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InfoMagic Standards 1994 January
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1988
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.\" Troff code generated by TPS Convert from ITU Original Files
.\" Not Copyright ( c) 1991
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.\" Assumes tbl, eqn, MS macros, and lots of luck.
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.EN
.nr LL 40.5P
.nr ll 40.5P
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\v | 5i'
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\v'12P'
\s12PART\ I
\v'4P'
.RT
.ce 0
.sp 1P
.ce 1000
\fBSeries N Recommendations\fR \v'2P'
.EF '% \ \ \ ^''
.OF ''' \ \ \ ^ %'
.ce 0
.sp 1P
.ce 1000
\fBMAINTENANCE\ OF\ INTERNATIONAL\ SOUND\(hyPROGRAMME\fR
.ce 0
.sp 1P
.ce 1000
\fBAND\ TELEVISION\ TRANSMISSION\ CIRCUITS\fR \v'2P'
.ce 0
.sp 1P
.LP
.rs
.sp 29P
.ad r
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.EF '% \ \ \ ^''
.OF ''' \ \ \ ^ %'
.ad b
.RT
.LP
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.LP
\fBMONTAGE:\fR PAGE 2 = PAGE BLANCHE
.sp 1P
.RT
.LP
.bp
.sp 1P
.ce 1000
\v'3P'
SECTION\ 1
.ce 0
.sp 1P
.ce 1000
\fBINTERNATIONAL\ SOUND\(hyPROGRAMME\ TRANSMISSION\fR
.ce 0
.sp 1P
.IP
\fB1.1\fR \
\fBInternational sound\(hyprogramme transmissions\fR \fB\(em\fR
\fBDefinitions\fR
.sp 1P
.RT
.sp 2P
.LP
\fBRecommendation\ N.1\fR
.RT
.sp 2P
.ce 1000
\fBDEFINITIONS\ FOR\ APPLICATION\ TO\ INTERNATIONAL\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.1''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.1 %'
.ce 0
.sp 1P
.ce 1000
\fBSOUND\(hyPROGRAMME\ TRANSMISSIONS\fR
.FS
Definitions
in this Recommendation apply both to analogue and digital
systems.
.FE
\u,\d
.FS
Annex A to this Recommendation gives definitions
for units of measurements for sound\(hyprogramme transmissions.
.FE
.ce 0
.sp 1P
.PP
The following definitions apply to the maintenance of
international sound\(hyprogramme transmissions. Other definitions are used for
other purposes, e.g., an international sound\(hyprogramme link and international
multiple destination sound\(hyprogramme link as defined in \(sc\(sc\ 11
and\ 12
respectively below, are within the definition of an international
sound\(hyprogramme circuit as defined by the CMTT.
.sp 1P
.RT
.PP
\fINote\ 1\fR \ \(em\ It is intended that the definitions given in
Recommendations\ N.1 and\ N.51 should remain identical, so far as is practical,
by use of only simultaneous amendments.
.PP
\fINote\ 2\fR \ \(em\ A sound\(hyprogramme circuit section, circuit, link or
connection is considered to be permanent for maintenance purposes if it is
always available for use when required, whether or not it is continuously in
use. Such a circuit may be used for the purposes of occasional transmission,
that is, transmissions of short duration, e.g. less than 24 hours, or it
may be used for a long duration, i.e. one day or more. A permanent sound\(hyprogramme
connection between broadcasting organizations' premises may be used at any
time, except only for periods of maintenance as agreed between the
Administrations and broadcasting organizations concerned.
.RT
.LP
A sound\(hyprogramme circuit section, circuit, link or connection is considered
to be temporary for maintenance purposes when it has no existence outside
the
period of transmission (including line\(hyup and testing time) for which it is
required.
.sp 2P
.LP
\fB1\fR \fBinternational sound\(hyprogramme transmission\fR
.sp 1P
.RT
.PP
The transmission of sound signals over the international
telecommunication network for the purpose of interchanging sound\(hyprogramme
material between broadcasting organizations in different countries.
.RT
.sp 2P
.LP
\fB2\fR \fBbroadcasting organization\fR
.sp 1P
.RT
.PP
A broadcasting organization is an organization which is concerned with
either or both sound and television broadcasting. Most of the customers
ordering facilities for sound\(hyprogramme and television transmission are
broadcasting organizations; for convenience, the term broadcasting organization
is used to denote the activity of any user or customer and, where so used,
it is equally applicable to any other customer requiring sound\(hyprogramme
or
television transmissions.
.bp
.RT
.sp 2P
.LP
\fB3\fR \fBbroadcasting organization (send)\fR
.sp 1P
.RT
.PP
The broadcasting organization at the sending end of an
international sound\(hyprogramme transmission.
.RT
.sp 2P
.LP
\fB4\fR \fBbroadcasting organization (receive)\fR
.sp 1P
.RT
.PP
The broadcasting organization at the receiving end of an
international sound\(hyprogramme transmission.
.RT
.sp 2P
.LP
\fB5\fR \fBinternational sound\(hyprogramme centre (ISPC)\fR
.sp 1P
.RT
.PP
A centre at which at least one international sound\(hyprogramme
circuit (see \(sc\ 9) terminates and in which international sound\(hyprogramme
connections (see \(sc\ 13) can be made up by the interconnection of international
and national sound\(hyprogramme circuits.
.PP
The responsibility of an ISPC is given in Recommendation\ N.5.
.RT
.sp 2P
.LP
\fB6\fR \fBnational sound\(hyprogramme centre (NSPC)\fR
.sp 1P
.RT
.PP
A centre at which two or more national sound\(hyprogramme circuits
terminate and at which national sound\(hyprogramme circuits may be
interconnected.
.RT
.sp 2P
.LP
\fB7\fR \fBsound\(hyprogramme circuit section\fR
.sp 1P
.RT
.PP
The unidirectional national or international sound\(hyprogramme
transmission path between two stations at which the programme is accessible
at audio frequencies. The transmission path may be established via terrestrial
or single destination satellite routing. (See Note\ 2 above and Figures\
1/N.1
and\ 3/N.1.)
.RT
.sp 2P
.LP
\fB8\fR \fBinternational multiple destination sound\(hyprogramme circuit
section\fR
.sp 1P
.RT
.PP
The unidirectional sound\(hyprogramme transmission path from one
frontier station to two or more of the frontier stations at which
interconnection is made at audio frequencies. (See Note\ 2 above and
Figure\ 4/N.1.)
