equipment.

To attain maximum capacity in the second phase, it may be necessary

to replace URC's of the MSM type with URC's of the MSS (Satellite Synchroniza-
tion Module) type.

Different Phases in Expansion of Minor Exchange

its —_| MSM

Centre Nodal

rains isc

E10

MSM

= me Gas

-_@

©. —y

secteur

Q.)
its de
Hocaux|

onl Centre
Se as ——|
Centre Nodal MSM Pj TNE; GAS! de
its —| MSM Loa
its —9 secteur EM
bains— yoo ew
Mss URA
Qremene EXTENSION
G Mss URA
wmsM Centre Nodal
‘ircuits —
= ou mss URA
irbains: Msc
E10
URA
Qrvune EXTENSION

Key:1.
3.
5.
6.
7.
8.

1o.

Interoffice trunks

E10 tandem office

Local circuits

Electromechanical minor exchange

Initial phase
First expansion
Second expansion

11. Mss:

Satellite Synchroniza-

tion Module
Terminal Numerical (Digital) Equipment 12. URA:

Unit.
13. GAS:

MSC: Circuit Synchronization Module
MSM: Multiplex Synchronization Module

14

Subscriber Connecting

Signal Converter Group


Comparison of Caducee, Visiophone, and Telephone

psn eae pe mn
OUREE AU PLUSEGALEAT =

atte §

8
g
3

S:
AN

XY

*)

10% du trafic Caducée
représenté par 70%
des appels courts

{6 DES COMMUN
o
3

10% du trafic téléphonique
représonté par 44%

7 des 6 courts
7705 mn.

‘COMPARAISON DES POIDS RESPECTIFS DES COMMUNICATIONS CLASSEES PAR TRANCHE DE DUREE
ET DES % DES NOMBRES CUMULES POUR CES CLASSES POUR 3 TYPES D’APPELS

{8g sgsas

(© -180.000 APPELS CADUCEE D'OCTOBRE-NOVEMBRE 1876

)V - UN ECHANTILLON DE 553 CONVERSATIONS VISIO~
PHONIQUES (2+ quadrimestre 1978)

‘T- UN ECHANTILLON DE 6672 COMMUNICATIONS.
‘TELEPHONIQUES DE TOUTES DESTINATIONS.
(MOLITOR 15-18 DECEMBRE 1975 - JOURNEES)

2 5 © 2 40°60 60 70 80 690 9 98 so Seb essI99 9999
‘% POIDS CUMULES DES COMMUNICATIONS DE DURE AU PLUS EGALE AT,

1. Percentage of calls of duration equal to T at most

2. 10 percent of Caducee traffic represented by 70 percent of short calls

3. Limiting point corresponding to calls all of the same duration

4, 10 percent of telephone traffic represented by 44 percent of short calls

5. Comparison of respective weights of communications classified by duration
and of percentages of cumulative numbers for these classes for three types
of calls.

6. C - 150,000 Caducee calls in October-November 1976

7. V- a sampling of 553 visiophonic calls (second 4 months of 1975

8. T - a sampling of 6,672 telephone calls to all destinations (Molitor [Paris
exchange], 15-18 December 1975-daytime calls)

9. Percentage of cumulative weights of calls cf duration equal to T, at most.

35,



Daily distribution, during a busy hour, of calls as a function of outcome of
calls

Outcome of call Number of calls per Number of busy-
per day in % hour calls, in %
Line busy 20.4 28
Unavailableness 20.8 22.5
Completed 57.1 46
Miscellaneous 1.7 3.5

Hourly variations in number of completed calls

Nombre d’appel¢ et nombre de communications efficaces
pour le jour chargé en appels (9 novembre 1976)

_~ SS

1.2.3 46567 8 9 0 N 213 4 BH 6 17 18 19 20 21 22 23 24 Heures
ee.

Key: 1. Number of calls and number of completed calls for a day with an
unusually large number of calls (9 November 1976). 2. Hours.

31



FRANCE

BRIEFS

STOLEN BROADCAST EQUIPMENT--There has been an increase in thefts at the
television broadcast and relay stations administered by Tele-diffusion de
France [Television Broadcast Network of France]. The police suspect the
leftist, ecologist and autonomist groups in the country of wanting to

equip their pirate stations at low cost and then have them begin
broadcasting during the electoral campaign. [Text] [Paris LE POINT in French
31 Oct 77 p 69]

cso: 5500

ho



PEOPLE®S DEMOCRATIC REPUBLIC OF YEMEN

BRIEFS

NEW RADIO TRANSMITIERS--Two new radio transmitters are being built at al-
Hiswah, a 200 kW mediumwave transmitter and a 100 kW shortwave transmitter.
Radio transmission via the 200 kW transmitter is expected to begin on

30 November, during our celebrations of the 10th anniversary of national
independence. [Aden Domestic Service in Arabic 1230 GMT 3 Nov 77

cso: 5500



However, if the interstices of the central conductor
are well filled by insulation, only external air layer is
to be considered so that (50) becomes:

(1) =

II. - DESIGN OF COAXIAL PAIRS.

The design of coaxial pairs by computer is descri-
bed in detail only for structures with a solid inner
conductor and a tubular outer conductor, which are
the most used in the field of telecommunication ca-
bles.

The input data are generally the nominal values
and tolerances of impedance and attenuation at a gi-
ven frequency.

A certain range of variation for dielectric constant
€, with the associated tan & is also prefixed in order
to give the possibility of choosing different types of
insulation.

The various solutions are examined under the ma-
nufacturing, technical and economical points of view
and one of them is chosen.

Considering the fact that the design data are usual-
ly given at high frequencies, the following approxi-
mate formulae can be employed for non magnetic
conductors:

VF [= |
[|S +

6 ane [Bas
+91- Ve,-Ftané
Ven | Vee
(3) Z=2+ > a

characteristic impedance (Q);

impedance at infinite frequency (Q);

ianer conductor diameter (mm);

inner diameter of the outer conductor (mm);
resistivity of inner conductor (Q- mm2/km);

a = resistivity of outer conductor (Q - mm?/km);
& average dielectric constant of the insulation;
tan§ tangent of loss angle of the dielectric;

frequency in MHz,

68



OL n 1
10 bm 20
Fig. 4, - Comparison of the behaviour of R = C,/w, and @/w,
vs. m. Curves refer to the same system of fig.”3, Tor 8 = 8%.

Ry Q1/%_ and C,/w,, versus the «study period »
length m, for the same waveguide systems of fig. 3,
when § = 8%, is shown.

The behaviour of @,/w,, and @,/w,, on the con-
trary is substantially dependent on the length of
the « study period », Clearly if the study period length
could be increased up to the end of the plant life, the
values of @,/w,, and @,/w,, approach the limit va-
lues R, and R, respectively.

In the example of fig. 4 the second system results
to be the more convenient one, according to the R
method, while an opposite result is obtained accor-
ding to the @/w,, method.

6.2. - Example n. 2: Comparison between a circular
waveguide system and a coaxial cable carrier
system.

In this example a comparison is made between a
circular waveguide system and a coaxial system to
be installed on the same transmission route (as that
of example n. 1). The main characteristics of the two
systems are summarized in the caption of fig. 4 (sub-
script 1 for the coaxial cable system and subscript
2 for the waveguide system).

The coaxial cable is a multitube cable (16 tubes)
with 10800 TF channels per tube.

Fig. 5 shows the maximum allowed value of
Cyo/Cy, in order that the waveguide system beco-
mes more convenient, according to the R method

(curve a) or to the PVAC method (curve 6), in case.

of N; = 40000 TFc. Curve a’ and 6’ have the same
meaning, but are evaluated in case of N; = 32000
TFc. Curves ¢ and c’ have the same meaning as cur-
ves a and a’ respectively, but are evaluated assuming

fue
Cu,
bE - oy J
7 I
ah 4
ras 4
0 t n i l
10 5 5m 20

Fig. 5. - Behaviour of Cyg/Cy, vs. 8, where C,o/Cy, is the ma-
ximum value of the ratio“betWeen the costs of the ‘installed tran-
smission media of a circular waveguide system (subscript 2) and
a multitube coaxial cartier cable (subscript 1) for which the wa-
veguide system is more convenient. Curves a (for N, = 40000 TFc)
and a’ (for N, = 32000 TFc) have been evaluated according to
the R method; curves b (for N, = 40000 TFc) and 6’ (for
N, = 32000 TFc) have been evaluated according to the PVAC
method; curves ¢ and c’ have the same meaning as that of cur-
ves @ and a’ respectively, but have been evaluated by assuming
the cost of the equipment of the repeater stations to be negli:
gible. The two systems have the following main characteristics
N, = 10800 TFe; N, = 7680 TFc; N,, = 86400 TFc: Nj, = 320000
Tei Cyy = 85-10 Y; d, = 15 km; dy = 40 km; Cy = 12°10 U.
t =m = 15,04 4, n, = 15,

= 8%,

the equipment cost to be negligible, if compared to
that of transmission media.

Fig. 6 shows the corresponding behaviour of @, and
Cy, By and Ry, Cy/ Wy, and Cy/Wyy fOr Cyn = 15 Cyy
and N,; = 32000 TFc.,

In this example the service capability of the coa-
xial cable carrier system would be saturated in only
8 years for § = 15%, when N, = 40000 TFc, and for
& = 18%, when N; = 32000 TFc. The corresponding
curves have been therefore plotted only for lower
values of §. However also in this example the PVAC
method gives results of doubtful meaning, when
s<m (ie. when §> ~ 8% for N; = 40000 TFc. or
&>~9% for N; = 32000 TFc).

In fig. 7. curves R, and R3 have the same mea-
ning as that of curves R, and R,, but have been eva-

luated with the approximate eq. (16) to give an idea
of the discrepancies which may be expected by using
eq. (16).

50



If p is the number of two-way RF channels or
coaxial tubes, used as spares or other services since’
the first year, and qo, 4, q2--. are the number of
two-way RF channels or coaxial tubes installed at
dates uy = 0, uy, uy... (years), g, may be evaluated
by the following relationship (assuming the salvage
r, = 0, m<n, and the annual operation cost per
repeater ¢, @, proportional to @,):

= fis #1 ,
BEN, 7 ara)I:

[ f (m, u,)
[PR

+90 FGay

f(m,s)
f (ny 8)

(14) cn f (m— uy &— 4) +
(1+ 7) f (My Uy — 4)
Cr f(m—uy, u,—W) + |
(L+t)% f(y tt3— 43)

In eq. (14) the functions f are given by eq. (5) or
eq. (5) by replacing u with n, or m or m—U; and s
with u;,,—4, or again s (6).

In the following section few examples are given
of application of the study form using the ratio R
in some very idealized cases and the method is com-
pared with the PVAC study form. Also in the PVAC
method we will refer to an unit cost @ = PVAC/
/N,,4, (cost per kim and per TFc). In addition we
will compare the R ratio with the ratio between
@ and w,, i.e. between PVAC and utility.

The evaluation of @ has been made with the same
eq. (12) when in the eq. (13) we replace (in case of
salvage r = 0) f(m,s) and f(n,s) with the new
functions:

(8) f(m) = 1-(+a)-", f(n) = 1-42)",

and in the eq. (14) we introduce the new functions
(15) (with n, instead of n in f(n) and m, or m—t,
or m—n,... instead of m in f(m)).

In the evaluation of R, as pointed out above, the
functions gy and g, do not coincide. However in a
first approximation it is possible to assume g, = &y
and, in case the same value of + is assumed in the

(@) When the «study period » m is longer than the equipment
life n,, it should be added also the cost of the replacement of the
obsoléte equipment. In this case an uniform distribution law
should be used and the appropriate functions f to be used are
given by the following eq.s (15).

evaluation of both utility and cost, it is possible
to use the following simple equation: :

Cut Cat Cr

Wr

(16) R=

6. - EXAMPLES OF APPLICATIONS OF THE STUDY FORM USING
R AND COMPARISON WITH THE PVAC STUDY FORM.

The ratio R, defined in sect. 5, may be used to
compare two different systems or to optimize one
system, by finding the best choice of its characte-
ristics (distance between repeater stations, overall
available bandwidth, channelling, repeater capacity,
kind of modulation, etc.) which results in a minimum
of R. In the following example the use of the R
method is compared with that of PVAC method to
evaluate different systems.

In the idealized examples, here given for the sake
of simplicity, we will consider only the contribution
of Cy and @, to R or @C and we will assume
ry =, = 0 and ey =e, = 0. The costs are given
in arbitrary cost units U.

In all the example it has been assumed n = 40,
n, = 15, m = 15, t = 8% (both for costs and uti-
lity); a fixed period of 5 years has been assumed
between new equipment installations.

6.1. - Example n. 1: Comparison between two cir
cular waveguide systems.

We want to compare two circular waveguide sys-
tems to be installed along a transmission route. The
initial service capability over other facilities is
N, = 40000 TFe. :

The main characteristics of the two different cir-
cular waveguide systems, are summarized in the
caption of fig. 2. The first system (subscript 1) has
a smaller service capability and a smaller cost of
the installed waveguide .The second system (sub-
script 2) besides a higher service capability (Nj >
>N,) has a smaller waveguide loss and therefore
the distance between repeaters is higher (d, > d,),
which results in a lower unitary cost of the repea-
ters (C4: < C41), because the same cost C, and the
same capacity N per repeater have been assumed.
The higher service capability and the lower loss are
attained with an expected higher cost of the installed
waveguide (Cy > Cy). Fig. 2 shows the maximum
value allowed to Cyp/Cy, in order that the higher
capacity system be more convenient, according to
the R method (curve a) or to the PVAC method
(curve b). The curve d has the same meaning of

48



then the formulae obtained have been modified for
application to other coaxial structures such as those
having inner and outer tubular conductors and those
with stranded conductors or braided outer conductor.

Configurations using the modified formulae are met
in practice with telecommunication signal transmis-
sion on very large coaxial cables, on flexible coaxial
cables for radio frequency and cables for power tran-
smission. The formulae adopted are the results of
both theoretical considerations and measurements.

This paper analyses in detail especially coaxial pairs
type 2.6/9.5 mm, 1.2/4.4 mm and 0.7/2.9 mm.

Computer programmes have been written to cal-
culate primary and secondary parameters, group and
phase velocity.

The calculation of transmission parameters is ba-
sed on dimensional data of cables manufactured by
Industrie Pirelli S.p.A. Results of measurements are
shown in addition to the calculated values in order
to make a comparison.

A special method for design of coaxial pairs is also
proposed; the values of characteristic impedance and
of attenuation at a given frequency with relevant to-
lerances are generally set as input data.

A certain range of variation for dielectric constant _
¢, is also considered. The dimensions of coaxial Pairs
for the imposed tolerances together with associated
attenuation and impedance values are printed out.

Among the various solutions, the designer chooses
the one which, according to his experience, best suits

to the imposed conditions which may be both tech-
nical and economical.

I. - CALCULATION OF TRANSMISSION PARAMETERS.

I. - Coaxial pair with solid inner conductor and tu-
bular outer conductor.

The formulae used for the calculation take into
account the geometric and electrical characteristics
of the coaxial pair, but do not consider the effect
of the screen over the outer conductor generally ob-
tained with steel tapes.

Fig. 1. - Cross section of coaxial pair with solid inner conductor
and tubular outer conductor.

5h



8 sh sin

ad a a

30) L, = 2.19-4 tt

(0) . d 2s 2s
— —cos ——
8 8

inductance of inner conductor (H/km)

The calculation of the other parameters is as de-
scribed in section I.1.

This configuration can be also generally employed
for submarine coaxial cables.

