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- .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'
- .LP
- \fBMONTAGE: FIN DE LA RECOMMANDATION R.102 EN\(hyT\* | TE DE CETTE PAGE\fR
- .sp 2P
- .LP
- \v'16P'
- \fBRecommendation\ R.103\fR
- .RT
- .sp 2P
- .ce 1000
- \fBCODE\ AND\ SPEED\(hyDEPENDANT\ TDM\ 600\ BIT/S\ SYSTEM\ FOR\ USE\ IN\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.103''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.103 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fBPOINT\(hyTO\(hyPOINT\ OR\ BRANCH\(hyLINE\ MULDEX\ CONFIGURATIONS\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- that telex subscribers are often geographically located in small groups;
- .PP
- (b)
- that TDM multiplexing systems are economical for the
- transmission of large numbers of channels;
- .PP
- (c)
- that certain telex switches handle TDM frames in
- accordance with Series\(hyR Recommendations directly and that frame fill
- should be optimized;
- .PP
- (d)
- that telex switches handle channels at 50 bauds and a
- 7.5\ unit code;
- .PP
- (e)
- that a facility for regenerating start\(hystop signals is
- used in new TELEX networks;
- .PP
- (f
- )
- that the branch\(hyline multiplexing system should be
- capable of accepting and regenerating all the signals of the TELEX signalling
- system;
- .PP
- (g)
- that the minimum signal transfer delay through TDM systems is achieved
- by the transmission of interleaved elements,
- .sp 1P
- .LP
- \fIrecommends\fR
- .sp 9p
- .RT
- .PP
- that, where banch\(hyline remote or low multiplex capacity TDM
- systems are to be used for telegraphy, the equipment shall comply with the
- following standards:
- .sp 2P
- .LP
- \fB1\fR \fBSystem capacity\fR
- .sp 1P
- .RT
- .PP
- The system shall be capable of multiplexing up to 8 channels at
- 50\ bauds (7.5\ bits including a stop element of 1.5\ units).
- .RT
- .sp 2P
- .LP
- \fB2\fR \fBStart\(hystop channel inputs\fR
- .sp 1P
- .RT
- .PP
- 2.1
- The modulation rate tolerance that shall be accepted on incoming 50\ baud
- start\(hystop signals with a stop element of 1.4\ units shall be at least
- \(+- | .4%.
- .sp 9p
- .RT
- .PP
- 2.2
- \fR When receiving characters at 50 bauds having nominally 1.5\(hyunit
- stop elements, the system shall be capable of transmitting without error
- isolated incoming characters that have a 1\(hyunit stop element, occurring at a
- maximum rate of one per second.
- .bp
- .PP
- 2.3
- The minimum interval between start elements of undistorted
- successive continuous characters that may be presented at the channel input
- when the nominal modulation rate is 50\ bauds shall be 145\ 5/6\ ms.
- .PP
- 2.4
- \fR There shall be no restriction on the continuous transmission of all
- characters (including combination No.\ 32 of International Telegraph
- Alphabet No.\ 2) when they are presented at the maximum permitted rate.
- .PP
- 2.5
- The effective net margin on all channel inputs when undistorted
- signals are received from a transmitter having a nominal character length
- and rate shall be at least 40%.
- .PP
- 2.6
- At the nominal modulation rate of 50 bauds, an input character
- start element shall be rejected if it is less than 0.4\ units duration
- and shall be accepted if it is more than 0.6\ units duration.
- .PP
- 2.7
- Elements corresponding to start polarity (at the distant
- multiplexer output) shall be inserted in the aggregate stream if the channels
- are unequipped.
- .PP
- 2.8
- In the case of an open\(hycircuit line condition at the start\(hystop
- channel input, it shall be possible to choose to transmit elements
- corresponding to a steady start or stop polarity in the aggregate bit stream,
- according to the availability polarity selected.
- .sp 2P
- .LP
- \fB3\fR \fBStart\(hystop channel outputs\fR
- .sp 1P
- .RT
- .PP
- 3.1
- The maximum degree of gross start\(hystop distortion, produced by the system
- on a start\(hystop channel, shall be 3% for all modulation rates.
- .sp 9p
- .RT
- .PP
- 3.2
- The maximum difference possible between the mean modulation rate of the
- channel output signals and the nominal modulation rate shall be 0.2%.
- .PP
- 3.3
- The minimum stop element duration released at the ouptut shall be 1.25\
- units, whatever the distortion, the length of the stop element or the
- input rate within the range specified in \(sc\(sc\ 2.1 to\ 2.4 of this
- Recommendation of the character recognized at the other end, whether this
- character is in
- accordance with this Recommendation of Recommendations\ R.101, R.102 or\ R.112
- (for a rate of 50\ bauds and a 7.5\ unit code).
- .PP
- 3.4
- Within 6 ms of the recognition of one of the failures described in \(sc\(sc\
- 8.3 and\ 8.4 or carrier loss signalled by the modem, the steady polarity
- as selected in accordance with \(sc\ 2.8 shall be applied to the channel
- outputs of
- the \fITDM system affected\fR .
- .PP
- 3.5
- The affected terminal shall signal its synchronization status to the distant
- terminal over the signalling channel provided (control channel).
- .sp 2P
- .LP
- \fB4\fR \fBMultiplexing details\fR
- .sp 1P
- .RT
- .PP
- 4.1
- Channel interleaving shall be on a \fIbit\(hyby\(hybit multiplexing\fR
- \fIbasis\fR .
- .sp 9p
- .RT
- .PP
- 4.2
- Both start and stop elements of each input character shall be
- transmitted through the aggregate.
- .PP
- 4.3
- The transfer delay shall not exceed 60 ms.
- .sp 2P
- .LP
- \fB5\fR \fBFrame structure\fR
- .sp 1P
- .RT
- .PP
- 5.1
- A unique frame of 12 bits, of duration 20 ms, equivalent to an
- aggregate signal rate of 600\ bit/s shall be used, as shown in Table\ 1/R.103:
- .sp 9p
- .RT
- .PP
- 5.2
- The frame may be considered as a 600 bit/s \fIstart/stop\fR character,
- time slot \*Q12\*U being the start element of polarity\ A, slots\ 10 and\
- 11 forming the stop element of polarity\ Z, as shown in Figure\ 1/R.103.
- .sp 2P
- .LP
- \fB6\fR \fBAggregate signal details\fR
- .sp 1P
- .RT
- .PP
- 6.1
- The aggregate signal rate shall be 600\ bit/s. The tolerance on the modulation
- rate of the receive aggregate signals of the TDM system shall be
- between\ +2.3% and\ \(em0.5%.
- .sp 9p
- .RT
- .PP
- 6.2
- The effective net margin of the aggregate signal receiver of the TDM system
- shall be at least 40%.
- .PP
- 6.3
- The maximum degree of isochronous distortion of the send aggregate signals
- of the TDM system shall
- be\ 5%.
- .bp
- .ce
- \fBH.T. [T1.103]\fR
- .ce
- TABLE\ 1/R.103
- .ce
- \fBFrame details\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(60p) | cw(60p) .
- Remote muldex slot Use
- _
- .T&
- cw(60p) | cw(60p) .
- \ 1 Data channel 1
- .T&
- cw(60p) | cw(60p) .
- \ 2 Data channel 2
- .T&
- cw(60p) | cw(60p) .
- \ 3 Data channel 3
- .T&
- cw(60p) | cw(60p) .
- \ 4 Data channel 4
- .T&
- cw(60p) | cw(60p) .
- \ 5 Data channel 5
- .T&
- cw(60p) | cw(60p) .
- \ 6 Data channel 6
- .T&
- cw(60p) | cw(60p) .
- \ 7 Data channel 7
- .T&
- cw(60p) | cw(60p) .
- \ 8 Data channel 8
- .T&
- cw(60p) | cw(60p) .
- \ 9 Control channel
- .T&
- cw(60p) | cw(60p) .
- 10 Z synchronization
- .T&
- cw(60p) | cw(60p) .
- 11 Z synchronization
- .T&
- cw(60p) | cw(60p) .
- 12 A synchronization
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 1/R.103 [T1.103], p. 1\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .rs
- .sp 17P
- .ad r
- \fBFigure 1/R.103, p. 2\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- 6.4
- When the TDM system is operated over an international
- telephone\(hytype circuit, a modem complying with the appropriate aspects
- of the Series\(hyV Recommendations (in particular Recommendation\ V.23)
- should preferably be employed.
- .sp 2P
- .LP
- \fB7\fR \fBControl channel encoding\fR
- .sp 1P
- .RT
- .PP
- 7.1
- The 50 bit/s control channel, the position of which in the frame described
- in\ 5 is accurately known, enables all risk of imitation to be
- eliminated.
- .sp 9p
- .RT
- .PP
- 7.2
- The structure of the control channel shall be in accordance with Figure\
- 2/R.103. It corresponds to an anisochronous character with a recurrence
- of 240\ ms, formed from a one unit start element of polarity\ Z, five information
- elements and a six unit stop element of polarity\ A.
- .bp
- .LP
- .rs
- .sp 11P
- .ad r
- \fBFigure 2/R.103, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- 7.3
- The control channel information provides for the transmission of information
- in accordance with Table\ 2/R.103.
- .ce
- \fBH.T. [T2.103]\fR
- .ce
- TABLE\ 2/R.103
- .ce
- \fBInformation transmitted by the control channel\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(102p) .
- 5 4 3 2 1 Information elements Function
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(102p) .
- 0 0 0 0 0 {
- Without alarm or other informations (default)
- }
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(102p) .
- 0 0 1 0 0 Loss of synchronism
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(102p) .
- 0 0 0 0 1 {
- Loop \*Qd\*U request
- (Remoteloop 2 on 600\ bit/s aggregate)
- }
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(102p) .
- 1 X X X X National use
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 0 1 0 0 0 {
- Remoteloop \*Qf\*U on TG channel\ 1
- } 0 1
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 0 0 1 2 0 1 0 1
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 0 3 0 1 0 1 1 4
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 0 1 1 0 0 5 0 1
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 1 0 1 6 0 1 1 1
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(66p) | cw(18p) .
- 0 7 0 1 1 1 1 8
- .TE
- .LP
- \fINote\fR
- \ \(em\ The least significant bits are sent first.
- .nr PS 9
- .RT
- .ad r
- \fBTableau 2/R.103 [T2.103], p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .sp 2P
- .LP
- \fB8\fR \fBSynchronizing\fR
- .sp 1P
- .RT
- .PP
- 8.1
- The maximum average synchronization time in the absence of error and imitation
- shal be 600\ ms.
- .sp 9p
- .RT
- .PP
- 8.2
- Synchronism shall be considered acheived after recognition of the frame
- positioning pattern (sequence of two elements of polarity\ Z followed by
- an element of polarity\ A) as described in\ 5 and at least two successive
- recognitions of the control channel (6\ elements of polarity\ A followed
- by one element of polarity\ Z modulo\ 12) in compliance witn\ 7.