.RT
.sp 2P
.LP
\fB9\fR \fBinternational sound\(hyprogramme circuit\fR
.sp 1P
.RT
.PP
The transmission path between two ISPCs which comprises one or
more sound\(hyprogramme circuit sections (national or international), together
with any necessary audio equipment. The transmission path may be established
via terrestrial or single destination satellite routing. (See Note\ 2 above
and Figures\ 1/N.1 and\ 3/N.1.)
.RT
.sp 2P
.LP
\fB10\fR \fBinternational multiple destination sound\(hyprogramme circuit\fR
.sp 1P
.RT
.PP
The unidirectional transmission path from one ISPC to two or more other
ISPCs comprising sound\(hyprogramme circuit sections (national or
international) one of which is an international multiple destination circuit
section, together with any necessary audio equipment. (See Note\ 2 above and
Figure\ 4/N.1.)
.RT
.sp 2P
.LP
\fB11\fR \fBinternational sound\(hyprogramme link\fR
.sp 1P
.RT
.PP
The unidirectional transmission path between the ISPCs of the two terminal
countries involved in an international sound\(hyprogramme transmission.
The international sound\(hyprogramme link comprises one or more international
sound\(hyprogramme circuits (see Figures\ 1/N.1 and\ 3/N.1 below) interconnected
at intermediate ISPCs. It can also include national sound\(hyprogramme
circuits in
transit countries. (See Note\ 2 above and Figure\ 2/N.1.)
.RT
.sp 2P
.LP
\fB12\fR \fBinternational multiple destination sound\(hyprogramme link\fR
.sp 1P
.RT
.PP
The unidirectional transmission path between the ISPCs of the
terminal countries involved in an international multiple destination
sound\(hyprogramme transmission. The international multiple destination
sound\(hyprogramme link comprises international sound\(hyprogramme circuits,
one of which is an international multiple destination sound\(hyprogramme
circuit. (See
Note\ 2 above and Figure\ 5/N.1.)
.bp
.RT
.sp 2P
.LP
\fB13\fR \fBinternational sound\(hyprogramme connection\fR
.sp 1P
.RT
.PP
The unidirectional transmission path between the broadcasting
organization (send) and the broadcasting organization (receive) comprising
the international sound\(hyprogramme link extended at its two ends over
national
sound\(hyprogramme circuits to the broadcasting organization. (See Note\
2 above
and Figure\ 2/N.1.)
.RT
.sp 2P
.LP
\fB14\fR \fBinternational multiple destination sound\(hyprogramme connection\fR
.sp 1P
.RT
.PP
The unidirectional transmission path between the broadcasting
organization (send) and two or more broadcasting organizations (receive)
comprising the international multiple destination sound\(hyprogramme link
extended at its ends over national sound\(hyprogramme circuits to the broadcasting
organizations. (See Note\ 2 above and Figure\ 5/N.1.)
.RT
.sp 2P
.LP
\fB15\fR \fBsend reference station\fR
.sp 1P
.RT
.PP
The transmit sub\(hycontrol station of an international multiple
destination sound\(hyprogramme circuit section (see \(sc\ 8), circuit (see
\(sc\ 10) or
link (see \(sc\ 12). (See Figures\ 4/N.1 and\ 5/N.1.)
.RT
.sp 2P
.LP
\fB16\fR \fBeffectively transmitted signals in sound\(hyprogramme
transmission\fR
.sp 1P
.RT
.PP
For sound\(hyprogramme \fItransmission\fR , a signal at a particular
frequency is said to be effectively transmitted if the nominal overall
loss at that frequency does not exceed the nominal overall loss at 800\
Hz by more than 4.3\ dB. This should not be confused with the analogous
definition concerning
telephone circuits given in the Recommendation cited in\ [1].
.PP
For sound\(hyprogramme \fIcircuits\fR , the overall loss (relative to that
at 800\ Hz) defining effectively transmitted frequency is 1.4\ dB, i.e.
about one
third of the allowance.
.RT
.sp 2P
.LP
\fB17\fR \fBtypes of sound\(hyprogramme circuit\fR
.FS
To reduce problems in
ordering and charging for sound\(hyprogramme circuits, Study Group\ II has a
classification of circuits based on their approximate bandwidth (see the
Recommendation cited in\ [2]).
.FE
.sp 1P
.RT
.PP
The various types of international sound\(hyprogramme circuit or
sections of such circuits should be referred to by quoting the top nominal
frequency, in kHz, effectively transmitted.
.PP
\fIExample:\fR \ 10\(hykHz sound\(hyprogramme circuit.
.RT
.LP
.rs
.sp 18P
.ad r
\fBFigure 1/N.1 p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 22P
.ad r
\fBFigure 2/N.1 p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 27P
.ad r
\fBFigure 3/N.1 p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure 4/N.1 p.3\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 28P
.ad r
\fBFigure 5/N.1 p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce 1000
ANNEX\ A
.FS
It is intended that the
text contained in this annex will be further studied and refined as
necessary.
.FE
.ce 0
.ce 1000
(to Recommendation N.1)
.sp 9p
.RT
.ce 0
.ce 1000
\fBLevel and loss units used for sound\(hyprogramme\fR
.sp 1P
.RT
.ce 0
.ce 1000
\fBand television transmission\fR
.ce 0
.LP
A.1
\fIUse of dB units in N Recommendations\fR
.sp 1P
.RT
.PP
This Recommendation gives the quantities and units for
sound\(hyprogramme transmissions used in N\ Recommendations and is in accordance
with existing Recommendations\ [3],\ [4].
.RT
.sp 2P
.LP
A.2
\fIUnits used\fR
.sp 1P
.RT
.sp 1P
.LP
A.2.1
\fBabsolute power level (dBm)\fR
.sp 9p
.RT
.PP
As a general rule, the dBm unit applies to the absolute power
level. The unit is based on the ratio between measured power and the reference
power of 1\ mW.
\v'6p'
.RT
.LP
\fIL\fR\d\fIm\fR\u= 10 log
@ { fIP\fR } over { fIP\fR\d0\ } @ dBm = 10 log
@ { \fIU\fR~\u2\d/\fIZ\fR ) } over { \fIU\fR~$$Ei:2:0_~/\fIZ\fR\d0\u) } @ dBm =
@ left ( 20~log { fIU\fR } over { fIU\fR\d0\ } \(em~10~log { fIZ\fR } over { fIZ\fR\d0\ } right ) @ \ dBm
.LP
.sp 1
Absolute power level
Absolute
Impedance
.LP
voltage
correction
.LP
level
.LP
.sp 1
.PP
Absolute voltage levels, for which terminal impedance is not
defined, are more rarely used. As a correction, power level may be calculated
for impedances other than 600\ ohms, with respect to 1\ mW.