For more precise calculations at low frequencies,
the following exact expressions of R; and L, should
be used [7]:

Gt) R= Re ZH® , NulP)J0(7) ~No (NO)
Pr Ny) Jy (PY —Ny (7) Jy (2)
2 _Ni(P) Jol) —No 7) )

32) L,=Im
@ Ny (2) Jy (PY) —N, (71) J, (BD)
where:
_ ( da s 4nop, |
n= (+-5) { aa
d
B=

Jo(p) and J,(p) are the Bessel functions of order
zero and one

weet TI ne

“AO

18
4

"ie

Fig. 4. - Skin effect in isolated tubes and wires [3].
¢ = frequency (kHz) .
= conductor d.c. resistance (f/km)



®) (PVAQ, = C, | 1 iar .
ee taper tt]:

“(0 4+%)4—(1+)-"].

Eq. (8) shows that the PVAC is coincident ob-
viously with the PVE given by eq. (6), when u = 0
and m = o, and is coincident with C, when r = 0,
e=0u=0man

The overall PVAC is evaluated by adding the
PVAC’s of all the expenditures made in the « study
period ».

The PVAC study form is therefore more general
than PVE and AC. It is a satisfactory form of study
to compare different plants, when they have the
same «utility » during their whole life and not only
during the study period. Only in this case it meets
the premises of sect. 2, However the result of this
form of analysis leads always to a value which is a
function of m (i.e. of the length of the study period)
and cannot be assumed as a figure of merit. In
cases where the systems under evaluation have not
the same capacity, also the PVAC study form does
not meet the basic premises e, f and g.

A tentative study form, which takes into account
both the different cost and the different « utility »
of different systems and meets all the premises
of sect. 2, is discussed in the next section.

5, - TENTATIVE DEFINITION OF A FIGURE OF MERIT AS A
CONVENIENT RATIO BETWEEN COST AND UTILITY.

In the above sections it has been pointed out that
a comparison among different systems based on
the simple evaluation of costs does not seem to
be satisfactory in the general case of different ser-
vice capabilities.

When the service demand expansion and the in-
vestment costs can be forecast along the whole life
of the plant, a reasonable comparison could be
made on the basis of the ratio between the present
value of all expenditures (PVE) and the present va-
lue of the overall utility W,,, as defined in sect. 3.
A possible extension of this criterion to the more
general case, where we may consider to be accept-
able forecasts those limited to a period of only m
years (the «study period»), could be made on the
basis of the ratio between the PVAC of all the
expenditures made in said period and the corres-
ponding present value of the utility provided in the
same period. Nevertheless this definition does not
seem satisfactory, because it leads to define a figure

hich depends also on the length rm of.

the «study period» and not only on the characte-
tistics of the system and of the given transmission
route.

It is easy to observe however that the variability
of said ratio with the length m is due only to the
fact that the annual utility distribution law along
the « study period » is different from the correspond-
ing distribution law of the annuities, which is used
for the evaluation of the PVAC. Said ratio would be
constant only if both distribution laws were the
same. However the annuities, for the amortization
of the investment costs of the plant equipment and
for the corresponding operation costs, already have,
in a first approximation, the same distribution law
as the annual «utility» (in fact the equipment is
installed following approximately the expansion of
the service demand). The main discrepancy between
the annuities distribution and the utility distribution
lies only on the fact that the annuities, correspond-
ing to the investment cost for the initial installation
of the transmission medium and for its maintenance,
according to the PVAC study form, follow an uni-
form distribution law along the plant life. The uni-
form distribution law, assumed by the PVAC me-
thod, may be justified since is the usual form of
amortization of an investment. However, from a ge-
neral logical point of view, it seems to be rather
arbitrary, that other laws of distribution, which are
mathematically equivalent to the uniform one, may
not be taken into account, although they could lead
to a more satisfactory study form (no matter if not
usable as actual forms of amortization).

For example the annuities distribution law may
be chosen to be mathematically equivalent to the
uniform distribution law in a way that the ratio
between the present value of annual costs and the
present value of the annual utility during the « stu-
dy period » is constant with the length of the « study
period » [3].

This distribution law is clearly the same as that
of the annual utility and therefore is the same as
that of the number N, of the available equivalent
telephone circuits.

The present value of annuai costs, evaluated ac-
cording to such non-uniform distribution law and
indicated here as PVWAC (Present Value of Weighted
Annual Costs) corresponds to a mathematically equi-
valent amortization law, where the sum of the an-
nual interest, recovery of investment and operation
costs has an annual distribution law proportional
to N,. This kind of hypothetical amortization law
is mathematically equivalent to an uniform distri-
buted amortization law in the sense that PVWAC =
PVAC, when the evaluation is extended to the whole
Jife of the plant. _

6



Removal of the electromechanical frames can be facilitated by using special
trailers as satellite exchanges, thereby permitting 2,000 subscribers to be
connected into four remote URA's. Each of these trailers actually consists
of a 9 meter by 2.4 meter container or. van that can be carried on the bed of
a semitrailer and loaded or mloaded by a "dumpster" type device on the
flatbed. Three other trailers have been designed along the same lines. One
includes a chain core for 840 circuits and 8,000 distant subscribers. The
second is a van housing the power supply unit for this chain core. The third
is an Information Processing Center (CTI) equipped with a Mitra 125 computer.
All of this equipment will be available for use in late 1977 and should, there-
fore, permit not only replacement of saturated SOCOTEL minor exchanges but
also their attached tandem offices frequently consisting of R6 equipment.

In a building standardized to house a minor exchange-type 1, 2, or 3, for
example--maximum expansion capabilities depend on the SOCOTEL equipment
existing at the time the E10 system is installed, and also on the capacity

of the distributing frame and power supply unit. The following three sketches
depict the possible positioning of E10 equipment in these buildings after
complete removal of the electromechanical equipment.

Operating Characteristics
Charging (Billing)

Connecting minor exchanges to an E10 exchange necessitates transferring
charging pulses onto local connecting circuits. Consequently these circuits
must be equipped with a TLT (Teletaxe [Telecharge]) discriminator at transla-
tor level. For each call, other than those worked locally in ‘the minor
exchange, the customary recording of a charging word is concomitant with the
recording of a word from a secondary storage of the charger unit. This
second word contains the coordinates of the circuit utilized--the number of
the selection channel and the number of the time channel--,thereby enabling
the charger unit to transmit, via a special link, a "calibration" at 128
milliseconds of the charging pulse pertaining to this circuit. This cali-
bration is accomplished by sending a "transmit" message followed by a "stop
transmitting" message.

Modification of Programs and Boards

In normal operations there are no such modifications on the URC's [Circuit
Connecting Units] except when carrying out correction orders. Any modifica-
tion in the nature of the connected circuits--change in code, modification of
the trunk groups--is made in the translator's lines and on a specific board
(or desk) of the Multiplex Synchronization Group (GSM) called Multiplex
Signaling Board (TSM). The TSM card is now made in the form of a reprogram-
able and easily changeable SITTER card.

The storage part of this card is in duplicate, thus permitting modification

of the parameters of one trunk group without disturbing the handling of other
trunk groups connected via the same GSM.

18



Geographical Distribution

Some 41 percent of the subscribers are in the Paris region and 59 percent in
other regions. This breakdown closely tallies with initial estimates. In con-
trast, the traffic is noticeably different. It was estimated traffic would be
mainly within the Paris region (65 percent) and from the provinces into Paris

(30 percent). In actuality, it is distributed as follows: 24 percent within
the Paris region, 36 percent from other regions into Paris, 18 percent from Paris
into other regions, and 22 percent between other regions. We note a balance
between the Parisian traffic and traffic of other regions, plus the existence

of appreciable traffic from Paris into the provinces, though twice less than
traffic in the opposite direction. This demonstrates that the network is truly
national despite the existence of only a single automatic switching system in
Paris. It is, therefore, important to take a closer look at the principal
regional characteristics: the number of subscribers, outgoing traffic, incoming
traffic, and internal traffic. The Paris inner-city region is, of course,
altogether exceptional with 39 percent of the subscribers, very heavy internal
traffic, and a very sharp imbalance in favor of incoming traffic over outgoing
traffic.

Of the 21 delimited regions, we shall dispense with considering six that have
an insufficient number of subscribers. It is no surprise that three regions--
lyon, Lille, and Marseille--each have 7 to 8 percent of the subscribers. Five
regions--Bordeaux, Nancy, Orleans, Rouen, and Toulouse--each have nearly 4
percent, while the seven others each have between 1.5 and 3 percent.

Lille has very substantial internal traffic: more than three calls per subscriber
per day. Marseille and suburban Paris have 4 times less calls per subscriber.
lastly, Lyon, Bordeaux, Strasbourg, and Rouen have significant internal traffic:
20 times less calls per subscriber than Lille.

If for each region, we establish the ratio between the percentage of traffic
(outgoing and incoming) and the region's percentage of subscribers, we bring
out four principal categories of regions:

a. Regions with "normal" traffic, i.e. ratios close to unity: Lille and subur-
ban Paris. These two regions are clearly in a class apart: Lille because it
has very heavy internal traffic and suburban Paris because of its geographical
location;

b. Regions with normal incoming traffic and heavy outgoing traffic: Lyon,
Nantes, and Nancy;

c. Regions with light incoming traffic and normal outgoing traffic: Marseille,

Bordeaux, Strasbourg, Rouen--all having normal internal traffic--Rouen, and
Toulouse;

36



2s. 2s

e
47) L, = 2-10-4-—*— - —--—
28 28

y+ 4) Ch —— —cos ——

'e 5.

effective inductance of outer conductor (H/km)

where:
is the d.c, resistance of the outer conductor;

Hi = is given by (6);
8, = is given by (5).
Moreover Ly and C in such a case are given by:
(48) Ip = 2 10-4 In O*4
bed

inductance of space between conductors (H/km)
55.6325 - 10-9 - €,

a.

loop capacitance (F/km)
The value of ¢, shall take into account the presence
of layer of air in the dielectric.

Considering for instance a cable with stranded inner
conductor and braided outer conductor, it could be
necessary to take into account two layers of air as
shown in fig. 8.

Fig. 8, - Insulation with two air layers.

In this case the average dielectric: constant is gi-
ven by:

A
in eS
(50) ¢, = :
. ty+in et +n 4e,-n t
” Dy qn

being ¢,, the dielectric constant of solid insulant (eg.
Polyethylene).



CONTENTS (Continued)
NEAR EAST AND NORTH AFRICA
LIBYA

Briefs
Undersea Cable

PEOPLE'S DEMOCRATIC REPUBLIC OF YEMEN

Briefs
New Radio Transmitters

SUB-SAHARAN AFRICA
UGANDA

Briefs
Live Television

USSR

Briefs
Khurmuli-Berezovyy Radio Line
Severo-Kurilsk Orbital Station

WESTERN EUROPE
FRANCE

Use of E10 Switching System in Tandem Offices Viewed
(Jean-Pierre Coudreuse; L'ECHO DES RECHERCHES, Apr 77)

Growth of Caducee Teleprocessing Network Reviewed
(Alain Dupont » Dominique Gefard-Hirtne; L'ECHO DES
RECHERCHES, Apr 77) cceccececcecceccceeecencceecceeees

Briefs
Stolen Broadcast Equipment

TTALY

Economic Evaluation of Telecommunications Systems
(Giovanni B. Stracca; ALTA FREQUENZA, Feb 77) ........

Calculation of Transmission Parameters, Design of Coaxial

Structures by Computer
(G. Corti, G. Tizzi; ALTA FREQUENZA, Sep 77) ...-.+- 7

-b-

Page

10
LO

1l

2h

ko

AL

53



Primary parameters R, L, C, G and characteristic
impedance Z can now be calculated with the precise
formulae of section 1.1.

If. the calculated Z is not in the prefixed range
Z,<Z<2Z,, a variation of D is considered.

This variation, taking into account (54), is given
with the step:

VE,
59) AD =——.D-AZ
6) 59.96

where AZ is the difference between the nominal and
calculated values of Z.

Once the correct impedance Z has been obtained, the
ratio k = D/d is considered and the attenuation a
is calculated with precise formulate of section I.1.

If the calculated attenuation is not in the prefixed
range % <@<«, dimensions d and D are adjusted
again.

From formula (52), the variation Aa as a function
of Ad and AD is given by:

F —
(60) aa=—e7 vf. [Pisce Ea]
Z @ D

With the scope to maintain the found value of Z,d
and D are contemporary variated as follows:

(61) AD=k-Ad

Substituting (61) in (60), Ad is given by:

(2) Ad=— Zoe
[ve Vv
a. vF. [Es oe «|

being Aa the difference between the nominal and cal-
culated values of attenuation.

With a few cycles, dimensions d and D are corrected
in order to obtain attenuation and impedance in the
prefixed limits. The computer prints d,D,S,a and Z
for every value of «, (see fig. 9).

The outer conductor thickness S can be modified
according to electrical, mechanical or economical cri-
teria; then d and D could be recalculated giving S
as an input value. This designing method is easily
extensible, with some modifications, to other kinds
of coaxial pairs.

IIL. - TABLES AND DIAGRAMS.

The calculations for the following coaxial pairs are
shown:

a) C.C.LT.T. standardized coaxial pairs
0.7/2.9 mm (foamed PE insulation)
12/44 mm (shaped PE insulation, bamboo type)
2.6/9.5 mm (PE disc insulation)

70


From these expressions, considering for « and Z
the design data, it is possible to calculate d and D:

1 ~ 2
6) d= &- | Vat+Vve-e
2Nq
(56) D=d-eTM
where:
(37) _
Ke (a—91- Ve, -F + tans) -Z

-{a—91- Ve, F- tana)

a. VF +
ve,-F
0.4772
Ve-F
The thickness S of the outer conductor can be de-

termined as a function of the diameter D. At first
approach it can be taken S =~ 0.03 D.

(58) y= Z—

READ MPUTOATA
1%, ZF AH, He, Er, tans

j me

(COMPUTE APPROXIMATE.
40,8

{

‘eouPuTE
RL COZ

<x eten 2 yo | ono a0

Yus

courte.

a,

i

mm RX senen 2 >
Yous

Paint
4.0,50.2. Ey

{

reer
tanG atand «a tang

___ Fig. 9. - Flow-chart for design of coaxial pairs.

69



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(@PH/S) J+ 9-01-18 = D

(ap{/au) 8y'9% = 2

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Te



Yet we noted that completed calls last 15 minutes on Saturday and 17 minutes
on Sunday (versus nearly 7 minutes on working days). Traffic on those days
probably flows into heavy incoming-traffic subscribers, i.e. into computers.

The distribution of traffic over the 5 working days is practically uniform.
Avery slight peak in traffic is noted on Wednesday with 22 percent of the
weekly calls handled on that day compared with 19 to 20 percent on other days.
The distribution of traffic by percentage is about the same except on Monday
which accounts for only 17 percent of the average traffic, but this irregu-
larity seems to be merely transitory.

Hourly Distribution of Traffic

Traffic on working days is distributed mainly between 0800 and 1900. A
total of 17,345 hours of traffic were observed during the 33 working days

in the period of 20 October to 19 November 1976. Some 86 percent, or 15,017
hours, of this traffic was handled between 0800 and 1900. The graph below
of the hourly distribution of traffic over 10 busy days shows how the average
traffic and number of calls remain concomitant and undergo the same varia-
tions except during reduced-rate hours.

For the latter, we note a longer duration of calls, hence the greater impact
of one call on the hourly traffic. For instance, the average duration of
calls is 6.5 minutes between 0800 and 1900, 9.6 minutes between 1900 and
2400, 21 minutes between 0000 and 0600 hours, and 15.6 minutes between 0600
and 0800. These readings were taken over 10 days in which an unusually large
number of calls were made.

Busy or peak hours are between 1000 and 1200 and 1400 and 1800. The graph
below shows a lower percentage of completed calls for these same hours.
Furthermore, generally speaking, the greater the number of calls the lower
the percentage of completed calls. It is important to underscore this out-
come because this situation can only be attributed to the subscribers, given
the relatively small load of the present central office and the singleness
of that office.