- .PP
- 8.3
- The maximum time loss of synchronization due to a steady polarity signal
- shall be 120\ ms.
- .PP
- 8.4
- The maximum time loss of synchronization for repeated error on the synchronization
- pattern in the control channel shall be 380\ ms.
- .sp 2P
- .LP
- \fB9\fR \fBTelex signalling\fR
- .sp 1P
- .RT
- .PP
- 9.1
- Specifications for the signals used to establish, to clear and to control
- telex calls are laid down in Recommendation\ U.1 (types\ A and\ B),\ U.11
- (type\ C) and\ U.12 (type\ D). Recommendation\ U.25 lists the modes of
- both\(hyway
- telex signalling on a single circuit and the signalling combinations on
- a given aggregate that a TDM terminal shall be capable of handling.
- .sp 9p
- .RT
- .PP
- 9.2
- Recommendation U.25 also lays down the tolerances on the control signals
- from a TDM terminal to telex and vice versa.
- .sp 2P
- .LP
- \fB10\fR \fBMaintenance\fR
- .sp 1P
- .RT
- .PP
- The branch looping facilities shall remain in accordance with
- Recommendation\ R.115.
- .RT
- .sp 2P
- .LP
- \fB11\fR \fBNumbering of channels\fR
- .sp 1P
- .RT
- .PP
- The numbering of channels for the branch line telegraph muldex is given
- in Tables\ 1/R.114 and\ 4/R.114 in accordance with the numbering scheme
- concerning Recommendations\ R.101 and\ R.102.
- .RT
- .sp 2P
- .LP
- \fB12\fR \fBChannel selection\fR
- .sp 1P
- .RT
- .PP
- Remote channels shall be grouped so as to provide maximum ease of use of
- heterogeneous frames, a time slot allocation involving little variation
- in the sampling rate being retained.
- .PP
- The selection of channel grouping and the method used shall be based on
- bilateral agreement, particularly when the channels of an existing system
- have to be branched without there being any possibility of a reconfiguration
- of the whole.
- .PP
- Tables 3/R.103 and 4/R.103 give an example of remote channel grouping on
- the basis of muldexes in conformity with Recommendation\ R.101 or\ R.102.
- .RT
- .LP
- .rs
- .sp 16P
- .ad r
- Blanc
- .ad b
- .RT
- .LP
- .bp
- .ce
- \fBH.T. [T3.103]\fR
- .ce
- TABLE\ 3/R.103
- .ce
- \fBExample of grouping of remote channels for an R.101 muldex\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- lw(36p) | cw(36p) | cw(108p) .
- 200 baud channels eliminated 50 baud channels extended
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- Remote channel 1 2001 2004 {
- \ \ \ 0501, 0513, 0525, 0536
- | 504, 0516(2), 0528, 0539
- }
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- Remote channel 2 2005 2009 {
- \ \ \ 0505, 0529, 0517, 0540
- \ \ \ 0509, 0532, 0521, 0544
- }
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- Remote channel 3 2002 2006 {
- \ \ \ 0502, 0526, 0514, 0537
- \ \ \ 0506, 0530, 0518, 0541
- }
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- Remote channel 4 2003 2010 {
- \ \ \ 0503, 0527, 0515, 0538
- \ \ \ 0501, 0533, 0522, 0545
- }
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- Remote channel 5 2007 2011 {
- \ \ \ 0507, 0531, 0519, 0542
- \ \ \ 0511, 0534, 0523, 0546
- }
- _
- .T&
- cw(36p) | cw(36p) | cw(108p) .
- {
- 0508, 0512, 0520, 0524, 0535,
- 0543(1)\fB512, 0520, 0524, 0535\fR
- }
- .TE
- .LP
-
- \fINote\ 1\fR
- \ \(em\ Although incomplete, a sixth remote channel could be implemented
- with the remaining 50\ baud channels.
- .LP
- \fINote\ 2\fR
- \ \(em\ Channel 0516 may not be remoted when the corresponding TS is used
- to transmit the maintenance channel in the R.101 multiplexer.
- .nr PS 9
- .RT
- .ad r
- \fBTableau 3/R.103 [T3.103], p. 5\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .ce
- \fBH.T. [T4.103]\fR
- .ce
- TABLE\ 4/R.103
- .ce
- \fBExample of grouping of remote channels for an R.102 muldex\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- lw(36p) | cw(84p) , ^ | c.
- {
- Remote
- channel
- 1
- \fBchannel\fR
- 2
- } 200 baud channels eliminated
- 2004 and 2016 2012 and 2020
- _
- .T&
- cw(36p) | cw(84p) .
- {
- \fBchannel \fR
- \ 3
- \fBchannel \fR
- \ 4
- \fB
- channel \fR
- \ 5
- } {
- 2001 and 2013
- 2005 and 2017
- 2009 and 2021
- }
- _
- .T&
- cw(36p) | cw(84p) .
- {
- \fBchannel \fR
- \ 6
- \fBchannel \fR
- \ 7
- \fB
- channel \fR
- \ 8
- } {
- 2002 and 2014
- 2006 and 2018
- 2010 and 2022
- }
- _
- .T&
- cw(36p) | cw(84p) .
- {
- \fBchannel \fR
- \ 9
- \fBchannel \fR
- 10
- \fB
- channel \fR
- 11
- } {
- 2003 and 2015
- 2007 and 2019
- 2011 and 2023
- }
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 4/R.103 [T4.103], p. 6\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .sp 2P
- .LP
- \fBRecommendation\ R.105\fR
- .RT
- .sp 2P
- .ce 1000
- \fBDUPLEX\ MULDEX\ CONCENTRATOR\fR \fB,\ CONNECTING\ A\ GROUP\ OF\ GENTEX\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.105''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.105 %'
- .ce 0
- .ce 1000
- \fBAND\ TELEX\ SUBSCRIBERS\ TO\ A\ TELEGRAPH\ EXCHANGE\ BY\ ASSIGNING\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fBVIRTUAL\ CHANNELS\ TO\ TIME\ SLOTS\ OF\ A\ BIT\(hyINTERLEAVED\ TDM\
- SYSTEM\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Malaga\(hyTorremolinos,\ 1984; amended at Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- that the specifications of code and speed dependent TDM
- muldexes are already given in Recommendation\ R.101;
- .PP
- (b)
- that code and speed dependent TDM muldexes can be
- successfully used for connecting a group of gentex and telex subscribers
- to an exchange;
- .PP
- (c)
- that a considerable increase in the efficiency of muldex channel utilization
- may be achieved by concentration, i.e.\ allocating time
- slots to subscribers only while they are operating;
- .PP
- (d)
- that the busy\(hyhour load generated by gentex
- and telex subscribers averages from 0.05 to 0.2\ erlang;
- .PP
- (e)
- that both the virtual and assigned (fixed) telegraph
- channels can be set up on the same aggregate channel using the TDM method;
- .sp 1P
- .LP
- \fIunanimously declares the view\fR
- .sp 9p
- .RT
- .PP
- that, when a
- bit\(hyinterleaved TDM system
- is used on gentex and telex subscriber lines for concentrating telegraph
- signals by assigning
- virtual channels
- to time slots in the 2400\ bit/s aggregate bit stream, the equipment should
- meet the following requirements:
- .sp 2P
- .LP
- \fB1\fR \fBChannel types\fR
- .sp 1P
- .RT
- .PP
- 1.1\fR The
- duplex muldex/concentrator
- should ensure that
- virtual channels are only allocated time slots in the 2400\ bit/s aggregate
- bit stream for the duration of their seizure.
- .sp 9p
- .RT
- .PP
- 1.2
- The duplex muldex/concentrator should also ensure that
- assigned (fixed) channels are permanently allocated specific time slots
- in the 2400\ bit/s aggregate bit stream.
- .PP
- 1.3
- Virtual channels should ensure the connection of gentex and telex subscribers
- operating at 50 bauds and using the International Telegraph
- Alphabet No.\ 2 (ITA2) code who have an average load of 0.05\ to 0.2\ erlang.
- The use of other rates requires further study.
- .PP
- 1.4
- Assigned (fixed) channels should ensure data and telegraph signal transmission
- in compliance with Recommendation\ R.101, alternative\ B.
- .sp 2P
- .LP
- \fB2\fR \fBSystem capacity\fR
- .sp 1P
- .RT
- .PP
- 2.1
- The duplex muldex/concentrator should ensure the setting\(hyup
- of virtual and assigned channels in any combination within the range of the
- 2400\ bit/s aggregate rate.
- .sp 9p
- .RT
- .PP
- 2.2
- When a system has only virtual channels, the number of connected subscribers
- with an average load of 0.05 to 0.1\ erlang each should not
- exceed\ 256 and with an average load of\ 0.1 to 0.2\ erlang each should not
- exceed\ 128. In either case, the percentage value of the failures to connect
- is not more than\ 0.1%.
- .PP
- 2.3
- When a system has only assigned (fixed) channels, their number,
- depending on the types and rates of the channels, should comply with
- Recommendation\ R.101, alternative\ B.
- .bp
- .sp 2P
- .LP
- \fB3\fR \fBMultiplexing system specifications\fR
- .sp 1P
- .RT
- .PP
- Multiplexing scheme, frame structure, frame synchronization,
- aggregate signal parameters, interfaces, telegraph signal parameters at
- input\(hyoutput and telegraph signal delay time should conform to
- Recommendation\ R.101, alternative\ B.
- .RT
- .sp 2P
- .LP
- \fB4\fR \fBVirtual channel\fR \fB parameters\fR
- .sp 1P
- .RT
- .PP
- 4.1
- Virtual channels are intended for use on the telex network
- subscriber section with type\ A and type\ B signalling (Recommendation\ U.1).
- .sp 9p
- .RT
- .PP
- 4.2
- Seizure of virtual channels may be from either end. In order to
- decrease the probability of call collisions it is necessary:
- .LP
- \(em
- to perform blocking of the backward path immediately after
- the first calling signal stop element polarity appearing in a receiver
- vacant channel position;
- .LP
- \(em
- to establish the following order for seizure of time slots in the opposite
- muldexes;
- .LP
- \(em
- for a muldex installed at the exchange seizure should start with the
- first in a frame\(hyfree channel time slot while for the opposite muldex
- seizure begins with the last free channel time slot.
- .PP
- When encountering a call collision, a through\(hyconnection should be given
- to a call coming from the telegraph exchange, and a busy signal should
- be sent to the calling subscriber.
- .PP
- 4.3
- \fIIn the initial state\fR , a virtual channel should be free and a
- start polarity should be transmitted over it between statistical
- muldex/concentrator assemblies.
