~

USSR

MOSCOW - YEREVAN SATELLITE COMMUNICATIONS LINK ESTABLISHED
Yerevan KOMMUNIST in Russian 5 Nov 77 p 4

{Article by Yu. Kozlov, Deputy Minister for Communications Armenian SSR:
"On the 'Orbita' System]

[Text] On the eve of the renowned 60th anniversary of the Great October
Revolution, residents of Yerevan and the Ararat Valley received the oppor-
tunity to watch Central Television's fourth program being retransmitted on
channel five on the azure screens of their television sets.

This became possible after the "Orbita-2" station in Yerevan was put into
service providing permanent, reliable communications to the republic across
the space bridge, Moscow - satellite - Earth - Yerevan.

Henceforth, Armenia, in addition to existing long range land and underground
communications lines connecting Yerevan with Moscow, has gained a stable,
high-quality communications channel with our nation's capital through
“Molniya" artificial earth satellites.

Today, with the assistance of the space communications station, Yerevan is

already receiving two supplementary Central Television (TsT) programs--the

fourth and the "Orbita" program which is basically a repeat of the first

TsT program with a three-hour time shift. These transmissions are received a
in color. Through the "Orbita-2" station, the republic received radio

programs from Moscow with the equipment permitting reception of these pro-

grams in stereo. By the end of the year, with the introduction of the

broadcast portion of the entire complex, it will be possible for the tele-

vision studios of Yerevan to join the Central Television and Intervision

networks.

The capabilities of satellite communications are expanding every year. By

1978, the space communications station will have direct telephone and tele~
graph lines with Moscow.

14



traditional type. In a large-sized area in which a new service is to be of-
fered, it is obviously not necessary to wait until a new system unit is in-
stalled in all the exchanges. On the other hand, it is not advisable to of-
fer a new service all over the territory when only one exchange of the new
type has been installed. In this case, the commercial aspect and the econo-
mical operation of the service would be affected adversely by a need for adopt-
ing very long user lines, by problems of numbering with regard to codes and by
problems of charging for both outgoing and incoming calls. Moreover, it does
not seem to be advisable to offer a new service only in a limited number of
areas scattered over the territory. A good compromise would be to install at
least one peripheral exchange in each local network that has its own district
code. Usually, these networks are sufficiently numerous and are in the
country's largest urban areas. In Italy, for example, there are 231 of these
networks (out of a total of about 2,000) and most of the subscribers belong

to them. With regard to the remaining local networks, it seems acceptable,
from the subscriber's point of view, for the new services not to be made avail-
able initially in rural areas. Nevertheless, when necessary, it is possible
to overcome every difficulty by means of temporary long user lines.

It will be necessary to install more than one peripheral exchange in large,

polycentric metropolitan networks. It will probably be advisable to install
a mew peripheral exchange for each of the old main exchanges, for the pur-

pose of avoiding problems in the user network. In smaller networks, on the

other hand, one single new peripheral xchange will be sufficient.

The location of transit networks and central controls will depend only on tech-
nical considerations concerning traffic, cost and reliability requirements.

By proceeding as shown above, the simultaneous, coordinated introduction of
a flexible superimposed network is achieved. This network will make it pos-
sible to offer new services to users located anywhere in the nation's terri-
tory. It will evolve subsequently until all users are connected to it.

The same superimposed network can be used to offer data service switched over
all the nation's territory. At least part of the connections have to be under
digital technique for this purpose. This is possible by using suitable MODEM
[modulator-demodulator], even in cases in which the transmitting carriers are
exclusively of the analog type.

5. Conclusions

Many requirements came to light during this study that have to be met by a new
digital system so that its introduction into a network will be favored. Some
of these requirements are obvious, like low cost, modular structure, capabili-
ty of decentralization, capacity for new services, and so on. Other require~
ments, although implicit, were not stressed particularly. They include, for
example, the capability of making direct connections between the new peri-
pheral exchanges and old-technique exchanges and the capability of generating
adequate accounting pulses even for calls originating under the old technique.

35


indicates that it is actually correct to go from the old technique to the new
as soon as possible, but only insofar as that is made possible by the degree
of filling of the field of numbering, and, on the other hand, to go from
the new technique to the old without expanding the existing switching stages
but taking care to use them as much as possible.

Another interesting guideline emerged for cases in which it may be necessary
to increase the number of digits. This increase is to be performed for new-
technique lines and not for old-technique lines (because that would entail an
increase in the number of selection stages).

Other criteria are applicable in connection with the sizes of the various net-
works. In this respect, the Italian situation is as follows:

a.) For areas of decreasing importance, one, two or three digit district :
codes are used. The corresponding user numbering is with six or seven di-
gits, five or six digits, four or five digits.

b.) In view of the fact that the maximum length of the national numbering
is nine digits, one more digit can be used in case of necessity.

3.1. Large Local Networks

Special attention has been devoted to u study of networks with a two-digit
district code. As has already been pointed out, at present user numbering

is with five and (more frequently) six digits. Seven-digit user numbers are
permitted, nevertheless, and are already used sometimes. All the first
digits assigned to local numbering are normally used, but for each of them
there is, at least, a second digit that is available or can easily be made
available.

(3) (4)
qa x +x
°—) in DIM D9]
» (5) .
wx (6)

Figure 6. Routings in a large local network.

Key: 1, new system; 2. old system; 3. originating exchange;
4. destination exchange; 5. first digits assigned to the lo-
cal network; 6. second digits available for expansions

31


The CT, designed for low and medium traffic volume, has a capacity for 2,048
users and 180 connections, used for outside connections, with the possibility
of handling 156 simultaneous conversations with a total accessibility network.

The CT can be decentralized with regard to CC and RT, offering great equipment
flexibility and the possibility of optimizing the telephone network by means
of equipment close to the user and a consequent reduction of line length.

The switching technique used in the PROTEO peripheral exchange is TDM/PAM
[Time-Division Multiplex / Pulse-Amplitude Modulation] with resonant transfer.

Connections with the transit network are accomplished through 2 Mbit/second

PCM channels, 30+2 channels (depending on the CCITT [International Telegraph
and Telephone Consultative Committee] recommendations), while connections with
the centralized control are accomplished by means of 64 kilobit/second channels.

1.2. The Transit Network and Central Control

.
The transit network is a time-division digital system capable of switching both
2,048 Mbit/second lines and 8,448 Mbit/second lines.

The transit network has been designed so that it will have no internal.bl cks,
in order to have maximum freedom in establishing connections and in serving
different tiaffic distributions, both with the initial equipment and in case
of expansions.

The central control is a recorded program system providing the following func-
tions in the area of switching:

[a.] Switching: storage of labile data for each connection, routing, rate
scale.

[b.] Optional services.
{c.] Centralization of operation and maintenance for the system: collection
of alarms, cyclic checks, isolation of units out of order, diagnosis and loca-

tion of modules out of order.

The central control consists of two computers operating in parallel in accord-
ance with master-slave operation.

The CC is capable of controlling a transit network and up to 32 peripheral ex-
changes, for a total of 30,000 users with a capacity of 150,000 BHC.

1.3. Maintenance Areas in the PROTEO System
The PROTEO system is completely autonomous for performing voice and data ser-

vices. A service processor takes care of implementing and providing mainte-
nance and administration services.

40



As a matter of priority the government had released funds, and supplies were
on the way to increase the telephone capacity of most of the principal towns.
When that equipment was installed the:towns on the outskirts of Colombo would
be able to have a further 6,000 telephones.

Rural switchboards would also be able to increase capacity ranging from 30
to 60 percent and the direct dialing system would be further expanded
appreciably, said Mr Jayasinghe.

Referring to the microwave linkup between Sri Lanka and India, Mr Jayasinghe
said he now found that India would benefit more when the linkup was estab-
lished. However, since the last government had committed the country to
such a linkup he would have to go through with it. India had agreed to

bear a higher percentage of the contribution and has also undertaken to
supply the equipment. Once the microwave linkup has been established it
would be possible for a number of towns in both countries to have direct
dialing telephones.

Mr Jayasinghe said he had emphasised the need for the government to pay
greater attention to the development of telecommunication in the country.
Teleconmunication, power and water were the three things that marched ahead
of any development. They did not march alongside development but ahead

and if those three ingredients werc neglected development in any sense could
never be achieved.

cso: 5500


[c.] Peripheral units near the control and the exchange to inform remote
Maintenance personnel.

{[d.] A traffic simulation system (MAV).

(1) 2)
9 = e
a ‘ TSS,
Le RSA? : — .

we wl

}--.

G3) —— « pot 4)

(5) Mav

Figure 9. Organization of the field trial.

