .LP 1006 \fBtelecommunication\fR [110] .sp 9p .RT .LP \fIF:\fR \fIt\*'el\*'ecommunication\fR .LP \fIS:\fR \fItelecomunicaci\*'on\fR .PP 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 systems. .RT .sp 1P .LP 1007 \fBcircuit, telecommunication circuit\fR [111] .sp 9p .RT .LP \fIF:\fR \fIcircuit, circuit de t\*'el\*'ecommunications\fR .LP \fIS:\fR \fIcircuito, circuito de telecomunicaci\*'on\fR .LP .PP A combination of two transmission channels permitting bidirectional transmission of signals between two points, to support a single communication. .PP \fINote\ 1\fR \ \(em\ If the telecommunication is by nature unidirectional (for example: long distance television transmission), the term \*Qcircuit\*U is sometimes used to designate the single channel providing the facility. .PP \fINote\ 2\fR \ \(em\ In a telecommunication network, the use of the term \*Qcircuit\*U is generally limited to a telecommunication circuit directly connecting two switching devices or exchanges, together with associated terminating equipment. .bp .PP \fINote\ 3\fR \ \(em\ A telecommunication circuit may permit transmission in both directions simultaneously (duplex), or not simultaneously (simplex). .PP \fINote\ 4\fR \ \(em\ A telecommunication circuit that is used for transmission in one direction only is sometimes referred to as a unidirectional telecommunication circuit. A telecommunication circuit that is used for transmission in both directions (whether simultaneously or not) is sometimes referred to as a bidirectional telecommunication circuit. .RT .LP .sp 1P .LP 1008 \fBinterface\fR [408] .sp 9p .RT .LP \fIF:\fR \fIjonction\fR (interface) .LP \fIS:\fR \fIinterfaz\fR .PP The common boundary between two associated systems. .RT .sp 2P .LP 2.2 \fIDigital signals\fR .sp 1P .RT .sp 1P .LP 2001 \fBdigit\fR .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ement num\*'erique\fR .LP \fIS:\fR \fId\*'igito\fR .PP A member selected from a finite set. .PP \fINote\ 1\fR \ \(em\ 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 duration. .PP \fINote\ 2\fR \ \(em\ 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. .PP \fINote\ 3\fR \ \(em\ The context of the use of the term should be such as to indicate the radix of notation. (The meaning of \*Qdigit\*U in Notes\ 1, 2 and\ 3 translates into French as \*Q\*'el\*'ement num\*'erique\*U.) .PP \fINote\ 4\fR \ \(em\ In telephone subscriber numbering, a digit is any of the numbers\ 1, 2, 3 . | | 9 or\ 0 forming the elements of a telephone number (Recommendation\ Q.10\ [1]). (This meaning of \*Qdigit\*U translates into French as \*Qchiffre\*U.) .RT .sp 1P .LP 2002 \fBbinary figure\fR .sp 9p .RT .LP \fIF:\fR \fIchiffre binaire\fR .LP \fIS:\fR \fIcifra binaria\fR .PP One of the two figures (that is, 0 or 1) used in the representation of numbers in binary notation. .RT .sp 1P .LP 2003 \fBbinary digit\fR (bit) .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ement binaire\fR .LP \fIS:\fR \fId\*'igito binario\fR (bit) .PP A member selected from a binary set. .PP \fINote\ 1\fR \ \(em\ Bit is an abbreviation for binary digit. .PP \fINote\ 2\fR \ \(em\ In the interest of clarity, it is recommended that the term \*Qbit\*U should not be used in two\(hycondition start\(hystop modulation instead of \*Qunit element\*U. .RT .sp 1P .LP 2004 \fBoctet\fR .sp 9p .RT .LP \fIF:\fR \fIoctet\fR .LP \fIS:\fR \fIocteto\fR .PP A group of eight binary digits or eight signal elements representing binary digits operated upon as an entity. .bp .RT .sp 1P .LP 2005 \fBcode word [character signal]\fR .sp 9p .RT .LP \fIF:\fR \fImot de code [signal de caract\*`ere]\fR .LP \fIS:\fR \fIpalabra de c\*'odigo [se\o"n~"al de car\*'acter]\fR .PP A set of signal elements representing the quantized value of a sample in PCM. .PP \fINote\fR \ \(em\ In PCM, the term \*QPCM word\*U may be used in this sense. .RT .sp 1P .LP 2006 \fBdigital signal\fR [105] .sp 9p .RT .LP \fIF:\fR \fIsignal num\*'erique\fR .LP \fIS:\fR \fIse\o"n~"al digital\fR .PP A discretely timed signal in which information is represented by a number of well\(hydefined discrete values that one of its characteristic quantities may take in time. .PP \fINote\fR \ \(em\ The term may be qualified to indicate the digit rate, for example: \*Q140\ Mbit/s digital signal\*U. .RT .sp 1P .LP 2007 \fBsignal element\fR .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ement de signal\fR .LP \fIS:\fR \fIelemento de se\o"n~"al\fR .PP A part of a digital signal, characterized by its discrete timing and its discrete value, and used to represent a digit. .RT .LP .sp 1P .LP 2008 \fBdigit position\fR .sp 9p .RT .LP \fIF:\fR \fIposition d'un \*'el\*'ement de signal; position d'un\fR \fI\*'el\*'ement num\*'erique\fR .LP \fIS:\fR \fIposici\*'on de d\*'igito\fR .PP The position in time or space into which a representation of a digit may be placed. .RT .sp 1P .LP 2009 \fBn\(hyary digital signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal num\*'erique n\(hyaire\fR .LP \fIS:\fR \fIse\o"n~"al digital n\(hyaria\fR .PP A digital signal in which each signal element has one of n permitted discrete values. .RT .sp 1P .LP 2010 \fBredundant digital signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal num\*'erique redondant\fR .LP \fIS:\fR \fIse\o"n~"al digital redundante\fR .PP The signal that is produced by encoding a given signal in accordance with a redundant line code. .RT .sp 1P .LP 2011 \fBredundant n\(hyary signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal n\(hyaire redondant\fR .LP \fIS:\fR \fIse\o"n~"al n\(hyaria redundante\fR .PP A digital signal whose elements can assume \fIn\fR | iscrete states where the average equivalent binary content per signal element is less than log\d2\u\fIn\fR . .PP \fINote\fR \ \(em\ The relative redundancy \fIR\fR , of an \fIn\fR \(hyary digital signal, is given by: \v'6p' .RT .sp 1P .ce 1000 \fIR\fR = 1 \(em @ { fIr~\de\u\fR } over { fIr~\dd~\u\fR~\(mu~log~\d2\u\fIn\fR } @ = @ left [ 1~\(em { fIr~\de\u\fR } over { fIr~\dd~\u\fR~\(mu~log~\d2\u\fIn\fR } right ] @ \(mu 100% .ce 0 .sp 1P .LP .sp 1 where \fIr\fR\d\fId\fR\uis the symbol rate of the \fIn\fR \(hyary signal and \fIr\fR\d\fIe\fR\uis the equivalent bit rate. .PP 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: .LP AMI (37% redundant), 1 binary digit per element; .LP 4B3T (16% redundant), 1.33 binary digit per element. .bp .sp 1P .LP 2012\fR \fBpseudo n\(hyary signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal pseudo n\(hyaire\fR .LP \fIS:\fR \fIse\o"n~"al seudo n\(hyaria\fR .PP A redundant \fIn\fR \(hyary digital signal that is derived from a \fIm\fR \(hyary digital signal without change of the line digit rate. .PP \fINote\fR \ \(em\ An alternate mark inversion signal is an example of a pseudo\(hyternary signal, i.e.\ \fIn\fR \ =\ 3, \fIm\fR \ =\ 2. .RT .sp 1P .LP 2013 \fBdigit rate\fR .sp 9p .RT .LP \fIF\fR : \fId\*'ebit num\*'erique\fR .LP \fIS:\fR \fIvelocidad digital\fR .PP The number of digits per unit time. .PP \fINote\ 1\fR \ \(em\ An appropriate adjective may precede the word \*Qdigit\*U, for example, binary digit rate. .PP \fINote\ 2\fR \ \(em\ In the interests of clarity it is recommended that this term should not be used to express the symbol rate on the line. .RT .sp 1P .LP 2014 \fBline digit rate [symbol rate]\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ebit num\*'erique en ligne [d\*'ebit de symboles]\fR .LP \fIS:\fR \fIvelocidad digital de linea [velocidad de s\*'imbolos]\fR .PP The number of signal elements of the line signal transmitted per unit time. .PP \fINote\ 1\fR \ \(em\ The baud is usually used to quantify this, one baud being equal to one single element per second. .PP \fINote\ 2\fR \ \(em\ Modulation rate is the term used in telegraphy and data communication; it is the reciprocal of the duration of the unit interval. .RT .sp 1P .LP 2015 \fBequivalent binary content\fR .sp 9p .RT .LP \fIF:\fR \fIcontenu binaire \*'equivalent\fR .LP \fIS:\fR \fIcontenido binario equivalente\fR .LP .PP The number of binary digits strictly necessary to convey the same information as a defined number of signal elements in a given digital signal. .RT .sp 1P .LP 2016 \fBequivalent bit rate\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ebit binaire \*'equivalent\fR .LP \fIS:\fR \fIvelocidad binaria equivalente\fR .PP 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. .RT .sp 1P .LP 2017 \fBsignificant instant, significant instant of a digital signal\fR .sp 9p .RT .LP \fIF:\fR \fIinstant significatif, instant significatif d'un signal\fR \fInum\*'erique\fR .LP \fIS:\fR \fIinstante significativo, instante significativo de una\fR \fIse\o"n~"al digital\fR .PP The instant at which a signal element commences in a discretely\(hytimed signal. .bp .RT .LP .sp 1P .LP 2018 \fBunit interval\fR .sp 9p .RT .LP \fIF:\fR \fIintervalle unitaire\fR .LP \fIS:\fR \fIintervalo unitario (o intervalo unidad)\fR .PP The nominal difference in time between consecutive significant instants of an isochronous signal. .RT .sp 1P .LP 2019 \fBdecision instant, decision instant of a digital signal\fR .sp 9p .RT .LP \fIF:\fR \fIinstant de d\*'ecision, instant de d\*'ecision d'un signal\fR \fInum\*'erique\fR .LP \fIS:\fR \fIinstante de decisi\*'on instante de decisi\*'on de una\fR \fIse\o"n~"al digital\fR .PP The instant at which a decision is taken as to the probable value of signal element of a received digital signal. .RT .sp 1P .LP 2020 \fBdecision circuit\fR .sp 9p .RT .LP \fIF:\fR \fIcircuit de d\*'ecision\fR .LP \fIS:\fR \fIcircuito de decisi\*'on\fR .LP .PP A circuit that decides the probable value of a signal element of a received digital signal. .RT .sp 1P .LP 2021 \fBregeneration\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eg\*'en\*'eration\fR .LP \fIS:\fR \fIregeneraci\*'on\fR .PP 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. .RT .sp 1P .LP 2022 \fBregenerator\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eg\*'en\*'erateur\fR .LP \fIS:\fR \fIregenerador\fR .PP A device that performs regeneration. .RT .sp 1P .LP 2023 \fBregenerative repeater\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'ep\*'eteur r\*'eg\*'en\*'erateur\fR .LP \fIS:\fR \fIrepetidor regenerativo\fR .PP A repeater