- .PP
- 4.4
- \fIWhen a call arrives\fR , i.e. stop polarity with an interval of
- more than 150 ms, either from the subscriber side or from the exchange
- side, a virtual channel should be seized, and a stop polarity having a
- duration of
- 140\(hy160\ ms should be transmitted over it to the remote side followed by the
- transmission of two start\(hystop characters having a length of 8\ units
- each in
- accordance with Figure\ 1/R.105.
- .PP
- The signal elements indicated as 1 to 8 are used for the
- transmission of an 8\(hydigit conventional number indicating which subscriber
- (maximum 2\u8\d\ =\ 256; see also \(sc\ 2.2 above) is/should be connected
- to the
- equipment.
- .PP
- 4.5
- For error protection of a conventional number, transmitted over a
- channel, the following should be carried out:
- .LP
- \(em
- a parity check;
- .LP
- \(em
- a check for anticoincidence of a convention number with any of the numbers
- of a circuit already seized.
- .PP
- In the case of an error or coincidence of a conventional number a service
- signal (a busy pulse signal or \*QOCC\*U) should be transmitted to the
- connection initiator side (a customer or exchange), returning a customer or
- exchange to initial state.
- .PP
- 4.6
- The element \*QC\*U of the second start\(hystop character
- (see Figure\ 1/R.105) is used for parity check.
- .LP
- .rs
- .sp 12P
- .ad r
- \fBFigure 1/R.105, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- A parity check element should correspond to the even number of
- elements in Z\ condition.
- .PP
- Element \*QC\*U of the first start\(hystop character remains vacant and
- may be used for service purposes.
- .RT
- .PP
- 4.7
- When the setting up of a virtual channel fails because all time slots
- are engaged by other virtual or assigned (fixed) channels, a busy signal,
- the structure of which is specified by current CCITT Recommendations should
- be
- returned to the calling subscriber side.
- .bp
- .sp 2P
- .LP
- \fBRecommendation\ R.111\fR
- .RT
- .sp 2P
- .ce 1000
- \fBCODE\ AND\ SPEED\ INDEPENDENT\ TDM\ SYSTEM\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.111''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.111 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fBFOR\ \fR \fBANISOCHRONOUS\ TELEGRAPH\ AND\ DATA\ TRANSMISSION\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Geneva, 1976; amended at Geneva, 1980 and Malaga\(hyTorremolinos,\
- 1984)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- that the use of voice\(hyfrequency telegraph\ (VFT) equipment on voice
- channels provided by frequency division multiplexing of a primary
- group or by time slots in a pulse code modulation\ (PCM) transmission system
- may not always be the optimum solution for telegraph and low\(hyspeed data
- transmission, if aspects of transmission quality, equipment complexity,
- technological progress, miniaturization, power consumption and overall
- cost are globally considered;
- .PP
- (b)
- that the economic transmission of telegraph and low\(hyspeed
- anisochronous data signals requiring code\(hy and speed\(hyindependent
- channels may be achieved by using time division techniques;
- .PP
- (c)
- that a relatively simple TDM (time division multiplex)
- system, even if less efficient in bandwidth utilization, might be preferred
- in some (e.g.\ short\(hyhaul) applications;
- .PP
- (d)
- that Administrations might be interested in conserving code and speed independence
- inherent in VFT systems when replacing them by TDM
- systems;
- .PP
- (e)
- that code and speed independent transmission systems are
- capable of transmitting any type of digital signal (anisochronous, isochronous,
- telegraph, data, signalling for switching purposes);
- .PP
- (f
- )
- that a
- code and speed independent TDM system
- can adapt its inherent telegraph distortion to the needs of a network,
- depending on the number of circuits connected in tandem;
- .PP
- (g)
- that a code and speed independent TDM system can adapt to a number of different
- types of channels (each being defined by its maximum
- modulation rate and inherent distortion);
- .PP
- (h)
- that a basic 64\ kbit/s telegraph multiplexer may provide
- interfaces for remote submultiplexers if required. The submultiplexers
- may be associated in some applications with Recommendations\ X.50\ [1]
- and\ X.51\ [2] data multiplexers and with telephone channel modems and/or
- baseband modems;
- .LP
- \fIunanimously declares the following views\fR
- .sp 1P
- .RT
- .sp 2P
- .LP
- \fB1\fR \fB64 kbit/s aggregate\fR
- .sp 1P
- .RT
- .sp 1P
- .LP
- 1.1
- \fIGeneral\fR
- .sp 9p
- .RT
- .PP
- 1.1.1
- Where code and speed independent TDM systems for transmission of telegraph
- and low\(hyspeed anisochronous data signals utilize the whole 64\ kbit/s
- capacity (e.g.\ provided by a PCM time slot or a primary group), the equipment
- shall be manufactured to comply with the following standards.
- .sp 9p
- .RT
- .sp 2P
- .LP
- 1.2
- \fIAggregate bearer channel\fR
- .sp 1P
- .RT
- .PP
- 1.2.1
- The aggregate bearer channel may be a 64\ kbit/s PCM\ time
- slot or a 64\ kbit/s synchronous data modem in accordance with the
- Recommendation cited in\ [3]. The nominal data signalling rate
- is 64 | 00\ bit/s with a tolerance of \(+- | \ bit/s.
- .bp
- .sp 9p
- .RT
- .sp 2P
- .LP
- 1.3
- \fIFrame structure\fR
- .sp 1P
- .RT
- .PP
- 1.3.1
- The frame consists of 240\ bits for information plus\ 16
- symmetrically distributed service bits for framing and other purposes. The
- 16th\ bit of the frame is the first service bit. The frame synchronization
- pattern comprises the first 12\ service bits in the sequence 101001010101.
- .sp 9p
- .RT
- .PP
- 1.3.2
- The 13th\ service bit is used to inform the opposite multiplexer
- terminal of bearer failure as follows: 1\ =\ no bearer failure; 0\ =\ bearer
- failure. A minimum of three consecutive\ 0 conditions is the criterion for an
- alarm indication.
- .PP
- 1.3.3
- The 14th\ service bit is used to inform the opposite multiplexer
- terminal of frame alignment loss as follows: 1\ =\ no loss of frame alignment;
- 0\ =\ frame alignment loss (this may be accompanied by bearer failure).
- A minimum of three consecutive\ 0 conditions is the criterion for an alarm
- indication.
- .PP
- 1.3.4
- The time delay between detection of a bearer failure or frame
- alignment loss and the sending of the 0\ condition is for further study.
- .PP
- 1.3.5
- The 15th service bit is provisionally fixed to\ 1 and its use is
- left for further study.
- .PP
- 1.3.6
- The 16th\ service bit (last bit of the frame) may be used for
- possible justification and is fixed to\ 1. However, the justification strategy,
- if used, must be agreed bilaterally.
- .PP
- 1.3.7
- The channel numbering scheme is specified in
- Recommendation\ R.114.
- .sp 2P
- .LP
- 1.4
- \fIType of multiplexing\fR
- .sp 1P
- .RT
- .PP
- 1.4.1
- Channel interleaving shall be on a bit basis.
- .sp 9p
- .RT
- .PP
- 1.4.2
- The coding method shall be the transition coding process in
- accordance with Annex\ A below.
- .sp 2P
- .LP
- 1.5
- \fIAllocation of information bits\fR
- .sp 1P
- .RT
- .PP
- 1.5.1
- The data signalling rate on the bearer for each multiplexed
- channel should be 250, 500, 1000, 2000 or 4000\ bit/s corresponding to
- one, two, four, eight or sixteen bits per frame (symmetrically distributed)
- respectively.
- .sp 9p
- .RT
- .PP
- 1.5.2
- The 64\ kbit/s aggregate stream is divided into 60\ kbit/s for
- information and 4\ kbit/s for framing and other purposes.
- .PP
- 1.5.3
- The 60\ kbit/s information bit stream may be subdivided into five
- bit streams of 12\ kbit/s or, for national use or by bilateral agreement,
- into twenty bit streams of 3\ kbit/s.
- .sp 2P
- .LP
- 1.6
- \fITelegraph and data channels\fR
- .sp 1P
- .RT
- .PP
- 1.6.1
- The nominal modulation rates are 50, 100, 200, 300, 600 and
- 1200\ bauds. A mixture of these rates should be possible.
- .sp 9p
- .RT
- .PP
- 1.6.2
- The maximum degree of inherent isochronous distortion due to the
- sampling process is\ 2.5, 5 or\ 7.5% according to the application as shown in
- Table\ 1/R.111, which gives the channel characteristics and full system
- capacity for various telegraph channel rates and for aggregate signalling
- rates of
- 64\ kbit/s and below (see \(sc\ 2\ below).
- .PP
- 1.6.3
- Where applicable, spurious elements with duration of 1.6\ ms (=\ 8%) or
- less shall be rejected and elements longer than 2\ ms shall be accepted
- at
- the 50\ baud channel input. The element lengths to be rejected or accepted at
- higher channel modulation rates is for further study.
- .sp 2P
- .LP
- 1.7
- \fIFrame alignment\fR
- .sp 1P
- .RT
- .PP
- 1.7.1
- Frame realignment is ensured within three correct consecutive
- frame synchronization patterns, i.e.\ within\ 12 to\ 16\ ms. In the absence of
- frame realignment, the telegraph channel outputs of the demultiplexer should
- be locked in their start polarity state for switched applications.
- .sp 9p
- .RT
- .PP
- \fINote\fR \ \(em\ Stop polarity might be required by some Administrations
- on a per channel basis for leased applications.
- .bp
- .ce
- \fBH.T. [T1.111]\fR
- .ce
- TABLE\ 1/R.111
- .ce
- \fBChannel characteristics and system capacities\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) sw(18p) sw(18p) sw(18p) , ^ | ^ | ^ | ^ | ^ | c | c | c | c.
- {
- Nominal
- modulation
- rate
- (bauds)
- } {
- Maximum degree of isochronous distortion due
- to sampling
- (%)
- } {
- Theoretical
- maximum
- modulation
- rate
- (bauds)
- } {
- Data signalling
- rate on the
- bearer per
- channel
- (bit/s)
- } {
- Shortest
- isolated
- element
- (ms)
- } {
- Maximum number of channels
- for an integrated system of
- }
- 64 kbit/s 9.6 kbit/s 4.8 kbit/s 2.4 kbit/s
- _
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- {
- \ \ 50\fB | fR\(ua\fBa\fR\(ua\fB)\fR
- } 5\fB.5\fR 2.5 \ \ 83 \ 167 \ 250 \ 500 {
- 4\fB.25\fR
- 2\fB.25\fR
- } 240 120 32 16 16 \ 8 8 4
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- {
- \ 100\fB | fR\(ua\fBa\fR\(ua\fB)\fR
- } 5\fB.5\fR 2.5 \ 167 \ 333 \ 500 1000 {
- 2\fB.25\fR
- 1\fB.25\fR
- } 120 \ 60 16 \ 8 \ 8 \ 4 4 2
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- {
- \ 200\fB | fR\(ua\fBa\fR\(ua\fB)\fR
- } 5\fB.5\fR \ 333 1000 1\fB.25\fR \ 60 \ 8 \ 4 2
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- {
- \ 300\fB | fR\(ua\fBa\fR\(ua\fB)\fR
- } 7.5 \ 333 1000 1\fB.25\fR \ 60 \ 8 \ 4 2
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- \ 600 | ua\d\u)\d 7.5 \ 666 2000 0.5\fB2\fR \ 30 \ 4 \ 2 \(em
- .T&
- cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) .