Key: 1. service processor; 2. data-processing center;
3. low-frequency connections; 4. PCM connections; 5. MAV
simulator

Tests of the exchange, started in 1972 in the SIT-Siemens laboratories, were
conducted with special attention to the dperational and environmental aspects.

Experiments that continued until July 1973 in the company's laboratories veri-
fied the predicted operation limitations (temperature, power supply variations,
and so on).

50



+ an

Figure 7. Supervisory control of the user's connection and

line.

Key: 1. 3-kilohertz crosstalk receiver; 2. attenuation re-

ceiver; 3. 3-kilohertz generator; 4. user simulator; 5. de-

coder breakdown actuator; 6. high-frequency TX receiver;

7. ringing current receiver; 8. line test actuator
The prinicipal tasks of the decentralized control are summarized as follows:
[a.] Routing.
[b.] Rating.

[c.] Control cycles on the CT to detect breakdowns.

48



This group has full access to all the laboratory data.. In addition, monthly
meetings were held between this group and a group of designers to discuss re-
sults from the field and to formulate strategies for tackling problems coming
up from time to time.

Units out of order are always sent to a repair center where they are examined
by reliability experts. During this period, the capacity of the exchange
reached the following size:

Users: 500, including
normal 50 percent
pay stations 7 percent
private equipment 23 percent
"friend" users 10 percent
test jacks 10 percent (automatic ringers, and so on)

Connections: 180, divided into:

60 PCM connections toward Milan Center

30 low-frequency connections toward Settimo Milanese
30 PCM connections toward a rural exchange

60 low-frequency connections for testing

A program we.3 also developed in this period for varying the numbering of the
exchange, since that kind of variation was anticipated shortly.

4. Public Service of the PROTEO Peripheral Exchange

The exchange, which began public service in April 1975, was unmanned, while
supervision took place during working hours in the control station.

In the remaining unsupervised period, alarms were transmitted to the manned
exchange in Milan Center.

In the first year of operation, 15 breakdowns in the subsystems were recorded,
as follows:

3 recordings of breakdowns in the PCM system toward Milan, owing to inter-
connection problems.

2 stops of one single computer (with automatic restart, without affecting
service) due to transientson the primary power distribution. The distribu-
tion structure was varied to eliminate these disadvantages.

3 software errors recorded without total shutdown. The proper corrections
were made together with the incorporation of new services required by main-
tenance.

3 shutdowns (including one total) with automatic restart owing to operator

errors. These possibilities were eliminated by protecting the system against
operator errors with keys and further controls depending on requirements.

54



4.1. Modifications Made to the Hardware

Four circuits were modified, in order to improve the solving of breakdowns and
two modifications, in order to correct errors in the UCL operating programs.
Some modifications were also made in the user line testing circuits, in order
to take into account the diversity existing in telephones and present user
lines.

4.2. Modifications Made to the Software

Twenty-two software modifications were made (to correct errors and for varia-
tions). These modifications, tested on a simulated system, were made during
operation, first making them on the slave CD and then switching to the master.

Variation in Exchange Numbering

As has already been pointed out, during operation, the Settimo Milanese ex-
change changed the numbering plan completely.

The problem was solved by using a suitable program based on two memory areas
reserved for routing.

The first area contains present routing; the second, subsequent routing. At

a predetermined time, the areas were exchanged, in order to achieve the desired
new routing.

The same method was used to change the form of connecting new connection lines.

4.3. System Reliability

From an examination of the breakdowns recorded, it appears that a certain num-
ber of them are due to two main reasons:

{a.] Design errors (software errors, incorrect sizing and use of components,
and so on). .

(b.] Technology not completely suitable for certain parts (first version of
the subscriber board, solder method for container wiring).

The other breakdowns recorded, on the other hand, are to be regarded as due
to the normal life of the components.

If only this last-mentioned type of breakdown is taken into account, bearing ~
in mind the limit imposed by the short observation period and the small num-
ber of specimens, it can be stated that the reliability predictions that had
been calculated were generally confirmed by the experimental results.

58



Table 1
Main Characteristics of the Peripheral Exchange

Capacity:
Users up to 2,048
Connections up to 180
Connection routes 2X 78
Traffic (1% loss) 137.5 E

Connection for:

Dial telephones
Pushbutton telephones 2 frequencies (i out

of 4) with key signal

Line characteristics:
Supply voltage -48 volts (CEI [Italian
Electrical Engineering
Commission] standards

Power supply bridge 2 xX 5102

Line resistance 1,400 Q (pushbutton)
. 3,000 2 (dial)

Line insulation >20 kQ

Immunity to over- 500 volts (after the

voltages arresters)

(ISPT standards)

Table 2
Sound Characteristics
Transmitted band 300-3,400 hertz
Internal transmission PAM with resonant transfer
80 1.56-microsecond time
intervals
User-user attenuation <2 decibels
User-low frequency con-
nection attenuation <1.7 decibels
User-PCM-PCM-user at-
tenuation CCITT standards
Table 3

Mechanical Characterisitcs
Number of cabinets: 4 3 for RC

1 for UCL
Cabinet dimensions 1,030 X 830 X 2,850 millimeters
Weight 3,500 kilograms
Ambient temperature S$40° Cc

46



INTERNATIONAL AFFAIRS

NEW DENMARK-NORWAY TELECOMMUNICATIONS CABLE BEGINS SERVICE
Oslo AFTENPOSTEN in Norwegian 2 Nov 77 p 20

{Unsigned article: "New Sea Cable Gives Better Telecommunication Contact
With Europe]

[Text] Today the Norwegian Telecommunications Administration inaugurates
the new undersea cable which was laid this summer between Norway and Denmark,
This will make it easier for all telephone subscribers in Norway to make
contact with Denmark and the rest of Europe, Section Chief Nils Taranger of
the Telecomaunications Administration's lines section tells AFTENPOSTEN,

The new cable will immediately provide 700 new overseas lines above and be-
yond the present heavily overloaded 600 telephone channels. The maximum
capacity of the cable is 2700 channels,

"We must wait for the inauguration of the rest of the capacity after we get

a new radio link between Arendal and Oslo and the new tower on the Roeverkollen
in Oslo in full use, Then we will be even better equipped to face the steadily
vising traffic," Taranger says.

The cable is 144’ km long, It was laid from Arendal by way of Vrakvika near
Hisoey and the laying cost 36.2 million kroner, The costs were shared by
the Norwegian Telecommunications Administration and the Danish postal and
telegraphic network, joint owners of the cable,

The 700 new connections thus far have been switched into existing connections
which have up to now not been fully utilized, Taranger points out.

In addition to carrying telephone traffic, the new cable will also be able
to carry telex traffic and data traffic, It is connected to the new tele-
vision center in Oslo by a radio link.

The laying of the cable took place in several stages, Japanese companies
delivered the cable and the electronic equipment, the amplifiers were mounted
on the cable in the port city of Vigo in Spain and the main cable was laid
by a British cable vessel, It is now under observation by a computerized
measuring apparatus,

18



Further requirements may emerge, for example, for more detailed studies on the
decentralization of switchboards or on the replacement of thousands of tradi-
tional lines with 2,000-line peripheral exchanges, and so on,

In summary, it seems advisable to draw the following conclusions:

I. The adoption of digital switching systems, within the framework of inte-
gration of techniques and services, seems to be promising for both long dis-
tance and local networks.

II. Administrations may obtain substantial advantages from the adoption of
appropriate introduction methods.

III. Manufacturers can facilitate the introduction of their systems into net-
works by making them capable of meeting certain specific requirements.

It is pointed out, as a final conclusion, that the objective of this paper was
certainly not to make a complete list of those requirements. An attempt was
made, rather, to emphasize how they can be disclosed only by means of a de-
tailed study of introduction techniques.

BIBLIOGRAPHY

1. Gigli, A. "“OCM Insertion in the Telephone Network,” TELECOMUNICAZIONI,
No 39, June 1971.

2. Ward, M. "A Digital Trunk Exchange in a Mixed Analogue, Digital Environ-
ment," Paper No 213, ISS, Monaco, September 1974.

3. McDonald, H.S. "An Experimental Digital Local System," Paper No 212, ISS,
Monaco, September 1974.

4. Schoeff, J.A. "A Versatile Integrated Codec for PCM System," Paper No B4,
International Seminar on Digital Communications, Zurich, March 1976.

5. Ferra, P.de, and Martinelli, S. "Basic Features of the Time Division
Switching System PROTEO," Paper No 22 E, ICC {International Conference
on Communications], San Francisco, June 1975.

6. Ritchie, A. E., and Smith, W. B. "System Planning for N. 4 ESS," Paper
No 223, ISS, Monaco, September 1974.

7. Bernard, R.; Dejean, J. H.; and Robin, G. "Analytical Cost Studies of
PCM-IST Networks," Paper No D2, International Seminar on Digital Communi-
cations, Zurich, March 1976.