that regenerates digital signals. .PP \fINote\ 1\fR \ \(em\ A regenerative repeater may operate in one or both directions of transmission, and the term may be qualified by \*Qunidirectional\*U or \*Qbidirectional\*U as appropriate. .PP \fINote\ 2\fR \ \(em\ Repeater is defined in Recommendation G.601. .RT .sp 1P .LP 2024 \fBjitter\fR .sp 9p .RT .LP \fIF:\fR \fIgigue\fR .LP \fIS:\fR \fIfluctuaci\*'on de fase\fR .PP Short\(hyterm non\(hycumulative variations of the significant instants of a digital signal from their ideal positions in time. .RT .sp 1P .LP 2025 \fBwander\fR .sp 9p .RT .LP \fIF:\fR \fId\*'erapage\fR .LP \fIS:\fR \fIfluctuaci\*'on lenta de fase\fR .PP Long term non\(hycumulative variations of the significant instants of a digital signal from their ideal positions in time. .bp .RT .sp 1P .LP 2026 \fBcontrolled slip [slip]\fR .sp 9p .RT .LP \fIF:\fR \fIglissement command\*'e [saut]\fR .LP \fIS:\fR \fIdeslizamiento controlado [deslizamiento]\fR .PP 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. .PP \fINote\fR \ \(em\ Where appropriate the term may be qualified, for example: controlled octet slip, controlled frame slip. .RT .sp 1P .LP 2027 \fBuncontrolled slip\fR .sp 9p .RT .LP \fIF:\fR \fIglissement non command\*'e\fR .LP \fIS:\fR \fIdeslizamiento incontrolado\fR .PP 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. .RT .LP .sp 1P .LP 2028 \fBscrambler\fR .sp 9p .RT .LP \fIF:\fR \fIembrouilleur\fR .LP \fIS:\fR \fIaleatorizador\fR .PP A device that converts a digital signal into a pseudo\(hyrandom digital signal having the same meaning and the same digit rate. .RT .sp 1P .LP 2029 \fBdescrambler\fR .sp 9p .RT .LP \fIF:\fR \fId\*'esembrouilleur\fR .LP \fIS:\fR \fIdesaleatorizador\fR .PP A device that performs the complementary operation to that of a scrambler. .RT .sp 1P .LP 2030 \fBerror, digital error\fR .sp 9p .RT .LP \fIF:\fR \fIerreur, erreur num\*'erique\fR .LP \fIS:\fR \fIerror, error digital\fR .PP An inconsistency between a digit in a transmitted digital signal and the corresponding digit in the received digital signal. .RT .LP .sp 1P .LP 2031 \fBerror ratio [error rate]\fR .sp 9p .RT .LP \fIF:\fR \fItaux d'erreur [rapport d'erreur]\fR .LP \fIS:\fR \fItasa de errores [proporci\*'on de errores]\fR .PP The ratio of the number of digital errors received in a specified period to the total number of digits received in the same period. .PP \fINote\ 1\fR \ \(em\ Numerical values of error ratio should be expressed in the form .RT .sp 1P .ce 1000 \fIn\fR | (mu | 0\fI\uD\dlF261\fI\fI \u\fIp\fR\d .sp 9p .RT .ce 0 .sp 1P .LP where \fIp\fR is a positive integer. .PP \fINote\ 2\fR \ \(em\ Error ratio may be qualified, for example by the term \*Qbit\*U or \*Qblock\*U. .sp 1P .LP 2032 \fBerror multiplication\fR .sp 9p .RT .LP \fIF:\fR \fImultiplication d'erreurs\fR .LP \fIS:\fR \fImultiplicaci\*'on de errores\fR .PP 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. .PP \fINote\fR \ \(em\ Line code converters and descramblers are examples of apparatus that may cause error multiplication. .bp .RT .sp 1P .LP 2033 \fBerror multiplication factor\fR .sp 9p .RT .LP \fIF:\fR \fIfacteur de multiplication d'erreurs\fR .LP \fIS:\fR \fIfactor de multiplicaci\*'on de errores\fR .PP The ratio of the number of digital errors in the output signal to the number of digital errors in the input signal. .PP \fINote\fR \ \(em\ The error multiplication factor may be expressed as either an average or maximum value. .RT .sp 1P .LP 2034 \fBerror spread\fR .sp 9p .RT .LP \fIF:\fR \fI\*'etalement d'erreurs [r\*'epartition des erreurs]\fR .LP \fIS:\fR \fIdispersi\*'on de errores\fR .PP 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. .RT .LP .sp 2P .LP 2.3 \fIDigital transmission\fR .sp 1P .RT .sp 1P .LP 3001 \fBdigital transmission\fR [107] .sp 9p .RT .LP \fIF:\fR \fItransmission num\*'erique\fR .LP \fIS:\fR \fItransmisi\*'on digital\fR .PP 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. .RT .sp 1P .LP 3002 \fBdigital channel, digital transmission channel\fR [109] .sp 9p .RT .LP \fIF:\fR \fIvoie num\*'erique, voie de transmission num\*'erique\fR .LP \fIS:\fR \fIcanal digital, canal de transmisi\*'on digital\fR .PP The means of unidirectional digital transmission of digital signals between two points. .RT .sp 1P .LP 3003 \fBdigital circuit, digital telecommunication circuit\fR [112] .sp 9p .RT .LP \fIF:\fR \fIcircuit num\*'erique, circuit \fInum\*'erique de\fR \fIt\*'el\*'ecommunications\fR .LP \fIS:\fR \fIcircuit\*'o digital, circuito de telecomunicaci\*'on\fR \fIdigital\fR .LP .PP A combination of two digital transmission channels permitting bidirectional digital transmission in both directions between two points, to support a single communication. .PP \fINote\ 1\fR \ \(em\ If the telecommunication is by nature unidirectional (for example, long\(hydistance television transmission), the term \*Qdigital circuit\*U is sometimes used to designate the single digital channel providing the facility. .PP \fINote\ 2\fR \ \(em\ In a telecommunication network, use of the term \*Qdigital circuit\*U is generally limited to a digital telecommunication circuit directly connecting two switching devices or exchanges, together with associated terminating equipment. .PP \fINote\ 3\fR \ \(em\ A digital telecommunication circuit may permit transmission in both directions simultaneously (duplex), or not simultaneously (simplex). .PP \fINote\ 4\fR \ \(em\ 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. .RT .sp 1P .LP 3004 \fBdigital connection\fR [310] .sp 9p .RT .LP \fIF:\fR \fIconnexion num\*'erique\fR .LP \fIS:\fR \fIconexi\*'on digital\fR .PP 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. .bp .RT .sp 1P .LP 3005 \fBdigital link, digital transmission link [digital path]\fR [302] .sp 9p .RT .LP \fIF:\fR \fIliaison num\*'erique, liaison de transmission num\*'erique\fR \fI[conduit num\*'erique]\fR .LP \fIS:\fR \fIenlace digital, enlace de transmisi\*'on digital\fR \fI[trayecto digital]\fR .PP The whole of the means of digital transmission of a digital signal of specified rate between two digital distribution frames (or equivalent). .PP \fINote\ 1\fR \ \(em\ A digital link comprises one or more digital sections and may include multiplexing and/or demultiplexing, but not switching. .PP \fINote\ 2\fR \ \(em\ The term may be qualified to indicate the transmission medium used, for example, \*Qdigital satellite link\*U. .PP \fINote\ 3\fR \ \(em\ The term always applies to the combination of \*Qgo\*U and \*Qreturn\*U directions of transmission, unless stated otherwise. .PP \fINote\ 4\fR \ \(em\ The term \*Qdigital path\*U is sometimes used to describe one or more digital links connected in tandem, especially between equipments at which the signals of the specified rate originate and terminate. .RT .LP .sp 1P .LP 3006 \fBdigital distribution frame\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'epartiteur num\*'erique\fR .LP \fIS:\fR \fIrepartidor digital\fR .PP A structure that provides flexibility of semipermanent interconnection of digital channels or digital circuits. .PP \fINote\fR \ \(em\ Digital sections and digital links normally terminate at digital distribution frames. .RT .sp 1P .LP Figure 1/G.701 gives examples of digital sections, digital links, digital line sections, etc. .FE 3007 \fBdigital section\fR .sp 9p .RT .LP \fIF:\fR \fIsection num\*'erique\fR .LP \fIS:\fR \fIsecci\*'on digital\fR .PP The whole of the means of digital transmission of a digital signal of specified rate between two consecutive digital distribution frames or equivalent. .PP \fINote\ 1\fR \ \(em\ A digital section forms either a part or the whole of a digital link, and includes terminating equipments at both ends, but excludes multiplexers. .PP \fINote\ 2\fR \ \(em\ Where appropriate, the digital rate or multiplex order should qualify the title. .PP \fINote\ 3\fR \ \(em\ The definition applies to the combination of \*Qgo\*U and \*Qreturn\*U directions of transmission, unless stated otherwise. .RT .sp 1P .LP 3008 \fBsection termination\fR .sp 9p .RT .LP \fIF:\fR \fIextr\*'emit\*'e de section\fR .LP \fIS:\fR \fIextremo de secci\*'on\fR .PP A connectional interface selected to be the boundary between a physical transmission medium and its associated equipment. .PP \fINote\fR \ \(em\ This point will usually be the connectors at the input and output of an equipment. .RT .sp 1P .LP 3009 \fBelementary cable section [repeater section]\fR .sp 9p .RT .LP \fIF:\fR \fIsection \*'el\*'ementaire de c\* | ble [section (\*'el\*'ementaire)\fR \fId'amplification]\fR .LP \fIS:\fR \fIsecci\*'on elemental de cable [secci\*'on con\fR \fIamplificaci\*'on]\fR .LP .PP The whole of the physical transmission medium between the section termination at the output of one equipment and the section termination at the input of the following equipment. .PP \fINote\ 1\fR \ \(em\ An elementary cable section usually consists of several factory lengths of cable connected together and any associated accessories (such as flexible cables) necessary to connect it to the section terminals. .PP \fINote\ 2\fR \ \(em\ Examples of the physical transmission media are a coaxial or symmetric pair, and optical fibre. .bp .RT .sp 1P .LP 3010 \fBelementary repeater section\fR .sp 9p .RT .LP \fIF:\fR \fIsection \*'el\*'ementaire amplifi\*'ee\fR .LP \fIS:\fR \fIsecci\*'on elemental de repetici\*'on\fR .PP In a given direction of transmission, an elementary cable section together with the immediately following analogue repeater. .RT .sp 1P .LP 3011 \fBelementary regenerator section [regenerator section]\fR .sp 9p .RT .LP \fIF:\fR \fIsection \*'el\*'ementaire r\*'eg\*'en\*'er\*'ee [section de r\*'eg\*'en\*'eration]\fR .LP \fIS:\fR \fIsecci\*'on elemental de regeneraci\*'on [secci\*'on de\fR \fIregeneraci\*'on]\fR .LP .PP In a given direction of transmission, an elementary cable section together with the immediately following regenerative repeater. .RT .sp 1P .LP 3012 \fBdigital line section\fR .sp 9p .RT .LP \fIF:\fR \fIsection de ligne num\*'erique\fR .LP \fIS:\fR \fIsecci\*'on de l\*'inea digital\fR .PP A digital section implemented on a single type of manufactured transmission medium, such as symmetric pair, coaxial pair, or optical