.PP
The power level thus calculated would be equal to that measured in a correctly
terminated system.
.RT
.sp 1P
.LP
A.2.2
\fBrelative level (dBr)\fR
.sp 9p
.RT
.PP
The relative power level of a point in a transmission system is
the nominal power gain at the reference frequency from a reference point
to the point considered. The same consideration is used for the relative
voltage level in a transmission system based on voltage levels.
.PP
Relative levels can be used to compare two or more points of a network
with respect to power (or voltage). One point of a network is usually defined
as the reference point at 0\ dBr, from which other measurement points are
derived.
.PP
For sound\(hyprogramme circuits, the zero relative level is located at
the injection point, i.e.\ usually at the transmission point of a
sound\(hyprogramme circuit.
.RT
.sp 1P
.LP
A.2.3
\fBabsolute zero power level (dBm0) (load level\fR
.FS
The term \*Qload level\*U is used provisionally and is subject to further
consideration.
.FE
\fB)\fR
.sp 9p
.RT
.PP
In a transmission system based on power levels the absolute power level
or load level (\fIL\fR\d\fIm\fR\\d0\u) with respect to 1\ mW is referred
to a point of zero relative level. That means that the absolute power level
(\fIL\fR\d\fIm\fR\u) minus the relative power level (\fIL\fR\d\fIr\fR\u) will
be
\v'6p'
.RT
.sp 1P
.ce 1000
\fIL\fR\d\fIm\fR\\d0\u= \fIL\fR\d\fIm\fR\u\(em \fIL\fR\d\fIr\fR\u
.ce 0
.sp 1P
.PP
.sp 1
This level indication is independent of the relative power level at the
measurement point considered. For a given signal the load level is
nominally the same along a transmission line. For this indication it is
necessary to know to what extent the power at the zero relative point is
greater or less than the reference power.
.bp
.sp 1P
.LP
A.2.3
\fBabsolute zero power level (dBm0) (load level\fR
.FS
The term \*Qload level\*U is used provisionally and is subject to further
consideration.
.FE
\fB)\fR
.sp 9p
.RT
.PP
In a transmission system based on power levels the absolute power level
or load level (\fIL\fR\d\fIm\fR\\d0\u) with respect to 1\ mW is referred
to a point of zero relative level. That means that the absolute power level
(\fIL\fR\d\fIm\fR\u) minus the relative power level (\fIL\fR\d\fIr\fR\u) will
be
\v'6p'
.RT
.sp 1P
.ce 1000
\fIL\fR\d\fIm\fR\\d0\u= \fIL\fR\d\fIm\fR\u\(em \fIL\fR\d\fIr\fR\u
.ce 0
.sp 1P
.PP
.sp 1
This level indication is independent of the relative power level at the
measurement point considered. For a given signal the load level is
nominally the same along a transmission line. For this indication it is
necessary to know to what extent the power at the zero relative point is
greater or less than the reference power.
.bp
.sp 1P
.LP
A.2.4
\fIRelation between quantities and units\fR
.sp 9p
.RT
.PP
There is a fixed relation between level quantities and units,
namely:
.RT
.LP
Absolute power level =
relative power level + absolute zero
power level (load level)
\v'6p'
.sp 1P
.ce 1000
\fIL\fR\d\fIm\fR\u= \fIL\fR\d\fIr\fR\u+ \fIL\fR\d\fIm\fR\\d0\u
.ce 0
.sp 1P
.LP
.sp 1
Therefore, for the level units: a dBm = b dBr + c dBm0.
.PP
When indications are given concerning the line signal, the
absolute zero power level (load level) (dBm0) is given, at which, at the
relative zero point, the absolute power level coincides with the relative
power level.
\v'6p'
.sp 1P
.ce 1000
\fIL\fR\d\fIm\fR\u= \fIL\fR\d\fIm\fR\\d0\u, for \fIL\fR\d\fIr\fR\u= 0
.ce 0
.sp 1P
.LP
.sp 1
.PP
In order to simplify the specification of the level of a circuit or a system,
it is most appropriate to specify the absolute power level which coincides
with the relative zero power level. Thus this absolute power level
and the absolute zero power level (load level) are the same.
.sp 1P
.LP
A.2.5
\fIWeighted level\fR
.sp 9p
.RT
.PP
Power level of disturbing signals are as a rule expressed in the
same units as those defined above. For noise measurements made by a weighting
filter (psophometric measurements), a \*Qp\*U (for \*Qpond\*'er\*'e\*U
= weighted) is added to the units, e.g., dbm0p, dBmp.
.PP
A \*Qq\*U indicates a quasi\(hypeak value where the \*Qm\*U is replaced
by a \*Qq\*U which, for instance, in dBm gives dBq.
.RT
.sp 1P
.LP
A.2.6
\fIExtra indications\fR
.sp 9p
.RT
.PP
Sound\(hyprogramme transmission level units are indicated by an extra \*Qs\*U
(s for sound): dBrs, dBm0s, dBm0ps, dBq0pS.
.PP
Extra indications for units should be used whenever they facilitate
understanding so as to prevent confusion when differing measurement techniques,
weighting filters or meters are used.
.RT
.sp 1P
.LP
A.3
\fIVarious measuring instruments\fR
.sp 9p
.RT
.PP
Absolute power level (in dBm) is obtained if a measurement is made on a
terminated line.
.PP
Various measurement instruments provide measurements related to a
(freely) preselected relative level value. The measurement will then directly
express the absolute zero power level (load level).
.RT
.sp 1P
.LP
A.4
\fIPractical problems\fR
.sp 9p
.RT
.PP
There is a wide range of measuring instruments used at different
measurement points, so that differences are always bound to appear. A state
which every Administration is prepared to define is the permitted maximum
level (PML). Despite different relative power levels, depending on the
systems, a direct relation can now be indicated between the value of the
level to be measured and the PML in dB. If, for instance, a signal of 21\
dB below the PML is transmitted as a measurement signal, it must also be
received as a
signal 21\ dB below PML, independently of local relative levels, which may
differ according to systems and Administrations.
.RT
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIGeneral performance objectives applicable to
all\fR \fImodern international circuits and national extension circuits\fR
,
Vol.\ III, Rec.\ G.151, Note\ 1, \(sc\ 1.