Various Types of Calls

The number of calls per day and per subscriber is 8.5 versus 1.2 per busy
hours. The corresponding number of completed calls is 4.8 and 0.55 respect—
ively. This means the percentage of completed calls is 57 on the average and
46 for the busy hour. Other types of calls are mainly those that are not
completed because the lines are busy or the called subscriber is unavailable.
As the table below shows, the percentage of these two types of uncompleted
calls is about the same.

29



|

24 éléments
SFP 250

URAD|URAD|URAD/URAD|URAD URA\ i

Batterie 25 elements
SCP 1000

12 | TELICS

Répartiteur 21 fermes

Infra

15



Certain average hourly ratios and percentages

(trafic local + arrivée)
Taux d'efficacité vrai par

rapport aux appels gg 4,
correctement formulés

Key: 1. Percentage of correctly dialed calls (after translation)
2. Percentage of completed calls made to local subscriber (local traffic
+ incoming traffic)
3. Real ratio of completed calls to correctly dialed calls.
4. Overall percentage of completed calls (all calls considered)
5. Ratio of completed local calls to correctly dialed calls.

al



On the other hand, transforming a distant URA into a local URA, or vice
versa, requires substantial modification of the program. The use of repro-
gramable stored programs makes it possible to change the program quite simply
by rewriting the contents of the REPROM unit or by replacing program storage
cards with cards programed beforehand by means of a MACHPRO.

Connecting Test Boards and Transmission Measuring Sets

Since a tandem office does not necessarily have local subscriber connecting
units it was not possible to connect devices working in subscriber code directly
to the office. Hence a special adapter was developed for connecting onto the
MSM--through the TNE and signal converter--a two-wire line worked in Subscri-
ber code. Prototypes were used for the first time in the Rennes E10 tandem
office. Regular production models reemploy the battery supply circuit designed
for the junctor cards (JCA) of the subscriber space concentrator (CSA).

Testing Local Circuits

The large number of circuits connected to a tandem office warrants installation
of a test board (or wire chief's desk) facilitating the adjustment of circuits
worked by signaling at 50 Hz pulses. However, such installation is not abso-—
lutely necessary if there is a large percentage of digital (numerical) cir-
cuits. The present test board was developed on request of the Regional Tele-
communications Directorate of Rennes because of the entirely analog environment
of the tandem office at the time it was put into service. The board had two
simulating devices, one generating signals transmitted by the tandem office,
the other generating signals trnasmitted by the minor exchange. Measuring
instruments are used to check exchanged alternating voltages and to measure
distortions of the code pulses. These checks and measurements are made on
calls initiated by the operator from the test board. For this purpose, the
board is linked to a circuit by a cord plugged into a connector on the band *
of the signal converter serving the circuit to be tested.

Traffic Observation Results

Prior to the introduction of complete load and traffic observation programs,
a series of hourly readings were taken at the Poitiers E10 toll office for
a period of 7 full but nonconsecutive days. Results obtained cover a total
of about 600,000 calls and were obtained entirely from the control element's
six peg count registers during the different reading periods.

At the time of these readings, the E10 office was equipped to handle approxi-
mately 13,300 subscribers. It was, therefore, quite near its maximum capa-
city in crass-connection boxes.

The following table and two charts summarize the results of these readings:

distribution of incoming calls, outgoing calls, and local calls, ratio of
completed calls, etc.

17



Hourly distribution of traffic over 10 busy days, of hourly completed
traffic, of average duration of completed calls, and of number of completed
calls.

durée Moyenne “A
des appels efficaces

/ sunid = i

TTminute

Nu

_——
ee
peeves SSeS P SO
{|
eS

ad TH 12H 1H 14H 16H 16H 17H 18H 18H.
Key: 1. Average duration of completed calls: 1 unit = 1 minute
2. Average traffic: 1 unit
3.

2 erlangs [Erlangian distribution]
Number of calls:

1 wit = 20 calls.

30



Hence this article discusses solely those characteristics specific to the
operation of an E10 automatic time-division switching system serving as

a tandem office: connecting distant subscribers through satellite equipment
(either a SOCOTEL minor exchange already in operation or a distant connecting
uit of the E10 type); development of these satellites for expansion of satur-
ated SOCOTEL's, initially by parallel operation and then by replacing existing
electromechanical equipment without major modification of the basic plant.

Connecting SOCOTEL eqiiipment into an E10 tandem office raises a certain number
of technical questions related to operations: billing SOCOTEL subscribers,
testing local circuits, connecting test boards and transmission measuring sets
to a pure tandem office, modification'of connecting-equipment programs and
boards. The readings from peg count. registers shown in this article were
obtained in early 1976 with very reduced programs. Complete load observation
programs are currently underway in some tandem offices.

Lastly, the example of the Rennes-Lavoisier tandem office, whose evolution
is characteristic of this type of application, is described in detail.

Use of the E10 System in Local Exchange Areas
Distant Subscriber Connecting Units

The possibility of establishing satellite exchanges by means of subscriber
connecting units (URA) identical to those used locally for servicing central
office subscribers, gives the E10 system the dual capability of being suitable
for establishing subscriber loops designed to service rural or suburban areas.
In fact, recourse to distant "concentrators" is almost a necessity in scattered
networks, instead of multiplying, at a prohibitive cost, the number of inor-
dinately low-capacity independent-routing exchanges. It should also be noted
that this remote siting in no way alters the possibilities of connecting
cross-connecting terminals (TELIC), PBX lines, Telex lines, or any other equip-
ment that can be connected into a subscriber connecting unit.

Moreover, systematic utilization of digital transmission between the core of
the E10 time-division chain and the URA carries at URA level all of the volume
equivalent available for the terminal system: the only restriction limiting
the length of the subscriber line is, therefore, generally the minimal amount
of power (or current) supply consistent with efficient operation of the URA's
calling equipment (or subscriber line). This amount of current is presently
on the order of 15 milliamperes. Use of dipoles of the Calliope type or of
intensity correctors for telephones with low current consumption is also still
possible under the same conditions as with electromechanical equipment.

Lastly, introduction of remote concentration substantially reduces distribu-
tion costs.

1e



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wal



Due to the strading of coaxial pairs, it is necessary
to take into account the fact that coaxial pair length
is greater than cable length, For instance, in a 8 coa-
xial pair cable 2.6/9.5 mm manufactured by Pirelli
this increase is about 0.5%.

The computer programme gives the possibility of
choosing three different frequency sequencies (see
fig. 2):
~— arithmetic progression;

—— geometric progression;
— fixed sequence.

The formulae employed are deduced from the ge
neral theory of transmission on circuits with unifor-
mely distributed constants and therefore they have
no frequency limit [1, 2].

The symbols used in the formulae are:

d inner conductor diameter (mm);

D = inner diameter of the outer conductor (mm);

Ss = thickness of the outer conductor (mm);

Pe; = resistivity of the inner conductor for the de-

Qmm?
sired temperature | ————] ;
(“e)
Pe = resistivity of the outer conductor for the de-
+ Qmm? .

sired temperature (=) H

u,; = relative magnetic permeability of the inner
conductor;

H,, = relative magnetic permeability of the outer
conductor;

&, = average relative dielectric constant of the in-
sulation between inner and outer conductor;

ft = frequency (kHz);

tan§ = tangent of loss angle of dielectric.

The computer programme is based on the follow-
ing relationships:

@

56



VIETNAM

SRV RADIO, TV COMMISSION HOLDS CONFERENCE IN HO CHI MINH CITY
Ho Chi Minh City Domestic Service in Vietnamese 2345 GMT 8 Nov 77 BK

[Text] On 8 November in Ho Chi Minh City, the Vietnam Radio and Television
Commission opened the first conference on broadcasting and wired radio
activities in the southern provinces. Attending the conference were
representatives of people's committees and of propaganda and training
departments of provincial party committees. Also present were cadres in
charge of radio and television stations in the southern provinces.

Comrade Tran Lam, alternate member of the party Central Committee and
chairman of the Vietnam Radio and Television Commission, reported on the
situation and duties of the local radio broadcasting and wired radio
networks. After pointing out the great achievements of the broadcasting
and wired radio networks over the past 30 years, he talked about the
duties and functions of the Radio and Television Commission and about the
present broadcasting and wired radio task.

The political task of the Radio Broadcasting and Television Network is
essentially the political task of the press organs aimed at contributing
to the propaganda, education, motivation and organization of the masses and
to the transformation of the party's resolutions into the mass revolutionary
action movement. Today, although most radio broadcasting stations and

the local wired radio network have just been built, the radio broadcasting
and wired radio task has enjoyed fundamental advantages. The radio broad-
casting and wired radio networks have been entrusted by the party and state
with a glorious political task and a worthy role in socialist construction.
They have been provided with fairly good material and technical means and
cadres and have acquired much experience serving as a basis for further
progress.

The conference heard a draft report on the functions, duties and organiza-
tion of the body managing the local radio broadcasting and wired radio
network and of organs in the southern provinces responsible for assisting
the Vietnam Radio and Television Commission in the radio broadcasting

and wired radio activities.

The conference will work for 3 days.

cso: 5500



Estimates made in 1969 of Caducee network subscriber traffic

Nombre en % 22

Nombre d'appels & Theure
concemant un terminal 7

Durée d'un échange

Ts
Fae partemina aroun oT 015 E

Key: 1. Expected load after setting rates 7. Number in percentage

2. Terminals 8. Number of busy-hour calls

3. Dialog for one terminal

4. Heavy 9. Duration of one call

5. Average for terminals 10. Traffic per terminal in busy
6. Computers hour

a. Consolidated-traffic terminals
b. Nonconsolidated-traffic
terminals

tantamount somewhat to the "no answer" in telephony. However, in such cases
the Caducee system's calling party is informed of this unavailableness situa-
tion, a procedure that should reduce the number of uncompleted calls. The
traffic billing and observation system installed back in 1972 analyzes all
calls, completed or not, thus giving detailed information, the equivalent of
which is difficult to obtain in telephony.

Lastly, the traffic flow between the various subscribers is important from

two standpoints: the distribution between light-traffic and heavy-traffic
subscribers shows specifically that calls between light-traffic subscribers
(terminals) are much more numerous than had been estimated. Geographical
distribution of the flow is most important, if only as a means of anticipating
the network's future development, but also as an indication of the telepro—
cessing situation in the various regions. Some regions actually have relations
practically only with the Paris region, while others have a real local flow "
of traffic.

eT



@ @ 2

07

1.06 %
1.05 | 4; 7

1.06 20
4.03

1m jss
yo a

1.90

o 4 2 3 4 RFR

Fig. 6. - Spirality effect coefficient [3].
f = frequency (kHz)

P= pitch of spirals

d’ = diameter of conductor

Ry = conductor d.c. resistance (/km)

For f = 0, the spirality effect coefficient is Q(0) = 1
and then Q increases with frequency.

However the increase of resistance due to spirality
is usually a small fraction of the increase due to skin
effect.

Calculation of L, and L, can be done with the fol-
lowing approximate formulae:

40;
37) L,= {|—]-
7) “i (; @)
q (ber q) (ber’q) + (bei q) (bei’g)
20 (ber 'q)? + (bei’g)?
inductance of inner conductor (H/km)
2s 28
. Sh —— —sin ——
(8) 2, = 2-108. ,__
° DotA 28 2s"
Ch —— —cos ——

inductance of outer conductor (H/km)

where:
A=02d,

q and 6, are given by (i) and (5) respectively.
Considering the particular shape of the inner con-
ductor, L, and C are calculated by:

DotA
(38) Ly = 2-10-41 E*
inductance of space between conductors (H/km)
55,6325 - 10-92,
DotA

ed

(40) C=
In

loop capacitance (F/km)

63


approximate formulae can be employed for attenua-
tion and impedance calculations:

VF [ye ky tke
(3) a = 97.1 [Aa py _ be ke]
Zy d (Dy + A)
+91 Ve,-F-tand (dB/km)
5996 Dota
(44) =— = h —— (Q)
% ve, td
The meaning of symbols employed is the following:
D, = diameter over solid dielectric (e.g. polyethy-
lene (mm);
d = overall diameter of inner conductor (mm);
k, = stranding factor for attenuation;
k, = braiding factor;
k,, = coating factor for inner conductor;
kj. = coating factor for outer conductor;
in = resistivity of inner conductor (Q mm?/km);
Pe = resistivity of outer conductor (Q mm2/km);
g = average relative dielectric constant of the

insulation;

frequency in MHz;
tangent of loss angle of the dielectric;
additional thickness due to braid shaping

of the outer conductor (mm);
e = effective diameter factor.

The parameters & and k, are functions of the num-
ber of wires n forming the inner conductor [6] as
shown in the following table:

n 1 7 12 19
1 0.939 0.957 0.970
k 1 13 13 13

The braiding f

‘actor k, is given as a function of the

diameter D, aver the insulation, according to the fol-
lowing fig. 7.

—

4 8

© 2

De Gon)

Fig. 7. - Braiding factor k, as a function of diameter over insu-
ation Dy [4].

65


When the construction details of the braided outer
conductor are known, the braiding factor k, can be
calculated by means of suitable formulae [5].

The coefficients k,, and k,, are the coating factors
for inner and outer conductors respectively.

For uncoated conductors the coefficient is k, = 1;
for tinned or silver plated conductors, the coefficient
k, dependes on thickness and resistivity of tin or
silver. .

The following table shows the values of k, for a
tinned copper surface, where the tin thickness is
equal to 0.005 mm. .

Coating factor for tinned copper surface (61.

Frequency k
(MHz) *
1 1
5 1
2» 1.03
100 1.16
200 126
600 1.9%
1500 2.65
3500 2.92

The additional thickness A takes into account the
air layer between the solid insulation and the outer
braided conductor. Usually A is small in comparison
with D, and can be taken:

A = 074,
where:
d, is the diameter of the braid wires.

To extend the calculations to frequencies lower than
10 MHz, it is necessary to calculate first of all the
primary parameters R, L, C and G and than it is pos-
sible to obtain secondary parameters (a,8,Z, etc.) by
means of formulae shown jin section I.1.

The calculation of primary parameters for a braided
conductor at frequencies lower than the ones pre-
viously examined is extremely complicated. However
some approximate results can be obtained considering
an outer conductor having the same d.c. resistance as
the braided conductor i.e.:

Perky
Ry, + % (Dy + A)

equivalent thickness of outer conductor for skin ef-
fect evaluation (mm)

(46) R, = Ry k,
effective resistance of outer conductor (Q/km)

(45) S=

66



FRANCE

GROWTH OF CADUCEE TELEPROCESSING NETWORK REVIEWED |
Paris L'ECHO DES RECHERCHES in French Apr 77 pp 22-31

[Article by Alain Dupont, senior telecommunications engineer in the Distribu-
tion, Terminals, and Services Division of the National Center for Telecommuni-
cations Studies (CNET) in Issy-les-Moulineaux, and Dominique Gerard-Hirne,
engineer in the CNET's Department of Data Transmission and Private Systems
(RTS-TOP [Systems, Terminals, and Service-Data Transmission and Private
Systems] in Issy-les-Moulineaux: "Caducee Traffic After 4 Years of Operations"]

[Text] After 4 years of operation, the Caducee network
appears to have basically satisfied the demand for data
transmission service and justified the technological choice
its adoption constituted. The authors of the article below
analyze the latest available traffic observations. Their
analysis is based on criteria similar to those employed for
the telephone system. After comparing these observations
with initial estimates, they highlight different types of
calls, peak traffic loads, dispersion of the duration of
calls, and the importance of certain geographical regions.