fibre. .PP \fINote\fR \ \(em\ A digital line section includes line terminating equipments at both ends, and regenerative repeaters if needed, but excludes multiplexers. .RT .sp 1P .LP 3013 \fBdigital line link [digital line path]\fR .sp 9p .RT .LP \fIF:\fR \fIliaison de ligne num\*'erique [conduit de ligne num\*'erique]\fR .LP \fIS:\fR \fIenlace de l\*'inea digital [trayecto de l\*'inea digital]\fR .PP A digital link that comprises a digital line section or a number of tandem\(hyconnected digital line sections. .RT .LP .sp 1P .LP 3014 \fBdigital transmission system\fR .sp 9p .RT .LP \fIF:\fR \fIsyst\*`eme de transmission num\*'erique\fR .LP \fIS:\fR \fIsistema de transmisi\*'on digital\fR .PP A specific means of providing a digital section. .RT .sp 1P .LP 3015 \fBdigital line system\fR .sp 9p .RT .LP \fIF:\fR \fIsyst\*`eme de ligne num\*'erique\fR .LP \fIS:\fR \fIsistema de l\*'inea digital\fR .PP A digital transmission system that provides a digital line section. .RT .sp 1P .LP 3016 \fBdigital radio section\fR .sp 9p .RT .LP \fIF:\fR \fIsection radio\*'electrique num\*'erique\fR .LP \fIS:\fR \fIsecci\*'on radiodigital\fR .PP A digital section implemented on a radio\(hyrelay system. .RT .sp 1P .LP 3017 \fBdigital radio link [digital radio path]\fR .sp 9p .RT .LP \fIF:\fR \fIliaison radio\*'electrique num\*'erique [conduit\fR \fIradio\*'electrique num\*'erique]\fR .LP \fIS:\fR \fIenlace radiodigital, [trayecto radiodigital]\fR .PP A digital link that comprises a digital radio section or a number of tandem\(hyconnected digital radio sections. .bp .RT .sp 1P .LP 3018 \fBdigital radio system\fR .sp 9p .RT .LP \fIF:\fR \fIsyst\*`eme radio\*'electrique num\*'erique\fR .LP \fIS:\fR \fIsistema radiodigital\fR .PP A digital transmission system that provides a digital radio section. .RT .sp 1P .LP 3019 \fBbit sequence independence\fR .sp 9p .RT .LP \fIF:\fR \fIind\*'ependance de la s\*'equence des bits\fR .LP \fIS:\fR \fIindependencia de la secuencia de bits\fR .PP The property of a binary transmission channel, telecommunication 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. .PP \fINote\fR \ \(em\ 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. .RT .sp 1P .LP 3020 \fBdigit sequence integrity\fR .sp 9p .RT .LP \fIF:\fR \fIint\*'egrit\*'e de la suite des \*'el\*'ements num\*'eriques\fR .LP \fIS:\fR \fIintegridad de la secuencia de d\*'igitos\fR .PP The property of a digital transmission channel, telecommunication circuit or connection, that permits a digital signal to be conveyed over it without change to the order of any signal elements. .RT .sp 1P .LP 3021 \fBoctet sequence integrity\fR .sp 9p .RT .LP \fIF:\fR \fIint\*'egrit\*'e de la suite des octets\fR .LP \fIS:\fR \fIintegridad de la secuencia de octetos\fR .PP The property of a digital transmission channel, telecommunication circuit or connection that permits a digital signal to be conveyed over it without change to the order of any octets. .RT .LP .sp 1P .LP 3022 \fBtransparency, digital transparency\fR .sp 9p .RT .LP \fIF:\fR \fItransparence, transparence num\*'erique\fR .LP \fIS:\fR \fItransparencia, transparencia digital\fR .PP The property of a digital transmission channel, telecommunication circuit or connection, that permits any digital signal to be conveyed over it without change to the value or order of any signal elements. .PP \fINote\fR \ \(em\ The digital transmission channel, telecommunication circuit or connection concerned may introduce delay, and may contain reversible code conversion functions. .RT .sp 1P .LP 3023 \fBalarm indication signal (AIS)\fR .sp 9p .RT .LP \fIF:\fR \fIsignal d'indication d'alarme (SIA)\fR .LP \fIS:\fR \fIse\o"n~"al de indicaci\*'on de alarma (SIA)\fR .PP A signal that replaces the normal traffic signal when a maintenance alarm indication has been activated. .RT .LP .sp 1P .LP 3024 \fBupstream failure indication\fR .sp 9p .RT .LP \fIF:\fR \fIindication de d\*'efaillance en amont\fR .LP \fIS:\fR \fIindicaci\*'on de fallo atr\*'as\fR .PP An indication provided by a digital multiplexer, line section or a radio section, that a signal applied at its input port is outside its prescribed maintenance limit. .bp .RT .sp 1P .LP 3025 \fBservice digits [housekeeping digits]\fR .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ements num\*'eriques de service\fR .LP \fIS:\fR \fId\*'igitos de servicio\fR .PP 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 facilities. .RT .LP .rs .sp 44P .ad r \fBFigure 1/G.701, p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 2P .LP 2.4 \fIDigital multiplexing\fR .sp 1P .RT .sp 1P .LP 4001 \fBhighway (American: bus)\fR .sp 9p .RT .LP \fIF:\fR \fIbus (jonction multiplex interne) [canal]\fR .LP \fIS:\fR \fIarteria (bus)\fR .PP A common path within an apparatus or station over which pass signals from a number of channels identified by time division. .RT .sp 1P .LP 4002 \fBchannel gate\fR .sp 9p .RT .LP \fIF:\fR \fIporte de canal\fR .LP \fIS:\fR \fIpuerta de canal\fR .PP A device for connecting a channel to a highway, or a highway to a channel, at specified times. .RT .sp 1P .LP 4003 \fBdigital multiplex hierarchy\fR .sp 9p .RT .LP \fIF:\fR \fIhi\*'erarchie de multiplexage num\*'erique\fR .LP \fIS:\fR \fIjerarqu\*'ia de los m\*'ulitplex digitales\fR .LP .PP A series of digital multiplexers graded according to capability 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 signals of the same rate in a digital multiplexer of the next higher order. .RT .sp 1P .LP 4004 \fBprimary digital group\fR .sp 9p .RT .LP \fIF:\fR \fIgroupe num\*'erique primaire\fR .LP \fIS:\fR \fIgrupo digital primario\fR .PP An assembly, by digital multiplexing, of digital signals occupying a specified number of channel time\(hyslots to form a composite signal having a digit rate of 2048\ kbit/s or 1544\ kbit/s. .PP \fINote\fR \ \(em\ Normally each channel time\(hyslot has eight digit time\(hyslots and an effective digit rate of 64\ kbit/s. .RT .sp 1P .LP 4005 \fBprimary PCM group [primary block] (American: digroup)\fR .sp 9p .RT .LP \fIF:\fR \fIgroupe primaire MIC [bloc primaire]\fR .LP \fIS:\fR \fIgrupo primario MIC [bloque primario]\fR .PP An assembly, by digital multiplexing, of PCM signals occupying a specified number of channel time\(hyslots to form a composite signal having a digit rate of 1544\ kbit/s or 2048\ kbit/s, in both directions of transmission. .PP \fINote\fR \ \(em\ The following conventions could be useful: .RT .LP Primary\ group\ \(*m \(em a basic group of PCM signals derived from 1544\(hykbit/s PCM multiplex equipment. .LP Primary\ group\ A \(em a basic group of PCM signals derived from 2048\(hykbit/s PCM multiplex equipment. .sp 1P .LP 4006 \fBn\(hyary digital group\fR .sp 9p .RT .LP \fIF:\fR \fIgroupe num\*'erique n\(hyaire\fR .LP \fIS:\fR \fIgrupo digital n\(hyario\fR .PP 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. .PP \fINote\ 1\fR \ \(em\ 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. .bp .PP \fINote\ 2\fR \ \(em\ A tertiary digital group may comprise four 8448 kbit/s secondary digital groups or five or seven 6312\ kbit/s secondary digital groups to form a composite signal having a digit rate of 34368, 32064 or 44736\ kbit/s. .PP \fINote\ 3\fR \ \(em\ 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. .RT .sp 1P .LP 4007 \fBframe\fR .sp 9p .RT .LP \fIF:\fR \fItrame\fR .LP \fIS:\fR \fItrama\fR .PP A cyclic set of consecutive time slots in which the relative position of each time slot can be identified. .RT .sp 1P .LP 4008 \fBmultiframe\fR .sp 9p .RT .LP \fIF:\fR \fImultitrame\fR .LP \fIS:\fR \fImultitrama\fR .PP A cyclic set of consecutive frames in which the relative position of each frame can be identified. .RT .sp 1P .LP 4009 \fBsubframe\fR .sp 9p .RT .LP \fIF:\fR \fIsous\(hytrame, secteur de trame\fR .LP \fIS:\fR \fIsubtrama\fR .PP A sequence of noncontiguous time\(hyslots within a frame, each occurring at n\ times the frame repetition rate where\ n is an integer\ >1. .RT .sp 1P .LP 4010 \fBparallel to serial converter (American: serializer)\fR \fB[dynamicizer]\fR .sp 9p .RT .LP \fIF:\fR \fIconvertisseur parall\*`ele/s\*'erie\fR .LP \fIS:\fR \fIconvertidor paralelo/serie\fR .PP A device that converts a group of signal elements, all of which are presented simultaneously, into a corresponding sequence of consecutive signal elements. .RT .sp 1P .LP 4011 \fBserial to parallel converter (American: deserializer)\fR \fB[staticizer]\fR .sp 9p .RT .LP \fIF:\fR \fIconvertisseur s\*'erie/parall\*`ele\fR .LP \fIS:\fR \fIconvertidor serie/paralelo\fR .LP .PP A device that converts a sequence of consecutive signal elements into a corresponding group of signal elements all of which are presented simultaneously. .RT .sp 1P .LP 4012 \fBtime\(hydivision multiplexing\fR .sp 9p .RT .LP \fIF:\fR \fImultiplexage temporel [multiplexage par r\*'epartition\fR \fIdans le temps]\fR .LP \fIS:\fR \fImultiplexaci\*'on por divisi\*'on en el tiempo\fR .PP Multiplexing in which several signals are interleaved in time for transmission over a common channel. .RT .sp 1P .LP 4013 \fBdigital multiplexing\fR .sp 9p .RT .LP \fIF:\fR \fImultiplexage num\*'erique\fR .LP \fIS:\fR \fImultiplexaci\*'on digital\fR .PP A form of time division multiplexing applied to digital channels which convey digital signals. .bp .RT .LP .sp 1P .LP 4014 \fBdigital multiplexer\fR .sp 9p .RT .LP \fIF:\fR \fImultiplexeur num\*'erique\fR .LP \fIS:\fR \fImultiplexor digital\fR .PP Equipment that combines by time\(hydivision multiplexing several digital signals into a single composite digital signal. .RT .sp 1P .LP 4015 \fBdigital demultiplexing\fR .sp 9p .RT .LP \fIF:\fR \fId\*'emultiplexage num\*'erique\fR .LP \fIS:\fR \fIdemultiplexaci\*'on digital\fR .PP The separation of a composite digital signal into its component digital signals. .RT .sp 1P .LP 4016 \fBdigital demultiplexer\fR .sp 9p .RT .LP \fIF:\fR \fId\*'emultiplexeur num\*'erique\fR .LP \fIS:\fR \fIdemultiplexor digital\fR .PP Equipment that separates a composite digital signal into its component digital signals. .RT .sp 1P .LP 4017 \fBdigital multiplex equipment\fR .sp 9p .RT .LP \fIF:\fR \fI\*'equipement de multiplexage num\*'erique\fR .LP \fIS:\fR \fIequipo m\*'ultiplex digital\fR .PP The combination of a