.LP
[2]
CCITT Recommendation \fIOccasional provision of circuits for\fR
\fIInternational sound\(hy and television\(hyprogramme transmissions\fR
, Vol.\ II,
Rec.\ D.180,\ \(sc\ 3.
.LP
\fR
.LP
[3]
CCITT Recommendation \fIUse of the decibel and neper in\fR
\fItelecommunications\fR , Vol.\ I, Rec.\ B.12.
.LP
[4]
CCIR Recommendation \fIUse of the decibel and neper in\fR \fItelecommunications\fR
, Vol.\ XIII, Rec.\ 574, ITU, Geneva,\ 1986.
.bp
.LP
\fR
.sp 2P
.LP
\fBRecommendation\ N.2\fR
.RT
.sp 2P
.sp 1P
.ce 1000
\fBDIFFERENT\fR \
\fBTYPES\ OF\ SOUND\(hyPROGRAMME\ CIRCUIT\fR
.FS
This
Recommendation applies also to 7\ kHz and 15\ kHz digital sound\(hyprogramme
circuits.
.FE
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.2''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.2 %'
.ce 0
.sp 1P
.PP
The characteristics of the various types of international
sound\(hyprogramme circuit defined in Recommendations\ J.21 [1], J.22 [2]
and\ J.23\ [3] are as follows:
.sp 1P
.RT
.LP
15\ kHz;
.LP
10\ kHz;
.LP
\ 5,\ 6.4\ and\ 7\ kHz.
.PP
From the point of view of sound\(hyprogramme transmission ordinary
telephone circuits are generally considered to be suitable only for the
transmission of speech. It should be noted that the limits of the
.PP
loss/frequency distortion cannot be guaranteed to be better than the limits
shown in Recommendation\ M.580\ [4].
.PP
When a telephone circuit is used for a sound\(hyprogramme transmission
the terminating sets and the signalling equipment must be disconnected
to avoid echo effects and false operation of the signal receiver.
.PP
When a telephone circuit is used for a sound\(hyprogramme transmission,
a point of zero relative level of the telephone circuit must coincide with
a
point of zero relative level on the sound\(hyprogramme circuit. (However,
see \(sc\ 2 of Recommendation\ N.15 in which it is pointed out that a 6\(hydB
loss should be
introduced in order to reduce the mean power level delivered to the telephone
circuit system).
.RT
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIPerformance characteristics of 15 kHz type\fR
\fIsound\(hyprogramme circuits\fR , Vol.\ III, Rec.\ J.21.
.LP
[2]
CCITT Recommendation \fIPerformance characteristics of 10 kHz type\fR
\fIsound\(hyprogramme circuits\fR , Red Book, Vol.\ III, Rec.\ J.22, ITU,
Geneva,\ 1984.
.LP
[3]
CCITT Recommendation \fIPerformance characteristics of narrow\(hybandwidth\fR
\fIsound\(hyprogramme circuits\fR , Vol.\ III, Rec.\ J.23.
.LP
[4]
CCITT Recommendation \fISetting up and lining up an international\fR
\fIcircuit for public telephony\fR , Vol.\ IV, Rec.\ M.580.
\v'6p'
.sp 2P
.LP
\fBRecommendation\ N.3\fR
.RT
.sp 2P
.sp 1P
.ce 1000
\fBCONTROL\ CIRCUITS\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.3''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.3 %'
.ce 0
.sp 1P
.LP
\fB1\fR \fBDefinition of\fR \fBcontrol circuit\fR
.sp 1P
.RT
.PP
A control circuit is a telephone\(hytype circuit between the point
of origin of the programme and the point where it terminates (recording
equipment, studio, switching centre, transmitter, etc.) used by a
broadcasting organization for the supervision and coordination of a sound or
television transmission.
.PP
More than one control circuit may be used in association with the
different programme connections involved in a single transmission, such
as:
.RT
.LP
a)
the
\fItelevision\fR | onnection
;
.LP
b)
the
\fIinternational sound\fR | onnection
(for
supervising the programme effects circuit provided for transmitting, for
example, the background noises of a programme);
.LP
c)
the
\fIcommentary\fR | onnection
(for supervising the
sound\(hyprogramme circuit transmitting a commentary in a given language);
.LP
\fI\fR
d)
the
\fIcomplete programme\fR | onnection
(for
supervising the sound\(hyprogramme circuit transmitting the whole of the sound
part of a programme).
.bp
.sp 2P
.LP
\fB2\fR \fBProvision of\fR
\fBcontrol circuits for sound\(hyprogramme\fR \fBand\fR \fBtelevision transmission\fR
.FS
The CCITT has noted the fact that broadcasting
organizations use a tone having a frequency of 1900\ Hz\ \(+-\ 6\ Hz and
a level not exceeding \(em10\ dBm0, for their signalling purposes on control
circuits. Under
the conditions of use specified in the CCITT Recommendations for control
circuits, the CCITT has no objections to the use of this tone.
.FE
.sp 1P
.RT
.PP
The conditions governing the provisions and lease of control
circuits for sound\(hyprogramme and television transmissions are given in
Recommendation D.180\ [1].
.RT
.sp 2P
.LP
\fBReference\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIOccasional provision of circuits for\fR
\fIInternational\fR sound\(hy and television\(hyprogramme\fR \fItransmissions\fR
, Vol.\ II,
Rec.\ D.180.
\v'6p'
.sp 2P
.LP
\fBRecommendation\ N.4\fR
.RT
.sp 2P
.ce 1000
\fBDEFINITION\ AND\ DURATION\ OF\ THE\ LINE\(hyUP\ PERIOD\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.4''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.4 %'
.ce 0
.sp 1P
.ce 1000
\fBAND\ THE\ PREPARATORY\ PERIOD\fR
.ce 0
.sp 1P
.PP
For each international sound\(hyprogramme transmission a
distinction is made between:
.sp 1P
.RT
.LP
\(em
\fBline\(hyup period\fR
.LP
The period during which the Administrations line up the
international sound\(hyprogramme link before handing it over
to the broadcasting organizations; and
.LP
\(em
\fBpreparatory period\fR
.LP
The period during which these broadcasting organizations do their own
adjustments, tests and other work before the
sound\(hyprogramme transmission itself commences.