Caducee Network

The Caducee switching network was conceived back in 1969 and installed in

1972. It was designed to meet a three-point goal: fill the gaps in tele-
processing services provided by PTT's [Postal, Telegraph, and Telephone Service],
experiment by developing a full-scale teleprocessing system, and orient data
processing equipment manufacturers and users toward systematic use of a public
switching network specifically adapted to their requirements. This network and
its innovative features have already been thoroughly described on several
occasions. Its main components have also been discussed in various publica-
tions: terminal facilities, line concentrators, maintenance of local loops

and automatic switching equipment. Although this was a revolutionary system
in many respects, it was meant to be only a transitional but long-lasting
phase prior to introduction of the digital switching network fully adapted

to high-speed data transmission, namely the Hermes network.

ak



“
| tae

Fig. 13. - Attenuation of power cable 32.44/57.2 mm

with tubular conductors at 20°C,

ah : ae :
T 1]

Py it

»

al

* Z

:

a

bere
:
& a i ; = 7% %
Fig. 14. ~ Attenuation of flexible coaxial pair

1/65 mm with outer wire braid

16

conductor at 10°C,



INTERNATIONAL

BRIEFS

INDO-HUNGARIAN MEDIA COOPERATION--India and Hungary have agreed in principle
to have wide-ranging mutual collaboration in the field of radio, TV and

other mass media to strengthen their bilateral relations, This was disclosed
by the visiting Hungarian minister for information, Doctor Peter Varkonyi,
after 2 days of talks with the minister for information and broadcasting,
Advani, and other Indian leaders in New Delhi. [Text] [Delhi ISI in English
1449 GMT 3 Nov 77 BK]

csO: 5500



CONTENTS (Continued)
TURKEY

Briefs
Kastamonu TV Reception

Page

78



Remote or distant URA differs from local URA by the contents of its stored
Program and by the addition of supplemental program cards designed chiefly for
transmitting signaling information via the semaphore channel and for synchroniz—
ing the URA with the tempo of the digital link. Within a period of time much
shorter than the service life of installed equipment, a satellite exchange
sometime becomes large enough to warrant converting it into an independent-
routing exchange. This situation is frequently noted in some fast growing |
suburban areas. In such cases, use of standard equipment permits converting
the exchange with a minimum of disturbance to both equipment and users. In
fact, conversion of a distant URA into a local URA merely requires substitution
of a few program cards.

Connecting SOCOTEL Minor Exchanges

Local trunks running into minor exchanges are connected in the same way as
interoffice circuits or short-haul toll circuits, namely via a Multiplex
Synchronization Module (MSM).

If the link is made digital by means of the TNE [Terminal Numerical Equip-:
ment (?)] terminal equipment in the minor exchange, the connection of each
30-channel multiplex is made directly, the remote power supply equipment
being preferably within the MSM so as to facilitate maintenance. Of course,
if the length of the link warrants, it may be necessary to provide a remote
power supply unit at each end of the link.

When the link is worked at low frequency the connection of each trunk is

made on a signal converter coupled to a TNE installed in the E10 exchange.

The code most generally used is the SOCOTEL pulse code. The only type of con-
verter developed is a converter for low-level 50 Hz pulses. There are two
versions of this converter, one for outgoing circuits, the other for incom-
ing circuits. The essential difference between these two versions is that the
latter has a filter designed to suppress the 50 Hz parasitic frequency detri-
mental to telephone calls. To facilitate adjustment and maintenance, the
ringing or signaling set used on the E10 converter is identical to the one
used in the minor exchange's SOCOTEL junctor.

Expansion of E10 Tandem Office for SOCOTEL Minor Exchanges

The E10 system uses two-way communications called "networks-lines" to tie
URA's and Circuit Connecting Units (URC's) into the connecting network, without
special assignment to one or the other function. Hence if'a subscriber loop
is initially planned to serve solely electromechanical minor exchanges, it

is perfectly conceivable--in a first phase--to add URA's to it so as to expand
certain minor exchanges, and then--in a second phase--make further expansion
by replacing electromechanical frames with new URA's. Control devices contain
programs common to all types of subscriber loops, thus making it possible to
carry out these operations without doing anything to the control devices,
except possibly to insert supplemental program parameters defining the added

13



THAILAND

ANTICORRUPTION REPORT NOTES SEIZURE OF RADIO TRANSMITTERS
Bangkok NATION REVIEW in English 9 Nov 77 pp 1, 3 BK

[Excerpt] Thirty-five persons have been arrested in a series of raids on
clandestine radio-transmitting stations in the northeast and Bangkok
"where Vietnamese were found to have illegally directed radio programmes
in collusion from some government officials."

Anti-corruption committee [ACC] Secretary General Suthi Akatsoloek reported
yesterday that in coordinated raids against the illegal radio stations in
the northeast, authorities seized 15 10-kilowatt radio transmitters, 2
1-kilowatt transmitters and 1 20-watt transmitter, valued at 25 million baht.

Two clandestine radio stations were raided in Bangkok, he said. Mr Suthi
said the raids were part of the coordinated work of ACC officials working
hand in hand with the customs, public relations, police and post and
telegraph departments.

He did not specify the period of time during which the raids were carried
out but the ACC secretary general said the activities were part of the
annual report filed by the ACC to the Revolutionary Party.

The annual report, covering the period from 1 October, last year until

30 September 1977, also says that the ACC had also assisted in discovering
corrupt forestry officials in the past year.

CSO: 5500



-

TURKEY

BRIEFS

KASTAMONU TV RECEPTION--Television broadcasts can be viewed from band 3
channel 6 in Kastamonu and its vicinity as of this evening, According to
information obtained by the TRT [Turkish Radio and TV Administration] tech-
nical officials, viewers in Kastamonu and its vicinity should direct their

antennas toward Ilgaz Mountain, [Text] [Ankara Domestic Service in Turkish
0530 GMT 4 Nov 77 TA]

csO: 5500 END

78



General Schematic of Test Board for Local Circuits

Qeerererce —— Qeratsennw -—fososionine —]@
Impulsographe 6

i Adaptateur 4 J Adaptateur E== —{ Contrdteur ucivorel] @
| . Simulateur E10 PO
° of.
@ Pupitre Commande }—* Connexion ‘Simelateur de CS Ampli BF
t f |
|
Key?
1. Service line 7. Console
2. Circuit to be tested 8. Control
3. Distortion meter 9. Connection
4. Adapter (converter) 10. E10 simulator
5. Pulse analyzer 11. Minor exchange simulator
6. Universal controller 12. Pulsed oscillator (?) or low-fre-

quency amplifier

Significance of Control Element's Peg Count Registers
Cl: New "confirmed" calls

C2: Completed calls

C3: Completed calls to local subscriber

: Correctly dialed calls )

C5: Calls to local subscriber ) After translation of routing

C6: Local calls )
C5-C6 : Incoming calls
C4-C5 : Outgoing calls
cé xX se : Completed local calls*
(C5-c6) x 8 : Completed local calls*
C2-C3 : Completed outgoing calls
(c2-c3) + c6 x G3 : Billed calls*

*The percentage of completed calls made to local
subscriber is determined for local and incoming
calls simultaneously.

19



JPRS 70200

21 November 1977

TRANSLATIONS ON TELECOMMUNICATIONS POLICY,
RESEARCH AND DEVELOPMENT

No. 21

Reproduced From
Best Available Copy

U. S. JOINT PUBLICATIONS RESEARCH SERVICE

20000315 071


An economic comparison among these systems
could be meaningless, if limited to cost analysis only,
because their service capability or utilization time,
as well as the investment costs or distributed invest-
ment costs can be very different. The large capacity
operation, offered by these systems, may be gradually
utilized only in many years, if installed in next future in
Italy or generally in European countries, by consider-
ing the present traffic situation on the main transmis-
sion routes and the forecasts of traffic expansion (!).
The difficulties to make forecasts of technological
advances, which may occur during the long expected
life of the plant and, perhaps, before the utilization
of its whole service capability, and of their impact
on future costs, make it very difficult to evaluate
the expenditures for the parts of the plant which
should be installed too far in the future, as well as
the expenditures for the replacements. It is even mo-
re difficult to forecast the cost of future plants to
be installed on a given transmission route either
when the system under evaluation will no longer
provide the service demand expansion or at the end
its life,

Because it is not possible to extend the costs
and the service demand expansion forecasts up too
far in the future and therefore up to the time t = ~,
it is necessary to limit the cost comparison to a con-
venient period of time (called the « study period »),
which should be short enough to make acceptable
forecasts. As discussed in the following sect. 4, the
economic comparison between different systems does
‘not seem in this case to be performed. satisfactorily
on the basis of the various methods, previously quo-
ted, because generally it is not made on the basis
of an equivalent overall service capability and/or
of an equivalent service capability at the end of the
«study period». It is therefore necessary to take
into account also the evaluation of the different ser-
vice capabilities and of the different services (or of
what will be called here system « utility »), provided
by different systems along the study period. __

(2) Some investements occur at the beginning of the plant life,
as those for the transmission medium (i.e. those for cables or
waveguides and their installation, for trenching and conduits,
land, accessory equipment for pressurization, etc., buildings-in-
cluding ancillary services and purchase or leasing of land for the
Stations).

Other investements occur at future dates. For example those
for the repeater equipment and their installation, as weli as
those for the terminal equipment, are distributed along the life
of the plant depending on the growing of the service demand.
Also the operation costs are distributed annually along the life
of the plant and are growing with the service demand.

Purpose of this paper is therefore to discuss (sect.
5) a temptative study form to compare different sy-
stems, which takes into account both cost and utility
forecasts in the limited « study period », where fore-
casts are still reasonable.

The basic premises to be considered for said study
form are discussed in sect. 2, while a tentative de-
finition of the system «utility» is given in sect. 3.
An analyis of available study forms, based on costs
only, is discussed in sect. 4. Examples of economic
comparisons among different systems, using both the
study form discussed in sect. 5 and other study forms,
are given in sect. 6.

2. - BASIC PREMISES FOR AN ECONOMIC STUDY FORM 10
COMPARE DIFFERENT TRANSMISSION SYSTEMS.

A study form for an economic comparison of dif-
ferent transmission systems should satisfy some ge-
neral basic premises, on which a general agreement
could be found. It seems that these premises could
be the followin;

a) The comparison should take into account the ser-
vice demand forecast over a given transmission
route in a period of time long enough to be mea-
ningful, but not too long to avoid forecasts ex-
tended too far in the future (for example the pe-
riod could be typically 10 to 15 years and not
greater than 20 years).

b) The cost evaluation should take into account the
timing of expenditures and retirements @) (which
are generally different for different systems) by
converting expenditures at different dates to an
equivalent amount at a common date.

ts for repeater equipment are those for the transmitting
and receiving equipment “and ancillary facilities installed both
in the intermediate and in the terminal stations of radio links or
of waveguide systems and those of the line amplifiers in cable
systems (including their installation). The costs of terminal equip-
ment are those of multiplex equipment installed in terminal sta-
tions and of their ancillary equipment for switching, control alarms
and protection.



CZECHOSLOVAKIA

BRIEFS
NEW TV TRANSMITTER--A new television transmitter for the second program was

put into operation at Tlusta Hora near Gottwaldov today, [Prague MLADA
FRONTA in Czech 28 Oct 77 p 2 AU]

cso: 5500



BULGARIA

BRIEFS

RADIOELECTRONICS SYMPOSIUM--Varna, 2 Nov (BTA)--The 6th Symposium on Radio-
electronics with the participation of scientists and experts from Bulgaria,
the GDR, Poland, the Soviet Union, Hungary, Czechoslovakia, Austria and Fin-
land began here today, The participants will discuss questions concerning
the design, technology and [word indistinct] in radio location, radio navi-
gation and radio relay lines and the possibilities for rapid and effective
solving of problems arising in the radioelectronic industry. [Text] [Sofia
BIA in English 1437 GMT 2 Nov 77 AU]

cso: 5500



The hypothesis of neglecting the screen is accep-
table over the whole frequency range generally con-
sidered.

Assuming an outer conductor sufficiently thin
(S/D < 0.2), the results obtained with the above hy-
pothesis have shown in fact a good approximation
to the measured values both for high “frequencies
where these cables are generally used (f > 60 kHz)
and at lower frequencies.

The tables and diagrams attached show some results
of calculated and measured values.

For the coaxial pair 2.6/9.5 mm the calculations
have been extended from 50 Hz to 500 MHz.

In particular, for rather high frequencies, if the
geometric dimensions and the electric characteristics
(resistivity, dielectric constant, magnetic permeability,
dielectric loss angle) of the coaxial pair are exactly
known, it can be considered on the basis of compa-
risons made with measured values, that the effective
values of secondary parameters can be calculated

__With an error less than a few thot

[Pea THE murat ATA

tone Tc
PROGRESSION?

eX

Fixe
seovence?

READ THE FREQUENCY UNIT AND
IN THIS UNIT, THE INITIAL F, THE STEP
‘AND THE FINAL F

Yes

‘COMPUTE AND PRINT
PARAILWITH F IN HZ.

No

yes ANOTHER EXECUTION
IS REQUIRED?

READ WHICH PARAMETERS.

ANOTHER FREQUENCY PRINT THE REQUIRED PARAMETERS
3€ IS REQUIRED WITH F INTHE REQUESTED UNIT
RANGE ?

Her)

MUST BE PRINTED

CONPUTE

Fig. 2. - Flow chart for calculation of transmission parameters.

dD



It may be of interest to compare the table below giving percentages of inter-
regional traffic with the estimated table for the Transmic network: a few slight
differences appear, in addition to the existence of internal traffic.

MATRICE INTERREGIONALE DE TRAFIC EN POURCENTAGE

5
du H
2 &é 8 i +
03 03 A
02
} 04
i f i |
os" oz 04 :
ujos i2z304 01 os 02
| a i i 202 :
orlo2 fiz oat 09 25 02-
W037 2 02 oa :
F i j ;
4 i |
(07 | On 02 !
f0102° 02 on
OB. :
; 02
oj
03° oa
03 oA
: 214 | Paris Extra-Mi

IMoyenne sur 10 jours chargé

Key: 1. Interregional Traffic Matrix, in Percentage
2. Suburban Paris + Inner-city Paris
3. Average over 10 busy days.

38



However the Caducee network can actually meet only part of the demand because
of its analog character and electromechanical automatic switching equipment.
It also demanded a new standardization effort on the part of automatic data
processing equipment manufacturers. Lastly, its growth could not help but
be limited on account of its single connecting point despite the development
of concentrators that made it possible to connect 60 percent of the network's
subscribers from outside the Paris region, mainly from Lille, Lyon, and Mar-
seille.

Importance of Traffic Analysis

Several reasons make traffic analysis of the Caducee system extremely valuable.
At the time the system was designed and put into operation, teleprocessing
traffic over a specialized switching network was absolutely unknown. Hence

it is essential to determine the characteristics of such traffic, not only in
preparation for the future Hermes network, but also so as to be able to com-
pare these characteristics with those of telephone traffic as much as possible.
To draw any valid conclusions from this analysis it was definitely necessary
to wait until the promotional period had passed, because the interest incited
during that period might give a false picture of the real requirements. It
was also necessary to wait until the number of subscribers became significant,
so that the number of test calls would be small in relation to the real traffic.
These considerations account for the relatively long period of time that has
elapsed between the date the system became operational and the writing of

this article. Yet Caducee traffic was observed throughout these 4 years and
showed a steady change, particularly in the now-stabilized duration of calls.

A feasibility survey made among major users and maufacturers in 1969 disclosed
traffic characteristics based exclusively on flows between computer and ter-
minals, assuming that the rates fixed did not favor certain categories of trans-
actions. This led to an average call duration of about 1 minute which was
unacceptable for the electromechanical type of automatic switching equipment.

To prompt users to plan longer calls, a handling charge was established for

a call lasting about 1 minute. The following table shows the characteristics
of the estimated traffic.