8. Lucantonio, F. "Preparatory Study for the Introduction of the Electronic
Technique in Switched Networks," L'ELETTROTECNICA, Vol 62, No 2, February
1975.

36



CONTENTS (Continued)

NEAR EAST AND NORTH AFRICA
LEBANON

Progress in Restoring Communications Reported
(L'ORIENT-LE JOUR, 4 Nov 77)...cseeeeee

USSR

Moscow - Yerevan Satellite Communications Link
Established
(Yu. Kozlov; KOMMUNIST, 5 Nov 77)...sceceseucecevees

Briefs
Chief of Orbita-2 Station Comments
Assembly Brigade Foreman Comments
WESTERN EUROPE
INTERNATIONAL AFFAIRS
New Denmark-Norway Telecommunications Cable Begins
Service
(AFTENPOSTEN, 2 Nov 77). .ccceccccccececesereescerece
ITALY
Techniques Used in Introducing Time-Division Switching
Systems
(Paolo de Ferra, Admeto De Giovanni; TELE-
COMUNICAZIONI, Sep-Dec 76).....ceeecccecccereveceves

Development of the Peripheral Exchange in the PROTEO

System
(Guido Arrigoni, et al.; TELECOMUNICAZIONI,
Sep-Dec 76)...eeeeeeeeee nec cece renee nee e eee ee cece

NORWAY

Nordsat Advantages Explained
(Carsten Middelthon; ARBEIDERBLADET, 2 Nov 77)..

Editorial Applauds NRK Decisions on Nordsat
(Editorial; AFTENPOSTEN, 7 Nov 77)..

-b-

Page

10

14

17
17

18

20

38

61

64


{a.] Both the transit network for switching these circuits and the
central control (not shown in figure 4) are installed in the transit cen-

ters on which the rural circuits converge.

[b.] The lines between digital exchanges are the last selection routes, not
only for traffic between new-technique lines but also for the overflow of traf-
fic between old-technique lines. It must be borne in mind that the so-called
preventive use of circuits must be avoided for centripetal traffic.

[c.] Both subdivision of lines and the need for replacing old-technique equip-
met are avoided, and there is no need for expanding the old technique, which
can remain "frozen" in its previous form.

2.3. Long Distance Network

* ‘| *

\< 208 has [- =} 200 km,
a a cH ae co
co ce cn ee co

* (1)
(2)

a) (3)

Figure 5. Long distance routings.
Key: 1. new digital switching sections; 2. existing last
selection lines; 3. overflows

The introduction of digital stages in 4-wire transit centers has al-

ready been shown to be advisable, even when local networks continue with an
analog technique (6). For the purpose of studying this topic, a network like
the Italian network with three relationship levels ~- national transit ”
centers (CN), divisional exchanges (CC) and district exchanges (CD) -- was

29


An extremely important advantage of space communications lies in the capa-
bility to transmit photocopies of the principal newspapers from Moscow
directly to the printing presses of the capitals of the union republics
and remote cities of the Soviet Union. With the aid of the high-speed
"Gazeta-2" equipment, a page of "Pravda" will be transmitted from Moscow
to the Yerevan printing office in only two and one-half minutes. This
will make it possible for Yerevanites to receive the principal newspapers
at the same time as Moscovites.

"Orbita-2" in Yerevan has still another important assignment--with the
assistance of ground radio relay lines, the Central Television programs
received from space will be relayed to the sister republics--Georgia and
Azerbaydzhan. In the future, the Yerevan - to ~ Moscow space channel will
transmit more and more information, and each year its capabilities will be
expanded and improved.

The design and construction of the station were accomplished in record time.
The project was executed by the Yerevan branch of the State Planning Insti-
tute for the USSR Ministry of Communications (Chief Engineer of the project
was L. Kolupayev). To the Institute's credit there are many "Orbita" sta-
tions which have been designed for regions of the Far East, extreme North,
and Siberia. The Yerevan station was completed along an independent
design. The project's author, architect R. Asatryan, applied many inter-
esting and original solutions.

45


It should be noted that time-division techniques have already been used in an
economically suitable manner in the transmitting sector with PCM [pulse-code
modulation] systems. An approximate indication of the costs of the various
transmission systems is given in figure 1, which shows how the PCM systems are

more economical, both in comparison with low frequency and in comparison with

FDM [frequency division multiplex] systems, over a broad range of circuit

lengths (1). In fact, several million PCM channels are already in operation

in many countries. In Italy, for example, 20-25 percent of all the high fre- .
quency channels owned by the SIP are already under the PCM technique. 7

The advisability of using numerical techniques increases considerably when one
or both exchanges used at the ends of a circuit are digital. With reference
to figure 1, when, for example, the cost of digital terminal tp is 2/3 of tag,
the present upper limit of the field of advisability of digital systems (L)
increases, respectively, 3 and 5 times under two conditions.

Figure 1. Transmission costs (per channel).
Key: 1. cost; 2. low frequency; 3. dis-
tance

It is normally anticipated that the progressive extension of transmission and
switching in digital form will follow from that, in order to make up an inte-
grated digital network. Obviously, this network will have the maximum extent
when not only the 4-wire exchanges but also present 2-wire exchanges are under

digital system.

Figure 2 gives an approximate indication of the costs for automatic 2-wire transit
switching with various limit capacities and produced with various switching me-
thods, on the basis of information provided by a manufactuer. in an analog en-
vironment, costs are represented as follows:

21



USSR

BRIEFS

CHIEF OF ORBITA-2 STATION COMMENTS--The construction and placing in operation
of the "Orbita-2" station is yet another vivid example of the fraternal
cooperation amongst the peoples of our nation. Tens of the Union's enter-
prises manufactured the equipment for the station. The entire assembly

and adjustment sequence was performed by a special-purpose brigade from

the Podol'sk Plant for Electrical Assembly Procurement headed by A. Zadykyan,
the plant's section chief. And it must be said that the boys made a con-
scientious effort and performed all the work at a high level of quality
which allowed us, the operators, to begin the reception and relay of trans-
missions quickly and confidently. [Text] [Yerevan KOMMUNIST in Russian

5 Nov 77 p 4]

ASSEMBLY BRIGADE FOREMAN COMMENTS--To the credit of our assembly crew stand
20 "Orbita" stations which have been constructed in regions of the Far East,
extreme North, and on Kamchatka and Sakhalin. And each such station is
specially memorable and dear to us. We shall carry away with us from Yerevan
the warmth of friendly hearts, and a special feeling of collectivism and
Partnership. The work for many was complex and unfamiliar. The people,
therefore, tried to see into the heart of the matter, and master the art of
assembling complex and precise technological equipment. In so doing, each
tried to offer his own interesting solutions to the technical problems
arising during the assembly of the equipment. Examples of valiant labor

were displayed during the "Orbita" construction by V. Novikov, G. Treshchalin,
A. Vasilenko, engineers S. Nersesyan and A. Nunyan, electrician G. Movsesyan,
and others. As a result of this friendly and selfless work, all the station's
systems were assembled with great precision and quality, and Yerevan's
viewers were able to watch on their own azure screens the many interesting
programs on the eve of the Great October Revolution holiday. [Text]

{Yerevan KOMMUNIST in Russian 5 Nov 77 p 4]

cso: 5500

17



considered. Two possible solutions were examined: the first one uses digi-
tal stages in expansion of the transit exchanges; the second uses them

as separate sections belonging to a superimposed network. This second solu-
tion seems more advisable when old exchanges are under electromechanical tech-
nique and without signaling on a common channel. ‘The diagram shown in figure 5
is particularly interesting for this last-mentioned case. The upper part
shows the routings of a last selection in the case of district exchanges not
equipped with digital-type local systems. On the other hand, in the lower
part it is assumed that digital systems have been introduced in the CD.

In a solution like the one in the upper part, the decision to introduce the
new superimposed network may entail greater costs in the intial phase. That
is owing to the initial smallness of the superimposed network, or to its
smaller yield and the smaller number of direct circuits. Nevertheless, even
a relatively small increase in overall traffic may suffice for the advantages
of this network to exceed the disadvantages. Moreover, when the district ex-
changes are equipped with digital systems (lower part), the advantages of the
new network are perceptible right from the initial phase of introduction.

3. Network Structures

Local networks equipped at present with step-by-step systems are discussed for
the purpose of studying and testing practical plans for introduction. into
networks. Cne of the features of these systems is the strict correlation be-
tween numbering and routing plans.