.sp 2P
.LP
\fB1\fR \fBLine\(hyup period\fR
.sp 1P
.RT
.sp 1P
.LP
1.1
\fIDuration\fR
.sp 9p
.RT
.PP
\fI\fI\fI\fR In principle, the duration of the line\(hyup period should be
15\ minutes. However, in the case of sound\(hyprogramme transmissions involving
more than two countries, the duration may be increased. On the other hand,
in certain cases, by agreement between the Administrations concerned, the
duration may be less than 15\ minutes, provided the line\(hyup is properly
carried out. This may be possible, for example, when there are two successive
international
sound\(hyprogramme transmissions on the same route and the second involves
extending the international sound\(hyprogramme link already laid up for the
first.
.PP
\fINote\fR \ \(em\ In the case of multiple destination transmissions the
line\(hyup period can have a longer duration, to be fixed by agreement
between the
Administrations concerned, e.g., on the order of 25\ to 30\ minutes.
.PP
At the end of the line\(hyup period the international sound\(hyprogramme
link and the control circuits are handed over to the broadcasting organizations
at the booked time.
.RT
.sp 2P
.LP
\fB2\fR \fBPreparatory period\fR
.sp 1P
.RT
.sp 1P
.LP
2.1
\fIBeginning and duration\fR
.sp 9p
.RT
.PP
When the tests during the line\(hyup period are completed, the
\fIinternational sound\(hyprogramme link\fR is not made available to the
broadcasting organizations at the two ends until the time fixed for the
beginning of the
preparatory period. The chargeable time for the sound\(hyprogramme transmission
commences at the beginning of the preparatory period. The duration of the
preparatory period\ \(em i.e. the time between handing over the international
sound\(hyprogramme link to the broadcasting organizations and the moment
when the programme properly begins\ \(em is chosen in each case by the
broadcasting
organizations so that they can carry out all the tests and adjustments
necessary before proceeding with the sound\(hyprogramme transmission.
.bp
.RT
.sp 2P
.LP
\fBRecommendation\ N.5\fR
.RT
.sp 2P
.sp 1P
.ce 1000
\fBSOUND\(hyPROGRAMME\ CONTROL,\ SUB\(hyCONTROL\ AND\fR |
\fBSEND\ REFERENCE\ STATIONS\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.5''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.5 %'
.ce 0
.sp 1P
.LP
\fB1\fR \fBResponsibilities of control and sub\(hycontrol stations\fR
.sp 1P
.RT
.PP
1.1
For a unidirectional international sound\(hyprogramme circuit, the
receiving end terminal ISPC is normally the control station. The other
terminal ISPC is a terminal sub\(hycontrol station. The functions of the
control and
sub\(hycontrol stations are the same as for ordinary telephone circuits. (See
Recommendations\ M.80 [1] and\ M.90\ [2].)
.sp 9p
.RT
.PP
\fINote\fR \ \(em\ In the case of a reversible sound\(hyprogramme circuit,
setting\(hyup reference measurements and maintenance measurements are carried
out for each direction of transmission.
.PP
1.2
The international sound\(hyprogramme link is in all cases the sole responsibility
of the telephone Administrations. If the international
sound\(hyprogramme link passes through one or more transit countries, an
intermediate sub\(hycontrol station is also designated for each transit
country.
.sp 9p
.RT
.PP
1.3
The national sound\(hyprogramme circuits at the ends of the link may be
the responsibility of either the Administrations or the broadcasting
organizations or the two together depending on local arrangements in each
particular country.
.sp 9p
.RT
.PP
1.4
The receiving ISPC stations on multiple destination
sound\(hyprogramme circuits or links act as control stations for the circuit or
link in accordance with Recommendations\ M.80 [1] and M.90\ [2]. In this
case the following additional responsibilities should apply:
.sp 9p
.RT
.LP
a)
reporting to the appropriate send reference station (see
\(sc\ 2) the results of measurements made on the circuit and link
and the quality assessments observed on the link;
.LP
b)
reporting fault conditions to the circuit or link send
reference station (see \(sc\ 2).
.PP
1.5
The intermediate ISPCs are intermediate sub\(hycontrol stations
for the international sound\(hyprogramme link.
.sp 9p
.RT
.PP
1.6
The ISPC or the repeater station at the sending end (country A in Figures\
2/N.1 and 5/N.1) is a terminal sub\(hycontrol station for the
international sound\(hyprogramme connection. When a send reference station (see
\(sc\ 2) is associated with a multiple destination communications\(hysatellite
link, it has the following responsibilities:
.sp 9p
.RT
.LP
a)
coordination of lining up the multiple\(hydestination
sound\(hyprogramme circuit sections, circuits and links, respectively;
.LP
b)
keeping a record of the measurements made during the
lining\(hyup period of the circuit section, circuit or link, and
recording the quality assessments observed at control stations
during the lining\(hyup of the link;
.LP
c)
relevant maintenance action for the sub\(hycontrol and control stations
at the request of one of these stations.
.PP
However, the choice of the station nominated as the terminal
sub\(hycontrol station is left to the discretion of the Administration
concerned.
.PP
1.7
Exchange of contact point information on sound\(hyprogramme
transmission should be made in accordance with Recommendation\ M.93\ [3].
.sp 9p
.RT
.sp 2P
.LP
\fB2\fR \fBSend reference stations\fR
.sp 1P
.RT
.PP
Sound\(hyprogramme transmissions provided on a multiple destination
basis using a communication satellite system, differ from those using only
terrestrial facilities in that the common transmitting path extends through
the transmitting earth station to the satellite. The receiving paths extend
from
the satellite through the receiving earth stations concerned to the terminal
ISPC control stations.
.bp
.PP
Operations on the common path of the connection affect all receiving stations,
whereas on any of the other paths the operations affect only the one receiving
terminal station involved. These distinctive features of a multiple destination
sound\(hyprogramme transmission provided in the above manner require the
assistance of certain stations designated as send reference stations.
.PP
Send reference stations are situated along the common path of the
sound\(hyprogramme circuit or link and are identified as follows:
.RT
.LP
a)
a sub\(hycontrol station located at the transmitting terminal of the
circuit section containing the space segment;
.LP
b)
the terminal sub\(hycontrol stations for the circuit and link containing
the space segment.
.PP
Figure 4/N.1 shows the basic composition for a multiple
destination sound\(hyprogramme circuit routed via a communication satellite
system. The send reference stations are shown as R and R` for the multiple
destination circuit section and circuit respectively.
.PP
Figure 5/N.1 shows the basic composition for a multiple destination
sound\(hyprogramme link and connection routed via a communication satellite
system. The send reference stations are shown as R` and R" for the
multiple destination circuit and link respectively.