In fact, as we shall see, these fears were not confirmed because the duration
of calls proved to be much longer than estimated. They were about 10 minutes
long in 1973 and have now stabilized at approximately 7 minutes. One plausi-
ble explanation: users quite frequently chose the Caducee network for rela-
tively low-speed purposes instead of the telephone system, probably because

it was much less congested and more error-free.

Hence it is highly useful to compare the findings of this analysis with corres-
ponding results of a telephone traffic analysis, notably peak hours, distribu-
tion of calls by duration, and their type and number. An original feature of
the Caducee. system should be noted at this point: it is possible for the
called subscriber not to answer the call, even when he is not busy. This case,
called "unavailableness" is designed to cover computer maintenance time and is

26



c) Only the expenditures made in a limited period of
time, the « study period » (for example in a period
smaller than 20 years) should be considered in
the cost evaluation. This is due to the fact that
cost forecasts on the basis of a given technology
cannot be reasonably extended to all the plant life,
because technological improvements may modify
equipment and change their costs, may render ob-
solete the system configuration under evaluation
and allow the introduction of new more advanced
systems over the same transmission medium.

d) The life of the equipment is generally smaller
than that of the transmission medium. Because
of the technological advances the equipment may
be considered obsolete after about 15 years, ac-
cording to the present experience. The operatio-
nal life of the transmission medium is much lon-
ger than the «study period» previously defined,
for example 40 to 50 years.

e) In the comparison among different systems the
right importance should be given to the fact that
over a given route some of the systems may offer
a service capability larger than that required or
forecast at a given future date (for example after
10 or 15 years or at the end of the « study pe-
riod »), which will be utilized for the future ex-
pansion of the service demand with generally mo-
dest additional investment costs.

f) The comparison among different systems should
be based on the evaluation of a convenient figure
of merit, to characterize any given plant, which
should be a convenient function of the ratio bet-
ween cost and the utility provided in the «study
period » by the given plant. In fact an economic
comparison among different plants may be per-
formed on a costs basis only, in the case they
meet the same service demand, provide service
over the same period of time, and have the same

@) Said figure of merit, according to previous criteria, cannot
be a constant, but will be a function of the service demand ex-
pansion rate & over the given route, of the initial service capa-
bility already available on the route through other existing faci-
lities, of the appropriate compound interest rate z, of the life
forecast for the plant and its parts, of the investments timing,
which has been planned out, etc. Because it is not convenient
to install new parts of a plant too frequently, it will be reaso-
nably to forecast investments for new equipment to meet expan-
sion of service demand at periods no shorter than 4 to 5 years
and investments for new transmission media at periods no shor-
ter than about 10 years.

This figure or merit, therefore, will characterize a given plant
only for a given transmission route and for a given service de-
mand forecast and for a given plan of investments. To compare
different systems it is therefore necessary to evaluate said figure
of merit for the same transmission route and under the same
assumptions of service demand expansion.

are not always met, it is also necessary an evalua-
tion of the differencies and qualities of service
(ie. an evaluation of what will be later defined the
«utility » forecast during the « study period »).

The figure of merit, which should characterize a
given plant, should be defined in a way that it
remains fairly constant as the length of the « stu-
dy period » is changed. Only in this case this fi-
gure of merit can really characterize the given
plant for all its life period, because it is then the
forecast of the cost-utility ratio of the plant, over
its entire life pericd, madc during the « study
period » (3).

&

In the above criteria it has been pointed out the
importance of taking into account, in addition to the
«costs», what we have called the «utility» provi-
ded by a system in a given plant, because it may be
different for different systems.

The word utility has been given here a wider
meaning than that of the income, expected during
the operation of the plant and due to paying tele-
phone traffic or other paying services. Its meaning
has been brodened out to take into account that so-
me of the available circuits may be used by the Ad-
ministrations for various operational services also
when they are not used for paying services (for exam-
ple when part of the circuits are used as spare cir-
cuits, or when the plant is used for alternate routing
in a communication network, etc).

3, - « Uritity» of a transmission system.

A quantitative evaluation of the utility of a trans-
mission system is not an easy problem, but it is
really not needed for the purpose of the paper (ie.
the definition and evaluation of a convenient figure
of merit to compare different systems). It is suffi-
cient to observe that the «utility» W(u), provided
during a given year u by a plant, should be a quan-
tity proportional to the overall number N,, of equi-
valent telephone circuits (TFc.) available in said year
(ie. installed up to the wth year).

43



Caducee subscribers have been increasing at a rate of nearly 300 per year.

The resultant total of more than 1,000 subscribers at the end of 1976 thus

confirmed estimates made in 1970 and warranted the installation of a second
automatic switching facility in Lyon in the near future. Lyon is France's

second leading data processing center after Paris.

Caducee's rate of growth may appear rather slow in comparison with the much
more rapid increase in the number of leased-line networks at 600-12,00 bauds,
at more than 1,200 bauds, or subscribers to data transmission at 600-1,200
bauds over the telephone switching network.

Increase in number of leased-line networks and connections made into the
telephone network and Caducee network.

Nombre de liaisons
spécialisées

7500 600/1200 bauds

‘sur liaisons spécialisées

> 1200 bauds
sur liaisons spécialisées

Key: 1. Number of leased-Iine networks 6. Caducee network
2. 600-1,200 bauds over leased-line networks 7. Years
3. Number of subscribers
4. “> 1,200 bauds over leased-line networks
5. 600-1,200 bauds over telephone network

25



Large coaxial pairs of this shape are generally em-
ployed for very high frequencies.

The transmission over power cables, usually covers
the frequency band between 40 and 500 kHz.

The formulae previously described are modified
only as far as the inner conductor is concerned.

Symbols are the same as in section I.1.

The depth of penetration of the inner conductor
is given by:

1 %

@ § = 04- uy F

Ss
For sufficiently thin inner conductor nm < 0.2),

the following approximate formulae can be used:

2s 2s
Sh — +sin 2%
(28) k= a
i=
3, 2 2
J Ch 2 cos 2
‘7 8

skin effect coefficient for inner conductor

The resistance of the inner stranded conductor is
calculated as follows:

4(1+C¢;
a3) Ry = sate)
und;
dic. resistance of inner conductor (Q/km)
(e)) Ry = Ry k-Q,

effective resistance of inner conductor (Q/km)

where:

k, is expressed by (3) and Q, is the spirality effect
coefficient of inner conductor.

The resistance of the outer stranded condi i
uci
calculated as follows: tor is

4(1+C,)
35) =
Roe = Nad
dc, resistance of outer conductor (Q/km)
(36) R, = Ry ke Q,

effective resistance of outer conductor (Q/km)
where:
k, is expressed by (6) and Q, is the s irality eff
€ t
coefficient of outer conductor. ° vy eues
The value of the «spirality effect coefficient » is
given in fig. 6 (where d’ is equal to d or Dy):

62



PEOPLE'S REPUBLIC OF CHINA

DIGITAL SATELLITE GROUND STATION OPERATIONAL
Peking NCNA in English 0813 GMT 8 Nov 77 OW

[Text] Peking, 8 November 1977 (HSINHUA)--The first digital satellite com-
munication ground station designed and built by China has been put into
operation with satisfactory results. The double-channel colour television
programmes relayed by the station from communication satellites are clear
and the sound effect is excellent.

The new station will be used to transmit the format of the PEOPLE'S DAILY,
radio and television programmes and other radio messages from Peking to
far-off areas. It is of tremendous importance for enhancing China's
endeavours in satellite communication and oceanic communication, accelerat-
ing the modernization of telecommunications, developing the national economy
and space projects and strengthening national defence.

China built an analogous satellite communication earth terminal in 1975.
Coming into use in a number of countries toward the end of the sixties and
the beginning of the seventies, digital satellite communication is highly
resistant to radio interference and ensures greater secrecy.

Both Chairman Mao and Premier Chou attached great importance to the develop-
ment of satellite communication and related projects. Encouraged by their
close attention, scientists, technicians, cadres and workers cooperated
closely in the course of designing and constructing the earth stations

and scored outstanding successes by emancipating their minds and following
China's own road of developing science and technology.

cso: 5500



Future door

Power panel

French Electric Power Company

24-cell battery SFP [expansion unknown] 250

Distant Subscriber Connecting Unit.

40-ampere rectifier

9-bay distributing frame

Type 1 building, E10 satellite, 1,000 subscriber lines
9 cross-connecting terminals

100-ampere rectifier

24-cell battery SCP [expansion unknown] 750 AM

21-bay distributing frame

Type 2 building, E10 satellite, 3,000 subscriber lines
160-ampere rectifier

Power units

25-cell battery SCP 1000

12 cross-connecting terminals

21-bay distributing frame

Type 3 building, E10 satellite, 4,500 subscriber lines.

16



ITALY

CALCULATION OF TRANSMISSION PARAMETERS, DESIGN OF COAXIAL STRUCTURES
BY COMPUTER

Milan ALTA FREQUENZA in English No 9, Sep 77 pp 213-223

[Brticle by G. Corti, G. Tizzi/
[text]

A method for calculating transmission parameters
and designing coaxial structures by computer is de-
scribed.

The paper deals with various types of coaxial struc-
tures for telecommunication purposes and with coa-
xial structures designed for power transmission which
may also be employed for telecommunication tran-
smission.

Measurements confirm the validity of the method.

There is a lot of literature on calculation of tran-
smission parameters of coaxial structures.

In the references are shown the more significant
Papers examinated.

As can be seen, each of them deals with a special
type of coaxial pair and usually in a limited range
of frequency.

The purpose of this paper is to extend the study to
all the more used coaxial structures and to the whole
frequency range of any interest in telecommunication
field.

The calculation of transmission parameters con-
cerns coaxial pairs standardized by C.C.LT.T., sub-
marine cables, microwave cables, radio frequency
cables and power cables.

Coaxial pairs with solid inner conductor and tu-
bular outer conductor have been studied first and

(*) G, Conrt - Sirti S.p.A. Milano. .
(**) G. Tizzx - Industrie Pirelli S.p.A. Milano.



cso:

5500

CONCLUSIONS.

The comparison between calculations and measu-
rements confirm the utility of this paper.

The degree of accuracy is very high for coaxial
pairs with solid inner conductor and outer tubular
conductor that are the most employed in telecom-
munication field.

For the other ones, calculations are less precise
but however in accordance with the approximation
usually required.

The proposed design method allows to find coaxial
pairs satisfying the input data with any prefixed to-
lerance. :

The paper was first received on June 23, 1977.

REFERENCES

{1] H. Kaven: Wirbelstréme und Schirmung in der Nachrichten-
technik, Springer Verlag, Berlin 1959.

12) K. Kurrmuur: Electricité théorique et appliquée, Dunod,
Paris 1959.

[3] M. B. Dwicur: Skin effect and proximity effect in tubular
conductors. « Transaction AIEE », February 1922, p. 189.

[4] LE.C.: Radio frequency cables, Recommendation 96-0, 1970.

[5] L. R. Spicer: Relationship between attenuation and wire-braid
design for flexible radio-frequency cables. « Electrical Commu-
nication », vol. 40, N. 4, 1965.

{6] ©. Mnpner: The power rating of radio frequency cables.
« AIEE transaction », vol. 68, 1949.

[7] G. Matoxe: Impedenza delle condutture tubulari. «L'Elettro-
tecnica», Novembre 1936.

[8] G. W. Dumaa, W. T. Bracksano: Wires and R.F. cables. Pit-

1961.

TT



e
W

average relative dielectric constant of the in-

" sulation between inner and outer conductor;

C; = stranding loss of the inner conductor;
Cc, = stranding loss of the outer conductor;
tf = frequency (kHz).

For cables of type a, it is possible to employ the
formulae of section 1.1 .with some modifications.

loop resistance of coaxial pair (Q/km)

D
(9) By = 2-10-+in —

inductance of space between conductors (H/km)
(10)

L, = Pad , (berg) - (berg) + (bei g)-- (bei q)
7 :

2w (ber 'q)? + (bei ‘gy?
effective inductance of inner conductor (H/km)
(it) :

2s 2s
5 Shao asin
L, = 2-10-4. <2. “ soy,
28 2s
Ch _ _ —cos ——

5. 5,
effective inductance of outer conductor (H/km)
(12) L=L+L,+L,
total loop inductance (H/km)

55.6325 - 10-9
(13) C= *
In—
d

loop capacitance (F/km)
(14) G = wCtand
dielectric conductance (S/km)

(15) &% = 8.68589 .

it (REDE +) + (RE—wLC)]

characteristic attenuation (dB/km)
(16)

i
8 7 WOOD CFS + wLc—Ro)]

phase constant (rad/km)



Distribution of calls by duration for the day (6 October 1976) with the heaviest

traffic.

T
Durée de ta communication
do.01 mn 802 mn
do02mna0Amn
de04mna08mn
de 08 mn 816 mn
do16mna32mn
de 3.2mna64mn
de 6A mna128 mn
do 12.8 mn 4 25,8 mn
do 256 mn 8612 mn
de 51 mn 41h 42 mn
do1h 42 mn &3h25 mn
de 3h 25 mn &6h40mn
plus de 400 mn

2H aT

3H Mo, 3

de chaque classe

ry
i
8
8
Z
5
3
é

Number of completed calis

(Total: 5,024)

18 percent of calls

Class Duration of call

From 0.1 minute to 0.2 minute

More than 400 minutes

Load by hours of calls in each class
(Total traffic: 660 hours)

33

72346 67 8 9 0 i 3 Classe fe durée

7.

8.

20.8 percent and 20.3
percent of traffic
Class of duration of call



UIUE [9 Ja}oWEIP oAIM JeUTWOU ‘prerq :JOJONpuCS Jayno —
WUT ¢'9 JoJaWeIpP [eUTWOU “qq PHOS :uoTefNsut —
WUE | JoJaWIeTp JeuTWION :10}ONpuCs JouUT —

Joyonpuos Jeddos preiq aim Jayjno pue JoyoNpuoD JauUT Jaddoo pros Survey uur ¢'9/] sed jerxeoo aIqQrxapy (9

(wxH/S) 9-01 + GF 7E0 + Fe) = D (wry/a8) TEEPE = D (w/v) z6r'0 = “W
ses e179 oorest | oreast | Izo— est est wet oro we 02
er az9 oszest | ovat | 1r0o— zest wet 569° nigg 96% Ost
ose 879 oxo 6st | osszst | zoo rst rst OT avo we oor
ag 1679 ose ast | oust | 900 zat zat 168°0 aro rz 08
$87 09 oze est | ooggst | sto set sat 269°0 siro 98 09
1s@ e9 ostsst | opogst | 970 19a ist 10s‘ ozo ort Or
aaa +869 roost | omest | #0 73°81 £881 1080 zero Tot 4
807 089 oessst | orest | wo 68 668 207'0 ero wo or
ane | CRUst) | (s/ern) (saa) (w) @) @) (axy/pex) | (aei/ap) | (my/HU) | (aDi/u) Grp)
= 2 A A zuy— Zh Izl e > T a fF

‘Je0Z 12 S4LOJONPUOD svINQnI YIM Wu TLS/pH'ZE 21q00 4amod Jo S4aJauLD4vd 21ISIAaIODADYD PaqnINIIDD - “S TEV,

(pea]) wr ¢'Z ssoUyo yeurWoU :10}ONpucD sano —

wu 71g JoJaWerp jeururou ‘iaded oyeuSeiduy Io :uonejsuy —

(aeddoo) wur 7j"y ssouyory) ‘wu pp'ZE JoJaWIeIP [eUIUIOU JeyNO :10j}oNpuOCD JoUUT —
:S1o}ONpuoo IJeINQny Joyo pue JouUT YIM s[qeo IJoMod (q

B



Classes 1 to 7 cover approximately one fourth of the hours of call while they
account for 85 percent of the number of calls. This distribution peculiarity
had already been noted during the initial observations and this distribution
pattern has remained constant. Classes 9 and 10 have also continued to produce
the traffic peaks.