When this study was started, it was thought that the best procedure was to
develop actual networks in accordance with various plans and to wait for the
most suitable methods of introduction to be able to emerge from a subsequent
analysis of the results. It was thought, moreover, that it was not necessary
to use simulated models, in view of the risk that they would prove to be in-
sufficiently representative. Nevertheless, during the study we realized that
it was excessively complicated to work only on actual cases (7). In addition,
the complexity of practical situations made it difficult to draw conclusions
of a general nature. It was decided, therefore, that the best method for
operating was to pursue three parallel approaches simultaneously: analytical
considerations, studies of simulated models and testing on practical cases. In
this way, guidance criteria that can be applied in most of the practical cases
were established.

One of those criteria concerns traffic between new and old technique. Initially
it was thought that the best way to avoid further expansions of the old tech-
nique was to go from the old to the new technique as quickly as possible (right
from the first digit) and from the new technique to the old as slowly as
possible. On the contrary, it was found, later, that this method would in-
volve generally not only a constant initial expansion of old-technique se-
lectors for the purpose of releasing first numbering digits, but’ also

an excessive subdivision of junction lines entering in the old technique, with

a resultant increase in the number of A/N converters required. A better solution

30



replaced exchanges destroyed with advanced manual exchanges certain exchanges
which had been destroyed (Hammana, Jubb Jannin), put back in order most of
the lines diverted during the events, carried out 'maintenance' work

on exchanges and annexed equipment, such as batteries, air conditioning,
emergency generators.

"We do not wish to omit the reference to inadequacies, but it is impossible
to deny the importance of the work completed and to fail to do justice

to those of our officials who performed it under frequently very difficult
conditions."

Disturbances

"Tt should be stated that these results were minimized in the eyes of the
public because of the problems the administration faces in respect to the
new requirements of the users.

The shifts of population and activities from one sector to the other disturbed
considerably urban communication. For example, on one hand, we have
available about 10,000 unused lines in the Riad Solh exchange, whereas

we are unable to satisfy 9,000 applications for subscription at Dora and
5,000 applications at Mazra'ah. On the other hand, for instance, the Mazraa
and Achrafieh, foreseen as mainly residential areas, suddenly become
commercial and cannot provide for the increase in communications. The

result is a congestion, which the public experiences as faulty tone quality.

The same thing happens in the communications from one exchange to the other,
when the changes in the communications cause blocking, with calls being
completed with difficulty at certain times.

"Add to that the fact that line availability is insufficient when the
network is not installed.

"All these problems are being studied and solved. ‘Redimensioning' the
network will permit the whole system to return to an operational state not
just equal to but superior to the one prevailing before the events. I should
however draw your attention to the fact, that the delivery of certain
equipment may require considerable time, from 8 to 12 or 14 months.

"Hence, while confirming that the whole of the exchanges and the network
will be restored to a good condition within a period of 3-4 months, I must
state, that we can only achieve the desired quality towards the end of 1978."

Expansion

"But our ambition is also to satisfy the need for expansion, and with this
in mind, we provided in the program of operations to be implemented in
1978, the installation of 80,000 new lines, i.e., an increase of one-third
of the existing equipment. This is a gigantic enterprise, in view of the
investments for exchanges, buildings, networks, and for the effort of
adaptation required on the part of the administration.

12



N
:
y
Z

6
(7) 6) |
(3)
(9) 9
A Y
Ge

~
L

EEE 2]
Ps
Ss
2

Wl

Figure 11. Distribution of breakdowns in the units of the
. exchange.

Key: 1. CD supply; 2. PCM breakdowns; 3. software errors;
4. operator interventions; 5. UCL breakdowns; 6. restarted
by operator; 7. not recorded; 8. automatic restarts; 9. re-
pairs; 10. replacements; 11. other

The distribution of repair time is described in figure 12. It should be noted
that no subscriber complaint was recorded during the entire period of opera-
tion, owing to the speed and accuracy of locating breakdowns.

Preventive maintenance on’ user lines, by means of automatic cyclic tests, gave
particularly good results.

56



can do to help in promoting economic and other areas of cooperation among
nations of Asia, the meeting noted. It expressed conviction that news ex-
changes in Asia can contribute to the promotion of peaceful cooperation
among Asian nations.

The conference has proposed that Asian news agencies endeavour to develop
a set of criteria for news values for purpose of news exchanges. It has
also proposed that accuracy, truthfulness and objectivity of information
should be guidelines for increasing the information and news flow among
Asian countries.

The conference has agreed that news and information should not mislead,

but should enlighten, create national identity and promote international
cooperation. Noting that news reports and articles should reflect a fair
and balanced account of eventg, the conference has agreed that emphasis
should be given to national, regional and subregional efforts at overcoming
poverty, hunger and diseases and at modernisation.

cso: 5500


these times on variations in the parameter values and the following conclu-
sions were reached:

1.) Obviously, the most important parameter is d (xatio between cost of the
digital system and cost of the previous system). It should be observed that,
if an intermediate technique (semielectronic) is adopted between the electro-
mechanical and the digital technique, the value of d@ increases and may have
an adverse effect on a subsequent introduction of digital techniques.

2.) The rate of increase r has considerable influence. Low rates of increase
(typical of countries with a high use density) are an obstacle to the introduc-
tion of digital techniques, while high rates of increase may make it possible
to recover greater initial costs in a rather limited number of years. With-
in a given country, recovery may be faster in some areas rather than in others.

3.) The initial disadvantage c also plays an important part. Since it in-
cludes every possible kind of disadvantage, the aim of an adequate introduc-
tion strategy is precisely to reduce their effects to the minimum.

4.) The other parameters (amortization period and financing interest rate)
have relatively minor influence, in the field of variation under consideration,
on the times for reaching the NPR and “xP.

5.) When the parameters take on very tavorable values, curveB (figure 3) is
obtained. If d +c = 1 (as in the case of curve B), there are no problems
of recovery of greater costs. If, on the other extreme, all the parameters
take on unfavorable values, curve C is obtained. In this case, although eco-
nomic advantages may be dreived starting at the "point of no return," they
may prove to be insufficient for compensating for interest on the capital
estimated for reaching that point (in other words, in this case it would be
uneconomical to introduce digital local exchanges).

2.2. Rural Areas

All that has been set forth above is applicable especially to large local net-
works, whose structure is not affected much by the presence of long distance
circuits under analog or digital technique. For small rural networks, there
are some factors that oppose the introduction of digital techniques, including
the following:

{a.]| The relatively large number of channels in first order multiple PCM.

{b.] The relatively small capacity of the exchanges, which may often often be
put in relation to field A in figure 2.

On the other hand, the use of digital switching systems in small rural net-
works is favored by three reasons:

27


Handel's opera "Xerxes," is an equally fabulous production, And next
Sunday it will be Puccini's grotesque one-act "Gianni Schicchi."

Can the positive opportunities latent in several television channels not

be seen, or at least slowly listened to? True enough, weak souls will
select the programmes which attract them most, We should permit ourselves
that thought, and that too is healthy, For people, i.e., television viewers,
to be allowed to do as they wish?

Take the Handel matineee, for example. Probably there were thousands in
this country who sat by their televisions that Sunday morning and who would
like to have more. Handel wrote an immense number of operas which have
not been performed for 200 years. European television can breathe life
into them and we can have a chance to experience them. Plus all the other
scenic musical works from the 17th and 18 centuries, there are thousands
of them. Originally composed for the small elites of the princely court
theatres, today they can be revived to make us all happy, actors and musi-
cians, singers and stage-setters, technicians and theatre artists, And a
world public numbering in the millions, which would also like to include
recalcitrant little Norway.

8739
cso: 5500

63



Norwegian Press Association--of all people--is negatively inclined toward
trial broadcasts, and gives that as its principal reason,

On the contrary, the Nordic challenge and the national need must go hand

in hand, A joint project would undoubtedly bring with it a far broader set
of program offerings--not to mention the availability of parallel programs
on different channels. We foresee that a Nordic agreement would not only
cover access to boost and relay signals from neighboring countries. We fore-
see a developed system of program exchange, cooperation in productions, items
which would give the greatest possible number of people a chance to use the
television offerings at various times of day.

Fundamentally it is probably the point of departure which differs when one
examines both Norwegian and Nordic television, .For us, television is a
medium with vast possibilities. For others the medium is a potential danger
you must protect yourself against.

Today parts of Norway have access to a limited output of the future Nordic
television. The committee of the Norwegian Broadcasting Corporation has
adopted a sensible stand on possible further development, Agreement to trial
broadcasts of satellite television must be the conclusion too, when Korvald
and his colleagues in the bodies elected by the people have had a chance to
evaluate future television coverage in the Nordic countries.