.RT
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIControl stations\fR , Vol.\ IV,
Rec.\ M.80.
.LP
[2]
CCITT Recommendation \fISub\(hycontrol stations\fR , Vol.\ IV,
Rec.\ M.90.
.LP
[3]
CCITT Recommendation \fIExchange of contact point information for the\fR
\fImaintenance of international services and the international network\fR
, Vol.\ IV, Rec.\ M.93.
\v'6p'
.IP
\fB1.2\fR \fBSetting\(hyup, lining\(hyup and monitoring the international
sound\(hyprogramme links and
\fBconnections\fR
.sp 1P
.RT
.PP
It is assumed that the international sound\(hyprogramme connection is as
shown in Figure\ 2/N.1. It is also assumed that the various sound\(hyprogramme
circuits to be interconnected to constitute the international sound\(hyprogramme
link are circuits established and maintained as given in Subsection\ 1.3
below.
.sp 1P
.RT
.sp 2P
.LP
\fBRecommendation\ N.10\fR
.RT
.sp 2P
.ce 1000
\fBLIMITS\ FOR\ THE\ LINING\(hyUP\ OF\ INTERNATIONAL\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.10''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.10 %'
.ce 0
.sp 1P
.ce 1000
\fBSOUND\(hyPROGRAMME\ LINKS\ AND\ CONNECTIONS\fR
.ce 0
.sp 1P
.LP
\fB1\fR \fBGeneral\fR
.sp 1P
.RT
.PP
This Recommendation gives limits in Tables\ 1/N.10 to 5/N.10 for the lining\(hyup
of international sound\(hyprogramme links as defined in
Recommendation\ N.1. These limits correspond to those for three audio sections
of the hypothetical reference circuit as defined in CCIR Recommendation\
502\ [1] for 5\ kHz, 6.4\ kHz, 7\ kHz and 10\ kHz type sound\(hyprogramme
circuits, but
correspond to four audio sections for 15\(hykHz type sound\(hyprogramme
circuits
except for noise limits, which correspond to three audio
sections\ [2]
.FS
Wider tolerance limits are recommended for 15\(hykHz type
sound\(hyprogramme circuits because of performance limitation of commercial
equipment.
.FE
.
.PP
It is not possible at the present time to recommend limits for the
sound\(hyprogramme connection. However, Administrations shall endeavour
to provide national sound\(hyprogramme circuits to as high a standard as
possible so that the performance of the sound\(hyprogramme connection is
not markedly different to that of the sound\(hyprogramme link.
.bp
.PP
Some Administrations arrange their apparatus in an ISPC so that at
the point of interconnection the output impedance of every receive channel
or circuit over the frequency band of interest is substantially lower than
the
input impedance of any send channel or circuit. This is the so\(hycalled
constant\(hyvoltage technique
. Other Administrations arrange for an
impedance match at the point of interconnection and choose the value of this
impedance to be equal to the design resistance of measuring instruments.
This is known as the
impedance\(hymatching technique
(previously referred to as the
constant electromotive force technique
). It should be noted that in both cases the through\(hylevel measurement
results relative to the through\(hylevel at 800\ Hz will be the same. Furthermore
the terminated\(hylevel measurement
results relative to the terminated\(hylevel at 800\ Hz will also be the same
value
.FS
This depends on the almost constant ratio of the impedances on the
send and receive sides at the various frequencies. (See \(sc\ 4 of
Recommendation\ N.11.)
.FE
.
.PP
Hence the limits recommended in the following tables are applicable
regardless of the arrangement adopted by Administrations at their ISPCs.
.PP
The test procedures are described in Recommendation\ N.21. The limits for
15\ kHz and 7\ kHz circuits are applicable both for analogue and digital
transmissions.
.RT
.sp 2P
.LP
\fB2\fR \fBLimits for the loss/frequency distortion of an international
sound\(hyprogramme link\fR
.sp 1P
.RT
.PP
The majority of international sound\(hyprogramme links are in practice
established with three or less circuits in series.
.PP
Many links could be established without additional equalizers but
links comprising four or more circuits will probably require equalization.
In this case the opportunity could again be taken to obtain as good a
loss/frequency characteristic as possible.
.RT
.LP
.sp 31
.bp
.ce
\fBH.T. [1T1.10]\fR
.ce
TABLE\ 1/N.10
.ce
\fBLimit for the lining\(hyup of 15 kHz sound\(hyprogramme links\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(126p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
_
.T&
lw(24p) | lw(66p) | lw(60p) | lw(30p) | lw(30p) , ^ | ^ | l | l | l.
.T&
lw(24p) | lw(126p) | lw(30p) | lw(30p) .
.T&
rw(24p) | cw(126p) | lw(30p) | lw(30p) .
{
TABLE\ 1/N.10\ \fI(cont.)\fR
}
.T&
cw(24p) | cw(126p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
.T&
lw(18p) | lw(24p) | lw(66p) | lw(60p) | lw(30p) | lw(30p) , ^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l.
{
12
Difference in gain between A and B channels
0.04 to 0.125 kHz
dB
\ 1.8
0.125 to 10 kHz
dB
\ 1
10 to 14 kHz
dB
\ 1.8
14 to 15 kHz
dB
\ 3.6
}
.T&
lw(18p) | lw(24p) | lw(66p) | lw(60p) | lw(30p) | lw(30p) , ^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l.
{
13
Phase difference between
A and B channels
0.04 to 0.2 kHz
degree
\ 36
0.2 to 4 kHz
degree
\ 18
14 kHz
degree
\ 36
15 kHz
degree
\ 48
}
.T&
lw(18p) | lw(24p) | lw(126p) | lw(30p) | lw(30p) .
{
14
Intelligible crosstalk ratio A/B
dB
\ 48
}
.T&
lw(18p) | lw(24p) | lw(126p) | lw(30p) | lw(30p) .
{
15
Crosstalk ratio (intermodulation) A/B
dB
\ 58
\fBMONTAGE:\fR
Additional parameters
for stereo transmission
}
.TE
.nr PS 9
.RT
.ad r
\fBTable 1/N.10 [1T1.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [2T1.10]\fR
.ce
TABLE\ 1/N.10\ \fI(cont.)\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(126p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
.T&
lw(18p) | lw(24p) | lw(66p) | lw(60p) | lw(30p) | lw(30p) , ^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l.