The graph below furnishes a comparison of telephone calls (sampling in December
1975 of 6,672 daytime calls to all destinations), "visiophonic" calls (sampling
of 553 calls in second 4 months of 1975), and Caducee network calls in October-
November 1976. We chose Gaussian coordinates indicating percentages of the
cumulative number of calls (ordinate) and percentages of the cumulative duration
of these calls (abscissa), because they furnish straight lines roughly parallel
to the first bisector and quite easy to compare, even though very close to each
other. In fact, the closer the straight line is to the vertical axes, the
greater the dispersion, and a good characterization is furnished by the point of
intersection with the second diagonal; thus we find:

a. For the telephone calls considered: 71-29
b. For the "visiophonic" calls: 76-24
ce. For the Caducee calls: 81-19

These figures can be read as follows: for the Caducee network, 81 percent of
the calls (of shortest duration) correspond to only 19 percent of the total
charged duration (or time), and inversely, 81 percent of the total charged
duration corresponds to only 19 percent of the calls.

This large dispersion of Caducee network calls is definitely confirmed by the
limiting values of durations indicated along the curves: from 5 percent to
85 percent for the number of calls, these durations range:

a. From 1 minute to 1 hour 50 minutes for Caducee,
b. From 1 minute to 40 minutes for the "visiophone,"
c. From 1 minute to 20 minutes for the telephone.
Traffic Between Different Types of Subscribers

Busy-hour analysis shows that estimates made prior to installation of the Caducee
network have far from materialized. First of all, as we saw earlier, the distri-
bution of subscribers by classes of traffic is not the one expected: 93.5 per-
cent of ordinary or "light-traffic" subscribers instead of the estimated 85
percent. Furthermore, 73.5 percent of busy-hour traffic is ascribable to calls
between ordinary subscribers, 26 percent to calls from ordinary subscriber to
“heavy incoming traffic" subscriber, while other possible calls account for only
0.5 percent of the total flow. A review of the number of calls leads to the
same conclusions for the period surveyed: of 269,910 calls recorded, 58,684,

or 21.7 percent of the total, were to "heavy incoming traffic" subscribers.

34



curve a, but it is evaluated by assuming that the
cost of the repeaters equipment is so low in both
systems (due for example to advances in technology)
to be negligible in comparison to the ‘waveguide cost.
The curve d shows therefore, if compared with
curve a, the influence of the equipment cost in the
given example,

Loe
Cu

25

2.0

1.5-

1.0L

Fig. 2. « Behaviour of Cyo/Cy, vs. 8, where Cyq/Cy, is the maxi-
mum value of the ratio "between the costs of"twe! installed cir.
cular waveguides, for which the system of larger capacity is
more convenient. Curve a has been evaluated according to the
R method; curve b according to the PVAC method; curve ¢ ac-
cording to the @/w,, method; curve d has the same meaning as
that of curve a, but it is evaluated by assuming the cost of the
equipment of the repeater stations to be negligible. The two sy-
stems have the following main characteristics: :

N, = N, = 7680 TFe; N,, = 200000 TF;
Njq = 320000 TFe; Cy = Cg = 60+ 100;
Cy = 70+ 108 U/km; 4, = 20 km; d, = 40 km.

It has been assumed N, = 40000 TFe; p = 2, m = 15, n =
n, = 15,2 = 8%,

40,

The comparison between curves a and b shows
that the two methods give the same result only for
5 = 15%, but quite different results for other va-
lues of 8. For example for a considerable higher
cost of the transmission medium (for example
Cya = 1,5 Cyq) the larger capacity waveguide, accord-
ing to the R method, is always more convenient,
while, on the contrary, the PVAC method for 8 < 14%
indicates more convenient the lower capacity system.
In addition the PVAC method seems to be too much
favourable for the higher capacity system, in case
of higher values of 8. However for 6 > 13% use of
PVAC method gives results of doubtfull meaning.
This is more clear from fig. 3, which gives the
behaviour of @, and @,, R, and R, for Cy, = 1,5 Cun
In this case @, presents a minimum for 8 = 13%,

ie. when s is equal to m for the system n. 1. When
& increases to higher values than 13% the PVAC in
the «study period» increases, because the expendi-
tures for the equipment must be planned at earlier
dates and the service capability of the system Nin
has reached its maximum value N, before the end
of the « study period », As a consequence also @; must
increase. However it must be pointed out again that
for 8 > 13% the service capability of the two sys-
tems at the end of the «study period» is different
and the PVAC method has lost any meaning.

Curve ¢ in fig. 2 and curves @,/w, and @,/W»
in fig. 3 show the results of calculation, if we use
as comparison study form the ratio between the
PVAC, and the utility, that is the ratio @ /W_. The
comparison by means of this last ratio seems more
satisfactory than that using @; and @,, but the re-
sult are still rather different than those given by

RU
Nin

ue

O4

ost \\ dos
me ww -_—"
o2b Ay dos
nN Qe
oe WS] 02
{ 1 1 ito.
rr es a

5%
Fig. 3. - Behaviour of R, and Ry, @, and @,, Q,/W, and C,/w,

vs. 6, for the same circular waveguide systems of ‘fig. 2,
Cp = 105 + 10 U/am.

the R method. For example for the C /w,, method,
if Cyg = 1,5 Cy, the larger capacity waveguide is

less convenient for 8 < ~ 16%, while on the contrary
it results to be always more convenient according
to the R method.

The R value, in addition, exhibits the significant
Property to be practically constant by varying m,
while both the values of @ and of Ce /w,, depend
on the length of the «study period», as shown in

hg



It should be noted that no special program was written for this office which
strictly uses the same programs as provincial toll offices (type B program).
Inasmuch as traffic handling capacities of electromechanical minor exchanges
will ultimately be insufficient, this use of nonspecific programs will be

such as to facilitate their replacement by E10 type Subscriber Connecting Units.

Future Developments

With 56 connected Selection Units (US) and about 18,000 subscribers, the Rennes
tandem office will reach its maximum capacity in October 1977. A plan for
completely equipping the suburban area with E10 systems has been prepared
because subscriber connection requirements are expected to become even much
greater in the outskirts of the city.

A second office, Rennes-Bru, was therefore inserted in the 1976 program. It
will relieve the Lavoisier office without, however being connected to SOCOTEL
exchanges. Lastly, two other short-haul toll (suburban) units are, in princi-
ple, to be included in the 1978 program, one designed to serve the eastern
area, the other the western area. The R6 tandem office, into which 12 minor
exchanges are still connected, should disappear about 1980. Electromagnetic
equipment in these exchanges is to be replaced gradually, with the first of
these operations scheduled for June 1977: because the E10 satellite-trailer
is not yet completed, subscribers will be changed over to a SOCOTEL trailer,
and then changed over once more to the E10 equipment installed as replacement
for the SOCOTEL equipment.

Lastly, it should be pointed out that almost all interoffice trunks connected
to E10 centers will become digital between now and 1979.

Conclusion

The two complementary methods of connecting distant subscribers--takeover

of the SOCOTEL exchanges and employment of distant connecting units--appear
simultaneously more often than not as soon as a new E10 automatic switching
system is installed. This tandem function we have just described may also
coexist perfectly--without any modification of the chain core--with an inter-
office function of connecting local subscribers.

The technical flexibility thus provided by the E10 system with respect to
methods of connecting subscribers also makes it possible to eventually con-
vert satellites initially made up of distant connecting units into Indepen-
dent Routing Exchanges (CAA). This technical flexibility has a corollary
financial flexibility as far as capital spending is concerned. In fact, such
investments can be better staggered because areas that would have had to be
equipped with a CAA space-division switching system can be temporarily served
by distant connecting units until their expansion warrants the presence of

a chain core.

22



The curves are plotted until s>8 years for the
8tube system. For larger values of N; the 16-tube
system may be more convenient (independently on
economic convenience) to avoid a too short period
of time between successive plant installations.

By varying the initial service capacity N; or the
rate of expansion 6 the range of the maximum
Ciz/Cyy, values, needed in order that the 16-tube
system becomes more convenient, results much nar-
rower for the R-method than for the PVAC method.

7. - CONCLUSIONS.

In the previous sections we have introduced and
discussed a convenient study method to perform an
economic comparison between transmission systems,
when they provide a different service capability or
have a different service duration, when it is dif-
ficult to extend costs and service demand fore
casts very far in the future and when it is necessary
to confine the study to a limited period of time. The
disadvantages of the PVAC study form have been
analyzed and different approaches based either on
the ratio between PVAC and utility or on the ratio
between PVWAC and utility have been discussed and
compared. Remarkable differences of results among
the various study forms have been pointed out. The
R method seems to be more attractive, because:

— it leads to a cost/utility ratio practically inde-
pendent on the length of the « study period »;

— it allows to take into account both different ser-
vice capability at the end of the study period and
different service demand expansion capability af-
ter the study period;

— it gives the best forecast of the cost/utility ratio
for the whole life of the plant.

The paper was first received on December 21, 1976.

REFERENCES

[1] International Telecommunication Union: Economic and Tech-
nical Aspects of the Choice of Transmission Systems. Pubbl.
by LT.U., Economic Studies and Comparisons, 1969.

[2] Yxore Rape: The economic optimum in urban network pro-
blem. « Ericson Technics », n. 49, 1950, p. 1-132,

[3] G. B. Stracca: Considerazioni su possibili criteri di confronto
economico tra diversi sistemi di telecomunicazioni. XXIV Con-
vegno Internazionale delle Comunicazioni, Genova, 11-13 otto-
bre 1975, p. 609-623.

cso: 5500

52



an V, = >

Phase velocity (km/s)

(18) t= 106. oo
group delay (us/km)
(19) V, = 105
group velocity (km/s)

TReap
em) 7 iai= [E82

modulus of characteristic impedance (Q)

(21): 9 = tan-!

(22) b= tant

(23) e ! @-—W)
=ze

characteristic impedance angle

(24) ReZ = |Z|-cos®

real part of characteristic impedance (Q)

(25) ImZ = |Z|-siné

imaginary part of characteristic impedance (Q)

es tw [=

modulus of characteristic impedance at infinite fre-
quency (Q)

The parameters Up, €, and tan6 are generally func-
tions of both the frequency f and the reference tem-
perature.

1.2. - Coaxial pair with inner and outer tubular con-
ductors.

The study of this coaxial structure mainly applies
to large coaxial pairs and to carrier communication
over power cables.

Fig. 3. - Cross section of coaxial pair with inner and outer tubular
conductors,

61



JPRS. 70200
21 November 1977

TRANSLATIONS ON. TELECOMMUNICATIONS POLICY,
RESEARCH AND DEVELOPMENT

No.. 21
ConTENTS PAGE
INTERNATIONAL
Briefs
Indo-Hungarian Media Cooperation 1
ASIA

PEOPLE'S REPUBLIC OF CHINA

Digital Satellite Ground Station Operational

(NCNA, 8 Nov 77) cescceceeceees cece cece cece cence ene 2
THAILAND
Anticorruption Report Notes Seizure of Radio Transmitters
(NATION REVIEW, 9 Nov 77) cceceececececccncececeeeee 3
VIETNAM
SRV Radio, TV Commission Holds Conference in Ho Chi Minh
ony (Ho Chi Minh City Domestic Service, 8 Nov 77) «+--+. 4
EASTERN EUROPE
BULGARIA
Briefs
Radioelectronics Symposium 5
CZECHOSLOVAKIA
Briefs
New TV Transmitter 6

-a- [III - INT - 140]



ITALY

ECONOMIC EVALUATION OF TELECOMMUNICATIONS SYSTEMS

Milan ALTA FREQUENZA in English No 2, Feb 77 pp 2-10E

[Article by Giovanni B. Stracca (Socio AEI) - Istituto di Elettrotecnica
ed Elettronica, Politecnico di Milano. Work done at Centro Onde
Millimetriche of Fondazione Ugo Bordoni, under the agreement with the

Istituto Superiore P.T.]
[Text]

Comparison of telecommunication systems requi-
res the consideration of an enormous number of tech-
nical and economic factors. Economic comparisons
are generally based on cost valuation methods such
as PVE (Present Value of Expenditures), AC (Annual
Costs) or PVAC (Present Value of Annual Costs);
the choice among them depends on the type of pro-
blem to be studied. Their use may present in some
cases a number of disadvantages, which are discus-
sed in the paper. A different approach is analyzed
in the paper, which refers to a cost/utility ratio as
a figure of merit. In evaluating this figure the cost
is defined as the present value of weighted annual
costs, ie. as if the annual costs were distributed along
the life of the systems in a mathematically equiva-
lent way with the same law as the annual utility of
the system.

Some examples are given to compare in some idea-
lized cases this method with the PVAC method.

1. - Foreworp.

The choice between alternative telecommunications
systems depends on various factors and characteri-
Stics of the systems (cost, technical features, mainta-
Rance, reliability, existing facilities, etc). Although

(?) For example a traffic expansion in Europe or in Italy is
expected to be of the order of 100000 or 150000 equivalent tele-
Phone circuits on the main routes in a period of time between
the next 10 to 15 years with a typical annual increment rate of
about 10% to 20%, a

ya

the economic factors are not the only ones, which are
to be considered, they pay surely an important role
on the choice of the system.

Economic comparisons are generally based on well
known cost evaluation methods, such as the Present
Value (or Worth) of Expenditures (PVE), the Annual
Costs (AC) or the Present Value (or Worth) of An-
nual Costs (PVAC). These three basic forms of cost
studies are mathematically equivalent {1] and the
choice among them depends on the type of problem
to be studied, as discussed in sect. 4, or also on
personal preference. In some cases however their use
does not seem to be satisfactory for an economic
comparison among different transmission systems,
as in the case of comparison among very large tran-
smission systems which will be available in next fu-
ture; for example circular waveguide systems (with
a two way capacity in the range between 150000 to
500000 telephone circuits), multitube coaxial cable
carrier systems (with one way capacity per tube bet-
ween 10800 to 30000 telephone channels) or satellite



Conclusion

Thanks to an advanced traffic observation system, we were able to obtain accurate
and extremely valuable information on traffic heretofore unknown (data trans-
mission over a switched network specifically designed for this purpose), whereas
corresponding information on telephone networks is barely beginning to be analyzed.
The most striking fact is unquestionably the large dispersion of the duration of
calls around an average duration substantially greater than had been estimated.

Now that this traffic is quite well known, we will have to even further extend
the comparison with telephone traffic once accurate information is available.

We will also have to begin making such comparison with Transpac and Transmic traf-
fic and try to deduce therefrom the basic characteristics to be taken into
consideration for the possible Hermes network.

8041
cso: 5500

39



where:

& is the «effective diameter factor » of the inner
conductor, whose value is given in section I.4.

Cables of type b differ from type a in the shaping
of inner conductor.

In such a case, R; and L, can be calculated by the
following approximate expressions:

(41) R, = Ry k;-Q;

effective resistance of inner conductor (Q/km)

(42)

effective inductance of inner conductor (H/km)
where:

Ry; is given by (33), k; by (28) and 6, by (27).

Due to stranding, an additional inductance Lp should
be taken into account for both configurations a and b.
In fact, each single wire (having diameter d,; or
d, in fig. 5) describes a spiral of pitch p to which
the following inductance in d.c. can be associated [8]:

needy
[=] -10-4- yu, (H/km)

‘?
being & the «effective diameter factor» (section 1.4)
and d* the overall diameter of the layer considered.

The total inductance Lp due to stranding is given by

nN
lp = EL,
1

Each L, can be positive or negative according to
the direction of spiralling.

For high frequencies, only layers run through by
current have to be considered. However, in practice,
the inductance Lp is usually a small, negligible part
of the total inductance L.

14. - Coaxial pairs with outer wire braid conductor.