digital multiplexer and a digital demultiplexer at the same location, operating in opposite directions of transmission. .RT .sp 1P .LP 4018 \fBPCM multiplex equipment\fR .sp 9p .RT .LP \fIF:\fR \fI\*'equipement de multiplexage MIC\fR .LP \fIS:\fR \fIequipo m\*'ultiplex MIC\fR .PP 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 direction of transmission. .RT .sp 1P .LP 4019 \fBdigital block\fR .sp 9p .RT .LP \fIF:\fR \fIbloc num\*'erique\fR .LP \fIS:\fR \fIbloque digital\fR .LP .PP The combination of a digital link and associated digital multiplex equipments. .PP \fINote\fR \ \(em\ The bit rate of the digital link should form part of the title. .RT .sp 1P .LP 4020 \fBtransmultiplexer\fR .sp 9p .RT .LP \fIF:\fR \fItransmultiplexeur\fR .LP \fIS:\fR \fItransmultiplexor\fR .PP An equipment that transforms a frequency\(hydivision multiplexed signal (such as group or supergroup) into a corresponding time\(hydivision 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. .RT .sp 1P .LP 4021 \fBdigital filling [digital padding]\fR .sp 9p .RT .LP \fIF:\fR \fIremplissage num\*'erique\fR .LP \fIS:\fR \fIrelleno digital [complementaci\*'on digital]\fR .LP .PP 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. .PP \fINote\fR \ \(em\ The added digits are not normally used to transmit information. .bp .RT .sp 1P .LP 4022 \fBjustification [stuffing, pulse stuffing]\fR .sp 9p .RT .LP \fIF:\fR \fIjustification\fR .LP \fIS:\fR \fIjustificaci\*'on [relleno de impulsos]\fR .PP The process of changing the digit rate of a digital signal in a controlled manner so that it can accord with a digit rate different from its own inherent rate, usually without loss of information. .RT .sp 1P .LP 4023 \fBpositive justification [positive stuffing, positive pulse\fR \fBstuffing]\fR .sp 9p .RT .LP \fIF:\fR \fIjustification positive\fR .LP \fIS:\fR \fIjustificaci\*'on positiva [relleno positivo de impulsos]\fR .PP A method of justification in which the digit time\(hyslots used to convey a digital signal have a digit rate that is always higher than the digit rate of that original signal. .PP \fINote\ 1\fR \ \(em\ Positive justification is usually achieved by the provision of a fixed number of digit time\(hyslots (justifiable digit time\(hyslots) per frame in the resultant signal which may be used to transmit either information from the original signal, or no information, according to the relative digit rates of the resultant signal and the original signal. .PP \fINote\ 2\fR \ \(em\ Information which indicates whether the justifiable digit time\(hyslots contain information digits or justifying digits is conveyed by means of the justification service digits. .RT .sp 1P .LP 4024 \fBnegative justification [negative stuffing, negative pulse\fR \fBstuffing]\fR .sp 9p .RT .LP \fIF:\fR \fIjustification n\*'egative\fR .LP \fIS:\fR \fIjustificaci\*'on negativa [relleno negativo, relleno\fR \fInegativo de impulsos]\fR .PP A method of justification in which the digit time\(hyslots used to convey a digital signal have a digit rate that is always lower than the digit rate of that original signal. .PP \fINote\ 1\fR \ \(em\ The deleted digits are conveyed by separate means. .PP \fINote\ 2\fR \ \(em\ Information which facilitates the recovery of the deleted digits is conveyed by means of the justification service digits. .RT .sp 1P .LP 4025 \fBpositive/zero/negative justification [positive/zero/negative\fR \fBstuffing, positive/zero/negative pulse stuffing]\fR .sp 9p .RT .LP \fIF:\fR \fIjustification positive/nulle/n\*'egative\fR .LP \fIS:\fR \fIjustificati\*'on positiva/nula/negativa [relleno\fR \fIpositivo/nulo/negativo de impulsos]\fR .PP A method of justification in which the digit time\(hyslots 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. .PP \fINote\ 1\fR \ \(em\ Justifiable digit time\(hyslots are provided in accordance with Note\ 1 of 4023 above. .PP \fINote\ 2\fR \ \(em\ Separate means of transmitting deleted digits are provided in accordance with Note\ 2 of 4024 above. .PP \fINote\ 3\fR \ \(em\ Information which facilitates the recovery of the original digits, which are conveyed by means of the justification service digits. .PP \fINote\ 4\fR \ \(em\ Usually the digit time\(hyslots used to convey a digital signal have the same nominal digit rate as the original signal. .RT .sp 1P .LP 4026 \fBjustifiable digit time\(hyslot [stuffable digit time\(hyslot]\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel \*'el\*'ementaire justifiable\fR .LP \fIS:\fR \fIintervalo de tiempo de d\*'igito justificable [intervalo\fR \fIde tiempo de d\*'igito rellenable]\fR .PP A digit time\(hyslot that is provided for the purpose of justification and which may contain either an information digit or a justifying digit. .bp .RT .sp 1P .LP 4027 \fBjustifying digit [stuffing digit]\fR .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ement num\*'erique de justification\fR .LP \fIS:\fR \fId\*'igito de justificaci\*'on [d\*'igito de relleno]\fR .PP A digit inserted in a justifiable digit time\(hyslot when that time slot is not required for an information digit. .RT .LP .sp 1P .LP 4028 \fBjustification service digit [stuffing service digit]\fR .sp 9p .RT .LP \fIF:\fR \fI\*'el\*'ement num\*'erique de service de justification\fR .LP \fIS:\fR \fId\*'igito de servicio de justificaci\*'on [d\*'igito de\fR \fIservicio de relleno]\fR .PP A digit that transmits information concerning the status of a justifiable digit time\(hyslot. .RT .sp 1P .LP 4029 \fBjustification rate [stuffing rate]\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ebit de justification\fR .LP \fIS:\fR \fIvelocidad de justificaci\*'on [velocidad de relleno]\fR .PP The rate at which justifying digits are inserted, or at which information digits are transmitted by other means. .RT .sp 1P .LP 4030 \fBnominal justification rate [nominal stuffing rate]\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ebit nominal de justification\fR .LP \fIS:\fR \fIvelocidad nominal de justificaci\*'on [velocidad\fR \fInominal de relleno]\fR .PP The justification rate that occurs when the digit rates of both the original signal and the justified signal are at their nominal values. .RT .sp 1P .LP 4031 \fBmaximum justification rate [maximum stuffing rate]\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ebit maximal de justification\fR .LP \fIS:\fR \fIvelocidad m\*'axima de justificaci\*'on [velocidad m\*'axima\fR \fIde relleno]\fR .PP The maximum possible justification rate that can be accommodated by a justification process. .PP \fINote\fR \ \(em\ In practice the tolerance limits of the original signal and of the system used to convey the justified signal might be such that the maximum justification rate is never realized. .RT .sp 1P .LP 4032 \fBjustification ratio [stuffing ratio]\fR .sp 9p .RT .LP \fIF:\fR \fItaux de justification\fR .LP \fIS:\fR \fIrelaci\*'on de justificaci\*'on [relaci\*'on de relleno]\fR .LP .PP The ratio of the actual justification rate to the maximum justification rate. .RT .sp 1P .LP 4033 \fBnominal justification ratio [nominal stuffing ratio]\fR .sp 9p .RT .LP \fIF:\fR \fItaux nominal de justification\fR .LP \fIS:\fR \fIrelaci\*'on nominal de justificaci\*'on [relaci\*'on nominal\fR \fIde relleno]\fR .PP The ratio of the nominal justification rate to the maximum justification rate. .RT .sp 2P .LP 2.5 \fIFrame alignment\fR .sp 1P .RT .sp 1P .LP Similar definitions are applicable to multiframe alignment. .FE 5001 \fBframe alignment\fR .sp 9p .RT .LP \fIF:\fR \fIverrouillage de trame\fR .LP \fIS:\fR \fIalineaci\*'on de trama\fR .PP The state in which the frame of the receiving equipment is synchronized with that of the received signal. .bp .RT .sp 1P .LP 5002 \fBframe alignment signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal de verrouillage de trame\fR .LP \fIS:\fR \fIse\o"n~"al de alineaci\*'on de trama\fR .LP .PP The distinctive signal inserted in every frame or once in every \fIn\fR frames, always occupying the same relative position within the frame, and used to establish and maintain frame alignment. .RT .sp 1P .LP 5003 \fBbunched frame alignment signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal de verrouillage de trame concentr\*'e\fR .LP \fIS:\fR \fIse\o"n~"al de alineaci\*'on de trama concentrada\fR .PP A frame alignment signal whose signal elements occupy consecutive digit time slots. .RT .sp 1P .LP 5004 \fBdistributed frame alignment signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal de verrouillage de trame r\*'eparti [signal de\fR \fIverrouillage de trame distribu\*'e]\fR .LP \fIS:\fR \fIse\o"n~"al de alineaci\*'on de trama distribuida\fR .PP A frame alignment signal whose signal elements occupy non\(hyconsecutive digit time slots. .RT .sp 1P .LP 5005 \fBframe alignment recovery time\fR .sp 9p .RT .LP \fIF:\fR \fItemps de reprise du verrouillage de trame\fR .LP \fIS:\fR \fItiempo de recuperaci\*'on de la alineaci\*'on de trama\fR .LP .PP The time that elapses between a valid frame alignment signal being available at the receive terminal equipment and frame alignment being established. .PP \fINote\fR \ \(em\ The frame alignment recovery time includes the time required for replicated verification of the validity of the frame alignment signal. .RT .sp 1P .LP 5006 \fBout\(hyof\(hyframe alignment time\fR .sp 9p .RT .LP \fIF:\fR \fIdur\*'ee de perte du verrouillage de trame\fR .LP \fIS:\fR \fIduraci\*'on de la p\*'erdida de la alineaci\*'on de trama\fR .PP The time during which frame alignment is effectively lost. .PP \fINote\fR \ \(em\ That time includes the time to detect loss of frame alignment and the frame alignment recovery time. .RT .sp 2P .LP 2.6 \fITiming\fR .sp 1P .RT .sp 1P .LP 6001 \fBtiming signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal de rythme\fR .LP \fIS:\fR \fIse\o"n~"al de temporizaci\*'on\fR .LP .PP A cyclic signal used to control the timing of operations. .RT .sp 1P .LP 6002 \fBtiming recovery [timing extraction]\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'ecup\*'eration du rythme\fR .LP \fIS:\fR \fIrecuperaci\*'on de la temporizaci\*'on [extracci\*'on de la\fR \fItemporizaci\*'on]\fR .PP The derivation of a timing signal from a received signal. .bp .RT .sp 1P .LP 6003 \fBretiming\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eajustement du rythme\fR .LP \fIS:\fR \fIreajuste de la temporizaci\*'on\fR .PP Adjustment of the intervals between the significant instants of a digital signal, by reference to a timing signal. .RT .sp 1P .LP 6004 \fBtime\(hyslot\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel [intervalle de temps]\fR .LP \fIS:\fR \fIintervalo de tiempo [sector de tiempo, celda de tiempo]\fR .PP Any cyclic time interval that can be recognized and defined uniquely. .RT .sp 1P .LP 6005 \fBdigit time\(hyslot\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel \*'el\*'ementaire [intervalle de temps\fR \fI\*'el\*'ementaire]\fR .LP \fIS:\fR \fIintervalo de tiempo de d\*'igito\fR .PP A time slot allocated to a single digit. .RT .sp 1P .LP 6006 \fBchannel time\(hyslot\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel de voie\fR .LP \fIS:\fR \fIintervalo de tiempo de canal\fR .PP A time slot occupying a specific position in a frame and allocated to a particular time\(hyderived channel. .PP \fINote\ 1\fR \ \(em\ Where appropriate a description may be added, for example \*Qtelephone channel time slot\*U. .PP \fINote\ 2\fR \ \(em\ In addition to its main function of transmitting a character signal, a channel time slot may also be used for in\(hyslot signalling or for transmitting other information. .RT .LP .sp 1P .LP 6007 \fBsignalling time\(hyslot\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel de signalisation\fR .LP \fIS:\fR \fIintervalo de tiempo de se\o"n~"alizaci\*'on\fR .PP A time slot occupying a specific position in a frame and allocated to the transmission of signalling. .RT .sp 1P .LP 6008 \fBframe alignment time\(hyslot\fR .sp 9p .RT .LP \fIF:\fR \fIcr\*'eneau temporel de verrouillage de trame\fR .LP \fIS:\fR \fIintervalo de tiempo de alineaci\*'on de trama\fR .PP A time slot occupying the same relative position in every frame and used to transmit the frame alignment signal. .RT .sp 1P .LP 6009 \fBclock\fR .sp 9p .RT .LP \fIF:\fR \fIhorloge\fR .LP \fIS:\fR \fIreloj\fR .PP Equipment that provides a timing signal. .PP \fINote\fR \ \(em\ Where replicated sources are used for security reasons, the assembly of these is regarded as single clock. .bp .RT .sp 1P .LP 6010 \fBreference clock\fR .sp 9p .RT .LP \fIF:\fR \fIhorloge de r\*'ef\*'erence\fR .LP \fIS:\fR \fIreloj de referencia\fR .PP A clock of very high stability and accuracy that may be completely autonomous and whose frequency serves as a basis of comparison for the frequency of other clocks. .RT .sp 1P .LP 6011 \fBmaster clock\fR .sp 9p .RT .LP \fIF:\fR \fIhorloge ma\* | tresse\fR .LP \fIS:\fR \fIreloj maestro\fR .PP A clock that is used to control the frequency of other clocks. .RT .sp 1P .LP 6012 \fBtime interval error\fR .sp 9p .RT .LP \fIF:\fR \fId\*'erive temporelle\fR .LP \fIS:\fR \fIerror de intervalo de tiempo\fR .PP The total difference over a specified interval of time in the significant instants of a digital signal from their ideal positions in time. .RT .LP .sp 1P .LP 6013 \fBrelative time interval error\fR .sp 9p .RT .LP \fIF:\fR \fId\*'erive temporelle relative\fR .LP \fIS:\fR \fIerror de intervalo de tiempo relativo\fR .PP The total difference over a specified interval of time in the corresponding significant instants of two digital signals. .RT .sp 1P .LP 6014 \fBisochronous\fR .sp 9p .RT .LP \fIF:\fR \fIisochrone\fR .LP \fIS:\fR \fIis\*'ocrono\fR .PP The essential characteristic of a time\(hyscale or a signal such that the time intervals between consecutive significant instants either have the same duration or durations that are integral multiples of the shortest duration. .PP \fINote\fR \ \(em\ In practice, variations in the time intervals are constrained within specified limits. .RT .LP .sp 1P .LP 6015 \fBanisochronous\fR .sp 9p .RT .LP \fIF:\fR \fIanisochrone\fR .LP \fIS:\fR \fIanis\*'ocrono\fR .PP The essential characteristic of a time\(hyscale 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. .RT .sp 1P .LP 6016 \fBsynchronous [mesochronous]\fR .sp 9p .RT .LP \fIF:\fR \fIsynchrone [m\*'esochrone]\fR .LP \fIS:\fR \fIs\*'incrono [mes\*'ocrono]\fR .PP The essential characteristic of time\(hyscales or signals such that their corresponding significant instants occur at precisely the same average rate. .PP \fINote\fR \ \(em\ The timing relationship between corresponding significant instants usually varies between specified limits. .RT .sp 1P .LP 6017 \fBhomochronous\fR .sp 9p .RT .LP \fIF:\fR \fIhomochrone\fR .LP \fIS:\fR \fIhom\*'ocrono\fR .PP The essential characteristic of time\(hyscales or signals such that their corresponding significant instants have a constant, but uncontrolled, time relationship with each other. .bp .RT .sp 1P .LP 6018 \fBnon\(hysynchronous [asynchronous/heterochronous]\fR .sp 9p .RT .LP \fIF:\fR \fInonsynchrone [asynchrone/h\*'et\*'erochrone]\fR .LP \fIS:\fR \fIno\(hys\*'incrono [as\*'icrono/heter\*'ocrono]\fR .PP The essential characteristic of time\(hyscales or signals such that their corresponding significant instants do not necessarily occur at the same average rate. .RT .sp 1P .LP 6019 \fBplesiochronous\fR .sp 9p .RT .LP \fIF:\fR \fIpl\*'esiochrone\fR .LP \fIS:\fR \fIplesi\*'ochrono\fR .PP The essential characteristic of time\(hyscales or signals such that their corresponding significant instants occur at nominally the same rate, any variation in rate being constrained within specified limits. .PP \fINote\ 1\fR \ \(em\ Two signals having the same nominal digit rate, but not stemming from the same clock or homochronous clocks, are usually plesiochronous. .PP \fINote\ 2\fR \ \(em\ There is no limit to the time relationship between corresponding significant instants. .RT .sp 1P .LP 6020 \fBheterochronous\fR .sp 9p .RT .LP \fIF:\fR \fIh\*'et\*'erochrone\fR .LP \fIS:\fR \fIheter\*'ocrono\fR .PP The essential characteristic of time\(hyscales or signals such that their corresponding significant instants occur at different nominal rates. .PP \fINote\ 1\fR \ \(em\ Two signals having different nominal digit rates, and not stemming from the same clock or from homochronous clocks are usually heterochronous. .PP \fINote\ 2\fR \ \(em\ Terms 6015 to 6020 are based on the following Greek roots: .RT .LP iso =\ equal .LP homo =\ same .LP plesio =\ near .LP hetero =\ different .sp 1P .LP 6021 \fBcodirectional interface\fR .sp 9p .RT .LP \fIF:\fR \fIinterface codirectionnelle\fR .LP \fIS:\fR \fIinterfaz codireccional\fR .PP An interface across which the signals to be transferred and their associated timing signals are transmitted in the same direction. .RT .sp 1P .LP 6022 \fBcentralized\(hyclock interface\fR .sp 9p .RT .LP \fIF:\fR \fIinterface \*`a horloge centralis\*'ee\fR .LP \fIS:\fR \fIinterfaz de reloj centralizado\fR .PP 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 terminal on the service side are supplied from a centralized clock. .PP \fINote\fR \ \(em\ The timing of the centralized clock may be derived from a nominated incoming line signal. .RT .sp 1P .LP 6023 \fBcontradirectional interface\fR .sp 9p .RT .LP \fIF:\fR \fIinterface contradirectionnelle\fR .LP \fIS:\fR \fIinterfaz contradireccional\fR .PP 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. .bp .RT .sp 2P .LP 2.7 \fISynchronization\fR .sp 1P .RT .sp 1P .LP 7001 \fBsynchronization\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation\fR .LP \fIS:\fR \fIsincronizaci\*'on\fR .PP The process of adjusting the corresponding significant instants of signals to make them synchronous. .RT .sp 1P .LP 7002 \fBtiming information\fR .sp 9p .RT .LP \fIF:\fR \fIinformation de rythme\fR .LP \fIS:\fR \fIinformaci\*'on de temporizaci\*'on\fR .PP Information contained in a signal relating to the timing of another signal. .RT .sp 1P .LP 7003 \fBsynchronization information\fR .sp 9p .RT .LP \fIF:\fR \fIinformation de synchronisation\fR .LP \fIS:\fR \fIinformaci\*'on de sincronizaci\*'on\fR .PP Information that indicates the relationship between the timing of two or more signals. .RT .sp 1P .LP 7004 \fBclock control signal\fR .sp 9p .RT .LP \fIF:\fR \fIsignal de commande d'horloge\fR .LP \fIS:\fR \fIse\o"n~"al de control de reloj\fR .PP A signal that directly controls the phase or frequency of a clock. .RT .sp 1P .LP 7005 \fBsynchronization node\fR .sp 9p .RT .LP \fIF:\fR \fInoeud de synchronisation\fR .LP \fIS:\fR \fInodo de sincronizaci\*'on\fR .PP A point in a synchronized network at which synchronization information is derived, sent or received. .RT .sp 1P .LP 7006 \fBsynchronization link\fR .sp 9p .RT .LP \fIF:\fR \fIliaison de synchronisation\fR .LP \fIS:\fR \fIenlace de sincronizaci\*'on\fR .PP A link between two synchronization nodes over which synchronization information is transmitted. .RT .sp 1P .LP 7007 \fBsynchronization network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau de synchronisation\fR .LP \fIS:\fR \fIred de sincronizaci\*'on\fR .PP An arrangement of synchronization nodes and synchronization links provided in order to synchronize the clocks at, or connected to, those nodes. .RT .sp 1P .LP 7008 \fBsingle\(hyended synchronization\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation locale [synchronisation unilat\*'erale]\fR .LP \fIS:\fR \fIsincronizaci\*'on uniterminal\fR .PP A method of synchronizing a specified synchronization node with respect to another synchronization node in which synchronization information at the specified node is derived from the phase difference between the local clock and the incoming digital signal from the other node. .bp .RT .sp 1P .LP 7009 \fBdouble\(hyended synchronization\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation locale et distante [synchronisation\fR \fIbilat\*'erale]\fR .LP \fIS:\fR \fIsincronizaci\*'on biterminal\fR .PP A method of synchronizing a specified synchronization node with respect to another synchronization node in which synchronization 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. .RT .sp 1P .LP 7010 \fBunilateral control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation unilat\*'erale [commande unilat\*'erale]\fR .LP \fIS:\fR \fIcontrol unilateral\fR .PP Control between two synchronization nodes