{
12
Difference in gain between A and B channels
0.04 to 0.125 kHz
dB
\ 1.8
0.125 to 10 kHz
dB
\ 1
10 to 14 kHz
dB
\ 1.8
14 to 15 kHz
dB
\ 3.6
}
.T&
lw(18p) | lw(24p) | lw(66p) | lw(60p) | lw(30p) | lw(30p) , ^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l
^ | ^ | ^ | l | l | l.
{
13
Phase difference between
A and B channels
0.04 to 0.2 kHz
degree
\ 36
0.2 to 4 kHz
degree
\ 18
14 kHz
degree
\ 36
15 kHz
degree
\ 48
}
.T&
lw(18p) | lw(24p) | lw(126p) | lw(30p) | lw(30p) .
{
14
Intelligible crosstalk ratio A/B
dB
\ 48
}
.T&
lw(18p) | lw(24p) | lw(126p) | lw(30p) | lw(30p) .
{
15
Crosstalk ratio (intermodulation) A/B
dB
\ 58
\fBMONTAGE:\fR
Additional parameters
for stereo transmission
}
.TE
.nr PS 9
.RT
.ad r
\fBTable 1/N.10 (cont.) [2T1.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T2.10]\fR
.ce
TABLE\ 2/N.10
.ce
\fBLimits for the lining\(hyup of 10 kHz sound programme\fR
.ce
\fBlinks\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(144p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
_
.T&
lw(24p) | lw(72p) | lw(72p) | lw(30p) | lw(30p) , ^ | ^ | l | l | l.
.T&
lw(24p) | lw(144p) | lw(30p) | lw(30p) .
.TE
.nr PS 9
.RT
.ad r
\fBTable 2/N.10 [T2.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T3.10]\fR
.ce
TABLE\ 3/N.10
.ce
\fBLimits for the lining\(hyup of 7 kHz sound\(hyprogramme links\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(144p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
_
.T&
lw(24p) | lw(72p) | lw(72p) | lw(30p) | lw(30p) , ^ | ^ | l | l | l.
.T&
lw(24p) | lw(144p) | lw(30p) | lw(30p) .
.TE
.nr PS 9
.RT
.ad r
\fBTable 3/N.10 [T3.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T4.10]\fR
.ce
TABLE\ 4/N.10
.ce
\fBLimits for the lining\(hyup of 6.4 kHz sound\(hyprogramme links\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(144p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
_
.T&
lw(24p) | lw(72p) | lw(72p) | lw(30p) | lw(30p) , ^ | ^ | l | l | l.
.T&
lw(24p) | lw(144p) | lw(30p) | lw(30p) .
.TE
.nr PS 9
.RT
.ad r
\fBTable 4/N.10 [T4.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T5.10]\fR
.ce
TABLE\ 5/N.10
.ce
\fBLimits for the lining\(hyup of 5 kHz sound\(hyprogramme links\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(144p) | cw(30p) | cw(30p) .
Item Parameter Unit Limits
_
.T&
lw(24p) | lw(72p) | lw(72p) | lw(30p) | lw(30p) , ^ | ^ | l | l | l.
.T&
lw(24p) | lw(144p) | lw(30p) | lw(30p) .
.TE
.nr PS 9
.RT
.ad r
\fBTable 5/N.10 [T5.10], p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCIR Recommendation \fIHypothetical reference circuits for\fR
\fIsound\(hyprogramme transmissions\fR , Vol.\ XII, Rec.\ 502, ITU, Geneva,\
1986.
.LP
[2]
CCIR Recommendation \fIEstimation of transmission performance of\fR
\fIsound\(hyprogramme circuits shorter or longer than the hypothetical
reference\fR \fIcircuit\fR , Vol.\ XII, Rec.\ 605, ITU, Geneva,\ 1986.
.LP
[3]
CCIR Recommendation \fIPerformance characteristics of 10\ kHz type\fR
\fIsound\(hyprogramme circuits\fR , Vol.\ XII, Rec.\ 504, ITU, Geneva,\ 1982.
.bp
.sp 2P
.LP
\fBRecommendation\ N.11\fR
.RT
.sp 2P
.ce 1000
\fBESSENTIAL\fR \
\fBTRANSMISSION\ PERFORMANCE\ OBJECTIVES\ FOR\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.11''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.11 %'
.ce 0
.sp 1P
.ce 1000
\fBINTERNATIONAL\ SOUND\(hyPROGRAMME\ CENTRES\ (ISPC)\fR
.ce 0
.sp 1P
.LP
\fB1\fR \fBTransmission level at interconnection points\fR
.sp 1P
.RT
.PP
Levels at interconnection points must be such that a signal level of 0\
dBm0 on the incoming circuit gives rise to a signal level of 0\ dBm0 on
the outgoing circuit. A nominal relative level of +6\ dBr is recommended
at
interconnection points (see also Figure\ 3/J.13 [1] and Recommendation\
J.14, \(sc\ 1 [2]).
.RT
.sp 2P
.LP
\fB2\fR \fBBalance with respect to earth\fR
.sp 1P
.RT
.PP
The balance with respect to earth (measured by the method defined in [3])
of nominally balanced apparatus should be at least 60\ dB in order to
give an adequate suppression against longitudinal interference induced by
power supplies, alarm circuits,\ etc.
.RT
.sp 2P
.LP
\fB3\fR \fBAccess points\fR
.sp 1P
.RT
.PP
There should be a well\(hydefined circuit access point associated with
the input to a sound\(hyprogramme circuit at which the transmission test
levels at all frequencies over the band are nominally the same. This access
point may be the interconnection point or separated therefrom by distortion\(hyfree
loss or
gain. A\fR well\(hydefined circuit access point should also be associated
with the output of a sound\(hyprogramme circuit.
.PP
The nominal relative level at each access point will be chosen by each
Administration, bearing in mind the dynamic range of their testing and
transmission apparatus.
.PP
Measurements on a sound\(hyprogramme circuit should be made between such
circuit access points.
.PP
Administrations may also find it convenient to arrange for
sound\(hyprogramme circuit sections to be equipped with similar access points.
International sound\(hyprogramme circuit sections which can be connected to a
variety of other circuit sections should always be equipped with such
access points.
.RT
.sp 2P
.LP
\fB4\fR \fBInterconnection of sound\(hyprogramme circuits\fR
.sp 1P
.RT
.sp 1P
.LP
4.1
\fIConstant voltage technique\fR
.sp 9p
.RT
.PP
If the modulus of the output impedance of any source is not
greater than one hundredth of the modulus of the lowest impedance that
can be connected to it (bearing in mind that it is possible to connect
two or more
loads in parallel) then the change in level due to change of load will be
negligibly small (less than 0.1\ dB approximately).
