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1991-12-31
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Recommendation R.140
1) Replace the Note to 31.086 by the following:
"Note - The character coding rules using the seven primary elements are the
subject of Recommendations T.50 and V.4.
2) Add a Note to 32.372:
"Note - The term scvf is usually applied to a telegraph circuit (32.02) rather than
to a telegraph channel (32.01)."
3) Amend existing terms and definitions as follows:
32.341 multiplexing
A process for combining signals from several separate tributary channels for
transmission in the same direction over a common bearer channel.
32.343 multiplexer
An equipment which combines a number of tributary channels onto a fewer
number of aggregate bearer channels, the relationship between the tributary and
aggregate channels being fixed.
32.345 muldex
An equipment which comines/separates a number of tributary circuits
onto/from a fewer number of aggregate bearer circuits, the relationship between the
tributary and aggregate circuits being fixed.
32.3451statistical (intelligent) muldex
A muldex which continuously re-allocates tributary circuits onto a fewer
number of aggregate bearer circuits in a manner determined by the data flow on the
tributaries.
concentrator
An equipment which allocates a number of tributary circuits onto a fewer
number of circuits on a call-by-call basis.
3) Add the following terms and definitions:
32.411 Branch line multiplex
A multiplex whose capacity is a submultiple of that of a main multiplex and
which gives the possibility to group a certain number of channels of the latter in
order to extend or deviate them into a specific direction with the aim, for example,
to connect a small group of subscribers.
32.3411Submultiplex
A multiplex whose bearer is part of a higher-order multiplex.
33.25 Regeneration
Elimination of telegraph distortion.
33.251 Inherent regeneration
Regeneration included in the very principle of the method of switching or
transmission.
32.3413Equipped channel
A channel having all the necessary equipment to enable usage in case of
need.
32.3414Allocated channel
A channel used for constituting a subscriber line, a link or a circuit.
31.025 Character length
Number of unit intervals contained in a character signal.
33.30 Loopback
Connection of the forward channel with the corresponding backward channel to
enable the observation on the backward channel of signals which have been emitted on
the forward channel in order to check quality of transmission.
33.252 Transfer delay
Duration between the beginning of transmission and complete reception of a
signal.
32.3491Filling bit
Bit with no specific meaning used to fill out a time of communication during
which there are no significant bits to be transmitted.
32.3512Frame structure
General rule of the establishment of a frame with allocation of each bit to
a determined channel.
32.3511Frame slot
An elementary time interval generally allocated to tributary channel.
32.3551Synchronization word
Sequence of bits allocated to synchronization and appearing periodically in
one or a fixed number of consecutive fundamental frames.
32.3552Synchronization frame
Sequence of a fixed number of consecutive fundamental frames containing one
synchronization word.
32.3415Hybrid multiplex
A multiplex providing simultaneously transparent and nontransparent (code-
and-speed independent and dependent) channels.
32.3451Muldex/concentrator
A muldex with the line concentrating function ensuring that tributary
channels are only allocated time slots in the aggregate bit stream for the duration
of their seizure.