such that the frequency of the clock of only one of these nodes is influenced by timing information derived from the clock of the other node. .RT .sp 1P .LP 7011 \fBbilateral control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation bilat\*'erale [commande bilat\*'erale]\fR .LP \fIS:\fR \fIcontrol bilateral\fR .PP Control between two synchronization nodes such that the frequency of the clock of each of these nodes is influenced by timing information derived from the clock of the other node. .RT .sp 1P .LP 7012 \fBanalogue control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation analogique [mode analogique]\fR .LP \fIS:\fR \fIcontrol anal\*'ogico\fR .PP A method of controlling clocks in which the clock control signal is a continuous (monotonic) function of the phase difference between clocks, at least over a limited range. .RT .sp 1P .LP 7013 \fBlinear analogue control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation analogique lin\*'eaire [mode analogique\fR \fIlin\*'eaire]\fR .LP \fIS:\fR \fIcontrol anal\*'ogico lineal\fR .PP Analogue control in which the clock control signal is proportional to the phase difference between clocks, at least over a limited range. .RT .sp 1P .LP 7014 \fBamplitude quantized control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation quantifi\*'ee [mode \*`a quantification\fR \fId'amplitude]\fR .LP \fIS:\fR \fIcontrol por cuantificaci\*'on de amplitud\fR .PP A method of controlling clocks in which the clock control signal is a quantized function of the phase difference between clocks. .PP \fINote\fR \ \(em\ 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. .RT .sp 1P .LP 7015 \fBtime quantized control\fR .sp 9p .RT .LP \fIF:\fR \fIsynchronisation \*'echantillonn\*'ee [mode \*`a quantification\fR \fItemporelle]\fR .LP \fIS:\fR \fIcontrol por cuantificaci\*'on temporal\fR .PP 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. .RT .sp 1P .LP 7016 \fBsynchronized network [synchronous network]\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau synchronis\*'e [r\*'eseau synchrone]\fR .LP \fIS:\fR \fIred sincronizada [red sincrona]\fR .PP A network in which the corresponding significant instants of nominated signals are adjusted to make them synchronous. .bp .RT .sp 1P .LP 7017 \fBnon\(hysynchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau non synchronis\*'e \fR .LP \fIS:\fR \fIred no sincronizada\fR .PP A network in which signals need not be synchronous. .RT .sp 1P .LP 7018 \fBmutually synchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau \*`a synchronisation mutuelle\fR .LP \fIS:\fR \fIred mutuamente sincronizada\fR .PP A synchronized network in which each clock exerts a degree of control on all others. .RT .sp 1P .LP 7019 \fBdemocratic network, democratic mutually synchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau d\*'emocratique, r\*'eseau \*`a synchronisation mutuelle\fR \fId\*'emocratique\fR .LP \fIS:\fR \fIred democr\*'atica, red democr\*'atica mutuamente\fR \fIsincronizada\fR .LP \fI\fI\fI\fI\fI\fI\fR .PP 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. .RT .sp 1P .LP 7020 \fBhierarchic network, hierarchic synchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau hi\*'erarchis\*'e, r\*'eseau \*`a synchronisation\fR \fIhi\*'erarchis\*'ee\fR .LP \fIS:\fR \fIred jer\*'arquica, red con sincronizaci\*'on jer\*'arquica\fR .PP A synchronized network in which each clock is assigned a particular status which determines the degree of control it exerts over the other clocks. .RT .sp 1P .LP 7021 \fBhierarchic mutually synchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau hi\*'erarchis\*'e \*`a synchronisation mutuelle\fR .LP \fIS:\fR \fIred jer\*'arquica mutuamente sincronizada\fR .PP 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. .RT .sp 1P .LP 7022 \fBmonarchic network, monarchic synchronized network [despotic network, despotic synchronized network]\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau despotique, r\*'eseau \*`a synchronisation despotique\fR .LP \fIS:\fR \fIred desp\*'otica, red con sincronizaci\*'on desp\*'otica [red\fR \fImon\*'arquica, red con sincronizaci\*'on mon\*'arquica]\fR .PP A synchronized network in which a single clock exerts control over all the other clocks. .RT .sp 1P .LP 7023 \fBoligarchic network, oligarchic synchronized network\fR .sp 9p .RT .LP \fIF:\fR \fIr\*'eseau oligarchique, r\*'eseau \*`a synchronisation\fR \fIoligarchique\fR .LP \fIS:\fR \fIred olig\*'arquica, red con sincronizaci\*'on olig\*'arquica\fR .PP A synchronized network in which a few selected clocks are mutually synchronized and exert control over all the other clocks. .RT .sp 2P .LP 2.8 \fIPulse Code Modulation\fR .sp 1P .RT .sp 1P .LP 8001 \fBpulse code modulation (PCM)\fR .sp 9p .RT .LP \fIF:\fR \fImodulation par impulsions et codage (MIC)\fR .LP \fIS:\fR \fImodulaci\*'on por impulsos codificados (MIC)\fR .PP 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. .bp .RT .sp 1P .LP 8002 \fBdifferential pulse code modulation (DPCM)\fR .sp 9p .RT .LP \fIF:\fR \fImodulation par impulsions et codage diff\*'erentiel\fR \fI(MICD)\fR .LP \fIS:\fR \fImodulaci\*'on por impulsos codificados diferencial\fR \fI(MICD)\fR .PP A process in which a signal is sampled, and the difference between each sample of this signal and its estimated value is quantized and converted by encoding to a digital signal. .PP \fINote\fR \ \(em\ The estimated values of the signal are calculated by a predictor from the quantized difference signal. .RT .sp 1P .LP 8003 \fBdelta modulation\fR .sp 9p .RT .LP \fIF:\fR \fImodulation delta\fR .LP \fIS:\fR \fImodulaci\*'on delta\fR .PP 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. .RT .sp 1P .LP 8004 \fBadaptive differential pulse code modulation (ADPCM)\fR .sp 9p .RT .LP \fIF:\fR \fImodulation par impulsions et codage diff\*'erentiel\fR \fIadaptatif (MICDA)\fR .LP \fIS:\fR \fImodulaci\*'on por impulsos y c\*'odigo diferencial\fR \fIadaptativo (MICDA)\fR .PP A form of differential pulse code modulation that uses adaptive quantizing. .PP \fINote\ 1\fR \ \(em\ The predictor may be either fixed (time invariant) or variable. .PP \fINote\ 2\fR \ \(em\ When the predictor is adaptive, the adaption of its coefficients is made from the quantized difference signal. .RT .sp 1P .LP 8005 \fBpredictor\fR .sp 9p .RT .LP \fIF:\fR \fIpr\*'edicteur\fR .LP \fIS:\fR \fIpredictor\fR .PP A device that provides an estimated value of a sampled signal derived from previous samples of the same signal or from a quantized version of those samples. .RT .sp 1P .LP 8006 \fBadaptive predictor\fR .sp 9p .RT .LP \fIF:\fR \fIpr\*'edicteur adaptatif\fR .LP \fIS:\fR \fIpredictor adaptativo\fR .PP A predictor whose estimating function is made variable according to the short term spectral characteristics of the sampled signal. .RT .sp 1P .LP 8007 \fBsample\fR .sp 9p .RT .LP \fIF:\fR \fI\*'echantillon\fR .LP \fIS:\fR \fImuestra\fR .PP A representative value of a signal at a chosen instant, derived from a portion of that signal. .RT .sp 1P .LP 8008 \fBsampling\fR .sp 9p .RT .LP \fIF:\fR \fI\*'echantillonnage\fR .LP \fIS:\fR \fImuestreo\fR .PP The process of taking samples of a signal, usually at equal time intervals. .RT .sp 1P .LP 8009 \fBsampling rate\fR .sp 9p .RT .LP \fIF:\fR \fIfr\*'equence d'\*'echantillonnage [taux d'\*'echantillonnage]\fR .LP \fIS:\fR \fIvelocidad de muestreo [frecuencia de muestreo]\fR .PP The number of samples taken of a signal per unit time. .bp .RT .sp 1P .LP 8010 \fBworking range\fR .sp 9p .RT .LP \fIF:\fR \fIplage de fonctionnement [gamme de fonctionnement]\fR .LP \fIS:\fR \fIgama de funcionamiento\fR .PP 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.) .RT .sp 1P .LP 8011 \fBquantizing\fR .sp 9p .RT .LP \fIF:\fR \fIquantification\fR .LP \fIS:\fR \fIcuantificaci\*'on\fR .PP 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.) .RT .sp 1P .LP 8012 \fBadaptive quantizing\fR .sp 9p .RT .LP \fIF:\fR \fIquantification adaptative\fR .LP \fIS:\fR \fIcuantificaci\*'on adaptativa\fR .PP Quantizing in which some parameters are made variable according to the short term statistical characteristics of the quantized signal. .RT .sp 1P .LP 8013 \fBuniform quantizing\fR .sp 9p .RT .LP \fIF:\fR \fIquantification uniforme\fR .LP \fIS:\fR \fIcuantificaci\*'on uniforme\fR .PP Quantizing in which all the quantizing intervals lying entirely with the working range are equal. (See Figure\ 2/G.701.) .RT .sp 1P .LP 8014 \fBnon\(hyuniform quantizing\fR .sp 9p .RT .LP \fIF:\fR \fIquantification non uniforme\fR .LP \fIS:\fR \fIcuantificaci\*'on no uniforme\fR .PP Quantizing in which not all the quantizing intervals lying entirely with the working range are equal. (See Figure\ 2/G.701.) .RT .sp 1P .LP 8015 \fBquantizing interval\fR .sp 9p .RT .LP \fIF:\fR \fIintervalle de quantification\fR .LP \fIS:\fR \fIintervalo de cuantificaci\*'on\fR .PP One of the intervals used in quantizing. (See Figure\ 2/G.701.) .RT .sp 1P .LP 8016 \fBdecision value\fR .sp 9p .RT .LP \fIF:\fR \fIvaleur de d\*'ecision [amplitude de d\*'ecision]\fR .LP \fIS:\fR \fIvalor de decisi\*'on\fR .PP A value defining the boundary between adjacent quantizing intervals. (See Figures\ 2/G.701 and 4/G.701.) .RT .sp 1P .LP 8017 \fBvirtual decision value\fR .sp 9p .RT .LP \fIF:\fR \fIvaleur virtuelle de d\*'ecision [amplitude virtuelle de\fR \fId\*'ecision]\fR .LP \fIS:\fR \fIvalor virtual de decisi\*'on\fR .PP Each of the two defined values, that provide conventional bounds for the working range in quantizing. (See Figure\ 2/G.701.) .PP \fINote\fR \ \(em\ These values are taken to represent hypothetical outer bounds for the two extreme quantizing intervals of the quantizing law. .bp .RT .sp 1P .LP 8018 \fBquantized value\fR .sp 9p .RT .LP \fIF:\fR \fIvaleur quantifi\*'ee [amplitude quantifi\*'ee]\fR .LP \fIS:\fR \fIvalor cuantificado\fR .PP The single discrete value used to represent any value in a particular quantizing interval. (See Figure\ 2/G.701.) .RT .sp 1P .LP 8019 \fBload capacity [overload point]\fR .sp 9p .RT .LP \fIF:\fR \fIcapacit\*'e de charge [point de surcharge]\fR .LP \fIS:\fR \fIcapacidad de carga [punto de sobrecarga]\fR .PP The level of a sinusoidal signal whose positive