Only non magnetic conductors (u,; = u,, = 1) are
here considered. At frequencies higher than 10 MHz
(where these cables are generally used), the following

64


UGANDA

BRIEFS

LIVE TELEVISION--Uganda television's outside broadcasting unit is already
in Nile Province on test transmission starting today up to Sunday daily

at 2030 hours. Uganda television will telecast live the laying of the
foundation stone of Uganda earth satellite station at Urua and the opening
of the OAU Ministers of Information Conference on Monday, 7 November.

The telecast will be for Uganda as well as any other countries interested
in receiving it. [Text] [Kampala Domestic Service in English 1700 GMT

4 Nov 77 LD/EA]

cso: 5500



aly ule
el Wm
Ob
415
oat
419
ob
dos
oat
ols : f ito
$1 1520
5%

Fig. 6. - Behaviour of R, and Ry @, and @, @,/w,, and @,/w,

vs. 8, for the two systems - coaxial cable carrier system (subscript

1) and waveguide system (subscript 2) - already considered in fig.
4, when Cy, = 130°10) U/km and N, = 32000 TFc.

a(u
ough 4
03h 4
O2- 7
oak 4
V3 ot
5 om

Fig. 7. - Comparison of the curves R, and R,, evaluated for the
same systems of fig. 6, with the approximate curves Ry, and
Rj , evaluated with ea. (16).

51l

6.3, - Example n. 3: Comparison between two coaxial
cable carrier systems of different capacity.

In this example the R and PVAC methods are com-
pared to find out the minimum initial service de-
mand N; (over existing facilities), above which a larger
capacity multitube coaxial carrier system becomes
more convenient than a lower capacity system. The
two systems to be compared use a 8-tube and a 16-tube
coaxial cable respectively and the same number
N = 10800 telephone channels per tube.

The main characteristics of the two systems are
summarized in the caption of fig. 8 (subscript 1 for
the 8tube system and subscript 2 for the 16-tube
system).

Fig. 8 gives the maximum allowed value of the ra-
tio Cip/Cyy, in order that the 16 tube system beco-
mes more convenient; this ratio is plotted versus
N,/N for different values of 8. Curves a@ are evalua-
ted according to the R method and curves b accor-
ding to the PVAC method (a, and 6, for § = 8%, a,
and b, for § = 10%, a, and 6, for § = 15%).

fue
Cus 7

1 1
3 4
> Nfl
Fig. 8. - Behaviour of Cyp/Cy, vs. N,/N. where Cyp/Cy, is the maxi-
mum value of the ratio betWeen the initial investment costs of the
transmission media relevant to two coaxial carrier systems (8-tube
cable, subscript 1, and lé-1ube cable subscript 2) for which the
J6-tube system is’ more convenient; N, is the initial service ca-
Pability through other facilities on the given transmission route
and N = N, = N, = 10800 TFe. is the number of telephone chan-
nels per tube of both systems. Other characteristics of both sy-
stems are: N,, = 43200 TFc., Ny = 86400 TFc., Cy, = 50+ 10
Ufkm, Cy ='Cy = 12+10 U, & = d, = 15 km. "Et has been
assumed ‘p, = Py = 0, m = 15, n = 40, n, = 15, + = 8%, Cur-
ves @ have been evaluated according to the R method: curves
b according to the PVAC method (a, and b, for 8 = 8%; a, and
b, for & = 10%, a, and'b, for 6 = 15%),



reference parameter for calculation of skin effect in
the inner conductor
4-2;

inner conductor d.c. resistance (Q/km)
@ ke 4, (berg): (bei’g) — (bei g) - (ber’g)
2 (ber’qy + (bei'g?

skin effect coefficient for the inner conductor
where:

ber q = ReJ,(q- V)
Jy = Bessel function of the order zero

beiq = —ImJ,(q- V)

ber'g = —ReVj-I(a Vp
J, = Bessel function of the order one

bei'g = Imv;-4,(4- v)
@) R, = Ry k;

effective resistance of inner conductor (9/km)

1 Pe
5) &=—-
® cn 04 + tre f
depth of penetration for outer conductor (mm)
28 28
Sh —— + sin ——
6 hee
"8, 28 2s
Ch —— —cos ——
8, 5,
skin effect coefficient for outer conductor
Pe ke
7 R, =
@ ° n+ S-(D+S/k,)
effective resistance of outer conductor (Q/km)
(8) . R=R +R,
where:
s = thickness of the inner conductor
ak,
(29) R= <—

fri
s

mS (-=)
k

effective resistance of, the inner conductor (9/km)

oT



FRANCE

USE OF E10 SWITCHING SYSTEM IN TANDEM OFFICES VIEWED
Paris L'ECHO DES RECHERCHES in French Apr 77 pp 4-11

[Article by Jean-Pierre Coudreuse, telecommunications engineer, head of
Electronic Systems Experimentation Department (RCI-ESE [Integrated Switching
Research-Electronic Systems Experimentation]) of the National Center for
Telecommunications Study (CNET) in Lannion, and Jean-Claude Faure, senior
inspector in the same department: "The E10 System in Tandem Offices"]

[Text] It was initially determined that the E10 system's
most favorable sphere of employment was in providing auto-
matic dial service in areas with a low density of telephones.
The system has now also proved to be highly suitable for hand-
ling local exchange areas equipped with SOCOTEL [Joint Company
for Development of Telecommunications Switching Techniques]
automatic switching systems nearing the saturation point.
Using the Rennes installation as an example, the following
article describes the E10's "pure tandem" utilization from
_ the standpoint of its specific aspects that differ from a
toll center equipped with E10 time-division switching equip-
ment.

The E10 time-division switching system has previously been amply described

in this review, both with reference to its principle as well as to its initial
applications in toll centers, switching centers, or in the switching of leased-
line networks.

Although providing dial service in local exchange areas with low telephone \
density was initially a suitable sphere of utilization for the E10 system,

another economically warranted application of time-division switching is

now the handling of SOCOTEL type electromechanical minor exchanges nearing
saturation in areas already converted to dial operations. Such handling is
generally concomitant with the installation of trunks connected directly

to the E10 tandem office as soon as that office is established. Such handling
eventually involves replacing all SOCOTEL minor exchanges with E10 connect-

ing units. However, a "pure E10 tandem office" operation was established

in Rennes.

il



BIBLIOGRAPHIC DATA
SHEET

T. Report No. 2

3. Recipient's Accession No.

JPRS 70200

4. Title and Subtitle

AND DEVELOPMENT, No.

TRANSLATIONS ON TELECOMMUNICATIONS POLICY, RESEARCH

3. Report Date

21 November 1977
6.

17. Author(s)

8. Performing Organization Repe.
‘ lo.

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V1. Contract/Grant No.

As above

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13. Type of Report & Period
Covered

14,

15. Supplementary Notes

16. Abstracts

This serial report contains translations from the world press and radio relating
to worldwide political, economic and technical developments in telecommunications,
computers, and satellite communications.

on France, Federal Republic of Germany, United Kingdom, Italy, Japan, the USSR,
People's Republic of China, Sweden, and the Netherlands.

Coverage will be worldwide with focus

Worldwide
Computers

Telecommunications
Telemetry

17b. Identifiers /Open-Ended Terms

17e. COSATI Fie !d/Group

V7. Key Words and Document Analysis.

Satellite Communications
Electronics and Electrical Engineering

09B, C, F, 17B, 22B

17a. Descriptors

18. Availability Statement

Unlimited Availability Report)
Sold by NTIS \ curity Class (This 22. Price
Springfield, Virginia 22151 1 Pans CLASSIFIED FeA0S
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THIS FORM MAY BE REPRODUCED Uscommrog 14982-P72



We notice that there are very few reputed wrong numbers or incomplete num-
bers upon translation, and it is interesting to compare these percentages
with those of telephone calls, it being understood, of course, that the
equivalence which seems to exist between the unavailableness of a Caducee
network subscriber and the no-answer of the telephone system's called
subscriber is only apparent. A survey made in early 1975 in the Marseille
area covering more than 50,000 national telephone calls furnishes some indi-
cation of the percentages of completed calls, and uncompleted calls for

“line busy" and "no answer" reasons: approximately 42 percent, 49 percent,
and 9 percent respectively. However the "line busy" calls include those uncom-
pleted because of subscriber error as well as those uncompleted because of tele-
phone system congestion. Consequently there is no possible correspondence
between these results and results observed on the nonsaturated Caducee net-
work and its single central office. An approximation consists in taking

the average percentage of "line busy" telephone calls and deducting therefrom
that percentage due to system congestion and then excluding the correspond-
ing calls. In this way, we obtain a new distribution of calls in which com-
pleted calls are certainly overestimated in relation to the real percentage
and "line busy" calls are underestimated. Thus we find: 63.5 percent (com-
pleted calls), 23 percent (uncompleted because of line busy), and 13.5
percent (uncompleted because of no answer). This distribution would corres-
pond, therefore, to the distribution in a "fluid" network for national calls
(excluding local and regional calls).

Comparison with Caducee thus basically shows a lesser percentage of completion
for Caducee calls and a corollary higher percentage of uncompleted calls for
reason of subscriber "unavailableness." This characteristic actually needs to
be verified by more accurate measurements on the telephone network.

Duration of Calls

All calls were broken down into 13 classes of duration. These classes in
geometric progression range from 0.1 to 400 minutes, thus enabling us to
detail the distribution of short-duration calls and take into account the very
long calls that have a very great impact on overall traffic.

Estimates made prior to installation of the Caducee network indicated a
distribution of calls in classes 3, 4, and 6 representing traffic emanating
from terminals of the electromechanical type from terminals with cathode

ray tube display, and from heavy terminals respectively. It was estimated
that class 3 would account for 45 percent of the calls and 18 percent of the
traffic, class 4 for 41 percent of the calls and 35 percent of the traffic,
and class 6 for 14 percent and 47 percent respectively.

Yet as shown in the graph below, classes 1 to 4 actually account for only 52

percent of the calls (instead of 86 percent) and less than 4 percent of the
traffic.

32



TABLE 6. - Calculated characteristic parameters of flexible coaxial pair 1/65 mm at 10°C.

F R L « “8 IZ] ReZ | —ImZ y, vy, . aF
(MHz) (Q/km) | (mH/km) | (dB/km) | (rad/km) (ay (ay (a) (km/s) (km/s) | (us/km)
0.060 2 | 0.425 ch 2 80.09 12 161 185700 | 189 460 5.28 696
0.100 38.8 0.418 24 33 79.06 78.85, 5.79 187 750 192 310 5.20 6.78
0.300 42 | 0.400 3.6 98 | 7707 77.00 3.26 192250 | 195 680 SL 6.5
0.500 812 | 0.398 46 162 | 76.46 76.40 2.49 193780 | 196 470 5.09 651
1.000 1126. | 0.388 65 322 | 75.81 75.19 174 195330 | 197260 507 651
4.000 20 0,380 29 127 75.05 75.05 0.85 197250 | 198 220 5.08 648
12.000 377 0.377 26 ‘381 44 4.14 0.48 198 070 198 630 5.03 6.52
30.000 594 0.376 36.2 950 7458 7458 0.30 198 480 198 840 5.03 6.61
61.160 846 0.375 52.6 1934 74.50 74.50 0.20 198 700 198 950 5.03 6.73
100.000 1080 0.375 68.5 3160 446 46 0.16 198 800 199 000 5.03 6.85
200.000 | 1525 0374 100 6317 Az 14.42 on 198920 | 199060 5.02 701
500.000 | 2409 0374 168 15 785 4.38 74.38 0.06 199020 | 199110 5.02 751
R, = 23.97 (Q/km) C = 67.55 (nF/km) G = 170+ 10-6 + F(S/km) Ze, = 7431 (Q)

Also the measured attenuation is given for these culated and measured values is also due to the prac-
cables to allow comparison with calculated values. tical difficulty of determining accurately the dimen-
We point out that the slight difference between cal- sional values.

“ :
(oho
so
i
20
A
» :
aa
: al
2+ fasabe abe
2
iar bid
:
a ® i 3 % ry 100

Fig. 10. - Attenuation of coaxial pair 0.7/2.9 mm at 10°C.

TH



Breakdown by number of calls handled (average hourly values)

Appels|
ose
ara

(3) Appels départ

_

TTI

Key: 1. Number of calls in the hour 4. Incoming calls
2. Incorrectly-dialed calls 5. Local calis
3. Outgoing calls 6. Hourly cross-section

Rennes-Lavoisier Tandem Office

This office became operational on 27 March 1975. It was the first E10 exchange
to serve as a tandem office. Equipment installed at that time permitted
connecting 440 local low-frequency circuits worked in SOCOTEL code. Since
then, that number has risen to 800, including 180 digital circuits (6 MIC
[expansion unknown] systems). Subscribers connected in this way total 8,100
distributed over 12 SOCOTEL exchanges. At the same time, approximately 2,000
subscribers distributed over six E10 concentrators of the CSA (Space-Time
Concentrator for Subscribers) type were also connected. This number will be
increased to 9,500 over 20 CSA's in October 1977. The office's load will then
be 18,500 subscribers, 540 long-distance dialing circuits, and 630° interoffice
circuits (including 360 digital circuits).

20



NOTE

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mation was summarized or extracted.

Unfamiliar names rendered phonetically or transliterated are
enclosed in parentheses. Words or names preceded by a ques-
tion mark and enclosed in parentheses were not clear in the
original but have been supplied as appropriate in context.
Other unattributed parenthetical notes within the body of an
item originate with the source. Times within items are as
given by source.

The contents of this publication in no way represent the poli-
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For a given transmission route, of length d, over
which different plants shall be compared, it is con-
venient to assume in the following that the utility,
which is clearly a quantity growing with the length
d, of the route, be a quantity proportional also
to dy:

(1) W(u) = K,,N,d,.

It should be: pointed out that the relationship bet-
ween W(u) and d, for different routes is generally
more complex than a linear one. However eq. (1)
may be assumed over a given route, provided that
the proportionality constant K,, is given the meaning
of average annual utility per unit length (for exam-
ple per km) of one telephone circuit over said route.
In the following K,, will be called average unit an-
nual utility of the given route.

Although K,, depends on the particular route under
consideration, however its evaluation is not needed,
because it is the same for all the systems, which
should be compared.

Both K,, and W(x) may be expressed in the same
unit as that used for cost, because utility can al-
ways be converted into an equivalent income, that
is into money. In this paper we will use, both for
costs and utility, the arbitrary account unit U.

To compare different plants we need to evaluate
the present value of the total utility W,,, provided
by a plant after a given number of years u, or the
corresponding normalized value w,:

W,

wW,
—“— = F(8,7,u,5).
Ky Nid,

tu

Wu)

Q) Wy

This quantity has therefore the meaning of the
average present value of utility per TFc., per km
and per unit of K,,

Because the utility can be converted into an equi-
valent income and therefore into money the present
value of utility (W,, or w,) can be evaluated follow-
ing the same rules used to obtain the present value
of the costs. This value is a function of the service
demand expansion rate 8, of the appropriate com-
pound interest rate t, of the number u of years
considered and of the number s of years expected
for a complete utilization of the total service capa-
bility N, of the system. Because s is also a function
of & and of the initial capability N; of the route,
available at the year u = 0 over other existing faci-
lities, w, may be expressed also as a function of
8, «, u and N,. N;, N, and N, will be considered here
for convenience as numbers of equivalent telephone

The function F depends on the expansion of the
expected service demand. In this paper, for the sake
of simplicity, we will assume an exponential expan-
sion law; however it is easy to modify the results,
when other laws of expansion are assumed. It fol-
lows therefore that the value of N, increases with
u according to eq. (3):

Q) N, = N,[0+8"—1],

up to year s-th of saturation of the overall plant
capability N, which is given by eq. (4):

Jog (1+ N,/N)
log (1 + 8)

For the assumed law of expansion the function
F is expressed by two different equations:

(4)

Fy = — f,(u,s), (for u>s);
(5)
F;, a f,(u, 8) (for u <5).