8739
cso: 5500

65



PORTUGAL

BRIEFS

AZORES SATELLITE COMMUNICATIONS--A message from President Ramalho Eanes to
the Azorian people will herald the introduction of a new Radiodifusao
Portuguese program to the Azores via satellite on Sunday afternoon, when
an earth satellite communications station is commissioned in the Azores,
boosting telecommunications between mainland Portugal and the outlying
nine-island archipelago in the Atlantic. Apart from being able to call
each other through a subscriber trunk dialing system, the people of the Azores
will, from Sunday, be able to receive better television and radio programs
from the mainland. To mark the event, the Portuguese ANOP News Agency is
opening a branch in Ponta Delgada. [“ummary] [Lisbon Domestic Service
in Portuguese 0900 GMT 15 Dec 77 LD]

cso: 5500 END

66


It should be pointed out that the marginal economic advantages just described
may be critically important to countries with a low per capita income. In fact,
for some countries with a high per capita income it is agreed that semielectron-
ic systems with recorded program control are economically suitable only if ac-
count is taken of greater revenue for new supplementary services and the savings
in costs of operation. In that case, in other countries, in which the costs of
operation are already low and in which there is probably little interest in
sophisticated services, it may turn out that the only valid choice is digital
systems, precisely owing to the above-indicated marginal advantages.

The new digital systems present, however, no slight shortcoming in comparison
with other systems: the cost of decoders, of demultipliers and of signaling
converters needed for interconnecting the new digital equipment with the old-
type analog equipment. This cost may be a serious burden in the initial phase,
but it decreases subsequently and finally disappears. The use of suitable me-
thods of introduction may reduce this burden considerably.

The objective of this paper is to show the principal technical and economic
aspect of introducing time-division switching systems in existing telecomnu-
nications networks, with special emphasis on local telephone networks. No
specific plan or program for introducing a time-division system in a national
network is given here. Nevertheless, special attention is devoted to problems
of Italy's telephone network and more specifically to that part of the network
(over 50 percent) equipped at present with step-by-step electromechanical
switching systems. With regard to technical solutions, special reference has
been made to the PROTEO switching system (5), at present in an advanced stage
of development by the SIT-Siemens company.

The system is designed to meet not only the requirements of telephone service,

but also the needs of data service. It consists of three main subsystems:
peripheral exchange, transit network and central control.

The peripheral exchange, with PAM [pulse amplitude modulation] type switching,
has a capacity for 8 groups of 256 users, for a total of 2,048. It can be de-
centralized with regard to the transit network and central control.

The transit network is a digital switching system capable of handling up to
512 2 kilobit/second PCM systems (15,000 channels). Up to seven’sections of
te transit network can be decentralized with a maximum of 32 PCM systems each.

The central control can service 150,000 calls at peak time, with a maximum of
32 peripheral exchanges and 30,000 users.

2. General Features

2.1. Large Local Networks

It might seem logical to install a new type of exchange in an existing local
network by observing the same criteria adopted for traditional systems and by

keeping the traditional routing and signaling plans for outside traffic un-
changed. From a technical point of view, this would be possible, in view of

24



.

WORLDWIDE AFFAIRS

BRIEFS

UN BROADCASTS TO SA--Johannesburg--The duties of the South African
Broadcasting Corporation [SABC] did not include the blocking of foreign
broadcasts into South Africa, Mr Andre Walters, a public relations officer
of the SABC said here today. He was reacting to reports that the United
States had agreed to start broadcasting United Nations shortwave programs
to the republic early next year. According to a spokesman for the UN Radio
Service, the main purpose of the daily broadcasts would'be to persuade
South Africans to do something about their isolation in the world. The
broadcasts, in English, Afrikaans and the languages of the black people

of South Africa, would not have military overtones, the spokesman said.
According to reports from New York this will be the first time the UN

will broadcast to a specific country without that country's permission.

The UN spokesman confirmed that they would be using as many broadcasting
stations as possible, including the powerful Voice of America transmitter
in Liberia. Two English, one Afrikaans and two black commentators will be
recruited. Mr Walters told a Johannesburg newspaper today that the matter
was an international affair which would probably be taken up by the South
African Government. [Text] [Pretoria Department of Information in English
1013 GMT 14 Dec 77 LD]

EARTH SATELLITE COMMUNICATIONS PROJECT--The minister of housing and public
buildings, Lieutenant Colonel Lukakamwa, has signed a 28-million shillings
contract with (?Mehtas Local) Company to construct an earth satellite com-
munication station at Mpoma, near Mukono, in about 1-1/2 years. The proj-
ect, known as (?Ugesa), will be a much bigger station than the Giligili
earth satellite [as heard] near Arua. While the:Giligili earth satellite
has its (?gateway) through Goonhilly in Britain, the one at Mpoma will have
direct communication with seven countries on the preassigned basis, that is
Zaire, Nigeria, the United States, Britain, West Germany, Italy and Saudi
Arabia. The station will have to have direct communication with 31 other
countries on demand. It will be possible to coordinate the Giligili Sta-
tion with the (?Ugesa) for communication purposes, both nationally and
internationally. The communication equipment will be supplied by a Japanese
firm, the Nippon Electric Company. [Excerpt] [Kampala Domestic Service
in English 1400 GMT 14 Dec 77 LD/EA]



CONTENTS (Continued)

PORTUGAL

Briefs
Azores Satellite Communications

Page

66



"By the end of the first half of 1978, the problems of the districts
of Mazra'ah, Ra's Beirut, Shiyah Judayah, and Dora will be solved, and
it will be possible to satisfy all the applications for subcriptions.
Juniyah, Sidon, and Tripoli will be in the same position at the end of
the year.

"As regards international communications, we are happy to declare that

we have not only completed all the repairs, but we exceeded the level

of equipment in service in 1974: the Beirut-Marseilles cable was revised,
the Beirut-Cyprus-Greece-Marseilles cable was put into operation, the
al-'Arbaniyah station was restored to working order, and its operation will
be increased from 5 to 13 directions, and the 2,000 line automatic telex
center, operating again since this morning.

"We are undertaking to extend the automatic telephone connections with
Greece (in 3 to 4 weeks) as well as the various European countries.

"We are beginning to install 2,000 new telex lines which will be put
into operation progressively from next May, while we are calling for
bids on a new bilingual electronic center with 5,750 telex terminals to
be delivered around mid-1979."

9018
cSO: 5500

13


by

INTER-ASIAN AFFAIRS

CONFERENCE AGREES TO SET UP ASIAN NEWS SYSTEM
Colombo WEEKEND in English 11 Dec 77 p 3 BK

[Text] Seventeen Asian nations last week agreed in principle to estab-
lish a system of Asian news exchange.

Consensus on this was reached at last Friday's concluding sessions of the
meeting of experts on development of news agencies in Asia.

The meeting appointed a six-member working group headed by Mr C. E. L.
Wickremasinghe, leader of the Sri Lanka delegation and comprising Mr P. S.
Kasbekar (India), Mr Mohamed Nahar (Indonesia), Mr Youri Laouri (Iran)
and Mr Lhavagjarvyn Zantav (Mongolia) to prepare an interim report.

The report to be presented to the intergovernmental conference ’on communica-
tion policies in Asia organised by the UNESCO for June, 1978, will deal
with:

--A feasibility study of establishing an Asian network, based on an ex-
change of news between national agencies.

--The interests of news agencies in the region to participate.
--To identify national news agencies in the region to participate.

--To identify national news agencies in the region willing to act as clearing-
houses or redistribution centers.

--To determine the technical needs of the system and the agencies inter-
ested in participating in network.

It has been resolved to invite the UNESCO and the International Telecom-
munications Union to cooperate with the working group.

The meeting noted that Asian news agencies have special functions as
instruments of social progress. There is much that national news agencies



Norway has the world's greatest undersea cable mileage, and the new cable
to Denmark has a capacity four and one half times greater than the exist-

ing cables, Predictions indicate that the 2700-channel capacity is suffi-
cient to handle traffice for the next ten years,

8739
cso: 5500

19


JPRS 70432

6 January 1978

4 WORLD

TRANSLATIONS ON TELECOMMUNICATIONS POLICY,
RESEARCH AND DEVELOPMENT

No, 26

Reproduced From
Best Available Copy

~ DISTRIBUTION STATEMENT A
* Approved for Public Release
Distribution Unlimited

_ U.S. JOINT PUBLICATIONS RESEARCH SERVICE
|

mem, 20000202 118

alas



Cs |

an (07

Figure 2. Typical floor plan of an exchange (30,000 users).
Key: 1. coder-decoder; 2 circuits; 3. users

Each UCL is connected independently to the CC by means of 4.8 kilobit/second
MODEM .[modulator-demodulator], with 20-bit messages and redundant code for
correction up to two wrong bits and detection up to three bits.