- 1200 | ua\d\u)\d 7.5 1333 4000 0.25 \ 15 \ 2 \ \(em \(em
- .TE
- .LP
- \ua\d\u)\d
- The number of channels indicated for modulation rates of
- 600 and 1200 bauds is for information only (homogeneous aggregates at these
- rates are not contemplated).
- .nr PS 9
- .RT
- .ad r
- \fBTABLE 1/R.111 [T1.111], p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- .sp 3
- 1.7.2
- Three consecutive erroneous frame synchronization patterns should
- be regarded as the criterion for loss of frame alignment.
- .sp 2P
- .LP
- 1.8
- \fILoss of telegraph input\fR
- .sp 1P
- .RT
- .PP
- 1.8.1
- In the absence of any signal at a telegraph channel input, the
- multiplexer system should reproduce start polarity at the corresponding
- output.
- .sp 9p
- .RT
- .PP
- \fINote\fR \ \(em\ Stop polarity might be required by some Administrations
- on a per channel basis for leased applications.
- .sp 2P
- .LP
- 1.9
- \fIBearer interface\fR
- .sp 1P
- .RT
- .PP
- 1.9.1
- For the interface between the aggregate bearer and a PCM time
- slot, either a codirectional or contradirectional 64\ kbit/s interface with
- the PCM equipment could be accepted. Even for a codirectional interface no
- stuffing device would be provided in the telegraph multiplexer, which would
- loop back the 64\ kHz clock.
- .sp 9p
- .RT
- .PP
- 1.9.2
- For the interface to a 64\ kbit/s modem the interchange
- circuits of Table\ 2/R.111 should be provided (see the Recommendation cited
- in\ [4]).
- .sp 2P
- .LP
- 1.10
- \fITelegraph interface\fR
- .sp 1P
- .RT
- .PP
- 1.10.1
- The interface between the multiplexer and the telegraph circuits should
- be in accordance with national requirements.
- .bp
- .sp 9p
- .RT
- .ce
- \fBH.T. [T2.111]\fR
- .ce
- TABLE\ 2/R.111
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(60p) | cw(108p) .
- {
- Circuit number
- (cf. Recommendation\ V.24 | 5])
- } Function
- _
- .T&
- cw(60p) | lw(108p) .
- 102 | ua\d\u)\d\fBb\fR {
- Signal ground or common return
- }
- .T&
- cw(60p) | lw(108p) .
- 102b | ub\d\u)\d DCE common return
- .T&
- cw(60p) | lw(108p) .
- 103 | uc\d\u)\d\fBb\fR Transmitted data
- .T&
- cw(60p) | lw(108p) .
- 104 | uc\d\u)\d\fBb\fR Received data
- .T&
- cw(60p) | lw(108p) .
- {
- 109\fBb | fR\(ua\fBb\fR\(ua\fB)\fR
- } {
- Data channel received line signal detector
- }
- .T&
- cw(60p) | lw(108p) .
- | 13 | uc\d\u)\d | ud\d\u)\d {
- Transmitter signal element timing
- (DTE source)
- }
- .T&
- cw(60p) | lw(108p) .
- | 14 | uc\d\u)\d | ud\d\u)\d {
- Transmitter signal element timing
- (DCE source)
- }
- .T&
- cw(60p) | lw(108p) .
- 115 | uc\d\u)\d\fBb\fR {
- Receiver signal element timing
- }
- .TE
- .LP
-
- \ua\d\u)\d
- The provision of this conductor is optional.
- .LP
- \ub\d\u)\d
- This conductor is used in conjunction with interchange
- circuit\ 109.
- .LP
- \uc\d\u)\d
- The electrical characteristics of the interchange circuits
- marked with a \uc\d\u)\d should be in accordance with
- Recommendation\ X.27 | 6]. The circuits not so marked should be
- in accord
- ance with Recommendation\ X.26 | 7].
- .LP
- \ud\d\u)\d
- Either circuit 113 or 114 is to be used.
- .nr PS 9
- .RT
- .ad r
- \fBTable 2/R.111 [T2.111], p.
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .sp 2
- .LP
- \fB2\fR \fBAggregate bearer rates lower than 64\ kbit/s\fR
- .sp 1P
- .RT
- .sp 2P
- .LP
- 2.1
- \fIGeneral\fR
- .sp 1P
- .RT
- .PP
- 2.1.1
- Where code and speed independent TDM systems for transmission of telegraph
- and low speed anisochronous data signals make use of capacities
- lower than 64\ kbit/s, the equipment shall be manufactured to comply with the
- following standards:
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.2
- \fIAggregate bearer channels\fR
- .sp 1P
- .RT
- .PP
- 2.2.1
- Aggregate rates of 2.4, 4.8 and 9.6 kbit/s shall be used. These rates can
- be provided either using modems in accordance with the Series\ V
- Recommendations or using data multiplexers in accordance with
- Recommendations\ X.50\ [1] or\ X.51\ [2].
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.3
- \fIFrame structure\fR
- .sp 1P
- .RT
- .PP
- 2.3.1
- The frame structure is independent of the frame structure of the 64\ kbit/s
- data multiplexer or of the 64\ kbit/s telegraph multiplexer. However, it
- must be designed to allow easy insertion of the carried telegraph channels
- on to the multiplexer defined in \(sc\ 1\ above (see also \(sc\ 3\ below).
- .bp
- .sp 9p
- .RT
- .PP
- 2.3.2
- For that purpose, one bit out of every six bits will carry
- framing information and other functions, which will result in effective
- binary rates of\ 2, 4 or\ 8\ kbit/s with actual aggregate rates of\ 2.4,
- 4.8
- and\ 9.6\ kbit/s respectively.
- .PP
- 2.3.3
- The frame consists of 160\ information bits plus 32\ symmetrically
- distributed service bits for framing and other purposes. The sixth bit
- of the frame is the first service bit.
- .PP
- 2.3.4
- This frame is subdivided into two subframes each consisting of
- 80\ information bits plus 16\ symmetrically distributed service bits.
- .PP
- 2.3.5
- The subframe synchronization pattern comprises the first
- 12\ service bits in the sequence\ 101001010101.
- .PP
- 2.3.6
- For the allocation of the 13th, 14th and 15th service bits,
- see \(sc\(sc\ 1.3.2 to 1.3.5\ above. The 16th\ service bit is set at\ 0
- for the first
- subframe and at\ 1 for the second subframe.
- .sp 2P
- .LP
- 2.4
- \fIType of multiplexing\fR
- .sp 1P
- .RT
- .PP
- 2.4.1
- See \(sc\ 1.4\ above.
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.5
- \fIAllocation of information bits\fR
- .sp 1P
- .RT
- .PP
- 2.5.1
- The same data signalling rates as defined in \(sc\ 1.5 should be
- used (250, 500 and 1000\ bit/s and, where applicable, 2000 and 4000\ bit/s).
- .sp 9p
- .RT
- .PP
- 2.5.2
- Table\ 3/R.111 shows the number of information bits per frame for
- the different data signalling rates on the bearer channel. These information
- bits are symmetrically distributed among the 160\ information bits of the
- frame.
- .ce
- \fBH.T. [T3.111]\fR
- .ce
- TABLE\ 3/R.111
- .ce
- \fBNumber of information bits per frame\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(78p) | cw(30p) sw(30p) sw(30p) , ^ | c | c | c.
- {
- Data signalling rate on the
- bearer per channel
- (bit/s)
- } {
- Number of information bits per frame
- for each channel in an aggregate system of
- }
- 9.6 kbit/s 4.8 kbit/s 2.4 kbit/s
- _
- .T&
- cw(78p) | cw(30p) | cw(30p) | cw(30p) .
- \ 250 \ 5 10 20
- _
- .T&
- cw(78p) | cw(30p) | cw(30p) | cw(30p) .
- \ 500 10 20 40
- _
- .T&
- cw(78p) | cw(30p) | cw(30p) | cw(30p) .
- 1000 20 40 80
- _
- .T&
- cw(78p) | cw(30p) | cw(30p) | cw(30p) .
- 2000 40 80 \(em
- _
- .T&
- cw(78p) | cw(30p) | cw(30p) | cw(30p) .
- 4000 80 \(em \(em
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTABLE 3/R.111 [T3.111], p.
- .sp 1P
- .RT
- .ad b
- .RT
- .sp 2P
- .LP
- .sp 2
- 2.6
- \fITelegraph and data channels\fR
- .sp 1P
- .RT
- .PP
- 2.6.1
- See \(sc\ 1.6\ above.
- .bp
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.7
- \fIFrame alignment\fR
- .sp 1P
- .RT
- .PP
- 2.7.1
- Frame realignment time is ensured within three correct
- consecutive subframe synchronization patterns. This frame realignment will
- be ensured within\ 40, 80 and\ 160\ ms for aggregate rates of\ 9.6, 4.8
- and\ 2.4 kbit/s respectively. In the absence of frame realignment the telegraph
- channel outputs of the demultiplexer should be locked in their start polarity
- state for
- switched applications.
- .sp 9p
- .RT
- .PP
- \fINote\fR \ \(em\ Stop polarity might be required by some Administrations
- on a per channel basis for leased applications.
- .PP
- 2.7.2
- See \(sc\ 1.7.2\ above.
- .sp 2P
- .LP
- 2.8
- \fILoss of telegraph input\fR
- .sp 1P
- .RT
- .PP
- 2.8.1
- See \(sc\ 1.8\ above.
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.9
- \fIBearer interface\fR
- .sp 1P
- .RT
- .PP
- 2.9.1
- The interface between the telegraph aggregate and higher
- aggregate bearer channels should be as laid down in the relevant
- Recommendations for modems and data multiplexers.
- .sp 9p
- .RT
- .sp 2P
- .LP
- 2.10
- \fITelegraph interface\fR
- .sp 1P
- .RT
- .PP
- 2.10.1
- See \(sc\ 1.10\ above.
- .sp 9p
- .RT
- .sp 2P
- .LP
- \fB3\fR \fBCompatibility\fR
- .sp 1P
- .RT
- .PP
- 3.1
- For the different subrates of 2, 4 and 8 kbit/s, there should
- be\ 8, 16 and\ 32 information bits respectively distributed symmetrically
- within the 64\ kbit/s aggregate frame.