and negative peaks coincide with the virtual decision values. .RT .sp 1P .LP 8020 \fBpeak limiting, peak limiting in quantizing\fR .sp 9p .RT .LP \fIF:\fR \fI\*'ecr\* | tage\fR .LP \fIS:\fR \fIlimitaci\*'on de cresta (en cuantificaci\*'on)\fR .PP 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.) .RT .sp 1P .LP 8021 \fBquantizing distortion\fR .sp 9p .RT .LP \fIF:\fR \fIdistorsion de quantification\fR .LP \fIS:\fR \fIdistorsi\*'on de cuantificaci\*'on\fR .PP The distortion resulting from the process of quantizing samples within the working range. .RT .sp 1P .LP 8022 \fBquantizing distortion power\fR .sp 9p .RT .LP \fIF:\fR \fIpuissance de distorsion de quantification\fR .LP \fIS:\fR \fIpotencia de la distorsi\*'on de cuantificaci\*'on\fR .PP The power of the distortion component of the output signal resulting from the process of quantizing. .RT .sp 1P .LP 8023 \fBencoding [coding, coding in PCM]\fR .sp 9p .RT .LP \fIF:\fR \fIcodage\fR .LP \fIS:\fR \fIcodificaci\*'on [codificaci\*'on en MIC]\fR .PP The generation of a code word to represent a quantized value. .RT .sp 1P .LP 8024 \fBencoder [coder]\fR .sp 9p .RT .LP \fIF:\fR \fIcodeur\fR .LP \fIS:\fR \fIcodificador\fR .PP A device that performs encoding. .RT .sp 1P .LP 8025 \fBuniform encoding\fR .sp 9p .RT .LP \fI \fIF:\fR \fIcodage uniforme\fR .LP \fIS:\fR \fIcodificaci\*'on uniforme\fR .PP The generation of code words to represent uniformly quantized values. .RT .sp 1P .LP 8026 \fBnon\(hyuniform encoding\fR .sp 9p .RT .LP \fIF:\fR \fIcodage non uniforme\fR .LP \fIS:\fR \fIcodificaci\*'on no uniforme\fR .PP The generation of code words to represent non\(hyuniformly quantized values. (See Figure\ 3/G.701.) .bp .RT .sp 1P .LP 8027 \fBencoding law\fR .sp 9p .RT .LP \fIF:\fR \fIloi de quantification [loi de codage]\fR .LP \fIS:\fR \fIley de codificaci\*'on\fR .PP The law defining the relative values of the quantizing intervals used in quantizing and encoding. (See Figure\ 4/G.701.) .RT .sp 1P .LP 8028 \fBsegmented encoding law\fR .sp 9p .RT .LP \fIF:\fR \fIloi de quantification \*`a segments [loi de codage\fR \fI\*`a segments]\fR .LP \fIS:\fR \fIley de codificaci\*'on por segmentos\fR .PP 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.) .RT .sp 1P .LP 8029 \fBdecoding\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ecodage\fR .LP \fIS:\fR \fIdecodificaci\*'on\fR .PP The generation of reconstructed samples. .RT .sp 1P .LP 8030 \fBdecoder\fR .sp 9p .RT .LP \fIF:\fR \fId\*'ecodeur\fR .LP \fIS:\fR \fIdecodificador\fR .PP A device that performs decoding. .RT .sp 1P .LP 8031 \fBreconstructed sample\fR .sp 9p .RT .LP \fIF:\fR \fI\*'echantillon reconstitu\*'e\fR .LP \fIS:\fR \fImuestra reconstruida\fR .PP The signal generated at the output of a decoder when a specified digital signal representing a quantized value is applied to its input. .RT .sp 1P .LP 8032 \fBcodec\fR .sp 9p .RT .LP \fIF:\fR \fIcodec\fR .LP \fIS:\fR \fIc\*'odec\fR .PP A combination of an encoder and a decoder operating in opposite directions of transmission in the same equipment. .PP \fINote\fR \ \(em\ When used to describe an equipment the function of the equipment should qualify the title, for example: supergroup codec, hypergroup codec. .RT .sp 1P .LP 8033 \fBdigilogue channel\fR .sp 9p .RT .LP \fIF:\fR \fIvoie digilogue\fR .LP \fIS:\fR \fIcanal digi\(hyanal\*'ogico\fR .PP 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. .PP \fINote\fR \ \(em\ The term may be qualified by \*QA to D\*U or \*QD to A\*U to indicate whether encoding or decoding is being performed. .RT .sp 1P .LP 8034 \fBdigilogue circuit\fR .sp 9p .RT .LP \fIF:\fR \fIcircuit digilogue\fR .LP \fIS:\fR \fIcircuito digi\(hyanal\*'ogico\fR .PP 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. .PP \fINote\fR \ \(em\ Because the digital interface is inherently 4\(hywire, the term may be qualified by \*Q2\(hyW\*U or \*Q4\(hyW\*U to indicate whether the analogue interface is 2\(hywire or 4\(hywire. .bp .RT .LP .rs .sp 26P .ad r \fBFigure 2/G.701, p.\fR .sp 1P .RT .ad b .RT .LP .rs .sp 21P .ad r \fBFigure 3/G.701, p.\fR .sp 1P .RT .ad b .RT .LP .bp .LP .rs .sp 18P .ad r \fBFigure 4/G.701, p.\fR .sp 1P .RT .ad b .RT .sp 2P .LP 2.9 \fICodes\fR .sp 1P .RT .sp 1P .LP 9001 \fBpulse code\fR .sp 9p .RT .LP \fIF:\fR \fIcode d'impulsions (code de modulation d'impulsions)\fR .LP \fIS:\fR \fIc\*'odigo de impulsos\fR .PP A set of rules giving the equivalence between each quantized value and its corresponding code word. .RT .sp 1P .LP 9002 \fBline code\fR .sp 9p .RT .LP \fIF:\fR \fIcode en ligne\fR .LP \fIS:\fR \fIc\*'odigo de l\*'inea, c\*'odigo en l\*'inea\fR .PP 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. .RT .sp 1P .LP 9003 \fBredundant line code\fR .sp 9p .RT .LP \fIF:\fR \fIcode en ligne redondant\fR .LP \fIS:\fR \fIc\*'odigo de l\*'inea redundante\fR .PP A line code that uses more encoded signal elements than strictly necessary to represent groups of digits of the original signal. .RT .sp 1P .LP 9004 \fBalternate mark inversion code (AMI code)\fR .sp 9p .RT .LP \fIF:\fR \fIcode bipolaire [code bipolaire alternant, code bipolaire\fR \fIstrict]\fR .LP \fIS:\fR \fIcodigo de inversi\*'on de marcas alternada (codigo AMI)\fR \fI[c\*'odigo bipolar]\fR .PP 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. .bp .RT .sp 1P .LP 9005 \fBmodified alternate mark inversion code\fR .sp 9p .RT .LP \fIF:\fR \fIcode bipolaire alternant modifi\*'e\fR .LP \fIS:\fR \fIc\*'odigo de inversi\*'on de marcas alternada modificado\fR .PP 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. .RT .sp 1P .LP 9006 \fBalternate mark inversion signal [bipolar signal]\fR .sp 9p .RT .LP \fIF:\fR \fIsignal bipolaire [signal bipolaire alternant]\fR .LP \fIS:\fR \fIse\o"n~"al de inversi\*'on de marcas alternada [se\o"n~"al\fR \fIbipolar]\fR .PP The encoded signal produced by alternate mark inversion code. .RT .sp 1P .LP 9007 \fBalternate mark inversion violation [bipolar violation]\fR .sp 9p .RT .LP \fIF:\fR \fIviolation de bipolarit\*'e\fR .LP \fIS:\fR \fIviolaci\*'on de inversi\*'on de marcas alternada [violaci\*'on\fR \fIbipolar]\fR .PP A non\(hyzero signal element in an alternate mark inversion signal that has the same polarity as the previous non\(hyzero signal element. .RT .sp 1P .LP 9008 \fBdisparity\fR .sp 9p .RT .LP \fIF:\fR \fIdisparit\*'e\fR .LP \fIS:\fR \fIdisparidad\fR .PP The algebraic sum of the values of the departure from notional zero level of one or more consecutive signal elements forming a defined group. .RT .sp 1P .LP 9009 \fBdigital sum\fR .sp 9p .RT .LP \fIF:\fR \fIsomme num\*'erique\fR .LP \fIS:\fR \fIsuma digital\fR .PP The algebraic sum of the disparities of a sequence of consecutive defined groups of signal elements. .RT .sp 1P .LP 9010 \fBdigital sum variation\fR .sp 9p .RT .LP \fIF:\fR \fIvariation de la somme num\*'erique\fR .LP \fIS:\fR \fIvariaci\*'on de la suma digital\fR .PP The difference between the maximum possible digital sum and the minimum possible digital sum of a specified number of groups of signal elements. .RT .sp 1P .LP 9011 \fBbalanced code\fR .sp 9p .RT .LP \fIF:\fR \fIcode \*`a somme born\*'ee\fR .LP \fIS:\fR \fIc\*'odigo equilibrado\fR .PP A code that generates only groups of signal elements that have zero digital sum. .RT .sp 1P .LP 9012 \fBpaired\(hydisparity code [alternate code, alternating code]\fR .sp 9p .RT .LP \fIF:\fR \fIcode \*`a disparit\*'e compens\*'ee\fR .LP \fIS:\fR \fIc\*'odigo con disparidad compensada [c\*'odigo alternado,\fR \fIc\*'odigo alternante]\fR .PP A code in which some or all of the digits in the original signal 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. .PP \fINote\fR \ \(em\ An alternate mark inversion signal is an example of a paired\(hydisparity code. .bp .RT .sp 1P .LP 9013 \fBPCM binary code\fR .sp 9p .RT .LP \fIF:\fR \fIcode binaire MIC\fR .LP \fIS:\fR \fIc\*'odigo binario MIC\fR .PP A pulse code in which all the quantized values are identified by binary numbers taken in order. .PP \fINote\fR \ \(em\ This term should not be used for line transmission. .RT .sp 1P .LP 9014 \fBsymmetrical binary code\fR .sp 9p .RT .LP \fIF:\fR \fIcode binaire sym\*'etrique\fR .LP \fIS:\fR \fIc\*'odigo binario sim\*'etrico\fR .PP A pulse code in which the sign of the quantized value, is represented by one digit, and in which the remaining digit constitute a binary number representing the magnitude. .PP \fINote\ 1\fR \ \(em\ In a particular symmetrical binary code, the order of the digits and the use made of the symbols 0 and 1 in the various digit positions must be specified. .PP \fINote\ 2\fR \ \(em\ This term should not be used for line transmission. .RT .sp 1P .LP 9015 \fBcode conversion\fR .sp 9p .RT .LP \fIF:\fR \fItranscodage\fR .LP \fIS:\fR \fIconversi\*'on de c\*'odigo\fR .PP The conversion of digital signals in one code to the corresponding signals in a different code. \v'2P' .RT .