Switching of the voice signal is accomplished with the resonant transfer me-
thod. Samples pertaining to a connection between two users are exchanged on
a multiple called "sound highway." A sound highway is capable of handling
80 simultaneous connections subdivided in an equal number of time channels.
Since the sampling frequency is 8 kilohertz (in accordance with international
recommendations), the time interval available for each connection is 1.56
microsecond. The time actually used for resonant transfer is equal to 920
nanoseconds. The rest is used as cushion time. Figure 4 is a functional
block diagram of the exchange. There are two main highways (HW), each con-
trolled by a preprocessor (UCL). Each user group or connection can have access
to one highway at a time.

Two of the 80 time intervals are used for scanning and control. Therefore,
there are 78 intervals usable as connection routes for each highway.

42



while the rest will be assigned to nongovernment radio broadcasters. As
of that moment, the use of radio frequencies outside those allocated by
the ITU is illegal and will be treated as such, because to do so would
interfere with other broadcasts and telecommunications and would only
invite foreign protests.

The workshop will close on 19 December 1977.

cso: 5500


INDONESIA

ADDRESS TO NONGOVERNMENT BROADCASTERS MEETING
Jakarta Domestic Service in Indonesian 0700 GMT 15 Dec 77 BK

[Text] The director general of radio, television and film, Sumadi, has
expressed the hope that development of nongovernment radio broadcasting
should concentrate on organizational, broadcasting and management sectors.

In a keynote address at the opening of the second workshop of the non-
government Radio Broadcasting Development Authority in Jakarta today, Sumadi
reminded his audience of a letter of decision of the information minister,
dated 8 December 1977, reaffirming the Indonesian Commercial Radio Broad-
caster Association, or PRSSNI [Persatuan Radio Siaran Swasta Niaga Indonesia],
as the only professional organization in the sector of commercial radio
broadcasting. This means that commercial radio broadcasters who are not
members of the PRSSNI will not get government recognition and access to
facilities. He hoped that the future status of nongovernment radio broad-
casters who work for other government agencies, such as the Indonesian
Republican Armed Forces, the Agriculture Department and so on, would be
decided upon in the workshop.

With regard to radio broadcasting, Sumadi called on nongovernment radio
broadcasters to become true partners of RRI [Radio Republik Indonesia],
especially in anticipation of the convocation of the People's Consultative
Assembly Plenary Session in March of next year. Specifically speaking,

he said that besides presenting entertainment programs, the nongovernment
radio broadcasters should also present programs conforming with the interests
of a developing nation, such as relays of RRI news bulletins.

Speaking on matters of management, Sumadi reminded all nongovernment radio
broadcasters that each one of them must soon establish its legal status in
order to obtain a permit to operate.

Sumadi also disclosed that at 0001 GMT on 23 November 1978, a new alloca-
tion of broadcast frequencies established by the International Telecommunica-
tions Union [ITU] will take effect. Indonesia has been allocated 120 radio.
broadcast channels. RRI will use 68 channels along with 20 cochannels,



4 breakdowns on a UCL owing to breakdowns of separate components, with no
shutdown of the system and resulting in an average loss of 50 percent of the

conversations in process of being set up.

“

isa

The PROTEO exchange in Settimo Milanese.

Malfunctions on the units of the exchange are shown in figure 11 and in table 5. :
Most of the breakdowns were recorded in circuits of the connection network and
especially in subscriber jacks (making up 60 percent of the exchange).

It should be noted, however, that the second version of the user jack constructed
with custom integrated circuits by SGS-ATES (in place of the separate circuits
provided in the first versions) reduced the breakdown rate to 25 percent of the

former rate.

55


ITALY

DEVELOPMENT OF THE PERIPHERAL EXCHANGE IN THE PROTEO SYSTEM
Milan TELECOMUNICAZIONI in Italian Nos 60-61 Sep-Dec 76 pp 21-34

{Article by Guido Arrigoni, Sergio Dal Monte and Giorgio Magnolfi, of SIT-
Siemens, and G. Battista Di Stefano, of the SIP, originally presented to
the International Switching Symposium, Kyoto, October 1976: "PROTEO System:
Peripheral Exchange Field Trials"”]

{Text] An integrated, completely electronic system, designed and
built by SIT-Siemens, in collaboration with various com-
panies in the STET Group with the technical assistance of
STP [Italian Telephone Operating Company], is in an advanced
stage of development and testing, in Italy. This article
gives a brief description of the PROTEO system in its gen-
eral features and deals in particular with the functions
of the peripheral exchange, the most repetitive unit in
the system. A peripheral exchange has been in public opera-
tion since April 1975. The various testing phases, its
Placing in service and its operation since July 1973 are
presented.

1. The PROTEO System

PROTEO is a modern integrated telecommunications system developed in the la-
boratories of the STET Group and, specifically, at SIT-Siemens (Milan), CSELT
[Telecommunications Research and Study Center] (Turin) and SGS-ATES (Agrate)
with the assistance of the SIP and built by SIT-Siemens.

Figure 1 shows a block diagram of the system in its three principal parts:
peripheral exchange (CT), PCM [Pulse-Code Modulation] transit network (RT)
and centralized control (CC). The main characteristics of the system are:

[a.] Completely electronic technique, based on time division (TDM [Time-
Division Multiplex]).

[b.] Capability of complete decentralization of peripheral exchanges.

[c.] 30,000 lines subdivided in 32 CT, maximum. Each CT can serve up to
2,048 numbers. .

38



«

(1)

a \ BG)

Figure 3. Difference in cost for into-
duction.

Key: 1. difference in cost (present
values); 2. curve; 3. years

If it is assumed that natural increase and replacement for obsolescence re-
main stationary, the trend in time of the cost for values of the parameters
regarded as "normal" is as indicated by curve A, figure 3:

{a.] Initially, the difference between the overall cost per line (present
value) with the new technique and the cost that would be encountered with the
old technique is greater than zero.

(b.] After some time, a"point of no return" (NRP) is reached, beyond which
the cost of expansions under the new technique are lower than the cost under
the old technique. At the NRP, the difference in cost reaches its maximum
value.

[c.] Subsequently, because of the constantly decreasing cost of the new sys-
tem, a "point of capital recovery" (CRP) is reached, according to which the
greater cost borne previously is entirely balanced by the advantages peculiar
to the new system. The new system offers only net profits from this point for-
ward.

The most impostant factors in the process of introduction are the times needed
for reaching the NRP and CRP. Analyses have been made of the dependence of

26



ce

Q—-

(3) (4) Pe

an

Figure 3. Block diagram of the periph-
eral exchange.

Key: 1. modulator-demodulator; 2. con-
nection; 3. low frequency; 4. connection
network

The various groups of units connected to the PAM highways are:

1.) User Groups (GU)

This consists of a’ group of circuit boards on which (figure 5) the components
pertaining to the user control circuits are mounted. Four of these circuits
are contained (with the accesses for controlling them) on a board 256 X 230
millimeters in size. The exchange is subdivided into eight user groups,

each of which has a maximum of 256 jacks. Each user circuit contains a TDM
filter, the power supply bridge, the ringing current supply, the line current
and half current measuring head, the circuits for connection control, and so
on.

Integrated MSI and LSI integrated circuits were developed by SGS-ATES for the
routing and switching circuits. An extensive use of Schottky technology made
it possible to obtain high operating speed and low dissipation at rest (a few
milliwatts).

43



the flexibility of the new systems, however it is not advisable to proceed in
that way, especially in networks equipped with step-by-step systems. In fact,
several difficulties would be encountered, including the following:

{a.] Unsuitability of theold routing and signaling systems for interconnec-
tions between new-type exchanges, with resulting disadvantages both to users
and administrations.

[b.] If suitable methods are not adopted, need for expanding the old-type
switching stages also at the time of introducing exchanges solely of the new

type.

When new systems with a recorded program control are introduced in a network,
these kinds of difficulties are frequent, in addition to management and per-
sonnel training problems. When the new system is digital, the situation is
further complicated by the completely different philosophy of the system for
which, as a result, all the connections between new and old systems are sub-
jected to the disadvantage of a need for converting both voice and signaling.
The cost of conversion may be considerable. For example, if it is assumed
that the present value of the cost of a new user's line under traditional tech-
nology (including switching, signaling, transmission, maintenance and locals)
equals one, the corresponding value estimated for a new user's line under di-
gital technology should not be greater than d = 0.9. It should be realized,
however, that, in the initial phase of introduction of user's lines with new
technique in a completely analog environment, the cost of conversion (whose
value might be around c = 0.2) must be added. Obviously, it is not advisable
to connect two new-technique lines with each other passing through old-technique
switching stages, because, in addition to the cost of selectors, two times the
cost of conversion in the environment of the same connection would be encoun-
tered. For this reason, when new-technique exchange networks are introduced,
they are usually interconnected with each other directly by means of a super-
imposed network without passing through the old technique, which may thus be
left completely "frozen."

It should be pointed out, however, that even if this is done, under certain
circumstances the disadvantage pertaining to connections between new and old
lines may be such as to make the introduction of digital local. exchanges un-
economical.