- .sp 9p
- .RT
- .PP
- 3.2
- The 160 information bits of the 2.4, 4.8 and 9.6 kbit/s aggregate
- rates should correspond to 20\ groups of 8\ bits, 10\ groups of\ 16 and
- 5\ groups of 32\ bits respectively. These\ 8, 16 and\ 32 information bits
- should be made to
- correspond to the\ 8, 16 and\ 32\ information bits of the 64\ kbit/s frame
- by means of a special padding/depadding unit.
- .PP
- 3.3
- Some examples of possible implementations are given in
- Figures\ 1/R.111, 2/R.111 and\ 3/R.111 for illustration purposes only.
- .LP
- .rs
- .sp 17P
- .ad r
- Blanc
- .ad b
- .RT
- .LP
- .bp
- .LP
- .rs
- .sp 23P
- .ad r
- \fBFigure 1/R.111, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .rs
- .sp 19P
- .ad r
- \fBFigure 2/R.111, p.
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .LP
- .rs
- .sp 24P
- .ad r
- \fBFigure 3/R.111, p.
- .sp 1P
- .RT
- .ad b
- .RT
- .ce 1000
- ANNEX\ A
- .ce 0
- .sp 1P
- .ce 1000
- (to Recommendation R.111)
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .ce 1000
- \fBTransition coding process\fR
- .sp 1P
- .RT
- .ce 0
- .LP
- .rs
- .sp 17P
- .ad r
- \fBFIGURE A\(hy1/R.111, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .PP
- A.1
- The sampling pulses are divided into groups of four and each
- transition of the anisochronous signal causes a code character of 3\ bits
- to be generated at the rate of one bit for a group of 4\ samples. The first
- T\ bit of this code character indicates the sense of transition while the
- two bits\ C\d1\uand\ C\d2\utranslate into binary code the position of the
- transition in the
- relevant group.
- .sp 9p
- .RT
- .PP
- A.2
- Following the acceptance of a transition into the coding system, a \*Qdata
- transition lockout condition\*U which inhibits entry of further
- transitions shall persist until code characters T, C\d1\uand C\d2\uhave
- been transmitted. Any transition which has been locked out in this manner
- shall enter the coder as soon as the lockout condition is removed and will
- be coded as if it had occurred in the first quarter of the next transmission
- period.
- .sp 9p
- .RT
- .PP
- A.3
- The code characters are transmitted over the digital channel at a rate
- of 1\ bit per group of 4\ sampling pulses and the subsequent bits\ P
- between the code characters confirm the polarity of the anisochronous signal
- at the relevant instant. The minimum number of P\ bits may be zero, so
- the maximum code character rate equals 1/3 of the maximum modulation rate
- allowed.
- .sp 9p
- .RT
- .PP
- A.4
- When the anisochronous signal has a permanent polarity, an
- error of one bit will never entail a continuous inversion of the decoded
- signal, but will cause a mutilation of this signal during a limited time.
- The duration of these mutilations is reduced to a minimum when the code
- characters are formed as shown in Table\ A\(hy1/R.111.
- .sp 9p
- .RT
- .ce
- \fBH.T. [T4.111]\fR
- .ce
- TABLE\ A\(hy1/R.111
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(18p) sw(18p) sw(18p) | cw(18p) sw(18p) sw(18p) | cw(60p) , c | c | c | c | c | c | ^ .
- {
- Code character for a
- transition from 1 to 0
- in the anisochronous signal
- } {
- Code character for a
- transition from 0 to 1
- in the anisochronous signal
- } {
- Position of the transition
- in a group
- of four sampling pulses
- }
- T C 1 C 2 T C 1 C 2
- _
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(60p) .
- 0 0 0 1 1 1 first quarter
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(60p) .
- 0 0 1 1 1 0 second quarter
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(60p) .
- 0 1 0 1 0 1 third quarter
- .T&
- cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(60p) .
- 0 1 1 1 0 0 fourth quarter
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTABLE A\(hy1/R.111 [T4.111], p.
- .sp 1P
- .RT
- .ad b
- .RT
- .sp 2P
- .LP
- \fBReferences\fR
- .sp 1P
- .RT
- .LP
- [1]
- CCITT Recommendation \fIFundamental parameters of a multiplexing scheme\fR
- \fIfor the international interface between synchronous data networks\fR
- ,
- Rec.\ X.50.
- .LP
- [2]
- CCITT Recommendation \fIFundamental parameters of a multiplexing scheme\fR
- \fIfor the international interface between synchronous data networks using\fR
- \fI10\(hybit envelope structure\fR , Rec.\ X.51.
- .LP
- [3]
- CCITT Recommendation \fIModems for synchronous data transmission using\fR
- \fI60\(hy108 kHz group band circuits\fR , Rec.\ V.36, \(sc\ 1 f
- ).
- .LP
- [4]
- \fIIbid.\fR , \(sc\ 10.
- .LP
- [5]
- CCITT Recommendation \fIList of definitions for interchange circuits\fR
- \fIbetween data terminal equipment and data circuit terminating equipment\fR ,
- Rec.\ V.24.
- .LP
- [6]
- CCITT Recommendation \fIElectrical characteristics for balanced\fR
- \fIdouble\(hycurrent interchange circuits for general use with integrated
- circuit\fR \fIequipment in the field of data communications\fR , Rec.\
- X.27.
- .LP
- [7]
- CCITT Recommendation \fIElectrical characteristics for unbalanced\fR
- \fIdouble\(hycurrent interchange circuits for general use with integrated
- circuit\fR \fIequipment in the field of data communications\fR , Rec.\
- X.26.
- .bp
- .sp 2P
- .LP
- \fBRecommendation\ R.112\fR
- .RT
- .sp 2P
- .ce 1000
- \fBTDM\ HYBRID\ SYSTEM\fR \fB\ FOR\ ANISOCHRONOUS\ TELEGRAPH\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.112''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.112 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fBAND\ DATA\ TRANSMISSION\ USING\ BIT\ INTERLEAVING\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Malaga\(hyTorremolinos,\ 1984; amended at Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- that there is a limited requirement on certain routes to provide for rates
- and codes not included in Table\ 1/R.101 which may be achieved by using
- time\(hydivision multiplexing (TDM) techniques;
- .PP
- (b)
- that wherever possible the rates and codes given in
- Table 1/R.101 should not be expanded in the future;
- .PP
- (c)\fR that Administrations may be asked to provide code and
- speed independent channels for cryptography, for telemetry, for rates outside
- the Recommendation\ R.101 tolerance of\ \(+-\ 1.4%, where the rate and
- code may be
- changed frequently, and for maintenance purposes;
- .PP
- (d)
- that the aggregate bit rate may be limited to 2400 bit/s
- and TDM equipment may be required to pass code independent and code dependent
- traffic;
- .PP
- (e)
- that the bearer may not be suitable for using the backward channel as defined
- by
- Recommendation\ V.26, \(sc\ 5\ [1], or in the provision of telegraph channels
- above the Recommendation\ V.26 aggregate by the technique of subdivision
- of the frequency band as given in Recommendation\ H.34\ [2],
- .sp 1P
- .LP
- \fIunanimously declares the view\fR
- .sp 9p
- .RT
- .PP
- that where bit\(hyinterleaved TDM systems are used for code dependent and
- code independent
- anisochronous telegraph and data transmission
- with an aggregate rate of 2400\ bit/s, carried either by analogue telephone\(hytype
- circuit or by higher order TDM system, the equipment should be constructed
- to comply with the following standards:
- .sp 2P
- .LP
- \fB1\fR \fBSystem capacity\fR
- .sp 1P
- .RT
- .PP
- 1.1
- The TDM system will be capable of multiplexing the rates shown in Table\
- 1/R.101 for code dependent channels to alternative\ B.
- .sp 9p
- .RT
- .PP
- 1.2
- Each code and rate independent channel should replace three, six or twelve
- 50\ baud code dependent channels.
- .PP
- 1.3
- The characteristics of the code independent channels should follow the
- limits shown in Table 1/R.112.
- .ce
- \fBH.T. [T1.112]\fR
- .ce
- TABLE\ 1/R.112
- .ce
- \fBCharacteristics of code independent channels\fR
- .ce
- \fBand system capacity\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- lw(36p) | lw(42p) | lw(36p) | lw(36p) | lw(36p) | lw(42p) .
-
- .T&
- lw(36p) | lw(42p) | lw(36p) | lw(36p) | lw(36p) | lw(42p) .
- {
- \ 50
- 8.3
- \ 51.06
- 153.2
- 6.5\
- 15
- 100
- 8.3
- 102.12
- 306.4
- 3.25
- \ 7
- 200
- 8.3
- 204.24
- 612.8
- 1.625
- \ 3
- }
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTable 1/R.112 [T1.112], p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .sp 2P
- .LP
- \fB2\fR \fBChannel inputs\fR
- .sp 1P
- .RT
- .PP
- 2.1
- The nominal modulation rate will be 50, 100 or 200 bauds; the
- theoretical maximum modulation rate shall be\ 51.06, 102.12 or 204.24\ bauds.
- .sp 9p
- .RT
- .PP
- 2.2
- The transition coding process of telegraph signals is in
- accordance with Recommendation\ R.111.
- .PP
- 2.3
- Each channel provides its individual coding intervals starting
- within the allocated time slots: each coding interval is subdivided into
- four quarters. In that coding interval where the skipping bit occurs in
- the
- subframe, the forth quarter is shortened by one time slot length.
- .PP
- For a 50 baud channel, transmission of the code character starts with the
- next corresponding time slot. For channels with higher modulation
- rates the transmission of the code characters should be delayed by the
- number of the allocated time slots in the subframe minus\ 3.
- .PP
- 2.4
- Where applicable, spurious elements with duration of 1.6\ ms (=\ 8%) or
- less shall be rejected and elements longer than 2\ ms shall be accepted
- at
- the 50\ baud channel input. The element lengths to be rejected or accepted at
- higher channel modulation rates is for further study.
- .sp 2P
- .LP
- \fB3\fR \fBChannel outputs\fR
- .sp 1P
- .RT
- .PP
- 3.1
- The maximum degree of inherent isochronous distortion due to the sampling
- process shall be\ 8.3%.
- .sp 9p
- .RT
- .PP
- \fINote\fR \ \(em\ The long\(hyterm system distortion on a tandem connection
- of transition encoded channels of an independent TDM system approximates
- in the
- worst case to the arithmetic summation of the individual link distortions.
- .PP
- 3.2
- After a TDM link failure, actions described in \(sc\(sc\ 3.5 and\ 3.6 of
- Recommendation R.101, should be taken on the derived channel output.
- .sp 2P
- .LP
- \fB4\fR \fBMultiplexing details\fR
- .sp 1P
- .RT
- .PP
- 4.1
- The multiplexing details are in accordance with
- Recommendation R.101, alternative B on a bit basis.
- .sp 9p
- .RT
- .PP
- 4.2
- The maximum transfer delay (excluding the modem) for 50, 100 and 200\ baud
- code and rate independent channels for back\(hyto\(hyback terminals shall
- not exceed 50\ ms for the rate 50\ bauds and 35\ ms for rates\ 100 and
- 200\ bauds. The values of the delay are subject to further study.