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation G.701) .sp 9p .RT .ce 0 .ce 1000 \fBAlphabetical list of terms defined in this Recommendation\fR .sp 1P .RT .ce 0 .LP .sp 3 .LP \s88004 adaptive differential pulse code modulation (ADPCM) .RT .LP 8006 adaptive predictor .LP 8012 adaptive quantizing .LP 3023 alarm indication signal (AIS) .LP 9012 [alternate code] .LP 9004 alternate mark inversion code (AMI code) .LP 9012 [alternating code] .LP 9006 alternate mark inversion signal .LP 9007 alternate mark inversion violation .LP 7014 amplitude quantized control .LP 7012 analogue control .LP 1002 analogue signal .LP 6015 anisochronous .LP 6018 [asynchronous/heterochronous] .LP 9011 balanced code .LP 7011 bilateral control .LP 2003 binary digit .LP 2002 binary figure .LP 9006 [bipolar signal] .LP 9007 [bipolar violation] .LP 3019 bit sequence independence .LP 5003 bunched frame alignment signal .LP 4001 (bus: American) .LP 6022 centralized\(hyclock interface .LP 1005 channel, transmission channel .LP 4002 channel gate .LP 6006 channel time\(hyslot .LP 2005 [character signal] .LP 1007 circuit, telecommunication circuit .LP 6009 clock .LP 7004 clock control signal .LP 2005 code word .LP 8032 codec .LP 8024 [coder] .LP 8023 [coding, coding in PCM] .LP 6021 codirectional interface .LP 6023 contradirectional interface .LP 2026 controlled slip .LP 2020 decision circuit .LP 2019 decision instant, decision instant of a digital signal .LP 8016 decision value .LP 8030 decoder .LP 8029 decoding .LP 8003 delta modulation .LP 7019 democratic network, democratic mutually synchronized network .LP 2029 descrambler .LP 4011 (deserializer: American) .LP 7022 [despotic network, despotic synchronized network] .LP 8002 differential pulse code modulation (DPCM) .LP 8033 digilogue channel .LP 8034 digilogue circuit .LP 2001 digit .LP 2008 digit position .LP 2013 digit rate .LP 3020 digit sequence integrity .LP 6005 digit time\(hyslot .LP 4019 digital block .LP 3002 digital channel, digital transmission channel .LP 3003 digital circuit, digital telecommunication circuit .LP 3004 digital connection .LP 4016 digital demultiplexer .LP 4015 digital demultiplexing .LP 3006 digital distribution frame .LP 2030 digital error .LP 4021 digital filling .LP 3013 digital line link .LP 3013 [digital line path] .LP 3012 digital line section .LP 3015 digital line system .LP 3005 digital link, digital transmission link .LP 4014 digital multiplexer .LP 4017 digital multiplex equipment .LP 4003 digital multiplex hierarchy .LP 4013 digital multiplexing .LP 4021 [digital padding] .LP 3005 [digital path] .LP 3017 digital radio link .LP 3017 [digital radio path] .LP 3016 digital radio section .LP 3018 digital radio system .LP 3007 digital section .LP 2006 digital signal .LP 9009 digital sum .LP 9010 digital sum variation .LP 3003 digital telecommunication circuit .LP 3001 digital transmission .LP 3002 digital transmission channel .LP 3005 digital transmission link .LP 3014 digital transmission system .LP 3022 digital transparency .LP 4005 (digroup: American) .LP 1003 discretely\(hytimed signal .LP 9008 disparity .LP 5004 distributed frame alignment signal .LP 7009 double\(hyended synchronization .LP 4010 [dynamicizer] .LP 3009 elementary cable section .LP 3011 elementary regenerator section .LP 3010 elementary repeater section .LP 8024 encoder .LP 8023 encoding .LP 8027 encoding law .LP 2015 equivalent binary content .LP 2016 equivalent bit rate .LP 2030 error, digital error .LP 2032 error multiplication .LP 2033 error multiplication factor .LP 2031 [error rate] .LP 2031 error ratio .LP 2034 error spread .LP 4007 frame .LP 5001 frame alignment .LP 5002 frame alignment signal .LP 5005 frame alignment recovery time .LP 6008 frame alignment time\(hyslot .LP 6020 heterochronous .LP 7021 hierarchic mutually synchronized network .LP 7020 hierarchic network, hierarchic synchronized network .LP 4001 highway .LP 6017 homochronous .LP 3025 [housekeeping digits] .LP 1008 interface .LP 6014 isochronous .LP 2024 jitter .LP 4026 justifiable digit time\(hyslot .LP 4022 justification .LP 4029 justification rate .LP 4032 justification ratio .LP 4028 justification service digit .LP 4027 justifying digit .LP 9002 line code .LP 2014 line digit rate .LP 7013 linear analogue control .LP 8019 load capacity .LP 6011 master clock .LP 4031 maximum justification rate .LP 4031 [maximum stuffing rate] .LP 6016 [mesochronous] .LP 9005 modified alternate mark inversion code .LP 7022 monarchic network, monarchic synchronized network .LP 4008 multiframe .LP 7018 mutually synchronized network .LP 4006 n\(hyary digital group .LP 2009 n\(hyary digital signal .LP 4024 negative justification .LP 4024 [negative stuffing, negative pulse stuffing] .LP 4030 nominal justification rate .LP 4033 nominal justification ratio .LP 4030 [nominal stuffing rate] .LP 4033 [nominal stuffing ratio] .LP 7017 non\(hysynchronized network .LP 6018 non\(hysynchronous .LP 8026 non\(hyunifrom encoding .LP 8014 non\(hyuniform quantizing .LP 2004 octet .LP 3021 octet sequence integrity .LP 7023 oligarchic network, oligarchic synchronized network .LP 5006 out\(hyof\(hyframe alignment time .LP 8019 [overload point] .LP 9012 paired\(hydisparity code .LP 4010 parallel to serial converter .LP 4018 PCM multiplex equipment .LP 8020 peak limiting, peak limiting in quantizing .LP 6019 plesiochronous .LP 4023 positive justification .LP 4023 [positive stuffing, positive pulse stuffing] .LP 4025 positive/zero/negative justification .LP 4025 [positive/zero/negative stuffing] .LP 4025 positive/zero/negative pulse stuffing .LP 8005 predictor .LP 4005 [primary block] .LP 4004 primary digital group .LP 4005 primary PCM group .LP 2012 psuedo n\(hyary signal .LP 9001 pulse code .LP 8001 pulse code modulation (PCM) .LP 4022 [pulse stuffing] .LP 8018 quantized value .LP 8011 quantizing .LP 8021 quantizing distortion .LP 8022 quantizing distortion power .LP 8015 quantizing interval .LP 8031 reconstructed sample .LP 2010 redundant digital signal .LP 9003 redundant line code .LP 2011 redundant n\(hyary signal .LP 6010 reference clock .LP 2021 regeneration .LP 2023 regenerative repeater .LP 2022 regenerator .LP 3011 [regenerator section] .LP 3009 [repeater section] .LP 6013 relative time interval error .LP 6003 retiming .LP 8007 sample .LP 8008 sampling .LP 8009 sampling rate .LP 2028 scrambler .LP 3008 section termination .LP 8028 segmented encoding law .LP 4011 serial to parallel converter .LP 4010 (serializer: American) .LP 3025 service digits .LP 1001 signal .LP 2007 signal element .LP 6007 signalling time\(hyslot .LP 2017 significant instant, significant instant of a digital signal .LP 7008 single\(hyended synchronization .LP 2026 [slip] .LP 4011 [staticizer] .LP 4026 [stuffable digit time\(hyslot] .LP 4022 [stuffing] .LP 4027 [stuffing digit] .LP 4029 [stuffing rate] .LP 4032 [stuffing ratio] .LP 4028 [stuffing service digit] .LP 4009 subframe .LP 2014 [symbol rate] .LP 9014 symmetrical binary code .LP 7001 synchronization .LP 7003 synchronization information .LP 7006 synchronization link .LP 7005 synchronization node .LP 7007 synchronization network .LP 6016 synchronous .LP 7016 synchronized network .LP 7016 [synchronous network] .LP 1006 telecommunication .LP 1007 telecommunication circuit .LP 4012 time\(hydivision multiplexing .LP 6012 time interval error .LP 7015 time quantized control .LP 6004 time\(hyslot .LP 6002 [timing extraction] .LP 7002 timing information .LP 6001 timing signal .LP 6002 timing recovery .LP 1004 transmission .LP 1005 tranmission channel .LP 4020 transmultiplexer .LP 3022 transparency, digital transparency .LP 2027 uncontrolled slip .LP 8025 uniform encoding .LP 8013 uniform quantizing .LP 7010 unilateral control .LP 2018 unit interval .LP 3024 upstream failure indication .LP 8017 virtual decision value .LP 2025 wander .LP 8010 working range .LP \s9 .RT .sp 2P .LP .sp 1 \fBReference\fR .sp 1P .RT .LP [1] CCITT Recommendation \fIDefinitions relating to national and\fR \fIinternational numbering plans\fR , Vol.\ VI, Rec.\ Q.10. .bp .sp 2P .LP \fBRecommendation\ G.702\fR .RT .sp 2P .sp 1P .ce 1000 \fBDIGITAL\ HIERARCHY\ BIT\ RATES\fR .EF '% Fascicle\ III.4\ \(em\ Rec.\ G.702'' .OF '''Fascicle\ III.4\ \(em\ Rec.\ G.702 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .sp 2P .LP The\ CCITT, .sp 1P .RT .sp 1P .LP \fIconsidering\fR .sp 9p .RT .PP (a) that digital hierarchy bit rates are those bit rates which are or will be used as the basis for higher digital hierarchy levels if such levels exist (see Recommendation\ G.701, definition\ 4003); .PP (b) that the specification of hierarchical bit rates is necessary to prevent the proliferation of interface standards used in digital networks; .PP (c) that international interconnections of digital network components are preferably carried out at hierarchical bit rates; .PP (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: .LP \(em characteristics of and suitable coding method for analogue source signals; .LP \(em bit rates of digital source signals; .LP \(em use of available transmission media; .LP \(em compatibility with analogue multiplex systems; .LP \(em modularity and flexibility in assembling and routing groups of source signals, .sp 1P .LP \fIrecommends\fR .sp 9p .RT .PP that the following bit rates should be used as hierarchical bit rates in digital networks: .LP .rs .sp 10P .ad r \fBTable [T1.702], p.\fR .sp 1P .RT .ad b .RT .PP Figure 1/G.702 and Figure 2/G.702 show the recommended hierarchical bit rates only, including references to related Recommendations on network interfaces, multiplex equipments, digital sections/systems. .PP Recommendations on the following may also exist, but are not identified in Figure\ 1/G.702 and Figure\ 2/G.702: .RT .LP \(em multiplex equipments operating between non\(hyadjacent levels of the digital hierarchy; .LP \(em network interfaces, multiplex equipments and digital sections/systems at non\(hyhierarchical bit rates. .PP Annex A to this Recommendation provides guidelines on usable bit rates available for services. .bp .LP .rs .sp 47P .ad r \fBFigure 1/G.702, p.\fR .sp 1P .RT .ad b .RT .LP .bp .LP .rs .sp 47P .ad r \fBFigure 2/G.702, p.\fR .sp 1P .RT .ad b .RT .LP .bp .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation G.702) .sp 9p .RT .ce 0 .ce 1000 \fBUsable \fR \fBbit rates available for services\fR .sp 1P .RT .ce 0 .PP 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. .sp 1P .RT .PP In general, with regard to bit rates available for transport of service signals, the following guidelines apply: .PP 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\(hy1/G.702 provides the necessary information. .sp 9p .RT .LP .rs .sp 21P .ad r \fBTable A\(hy1/G.702 [T2.702], p.\fR .sp 1P .RT .ad b .RT .PP A.2 In case of networks using 2048 kbit/s based hierarchy there is in principle no basic restriction on the use of full capacity of the digital path. However, it is recognized that compatibility 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 following advantages: .sp 9p .RT .LP \(em use of the same framing devices for switched and non\(hyswitched applications; .LP \(em end\(hyto\(hyend 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; .LP \(em possibility of performing additional network management functions that could be required, depending on the applications. .PP The preference for compatibility with recommended frame structures could be reconsidered for the applications where significant restrictions on the efficient use of the digital path capability can be identified. .LP .bp