There are five significant parameters for a through analysis of these situa-
tions; namely:

d = ratio between cost of a new digital line and cost of a traditional line.
c = initial disadvantage (with the same cost unit).

xr = rate of natural use increase in the local network.

t = amortization period.

i = financing interest rate.

25


frighteningly expensive. And even if it is written on paper that a Nordic
satellite will have its coverage area limited on the map, it is, remarkably
enough, not the map which decides.

Technical developments will proceed, now as before, whether the Norwegian
press likes it or not. Quite soon, or let us say comparatively soon, we
will be able to receive broadcasts via satellites outside the Nordic region,
too, Even if there are no plans for this. In a television series with

Jan P, Jansen, we heard the heads of Nordic broadcasting express their
Nordic desires and they were, taken overall, restrictive, with the partial
exception of the Danish one. This, too, is as expected, but it is no less
depressing.

While our Scandinavian home is clothed in deep November, we can all see the
winter darkness approaching. Darkness created for those who want to listen,
perhaps because the radio waves wished it to be so. From higher spheres
they are reflected down when daylight is gone, and while we are girding our-
selves for our daily routine early one morning we can catch the liveliest
music, From those dangerous foreign countries, where at least at that time
of the day they understand that we want something else besides pop, Quite
the contrary, They enliven the day's cthythm with fresh little scherzos
from the music of the Renaissance and the Baroque, An inexhaustible source
of happiness and well-being, which NR& should also dip into,

It is particularly Belgian and Dutch morning broadcasts which allow us to
shake off the soulless commercial, machine-produced pop which is otherwise
force-fed to us day in, day out, from NRK. How would it be if current-
affairs programs like "Echo" and "The end of the school day" got in touch
with NRK's outstanding music department, which, as far as I know, has less
and less to do with the selection of the total quantity of sound which is
broadcast? It is far from impossible that the many capable program pro-
ducers could be provided with fruitful new musical ideas.

And in this we can use the satellite too, it can bring us more music, With
pictures, they need no help, the orchestral broadcasts on television are

now done so capably that most objections vanish, And with its fine adventur-
ous Sunday matinees, television, throwing aside all caution, is catering

to our highest expectations, Most recently it was Rossini's "Italian in
Algiers," a comic opera which we in this country did not have the least
chance of seeing, except right there on television, Under relaxed, artistic,
indeed almost freely balancing direction which did justice to bold, often
facile music which would completely lose its character if it were to be
presented outside the theatre.

Rossini and other Italians have so much more than we ever find anywhere

else, and they can only be played by Italians, This time in collaboration
with East German television in Dresden, which last time let us experience

62


SOVIET-BURUNDIAN AGREEMENT-~An agreement was signed in Moscow today on co-
operation in the field of broadcasting between the USSR State Committee for
Television and Radio Broadcasting and the National Radio of the Republic of
Burundi. The agreement was signed by Orlov, deputy chairman of the USSR
State Committee for Television and Radio Broadcasting and (Gahungu), gen-
eral director of the National Radio of the Republic of Burundi. [Text]
[Moscow Domestic Service in Russian 1130 GMT 16 Dec 77 LD]

cso: 5500


The building's construction was carried out by the RSU collective of the
"Armsvyaz'stroy" combine. The builders worked well at full performance
and completed construction of the station in only 10 months. Particularly
distinguished were the foreman R. Gegyan, bulldozer operator A. Manukyan,
arc welder Zh. Yeremyan, concrete worker A. Gevorkyan, carpenter M. Shakh-
bazyan, electrician G. Oganesyan and the ATP drivers from the "Armsvyaz'-
stroy" combine V. Matevosyan, A. Martirosyan and A. Ayrapetyan.

The State Certification Commission accepted the station's building for
operations with a rating of "excellent".

Created by the labor of a large group of people, the Moscow - Yerevan space

bridge lives, functions, draws the people still closer together, and
strengthens their friendship.

9082
cso: 5500

16



[b.] Time for restoration: on the order of about 10 milliseconds for malfunc-
tions in the subsystems; on the order of minutes for decentralized units (in-
dividual connections); on the order of about 10 minutes for subscriber jacks
(testing of a user's jack and the pertinent line takes about 2 seconds).

[c.] Diagnostic selectivity: for user jacks (60 percent of the volume of the
exchange) 100 percent on a circuit board; for other circuits of the RC, 90 per-
cent on two circuit boards; preprocessor (UCL), 75 percent on 3 circuit boards.

Table 4
Main Results of Measurements

Connection
First type Second type

Insertion attenuation 4B 2 2
Group delay distortion see note see note
Reflection attenuation 4B >15 >12
Symmetry dB >55 >50
Psophometric noise aBm0p -73 -72
Noise on a single

frequency daBm0p -73 -73
Extraband attenuation e >50 >50
Caused by intermodulation dB >75 >50
Total distortion -- see note
Spurious signals on

output band dB -- >47
Gain variation with

input signal level -- see note
Crosstalk attenuation dB >74 see note

First type: PAM connections

Second type: PAM-PCM~PAM connections

Note: within the limits of Recommendation G-712 of
the CCITT

The period between August 1974 and March 1975 was used to organize transition
from a test and development phase, based on the work of groups of designers
in close contact with SIP experts, to an operation and maintenance phase con-
ducted by SIP operating personnel.

The operating organization was structured on two levels:
{a.] A first-intervention level capable of easily deriving, from alarms de-
tailed on a printout, the units out of order to be replaced and capable of

handling the simple operations of operation data collection.

{b.] A second specialized level capable of solving more complicated problems
and of performing special tests.

53


10,0
cso:

BIBLIOGRAPHY

Ferra, P. de,.and Martinelli, S. "Basic Features of the Time Division
Switching System PROTEO,” International Conference on Communications ’
San Francisco, June 1975.

Lucantonio, F. "Preliminaries to the Introduction of Electronically
Switched Networks," REVUE FITCE, No 6, 1975.

Valbonesi, G., Formenti, F., Musumechi, L., Bovo, A. "PROTEO System:
Transit Network and Central Control," TELECOMUNICAZIONI, 1975, 54,

ITALTEL. "“PROTEO," special issue, No 359-1-E01, Dec 1975.

Carrelli, C., Galimberti, R., Rosci, G., Taroni, P. "The Production of
Software for the PROTEO System," Software Engineering for Telecommunica-
tion Seitching Systems, Salzburg, Feb 1976.

Husu, E., Martucci, R., Rosci, G., "PROTEO System: Managing the Manufac-
ture of Software," AICA [International Association for Analog Computing]
Congress, Genoa, Italy, 1975.

Alleva, I., Corti, M.G., Galimberti, R., Pescarolo, F. "A Simulation
System for Implmentation and Evaluation of Diagnostic Programs of a Spe-
cial Processor," 12th Design Automation Conference, Boston, June 1975.

Arrigoni, G., Di Stefano, G.B., Dal Monte, S., Magnolfi, G. “PROTEO Sys-
tem: Field Experience of PROTEO Peripheral Exchange," ISS, 1976.

42
5500

60



In this case, it is preferable to differentiate the new technique right from
the first digit. This procedure is made possible by the fact that there is
normally one single exchange in small local networks. Therefore, it is not
necessary to make a differentiation between various directions in the new-
technique environment. Moreover, a smaller number of A/N converters is needed,
both because there is greater accessibility in the output of the I SG and be-
cause, by entering under the old technique at the II SG level, breaking up of
the entering lines is avoided.

3.3. Rural Areas

Traffic originated in rural exchanges does not adhere rigidly to the routing
plans of direct control systems, since there already are units capable of a
limited numbering analysis. Therefore, there is no problem in routing local
traffic from the old technique to thenew, right from the first switching stage,
independently of numbering.

On the other hand, a special numbering problem comes up for calls intended for
new technique rural exchanges and coming from existing old technique plants
in the higher ranking transit center. The possible solutions are:

a.) To select, first, the destination rural area and then to differentiate
between new and old technique with a subsequent digit.

b.) To differentiate, first, between new and old technique and then to select
the destination rural area with one or more subsequent digits.

Solution a) is simpler, especially since it concerns modifications in the
routing and charging analyzers. Nevertheless, a technical-economic evaluation
has shown that, in most cases, the presence of PCM connections makes solution

b) preferable, when the old exchanges are capable of meeting certain numbering
requirements. In this solution (figure 4), traffic may be routed immediately
toward the transit network (RT) and from the RT to the respective decentralized
section (RTD). Thus, connections involve one single analog-digital converter,
rather than three. It should also be noted that, if there is sufficient analy-
sis capability in a present rural exchange, it is also advisable to route di-
rect centripetal traffic toward the new technique through new technique circuits.