- .sp 2P
- .LP
- \fB5\fR \fBFrame structure\fR
- .sp 1P
- .RT
- .PP
- This is as defined in Recommendation R.101 alternative B.
- .RT
- .sp 2P
- .LP
- \fB6\fR \fBSynchronizing\fR
- .sp 1P
- .RT
- .PP
- This is defined in Recommendation R.101, alternative\ B.
- .RT
- .sp 2P
- .LP
- \fB7\fR \fBAggregate signals and interface, system clock arrangements\fR
- \fBand system control and alarms\fR
- .sp 1P
- .RT
- .PP
- These are defined in Recommendation R.101.
- .RT
- .sp 2P
- .LP
- \fB8\fR \fBChannel numbering scheme of code independent channels\fR
- .sp 1P
- .RT
- .PP
- Channel numbers used in the given Recommendation represent two last digits
- of the four\(hydigit numbering scheme in respect to the Figure\ 1/R.112,
- first two digits are shown in Recommendation\ R.114.
- .bp
- .RT
- .LP
- .rs
- .sp 44P
- .ad r
- \fBFigure 1/R.112, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .sp 2P
- .LP
- \fBReferences\fR
- .sp 1P
- .RT
- .LP
- [1]
- CCITT Recommendation \fI2400 bit per second modem standardized\fR
- \fIfor use on 4\(hywire leased telephone\(hytype circuits\fR , Rec.\ V.26.
- .LP
- [2]
- CCITT Recommendation \fISub\(hydivision of the frequency band of a\fR
- \fItelephone\(hytype circuit between telegraph and other services\fR ,
- Rec.\ H.34.
- .bp
- .sp 2P
- .LP
- \fBRecommendation\ R.114\fR
- .RT
- .sp 2P
- .sp 1P
- .ce 1000
- \fBNUMBERING\ OF\ INTERNATIONAL\ TDM\ CHANNELS\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.114''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.114 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- that in view of the introduction in the international
- service of time division multiplex (TDM) channels with different
- characteristics, configured for various nominal modulation rates and for
- different character structures, it has become necessary to evolve a method
- of numbering TDM channels;
- .PP
- (b)
- that this numbering method must make it possible to
- recognize:
- .LP
- \(em
- the type of TDM (code\(hydependent or code\(hyindependent);
- .LP
- \(em
- the nominal modulation rate and (in the case of
- code\(hydependent TDM) the character length;
- .LP
- \(em
- the position of the channel in the frame,
- .sp 2P
- .LP
- \fIunanimously declares the view\fR
- .sp 1P
- .RT
- .PP
- \fB1\fR
- The channels in an international TDM system conforming to
- Recommendation R.101 should be numbered as shown in Table\ 1/R.114.
- .sp 9p
- .RT
- .PP
- \fB2\fR
- The number assigned to a channel should be selected from the
- series applicable to the type of channel and should correspond to its position
- in the multiplex tables in Recommendation\ R.101.
- .sp 9p
- .RT
- .PP
- \fB3\fR The channels in an international TDM system conforming to
- Table\ 1/R.111 should be numbered as shown in Table\ 2/R.114.
- .sp 9p
- .RT
- .PP
- \fB4\fR The channels in systems conforming to Table 1/R.111 should be
- numbered in the same way as their positions in the frame; i.e.\ in the
- sequence from\ 1 to\ 255 excluding the channel numbers that are multiples
- of\ 16. In
- establishing a channel having a rate of more than 50\ bauds, the number
- assigned coincides with the number of the first 50\ baud channel taking
- part in the
- integration.
- .sp 9p
- .RT
- .PP
- \fB5\fR International TDM channels to Recommendation\ R.112 should have
- the numbering scheme shown in Table\ 3/R.114.
- .sp 9p
- .RT
- .PP
- \fB6\fR The numbers assigned to the channels should be selected from the
- series applicable to the type of channel and should correspond to its position
- in the Figure\ 1/R.112 to Recommendation\ R.112.
- .sp 9p
- .RT
- .PP
- \fB7\fR International code independent and code dependent channels to
- Recommendation\ R.102 should have the numbering schemes shown in Tables\
- 3/R.114 and\ 4/R.114, respectively.
- .sp 9p
- .RT
- .PP
- \fB8\fR The numbers assigned to the channels should be selected from the
- series applicable to the type of channel and should correspond to its position
- in Tables\ 2/R.102 to\ 4/R.102 to Recommendation\ R.102.
- .sp 9p
- .RT
- .PP
- \fB9\fR Channel numbering of 50 baud channels for branch\(hyline muldexes
- conforming to Recommendation\ R.103 should be in accordance with the numbering
- scheme in Tables\ 1/R.114 and\ 4/R.114.
- .sp 9p
- .RT
- .LP
- .rs
- .sp 3P
- .ad r
- Blanc
- .ad b
- .RT
- .LP
- .bp
- .ce
- \fBH.T. [T1.114]\fR
- .ce
- TABLE\ 1/R.114
- .ce
- \fBNumbering scheme for TDM systems conforming\fR
- .ce
- \fBto Recommendation R.101\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- lw(60p) | lw(168p) .
-
- .T&
- lw(60p) | lw(168p) .
- {
- \ 50 |
- 0501 | (hy | 546
- \ 75 |
- 0701 | (hy | 742 (for alternative A). See Table 3/R.101
- for numbers not used
- 0701 | (hy | 731 (for alternative B, 0716 not used)
- 100 |
- 1001 | (hy | 023 (for 10 unit, 1008 not used)
- 1701 | (hy | 723 (for 7\(12 unit, 1708 not used)
- 110 |
- 1101 | (hy | 123 (1108 not used)
- 134.5
- 1301 | (hy | 315
- 150 |
- 1501 | (hy | 515
- 200 |
- 2001 | (hy | 011 (for 10 unit, 2008 not used)
- 2101 | (hy | 111 (for 11 unit, 2108 not used)
- 2701 | (hy | 711 (for 7\(12 unit, 2708 not used)
- 300 |
- 3001 | (hy | 007 (for 10 unit)
- 3101 | (hy | 107 (for 11 unit)
- }
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 1/R.114 [T1.114], p. 18\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .sp 2
- .ce
- \fBH.T. [T2.114]\fR
- .ce
- TABLE\ 2/R.114
- .ce
- \fBNumbering scheme for TDM systems\fR
- .ce
- \fBconforming to Table 1/R.111\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- lw(48p) | lw(48p) | lw(132p) .
-
- .T&
- lw(48p) | lw(48p) | lw(132p) .
- {
- \ \ 50
- \ (300)
- 5
- \ (7.5)
- 5001 | (hy | 255 (The numbers 16, 32, 48, 64, 80, 96, 112,
- 128, 144, 160, 176, 192, 208, 224 and 240 are not
- used)
- \ 100
- \ (300)
- 5
- \ (7.5)
- 6001 | (hy | 127 (The numbers 16, 32, 48, 64, 80, 96 and 112 are
- not used)
- \ 200\ (300)
- 5\ (7.5)
- 7001 | (hy | 063 (The numbers 16, 32 and 48 are not used)
- \ 600
- \ (300)
- 7.5
- \ (5)
- 8001 | (hy | 031 (The number 16 is not used)
- 1200
- \ (300)
- 7.5
- \ (5)
- 8101 | (hy | 115
- }
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 2/R.114 [T2.114], p. 19\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .ce
- \fBH.T. [T3.114]\fR
- .ce
- TABLE\ 3/R.114
- .ce
- \fBNumbering scheme of code independent channels for TDM\fR
- .ce
-
- .ce
- \fBsystems\fR
- .ce
- \fBconforming to Recommendations R.112 and R.102\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(30p) | cw(66p) | cw(48p) sw(48p) , ^ | ^ | c | c.
- {
- Nominal modulation rate
- (bauds)
- } {
- Maximum degree of
- isochronous distortion
- due to sampling
- (%)
- } Channel numbers
- R.112 (2400 bit/s) R.102 (4800 bit/s)
- _
- .T&
- cw(30p) | cw(66p) | cw(48p) | cw(48p) .
- \ 50 8.3 5801 | (hy | 815 {
- 5801 | (hy | 831
- (5816 not used)
- }
- .T&
- cw(30p) | cw(66p) | cw(48p) | cw(48p) .
- 100 8.3 6801 | (hy | 807 6801 | (hy | 815
- .T&
- cw(30p) | cw(66p) | cw(48p) | cw(48p) .
- 200 8.3 7801 | (hy | 803 7801 | (hy | 807
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 3/R.114 [T3.114], p. 20\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .sp 5
- .ce
- \fBH.T. [T4.114]\fR
- .ce
- TABLE\ 4/R.114
- .ce
- \fBNumbering scheme of code dependent channels for TDM
- .ce
- \fBsystems\fR
- .ce
- \fBconforming to Recommendation\ R.102\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(60p) | cw(144p) .
- {
- Nominal
- modulation rate
- (bauds)
- } Channel numbers
- _
- .T&
- cw(60p) | lw(144p) .
- \ 50 | 0501 | (hy | 592
- _
- .T&
- cw(60p) | lw(144p) .
- \ 75 | 0701 | (hy | 746
- _
- .T&
- cw(60p) | lw(144p) .
- 100 | {
- 1001 | (hy | 046 \ \
- (for 10 unit)
- 1701 | (hy | 746 \ \
- (for 7.5 unit)
- }
- _
- .T&
- cw(60p) | lw(144p) .
- 110 | 1101 | (hy | 146
- _
- .T&
- cw(60p) | lw(144p) .
- 134.5 {
- 1301 | (hy | 331 \ \
- (1316 not used)
- }
- _
- .T&
- cw(60p) | lw(144p) .
- 150 | {
- 1501 | (hy | 531 \ \
- (1516 not used)
- }
- _
- .T&
- cw(60p) | lw(144p) .
- 200 | {
- 2001 | (hy | 023 \ \
- (for 10 unit, 2008 not used)
- 2101 | (hy | 123 \ \
- (for 11 unit, 2108 not used)
- 2701 | (hy | 723 \ \
- (for 7.5 unit, 2708 not used)
- }
- _
- .T&
- cw(60p) | lw(144p) .