.RT
.sp 1P
.LP
4.2
\fIImpedance matching technique\fR
.sp 9p
.RT
.PP
If the return loss versus the nominal design resistance of the
measuring instruments of the impedance presented by incoming and outgoing
circuits to the points where they are interconnected is at least 26\ dB
over the range\ 50\ Hz to\ 10 or 15\ kHz, the error due to mismatch will
be insignificant, assuming that the impedance of testing apparatus has
at least 30\(hydB return loss versus the nominal design resistance, which
can be, for example, 600\ ohms
non\(hyreactive.
.RT
.sp 1P
.LP
4.3
\fIDigital technique\fR
.sp 9p
.RT
.PP
The interconnection of digital sound\(hyprogramme circuits will be
made by preference with the aid of a digital interface presenting the following
characteristics:
.RT
.LP
\(em
plesiochronous or synchronous operation
.LP
\(em
bit rate of 384\ kbit/s, 1544\ kbit/s or 2048\ kbit/s
.LP
\(em
384 kbit/s to carry either one 15\ kHz or two 7\ kHz
sound\(hyprogramme signals.
.PP
Interface for other bit rates, namely to provide for 15\ kHz
monophonic and stereophonic circuits with linear coding and for 7\ kHz
monophonic sound\(hyprogramme circuits with companded coding are the subject of
further study.
.bp
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIDefinitions for international sound\(hyprogramme\fR
\fIcircuits\fR , Vol.\ III, Rec.\ J.13.
.LP
[2]
CCITT Recommendation \fIRelative levels and impedances on an\fR
\fIinternational sound\(hyprogramme connection\fR , Vol.\ III, Rec.\ J.14.
.LP
[3]
CCITT Recommendation \fITransmission aspects of unbalance about earth\fR
Vol.\ III, Rec.\ G.117.
.sp 2P
.LP
\fBRecommendation\ N.12\fR
.RT
.sp 2P
.ce 1000
\fBMEASUREMENTS\ TO\ BE\ MADE\ DURING\ THE\ LINE\(hyUP\ PERIOD\fR
.EF '% Fascicle\ IV.3\ \(em\ Rec.\ N.12''
.OF '''Fascicle\ IV.3\ \(em\ Rec.\ N.12 %'
.ce 0
.sp 1P
.ce 1000
\fBTHAT\ PRECEDES\ A\ SOUND\(hyPROGRAMME\ TRANSMISSION\fR
.ce 0
.sp 1P
.PP
After the connection of the various circuits to form the
international sound\(hyprogramme link
(conforming to the level diagrams of these circuits) it is necessary to
verify, by means of an automatic measuring equipment (see Recommendations\
O.31\ [1],\ O.32\ [2] and\ O.33\ [3]) or by
measurements at individual frequencies, that the received
level at the distant incoming terminal ISPC is at the correct value (see
Recommendation\ N.10) at the following frequencies:
.sp 1P
.RT
.LP
for an international sound\(hyprogramme link composed
entirely of 15\(hykHz sound\(hyprogramme circuits
.ad r
\ 40, 800 and 15 | 00 Hz |
\u1\d\u)\d
.ad b
.RT
.LP
for an international sound\(hyprogramme link composed
entirely of 10\(hykHz sound\(hyprogramme circuits
.ad r
\ 50, 800 and 10 | 00 Hz |
\u1\d\u)\d
.ad b
.RT
.LP
for an international sound\(hyprogramme link comprising at least one 7\
kHz sound\(hyprogramme circuit
.ad r
\ 50, 800 and \ 7 | 00 Hz |
\u1\d\u)\d
.ad b
.RT
.LP
for an international sound\(hyprogramme link comprising at least one
6.4\(hykHz sound\(hyprogramme circuit
.ad r
\ 50, 800 and \ 6 | 00 Hz |
\u1\d\u)\d
.ad b
.RT
.LP
for an international sound\(hyprogramme link comprising at least one 5\
kHz sound\(hyprogramme circuit
.ad r
100, 800 and \ 5 | 00 Hz |
\u1\d\u)\d
.ad b
.RT
.LP
for an international sound\(hyprogramme link comprising at least one
ordinary telephone circuit
.ad r
300, 800 and \ 3 | 00 Hz
.FS
Or the frequency appropriate to the
telephone\(hytype circuit used.
.FE
.vs +3p
.RT
.ad b
.RT
.PP
The send level during these measurements should be \(em12\ dBm0.
.PP
In the case of 15\(hykHz sound\(hyprogramme links forming a stereophonic
pair, it is necessary to verify the interchannel parameter limits specified
in Table\ 4/N.10.
.PP
A measurement of other parameters such as nonlinear distortion and
noise should be measured on all links and the results recorded. At the
present time the limits cannot be specified.
.PP
The national sound\(hyprogramme circuits should be so adjusted that, when
they are connected to the international sound\(hyprogramme link, the level
diagrams of the international sound\(hyprogramme circuits are respected.
In this regard, a useful and quick method which Administrations could use
to verify the correct alignment of sound\(hyprogramme links is given in
Annex\ A of
Recommendation\ N.13.
.PP
Any necessary adjustments having been made, the national circuits are connected
to the international sound\(hyprogramme link at the terminal ISPCs.\fR
This is the end of the line\(hyup period and the beginning of the preparatory
period and is the instant when the complete connection is placed at the
disposal of the broadcasting organizations.
.PP
\fR \fI\fR \fB
The latter then proceed to measure and adjust as necessary.
.RT
.sp 2P
.LP
\fBReferences\fR
.sp 1P
.RT
.LP
[1]
CCITT Recommendation \fIAutomatic measuring equipment for sound\(hyprogramme\fR
\fIcircuits\fR , Vol.\ IV, Rec.\ O.31.
.LP
[2]
CCITT Recommendation \fIAutomatic measuring equipment for stereophonic\fR
\fIpairs of sound\(hyprogramme circuits\fR , Vol.\ IV, Rec.\ O.32.
.LP
[3]
CCITT Recommendation \fIAutomatic equipment for rapidly measuring\fR
\fIstereophonic pairs and monophonic sound\(hyprogramme circuits, links
and\fR \fR
\fIconnections\fR , Vol.\ IV, Rec.\ O.33.
.LP
.bp