In eqs (5), according to the two cases u>s or
u<s, f, and f, are the following functions, which
for given 6 and + depend only on u and N, (or s):

(147) 7/148) )5
5 1s) =f —) ae
G) f(s) =e (722) |
(1+8)—1
a(l+e}

b(1+ 7%) 145\4"
f,(u,s) = cna) (=) —] _

_ G+ 8-1

, (for a> s);

6"

» (for u<s).

ah



A few main characteristics determined from all the calls made during a 7-week
period in October-November 1976 are shown in the table below.

General characteristics of Caducee network traffic during the period
October-November 1976

Busy-hour average: Daily average:

Total/completed Total/completed
Number of calls
-Working days 1117/506 8058/4598
~Busy days 1367/579 9300/4940
Average duration of calls in minutes
Working days 16.7 16.9
-Busy days /7.2
Traffic by hours
-Working days 156 /526
-Busy days 1604
Number of calls per subscriber 0.56
-Outgoing or mixed
Traffic per type of subscriber
-Ordinary 93.5 percent 0.10E
-Heavy outgoing traffic 0.5 percent 0.04E
-Heavy incoming traffic 6 percent 0.24E

Traffic per ordinary subscriber fully corresponds to the initial estimates.
The distribution of this traffic does not, however. These subscribers com-
municate chiefly with each other and very little with the so-called "heavy
incoming-traffic" subscribers. This situation explains to a great extent
the fact that the latter's traffic is less than had been estimated. It also
is reflected in the breakdown by number of calls.

Variations in Traffic During the Week

Examination of the sample observations of 4 weeks in October 1976 reveals that
traffic is concentrated within the 5 first working days of the week: an
average of 8,000 calis daily and about 520 hours of communications were
recorded. Saturday traffic is comparatively very light. It represents only
6 percent of the number of calls and 11 percent of the average traffic on the
other working days. Sunday traffic is practically negligible despite the
special low rates on that day: 0.16 percent of the number of calls and 0.4
percent of the traffic on working days.

28



Principal characteristics of the following regions: inner-city Paris,
suburban Paris, Lille, Lyon, and Marseille

d.

RLM.: Paris Intra-Muros.
PEM.: Paris Extra-Muros

A: trafic d'arivée | pourcentege.du nombre d'appels/ pourcentage
D: trafic départ § d'abonnés|

| : trafic interne en nombre d’ap] bonné pour 10 jours chargés
en trafic

PIM: inner-city Paris

PEM: suburban Paris

A: incoming traffic

D: outgoing traffic

Percentage of number of calls over percentage of subscribers.

I: internal traffic by number of calls per subscriber for 10 heavy-
traffic days.

Satellite regions with characteristics the opposite of Paris characteristics

(light incoming traffic, heavy outgoing traffic, and no internal traffic):
Clermont-Ferrand, Grenoble, and Nice.

Lastly, Orleans is somewhat apart, having light traffic (outgoing or incoming) and
zero internal traffic.

37



Furthermore, thanks to the savings achieved in connecting distant subscribers,
juxtaposition of the tandem and local interoffice functions will make it
possible to show a positive balance sheet in some cases, even if local service
area subscribers still currently cost more compared with other systems.

The broad sphere of employment thus described is currently favorable to the
E10 system. A few examples of the facilities either under construction or
planned include: toll offices in the Paris regional Area No 2 (Luzarches and
Villepreux), tandem offices in the 1976 program (Quimper, Toulon, Lorient)

or in the 1977 program (Rouen, Dreux). The first application of the E10
automatic switching system to 129 selection units of double the capacity of
standard E10 exchanges, will also be of the tandem type and installed in Brest.

Rennes tandem office as of 1 May 1977

Sens-de-Bretagne

367 Montreuil

(«) ‘St-Aubin d‘Aubigné

Circuits interurbains —=T2:
Circuits urbains
Circuits urbains
Circuits interurbains 1

L'Hermitag

Key: 1. Toll circuits 4. SOCOTEL exchanges; n = number of
2. Interoffice trunks subscribers
3. E10 tandem office . 5. E10 concentrator

8041 23

cso: 5500



LIBYA

BRIEFS

UNDERSEA CABLE--The General Public Committee of the Communications Secre-
tariate approved the budget for the building of an undersea cable between
Tripoli and Benghazi, This budget is estimated at 10.485 million Libyan
dinars. This project is considered to be one of the largest being executed
by the Post and Telecommunications Corporation during the current plan. It
is being executed by an international company and has a capacity of 900
telephone and telecommunication channels with special two-way channels for
radio and television, The importance of this project is the fact that it
is a successful and practical replacement for the existing centimetric waves
from Tripoli to Benghazi. The project will be ready for operation according
to the most modern international specifications 2 years from now. The com-
pany building the project will be in charge of training a sufficient number
of nationals to operate the project, in addition to that company's respon-
sibility to carry out all maintenance work for a period of 2 years after the

completion of the project. [Text] [Tripoli AL-FAJR AL-JADID in Arabic
3 Oct 77 p 1] 8988

cso: 5500



No(p) and N,(p) are the Neumann functions of order
zero and one.

However the calculation of R; and L; is quite com-
plicated with (31) and (32), so that at least for the cal-
culation of effective resistance R, the diagram of fig. 4
can be employed.

13. - Coaxial pair with stranded conductors.

The calculation of transmission parameters of stran-
ded structures is carried out using the same formulae
employed for the equivalent solid structure introdu-

Fig. 5. - Cross section of coaxial pairs with stranded conductors.

cing a coefficient taking into account the increase

of resistance due to the spiral path of the current.
The following types are considered:

a) coaxial pair with a central stranded conductor and
outer tubular stranded conductor (fig. 5a);

b) coaxial pair with concentric tubular stranded con-
ductors (fig. 5b).

Symbols appearing in the formulae are the follo-
wing:

d = diameter of the inner conductor (outer dia-
meter if formed by a stranded tube);

d; = diameter of wires forming the inner conduc-
tor (mm);

n = number of wires of the inner conductor;

A = additional thickness due to strand shaping of
outer cond. (mm);

Dy = inner diameter of the outer conductor (mm);

d, | = diameter of the wires forming the outer con-
ductor (mm);

N = number of wires of the outer conductor;

Ss = thickness of the inner conductor (mm);

Ss = thickness of the outer conductor (mm);

u,; = relative magnetic permeability of the inner
conductor;

U,, = relative magnetic permeability of the outer
conductor;

2; = resistivity of the inner conductor for the de-
sired temperature (92 mm?/km);

Pe = resistivity of the outer conductor for the de-

__ sired temperature (Q mm?/km);

59



“
(0870)
s0
A
2 zs
20
a
1°
. i
‘ ip Tienes
DB Xe este whe
2
1
or as 1 3 cf 00
Fig. 11. - Attenuation of coaxial pair 1.2/44 mm at 10°C.
rad
——t heanwes
wa saes etetee
207
26
fh
23s
2 z
23a oF
a2 2
y = 2
at S=sSs>
an LX
an y estenren)
i
226 rs (ini)
fFreewency (uni),
or ry 0 30 "eo 7300 800
Fig. 12.'- Ratio a/VF of coaxial pair 2.6/

at 10°C,

9.5 mm

2)



If the plant life is equal to n years, eq. (2) with

u = n gives the normalized value w, of the utility,

W, — Wn

wl --- Wa 3m
n sree Sig

5=8% 6=12% 6=15%

iy L 1 1 } 1 rn il 1
1 5 40 Ni /Ni

Fig, 1. - Behaviour of 1, Wy By = Wy/W vs. N,/N, for dif-
ferent values of the rate 5 of service demand expansion, The cur-
ves are calculated for m = 15, n = 40,7 = 8%.

provided along the total life of the considered plant;
if the length of the study period is equal to m years,
eq. (2) with u = m gives the normalized value w,,
of the utility, provided along the study period.

Fig. 1 shows the behaviour of w,, and w, (for
m 15 and n = 40) as a function of N,/N; for
< = 8% and for different values of 6.

The overall utility w, (or W,,) is obviously a
decreasing function of s and a growing function of n
(but slower and slower for larger n).

4, - AVAILABLE METHODS FOR THE COSTS EVALUATION.

Before discussing possible methods of evaluation
of a figure of merit of a plant, which takes into
account both cost and utility, it may be useful to
recall in this section the available methods of eva-

(*) For example the PVE of the expenditure C,, made in the
year uth, is given by C/U + <4.

©) The overall PVE of a plant, with a life of m years which
requires an investment C at the year 0, an annual operation cost
£C and alloys a salvage rC at the end of its life, in case of ex-
tension up to the year u = ©, is as well known [2]:

1-r .
© PVE =C J 1+ — "og FO
(+cyK—1 7
() The AC of the expenditure C, of which we have already
considered the corresponding PVE (°) is:

7 ac=c [: ort
@ =Ct + a7 +4].

Economic comparisons are generally based on the
three basic forms of cost studies of PVE, AC and
PVAC. The three methods are mathematically equi-
valent [1] and their use is sufficient when the sys-
tems to be compared meet the same service demand,
provide service over the same period of time, pro-
vide the same service capability (ie. the same « uti-
lity »).

In such cases the choice among them depends on
the timing of expenditures and retirements [1]. Ge-
nerally the PVE (Present Value of Expenditures) stu-
dy form (where all the investments are converted
to the present year - or year u = 0 of the plant) is
a convenient form for both coincident and non coin-
cident investment costs, provided the retirements
are coincident (4). It requires the forecast of the
investment costs up to the end of the plant. Such
evaluation can be extended to a very far date, pro-
vided it is possible to anticipate that the future ex-
pansion of the plant will be performed by using
systems of the same type and the same technolo-
gy () [2].

The study form AC (Annual Costs) converts the
lump-sum first cost, with consideration given to net
salvage, into an annual cost or annuity, sum of in-
terest and of recovering of investment (amortiza-
tion), with uniform distribution along the life and
adds it to the operations annual cost which is gene-
rally constant. This study form seems to be conve-
nient both for coincident and for non-coincident
retirements, provided the investments are coinci-
dent (6) and the annual cost is constant during the
life of the plant [1].

When both the investment costs and the retire-
ments are non-coincident it is more convenient the

_Study form PVAC (Present Value of Annual Costs)
[1], which first converts any expenditure into an-
nual costs and then converts all the annual costs
in their present value. The PVAC may be evaluated
only up to a limited length of time, the « study pe-
riod» .and therefore allows to compare different
plants by avoiding forecasts extended too much in
the future, according to criteria a and c of sect. 2.

In the case of a «study period » of m years, eq.
(8) gives the PVAC, during this period of time, re-
levant to an investment cost C,, carried out in the
wth year, requiring an operation annual cost &C,
with a salvage rC,, at the end of its life of x years:



As pointed out in sect. 3 the use of the quantity
W,,, is not convenient, because W,,, depends on the
average unit annual utility K,,, which is of not easy
evaluation. Due to the fact that K,, on a given
transmission route, is the same for all the trans-
mission systems to be compared, it is possible to
overcome this difficulty, by using a study form ba-
sed on the figure of merit R defined [3] as the ratio
between the (PVWAC),, and W,,,/K,, evaluated in
the «study period», which is no longer a function
of K,, This ratio R may also be defined as the ratio
between the unit value @,, of the PVWAC, ie. the
average value per km and per TFc of the PVWAC
in the «study period», and the unit value w,, of
the utility in the same period. In fact @,, i:

(PVWAC),
(9) y=
Nn de
and then R is given by
PVWAC)

(10) R= SYA _ :

Wun

K,

R is therefore expressed in the same cost unit used
for @,, and has the meaning of the minimum value
of K,, on the considered transmission route, for
which the utility of the plant is greater than the
correspondent cost. The ratio R/K,, gives the actual
ratio between (PVWAC),,/W,,,, ie. between cost and
utility, when the annuities arde distributed along the
life of the plant in the same way as the utility.

Because R does not depend on m, it may be con-
sidered as the more probable value along the whole
life of the plant (ie. when costs and technologies
remain the same along the whole life) and therefore
takes automatically into account the different ser-
vice capability expansion that different systems may
provide after the «study period» along their life
period.

It may be convenient to evaluate the unit cost

~@,» as a function of unit costs Cy, C, and @, (re-

ferred to the transmission medium, the repeater
equipment and the terminal station equipment res-
pectively), conventionally defined for the plant equipp-
ed for its maximum capacity (7) at the year u = 0,
and therefore defined in a non-ambiguous way.

() If Cy is the cost per km of the transmission medium, N, the
system overall capacity in TFc., C, the cost of a two-way repeater
equipment of N channels capacity, d the repeater stations distan-
ce, C, the cost of a two-way additional equipment available in a
terminal station and associated to any N TFe, d, the distance
between terminal stations, @y, @, and @; are given by:

G G

Cas yh a

diy Nd,

The cost @,, can be written as the following weigh-
ted sum:

(12) Cw = Bu Cut 8s Cat’ Cr-

In eq. (12) the weights gy, g, and g, are conve-
nient functions of 8, t, N;, N, m and of the forecast
life both of the plant (7) and of the equipment (n,)
and take also into account the corresponding sal-
vage (ry, fr, and r;) and the operation annual costs
(ey £4, and ¢;7) in percent values of the corresponding
plant costs.

The functions gy, g, and g; are easily obtained.
For example, if the salvage is ry = 0, gy is given by:

fms) Ny
(7,8) Ny’

where N,, = N, if s<m. In eq. (13) & Cy is the
unit annual operation and maintenance cost for the
transmission medium and for the general facilities,
f (7,5) is given by eq. (5’) (because it must be s < »)
and f(m,s) is given by eq. (5’), when s <m, or by
eq. (5") when s > m.

Fig. 1 shows the behaviour of gy (for ey = 0 and
r = 0) versus N,/N;, for different values of 6, when
m = 15, n = 40, t = 8%, It can be shown that the
curves do not change appreciably by varying + or 1.

The ratio g,,/w,, is not a function of m also in
the general case, where a different value of + is
convenient to evaluate cost and utility. When the
same value of + is used, the ratio [N,f(m,5)]/
JIN, f (2, 5)] is equal to w,,/w, and the ratio gy/W),
is equal to 1/w,.

The functions g, and g, are generally equal, be-
cause the installation of new terminal equipment
follows the same expansion law as the repeater equip-
ment. However g, and g, do not coincide with gy,
because they depend on the planned investment tim-
ing; this may not bring about the minimum value
of g,/w,, and therefore of R to allow elapsing a
convenient period of time between the installation
of new equipment, and to take into account a pos-
sible unforeseen service demand expansion. For these
reasons the ratio g,/w,, may exhibit small changes
by varying mm, which may be tolerated. Also in the
evaluation of g,, it is convenient to use suitable
weights of the annualities for any investment in
order to reduce the variation of g,/w,, with m.__

Eu
(13) uy -{ie% u—a+ea}

LT



USSR

BRIEFS

KHURMULI-BEREZOVYY RADIO LINE--Workers of the eastern section of the Baykal-
Amur railway report that the Khurmuli-Berezovyy radio relay line has been
put into operation, making it possible for residents of remote settlements
in Solnechnyy Rayon such as Perezovyy, (Obolin) and Duki to watch central
television programs. Their first television program was a direct relay
from Moscow of the joint solemn meeting devoted to the 60th October
Revolution anniversary. [Khabarovsk Domestic Service in Russian

0930 GMT 5 Nov 77 OW]

SEVERO-KURILSK ORBITAL STATION-~Another orbital station has been put into
operation in Severo-Kurilsk, which made it possible for thousands of its

residents to watch the festivities in Moscow. [Vladivostok Maritime
Service in Russian to the Pacific Far East 0700 GMT 6 Nov 77 OW]

cso: 5500

10