- 300 | {
- 3001 | (hy | 015 \ \
- (for 10 unit)
- 3101 | (hy | 115 \ \
- (for 11 unit)
- }
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 4/R.114 [T4.114], p. 21\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .sp 2P
- .LP
- \fBRecommendation\ R.115\fR
- .RT
- .sp 2P
- .sp 1P
- .ce 1000
- \fBMAINTENANCE\ LOOPS\ FOR\ TDM\(hySYSTEMS\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.115''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.115 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- the increasing use of TDM transmission systems;
- .PP
- (b)
- the volume of information circulating on data and telegraph transmmission
- networks;
- .PP
- (c)
- the savings to be made by reducing interruption time on
- such links;
- .PP
- (d)
- the importance of being able to determine responsibilities between the
- several parties who, of necessity, are involved in maintenance
- questions for the networks;
- .PP
- (e)
- the advantages of standardization regarding maintenance,
- .sp 2P
- .LP
- \fIunanimously declares the following:\fR
- .sp 1P
- .RT
- .PP
- \fB1\fR The locating of faults can be facilitated in many cases by looping
- and other maintenance procedures in the TDM equipments. These maintenance
- facilities allow local or remote measurements to be carried out optionally
- by the Administrations and/or users concerned.
- .sp 9p
- .RT
- .sp 2P
- .LP
- \fB2\fR \fBLocation of the loops\fR
- .sp 1P
- .RT
- .PP
- The maintenance loops are positioned in order to make it possible for the
- Administrations to locate faults to the following function
- blocks:
- .RT
- .LP
- \(em
- aggregate modem;
- .LP
- \(em
- TDM central logic;
- .LP
- \(em
- tributary interface unit;
- .LP
- \(em
- aggregate line;
- .LP
- \(em
- subscriber line.
- .PP
- The loops necessary to fulfil the above listed demands are shown in Figure\
- 1/R.115. Additional loops may be used for the location of faulty
- boards but these loops are relevant to each particular manufacturer's
- implementation and are not included here. The number of maintenance loops
- may be extended to include the subscriber terminal equipment. These loops
- are left for further study.
- .sp 2P
- .LP
- \fB3\fR \fBNames, types and definitions of the loops\fR
- .sp 1P
- .RT
- .PP
- See Figure\ 1/R.115.
- .RT
- .sp 1P
- .LP
- 3.1
- \fILoop\ a\ \(em\ \fR \fIdigital multiplexer aggregate loop\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway or optionally an
- echo\(hyback loop
- (see Figures\ 2/R.115 and\ 3/R.115) that shall connect the aggregate data
- output to
- the aggregate data input of the TDM central logic. This loop shall be
- accomplished as close as possible to the digital aggregate interface.
- .RT
- .sp 1P
- .LP
- 3.2
- \fILoop\ b\ \(em\ \fR \fIanalogue aggregate modem loop\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop or optionally an echo\(hyback loop (see
- Figures\ 2/R.115 and\ 3/R.115). With this loop, the line signal from the
- output of the aggregate modem is looped back to the input of the aggregate
- modem. The loop should include the maximum number of aggregate modem components
- used in
- normal working.
- .bp
- .RT
- .LP
- .rs
- .sp 23P
- .ad r
- \fBFigure 1/R.115, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .sp 1P
- .LP
- 3.3
- \fILoop\ c\ \(em\ \fR \fIanalogue line loop\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop or optionally an echo\(hyback loop (see
- Figures\ 2/R.115 and\ 3/R.115). With this loop, the incoming line signal
- at the receiver input of the aggregate modem is looped back to the outgoing
- direction of the line. It is noted that it may not be possible to correctly
- receive data that has been sent over the looped circuit.
- .RT
- .sp 1P
- .LP
- 3.4
- \fILoop\ d\ \(em\ \fR \fIdigital aggregate modem loop\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop or optionally an echo\(hyback loop (see
- Figures\ 2/R.115 and\ 3/R.115). In this loop the received aggregate digital
- data from the modem is looped back to the originating side. This loop shall
- be
- located as close as possible to the digital aggregate interface.
- .RT
- .sp 1P
- .LP
- 3.5
- \fILoop\ f\ \(em\ \fR \fItributary analogue loop\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop (see Figure\ 2/R.115). With this loop, the
- tributary signal to be sent to the subscriber is looped back towards the
- multiplex system. This loop shall be accomplished at the subscriber line
- interface and shall include as many parts of the tributary interface unit as
- possible. As long as the loop is set the subscriber connection is
- interrupted.
- .RT
- .sp 1P
- .LP
- 3.6
- \fILoop\ g\ \(em\ tributary digital loop towards the Muldex\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop (see Figure\ 2/R.115) with the output
- polarity towards the tributary interface unit strapable to A\ or Z\ polarity.
- Through this loop the channel data as received from the aggregate is looped
- back to the aggregate towards the distant TDM equipment. This loop shall be
- accomplished as close as possible to the internal tributary interface which
- can be located on the tributary interface unit or in the TDM central logic.
- .RT
- .sp 1P
- .LP
- 3.7
- \fILoop\ h\ \(em\ tributary digital loop towards the tributary interface\fR
- \fIunit\fR
- .sp 9p
- .RT
- .PP
- This loop is a one\(hyway loop with the output polarity towards the
- muldex\(hypart of the given channel strapable to A\ or Z\ polarity. Through
- this
- loop the channel data at the tributary input is looped back to the channel
- output through the tributary interface unit. This loop shall be accomplished
- as close as possible to the TDM central logic.
- .bp
- .RT
- .LP
- .rs
- .sp 15P
- .ad r
- \fBFigures 2/R.115, 3/R.115, 4/R.115, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .sp 2P
- .LP
- \fB4\fR \fBUse of the loops\fR
- .sp 1P
- .RT
- .PP
- Loops\ c and\ d may be used under remote control on international
- links after bilateral agreements only.
- .RT
- .sp 2P
- .LP
- \fB5\fR \fBMethods of control\fR
- .sp 1P
- .RT
- .PP
- 5.1
- Two types of control might be possible:
- .sp 9p
- .RT
- .LP
- a)
- \fILocal control of a loop\fR
- .LP
- A loop is locally controlled when the loop request
- originates at the location of the equipment to be looped.
- .LP
- b)
- \fIRemote control of a loop\fR
- .LP
- A loop is remotely controlled when the loop request
- originates at a location other than that of the equipment to be
- looped.
- .PP
- 5.2
- When the aggregate modem is using a standard interface to the
- TDM\(hyequipment, the implementation of the echo\(hyback function and the
- controls
- through the digital aggregate interface of loops\ b, c and\ d are left for
- further study.
- .PP
- 5.3
- The control of loops\ a, b, c and\ d should be supervised by a time\(hyout
- function. The time\(hyout function shall automatically open the loop after a
- specified time period, measured from the closing of the loop. The length
- of the time period should be chosen from time intervals\ 5, 20 or 40\ seconds
- by
- bilateral agreement between Administrations.
- .PP
- The operation and test procedure for loop f to h is a national matter.
- .sp 2P
- .LP
- \fB6\fR \fBControl signalling\fR
- .sp 1P
- .RT
- .sp 1P
- .LP
- 6.1
- \fIAlternative A\fR
- .sp 9p
- .RT
- .PP
- When the maintenance facilities are controlled by the software
- within an exchange, a maintenance centre or a TDM terminal, a control
- signalling code (CSC) is used where the control signalling characters on
- the selected maintenance channel shall be in accordance with Table\ 1/R.115
- (see
- also Recommendation\ U.12, Table\ 8/U.12).
- .bp
- .RT
- .ce
- \fBH.T. [T1.115]\fR
- .ce
- TABLE\ 1/R.115
- .T&
- lw(66p) | lw(30p) | lw(18p) | lw(12p) | lw(18p) | lw(12p) | lw(72p) .
-
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTable 1/R.115 [T1.115], p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- A complete control signalling code character consists of one start element
- (Start), followed by four information elements (b\d0\u, b\d1\u, b\d2\u,
- b\d3\u) one parity element (b\d4\u),and a stop element (Stop) of nominally one
- and a half unit element, see Figure\ 5/R.115.
- .LP
- .rs
- .sp 10P
- .ad r
- \fBFigure 5/R.115, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .PP
- Bit b\d0\uis the least significant bit (LSB) and b\d3\uis the
- most significant bit (MSB). For the transmission of decimal numbers from\
- 0 up to\ 99 the binary code should be used. The 8\ binary bits should be
- split into
- two characters, No.\ 1 and No.\ 2, character\ No.\ 1 holding the least
- significant bits and character\ No.\ 2 the most significant bits.
- .sp 1P
- .LP
- 6.2
- \fIAlternative B\fR
- .sp 9p
- .RT
- .PP
- When maintenance facilities do not use control signal according to Recommendation\
- U.12, the signalling characters on the maintenance channel
- selected must conform to International Alphabet\ No.\ 5 (IA5), with an even
- parity check (see Figure\ 6/R.115).
- .RT
- .LP
- .rs
- .sp 8P
- .ad r
- \fBFigure 6/R.115, p.\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .sp 1P
- .LP
- 6.3
- \fIMaintenance channel signalling\fR
- .sp 9p
- .RT
- .PP
- Standardization of signalling on the maintenance channel is left
- for further study.
- .RT
- .sp 2P
- .LP
- \fB7\fR \fBRouting of the maintenance control signals\fR
- .sp 1P
- .RT
- .PP
- One 50\ baud channel, or a channel of more than 50\ bauds may be
- allocated (on an optional basis) for maintenance purposes, where possible
- on a separate system using a parallel route. Where this option is exercised
- the
- allocation of the maintenance channel is specified within the respective
- CCITT Recommendation or bilaterally between Administrations.
- .PP
- The selected maintenance channel should only be used for the
- transmission of alarms, supervision and remote control signals.
- .PP
- When there is no possibility to use a separate system on a parallel
- route the control of the loops\ c and\ d is left for further study.
- .RT
- .sp 2P
- .LP
- \fB8\fR \fBApplication\fR
- .sp 1P
- .RT
- .PP
- It may be possible to apply the described maintenance technique to multiplexors
- conforming to Recommendations\ R.101, R.111 and other standardized multiplexors.
- .RT
- .sp 2P
- .LP
- \fB9\fR \fBUse of the maintenance channel\fR
- .sp 1P
- .RT
- .PP
- Use of the maintenance channel for purposes other than loop control is
- left for further study.
- \v'6p'
- .RT
- .sp 2P
- .LP
- \fBRecommendation\ R.116\fR
- .RT
- .sp 2P
- .ce 1000
- \fBMAINTENANCE\ TESTS\ TO\ BE\ CARRIED\ OUT\ ON\ INTERNATIONAL\fR
- .EF '% Fascicle\ VII.1\ \(em\ Rec.\ R.116''
- .OF '''Fascicle\ VII.1\ \(em\ Rec.\ R.116 %'
- .ce 0
- .sp 1P
- .ce 1000
- \fBTDM\ SYSTEMS\fR
- .ce 0
- .sp 1P
- .ce 1000
- \fI(Melbourne, 1988)\fR
- .sp 9p
- .RT
- .ce 0
- .sp 1P
- .LP
- The\ CCITT,
- .sp 1P
- .RT
- .sp 1P
- .LP
- \fIconsidering\fR
- .sp 9p
- .RT
- .PP
- (a)
- the savings to be made by reducing interruption time on
- TDM links;
- .PP
- (b)
- the importance of being able to determine responsibilities between the
- several parties who, of necessity are involved in maintenance
- questions for the networks;
- .PP
- (c)
- the advantages of standardization regarding maintenance;
- .PP
- (d)
- maintenance loops are standardized in
- Recommendation\ R.115,
- .sp 1P
- .LP
- \fIunanimously declares the following:\fR
- .sp 9p
- .RT
- .PP
- that when the quality of the TDM\(hylink has deteriorated beyond the alarm
- limit or if the local muldex gives an alarm, supplementary measurement
- should be performed. The following test and supervision methods can be used.
- .sp 2P
- .LP
- \fB1\fR \fBTesting and supervision of TDM systems\fR
- .sp 1P
- .RT
- .sp 1P
- .LP
- 1.1
- \fIBit error rate\fR
- .sp 9p
- .RT
- .PP
- The synchronization bits are supervised and an error rate alarm is issued
- when the error rate exceeds a preset limit, 10\uD\dlF261\u3\d, 10\uD\dlF261\u4\d
- or\ 10\uD\dlF261\u5\d.
- .RT
- .sp 1P
- .LP
- 1.2
- \fIBit error counter\fR
- .sp 9p
- .RT
- .PP
- All synchronization bit errors shall be registered in a cyclic
- counter and it shall be possible to read the value of this counter by
- command.
- .bp
- .RT
- .sp 1P
- .LP
- 1.3
- \fIRoutine supervision\fR
- .sp 9p
- .RT
- .PP
- The operation of the TDM equipment and maintenance channel should continuously
- be supervised by a repetitive test signal. An alarm is issued when a correct
- acknowledgement is not received for a specified number of test
- signals. The alarm is reset automatically when the fault situation ceases.
- .RT
- .sp 1P
- .LP
- 1.4
- \fIAlarm reset\fR
- .sp 9p
- .RT
- .PP
- It shall be possible to reset all alarms from the local side. The command
- shall also be able to reset the error rate value.
- .RT
- .sp 1P
- .LP
- 1.5
- \fISystem alarms\fR
- .sp 9p
- .RT
- .PP
- Failures that affect operation of the whole or a major part of the TDM
- equipment are classified as one category. The supervised functions
- are:
- .RT
- .LP
- \(em
- Carrier:
- .LP
- Loss of carrier is detected by the data modem through
- CCITT circuit\ 109 or the corresponding circuit.
- .LP
- \(em
- Synchronization:
- .LP
- Loss of synchronization is detected by the TDM
- multiplexer in accordance with the respective CCITT
- Recommendation.
- .LP
- \(em
- Multiplexing logic:
- .LP
- Failure of the TDM central logic is detected by
- internal supervision facilities within the multiplexer.
- .LP
- \(em
- Power:
- .LP
- Failure of the power supply is detected when the
- telegraph power supply exceeds tolerance limits.
- .sp 1P
- .LP
- 1.6
- \fIChanging of active side\fR
- .sp 9p
- .RT
- .PP
- When the TDM equipment is duplicated the active side can be
- changed by command or manually.
- .PP
- When the remote or local side is changed automatically or manually,
- information about what side is executive must be sent when the change has
- been executed.
- .RT
- .sp 1P
- .LP
- 1.7
- \fILooptest on standby side\fR
- .sp 9p
- .RT
- .PP
- When the TDM equipment is duplicated the standby modem can be
- tested by the setting of loop\ b by command. The test result is sent over the
- active maintenance channel.
- .RT
- .sp 1P
- .LP
- 1.8
- \fIAutomatic restart\fR
- .sp 9p
- .RT
- .PP
- When the remote TDM is automatically restarted, information shall be sent
- informing about the restart and alarm status.
- .RT
- .sp 1P
- .LP
- 1.9
- \fIAcknowledgement\fR
- .sp 9p
- .RT
- .PP
- The acknowledgement consists of one character and should have the following
- values:
- .RT
- .LP
- 5
- acknowledgement;
- .LP
- 0
- not acknowledgement.
- .sp 2P
- .LP
- \fB2\fR \fBFormat of the messages\fR
- .sp 1P
- .RT
- .PP
- The messages which will be sent over the 50 baud maintenance
- channel shall have the following structure:
- .RT
- .LP
- C\d1\uC\d2\uM\d1\uM\d2\u. | | | M\dn\u
- .LP
- C\d1\uC\d2\u:
- Message category (two characters)
- .LP
- M\d1\u\(emM\dn\u:
- Information (number of characters unlimited)
- .PP
- After the reception of a message at the receiving end, the
- receiving end shall send one character to the originating end as an
- acknowledgement of the reception.
- .bp
- .sp 1P
- .LP
- 2.1
- \fIMessage categories\fR
- .sp 9p
- .RT
- .PP
- The purpose of the message categories (called MC) is to give a
- direct command or to inform the control equipment in an exchange, a maintenance
- centre or a TDM about what type of information the following message contains.
- .PP
- The MC consist of two characters, and each character is a decimal
- number from 0\ to\ 9. The numbers are coded according to alternative\ A
- (CSC) in Recommendation\ R.115.
- .RT
- .sp 1P
- .LP
- 2.2
- \fIInformation\fR
- .sp 9p
- .RT
- .PP
- The information characters are a part of an order to the remote TDM equipment
- or information from the remote TDM\(hyequipment, depending on the
- Message Category Signal.
- .PP
- The number of information characters in a message is not limited.
- .PP
- The characters are decimal numbers from 0 to 9, coded according to
- alternative\ A (CSC) in Recommendation\ R.115.
- .RT
- .sp 2P
- .LP
- \fB3\fR \fBMaintenance messages\fR
- .sp 1P
- .RT
- .PP
- Using the format described in \(sc\ 2 the maintenance messages shall
- have a message category and information as given in the table below:
- .RT
- .LP
- .rs
- .sp 34P
- .ad r
- Blanc
- .ad b
- .RT
- .LP
- .bp
- .ce
- \fBH.T. [1T1.116]\fR
- .ce
- TABLE\ 1
- .ce
- \fBMaintenance messages\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(90p) | cw(36p) | cw(102p) .
- Types of messages Message category Information
- _
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- C 1 C 2 M 1\(hyM n
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Routine supervision 01 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- System alarm reset 02 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop a 03 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop b 04 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop c 05 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop d 06 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop g 07 M 1\(hyM 3: Channel No.
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop h 09 M 1\(hyM 3: Channel No.
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Setting of loop f 10 M 1\(hyM 3: Channel No.
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Connection of automatic test eq.
- } 11 {
- M
- 1\(hyM
- 3:
- Channel No.
- M
- 4\(hyM
- 2
- 3:
- Answer back (See Note)
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Disconnection of automatic test eq.
- } 12 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Distortion measurement on sub. line
- } 13 M 1\(hyM 3: Channel No.
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Line measurements 14 {
- M
- 1\(hyM
- 3:
- Channel No.
- M
- 4:
- Type of line
- 0 =
- SC
- 1 =
- DC
- 2 =
- FS
- M
- 5:
- Type of measurement
- 0 =
- Current
- 1 =
- Voltage
- 2 =
- Leakage to earth
- 3 =
- Leakage betw. conductors
- 4 =
- Level FS
- 5 =
- Interface test
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Change side 15 {
- M
- 1:
- Side
- b
- 0 =
- 0 A side executive
- b
- 0 =
- 1 B side executive
- b
- 1 =
- 0 Standby side halted
- b
- 1 =
- 1 Standby side
- working
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Restart of control unit 16 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Read bit error counter 17 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Set loop b on remote standby side modem
- } 18 \(em
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Open line alarm 26 {
- M
- 1\(hyM
- 3:
- Channel no.
- M
- 4:
- Alarm
- b
- 0 =
- 1 Alarm
- b
- 0 =
- 0 No alarm
- }
- _
- .TE
- .nr PS 9
- .RT
- .ad r
- \fBTableau 1/R.116 [1T1.116], p. 29\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
- .ce
- \fBH.T. [2T1.116]\fR
- .ce
- TABLE\ 1 \fI(continued)\fR
- .ps 9
- .vs 11
- .nr VS 11
- .nr PS 9
- .TS
- center box;
- cw(90p) | cw(36p) | cw(102p) .
- Types of messages Message category Information
- _
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Distortion alarm 27 M 1\(hyM 3: Channel No.
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Bit error rate 28 {
- M
- 1:
- Failure rate
- 3 =
- 10\uD\dlF261\u3\d
- 4 =
- 10\uD\dlF261\u4\d
- 5 =
- 10\uD\dlF261\u5\d
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Results of distortion measurement sub. line
- } 29 {
- M
- 1 |
- 2:
- Number of measured transitions
- M
- 3 |
- 4:
- Maximum distortion
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Result of line measurement 30 {
- M
- 1\(hyM
- 1
- 0:
- Test result
- M
- 1 = 0
- Level FS OK
- M
- 1 = 1
- Level FS not OK
- M
- 2 = 0
- Interf. OK
- M
- 2 = 1
- Interf. not OK
- M
- 3 |
- 4:
- Voltage or current on wire\ 1 and resistance
- between wire\ 1 and\ 2. Resistance to
- earth,\ w.1
- M
- 5 |
- 6:
- Voltage or current on wire\ 2 or resistance between
- wire\ 3 and\ 4. Resistance to earth,\ w.2
- M
- 7 |
- 8:
- Voltage or current on wire\ 3.
- Resistance to earth,\ w.3
- M
- 9 |
- 1
- 0:
- Voltage or current on wire\ 4.
- Resistance to earth,\ w.4
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- System alarms 31 {
- M
- 1:
- Type of alarm
- b
- 0 =
- 1 Carrier alarm
- b
- 0 =
- 0 No carrier alarm
- b
- 1 =
- 1 Synchronization alarm
- b
- 1 =
- 0 No synchronization alarm
- b
- 2 =
- 1 Power alarm
- b
- 2 =
- 0 No power alarm
- b
- 3 =
- 1 Mux logic alarm
- b
- 3 =
- 0 No Mux logic alarm
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Manually initiated change side
- } 32 {
- M
- 1:
- Side
- b
- 0 =
- 0 A side executive
- b
- 0 =
- 1 B side executive
- b
- 1 =
- 0 Standby side halted
- b
- 1 =
- 1 Standby side working
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- {
- Looptest result from standby side
- } 33 {
- M
- 1:
- Result
- 0
- Test OK
- 1
- Test not OK
- }
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Automatic restart 34
- .T&
- lw(90p) | cw(36p) | lw(102p) .
- Bit error counter 35 M
- .TE
- .LP
- 1\(hyM
- 3:
- Result
- \fINote\fR
- \ \(em\ The answer back message shall be sent using International
- Alphabet No.\ 2.
- .nr PS 9
- .RT
- .ad r
- \fBTableau 1/R.116 [2T1.116], p. 30\fR
- .sp 1P
- .RT
- .ad b
- .RT
- .LP
- .bp
-