4. Other Services
4.1. General Aspects

An integrated network is capable, in principle, of furnishing users both sup-
plementary telephone services and other services, like synchronous data (10).

Other services, like videophone and cable television, should be borne in mind
when a new digital telecommunications network is designed. On the other hand,
integration of these two services pertains primarily to transmission rather

than to switching. Therefore and also in view of the special questions raised

33


by these services, it seems advisable to take up these topics not in this
paper but, rather, at some other time.

It is generally known that systems with recorded program control can offer a
vast series of supplementary telephone services, including, for example, short~
ened selection by pushbutton equipment.

Some of these services may be quite an absolute necessity for certain users,
including, for example, written documentation of debit entries for direct
dialing calls. It should be noted that this kind of service would also make
it possible to offer an outward wide area telecommunication service* even in
countries where debit entry by accounting pulses is used.

An integrated network can offer economically and technically suitable solutions
for certain services, like, for example, the three-way conference service, for
which a single device made with the time-division technique can handle several
conference calls simultaneously. The quality of this service improves when
all the users belong to an integrated network, because of the more favorable
transmitting characteristics of digital means. Another of these services is
the transfer of calls to another number. In this case, even if the call ori-
ginates from an 01d analog network and rerouting cannot be accomplished, good
quality is ensured when the transferring line and the receiving line belong
to a digital network.

It should be observed that, if the destination user has a ‘sufficient number of
local lines of his own, the quality of the long distance network can be main-
tained up to the user's equipmert by means of PCM transmission systems. The
call transfer service enables a user to be called by normal users belonging
to another network, without a long distance charge for the caller.

For the synchronous data service, the peripheral exchange has to make possible
not only the connection of telephone user lines but also of data user lines,
consisting of four-wire circuits in base band (11). Data users can have ac-
cess to the exchange individually or through submultipliers. In the first
case, the peripheral exchange has the task of concentrating data calls on the
PCM channels used for telephony. Data calls, therefore, can be routed through
the transit network toward the nearest exchange equipped for data processing.
For submultiplied lines, the peripheral exchange only performs a semipermanent
kind of switching. Either of these two solutions may be preferable for a spe-
cific user, depending on the speed of transmission of the specific traffic
and the distances.

4.2. Remarks on Introduction

There may be several reasons for giving users requiring new supplementary tele-
phone services priority access to the new system over subscribers to the

* A service in which debit entries for direct. calls going out to specific
numbers or number classes are on a flat-rate basis.

34



{d.] First-level diagnosis for isolation of units out of ‘order.
fe.] Man-machine dialog.
{f.] Subscriber services.

The CD consists of a control unit (watch dog) and two computers operating with
the master-slave system, supervised by the Watch Dog itself.

A data channel makes it possible to synchronize the software of both computers.
In case of a breakdown in the master computer, the structure makes an exchange
with the slave computer possible without causing any outside effect.

eon  - +
H $5 1

cor fete wa fey WS peel wat ec
4 1
LoL J

Figure 8. Decentralized contro” redundance structure.

Figure 8 shows the block diagram of the watch dog [WD] connection with the two
computers, by means of the master-slave units.

The watch dog section determines the proper operation of the supervised com-
puter and informs the M/S [master-slave] section.

The two M/S sections determine which computer is to be regarded as the master
and they inform the periphery that it is ready to receive controls from one
single master unit.

The watch dog and master-slave sections were designed to have excellent relia-
bility and, at any rate, to ensure exclusion of a single computer.

The software in the 32,000-word memory handles control of the peripheral ex-
change in real time. It consists of a supervision program, which coordinates
the intervention of applicable programs handling switching, supervision, re-
configuration, dialog with the operator and documentation. Figure 9 shows
the block diagram of the system developed for field trials.

The following units are indicated, in addition to the decentralized control
(CD), the UCL and the RC:

[a.] A service processor for tracing connections and for experimental tests.
[b.] Connection with a computer center for transferring data, available on

punched tape in the CD, in tables and charts required by operating procedures,
for maintenance, traffic statistics and administrative support.

49


{a.] Costs depending on the limit capacities of the exchange, increasing pro-
portionately to the increase in the number of switching stages and the complex-

ity of the system. The following might be a very approximate expression of the
cost:

cost per connection = limit capacity k
in which k = 0.2 + 0.5.

{b.] Colored areas: costs not depending on the limit capacities. For digi-

tal exchanges, the costs for voice and signaling conversion are shown separ-
ately (darker areas).

Figure 2. Transit switching costs

(per connection)

Key: 1. increasing limit capacities;
2. digital exchanges; 3. semielectronic

exchanges; 4. electromechanical stages;
5. field

The drawing was made so that costs will be equal:

{a.] Between semielectronic switching and electromechanical switching in the
left-hand column.

[b.] Between digital switching and semielectronic switching in the right-hand
column.

22



The phases of the trial are subdivided as follows:
{a.] Until November 1973, checking the switching services.
{b.] Until May 1974, completion of services of supervision and diagnosis.

[c.] Until August 1974, completion of services for survival of the system in
case of breakdown.

The tests were conducted by using artifical traffic (generated automatically
within the system, like test calls, and so on), simulated traffic (generated
by outside devices, like the MAV block devices) and "real" traffic generated
by subscriber "friends." From September to December 1974, the SIP conducted
the following acceptance trials:

1.) General Tests on the Switching Services. The tests covered all possible
types of connection, simulating the correct and incorrect user behavior (with
various kinds of telephones) and of connections, for each of the signaling
codes provided. Over 300 tests of this nature were performed.

2.) Load Tests. Two types of tests were conducted:
[a.] Tests to ascertain if the exchange is capable of handling normal traffic.

[b.] Tests to determine the reaction of the system to conditions of overload
(for example, with 400 simultaneous call attempts. It was ascertained-that
the delay in handling the calls was within predicted limits).

3.) Tests of Exchange Services under limiting conditions created by the user
and connection network (for example, resistance limit of wire insulation, heat
overload due to the entire subscriber network in short circuit, various con-
ditions of impedence of the subscriber and connection network, immunity to
lightning, and so on).

4.) Tests Concerning Transmission Characteristics. The main results of the
Measurements are given in table 4.

5.) Tests of the Exchange's Capability of Recognizing and Isolating Breakdowns.
Over 3,000 breakdowns were caused artificially in the subsystems of which the

exchange consists.

For each breakdown induced, both the types of circuits detecting it and the
time of restoring the breakdown itself and specification of its location
were recorded.

The principal results obtained were as follows:

[a.] Recognition of 98 percent of the breakdowns.

52



NORWAY

NORDSAT ADVANTAGES EXPLAINED
Oslo ARBEIDERBLADET in Norwegian 2 Nov 77 p 15
[Commentary by Carsten Middelthon: "The Dangerous Satellite"]

[Text] Reason has spoken, cautiously and quietly, Certainly we should not
expect too much, but the administration of the Norwegian Broadcasting
Corporation (NRK) has taken a short step, Not with open eyes; that would
be too much to expect from a responsible institution, they just glanced so
far and glimpsed the light, And light has an annoying characteristic: it
is inclinea to blind one, So a person who thinks he is clever and cautious
squints, heeding all sides, and that brings us to the point: Norway is not,
after all, to say "no" to satellites, not an absolute "no," Rather, we may
go forward in stages, as they put it. As if we ever did anything else?

So, it is a kind of "yes," then, And just to a little slice of satellite,
nothing more, Preferably one just to hang on the wall as a trophy, Since
no one knows what the good people can tolerate. Those sitting in the
leadership of NRK are sitting there to watch out!

It is, after all, only half a year since the howls of outrage rose to the
heavens from almost the entire Norwegian press, with cries in unison from
writers and actors, preachers and politicians, A howl which culminated in
something close to a kind of doomsday prophecy when Prime Minister Nordli
went so far as to say that perhaps we had nothing to fear. That would be
the end of good old Norway which had steadfastly and valiantly tried to
prevent so much, including the introduction of something as evil as tele-
vision, not to speak of color'television, or stereo radio transmissions.
Luckily, reaction says, we still have only one radio program and one tele-
vision channel, which are destructive and dangerous enough to the salvation
of the people, But is there still hope?

Unfortunately, I do not think so, Developments are proceeding at quite a
rate, measured against Norwegian circumstances. And before NRK knows what
is happening, we will have Nordic broadcasts, ‘we will have satellites with
direct link-ups to our own small antennas, which do not have to be

61



JPRS 70432

6 January 1978

TRANSLATIONS ON TELECOMMUNICATIONS POLICY,
RESEARCH AND DEVELOPMENT

No. 26
CoNTENTS PAGE

WORLDWIDE AFFAIRS

Briefs
UN Broadcasts to SA
Earth Satellite Communications Project
Soviet-Burundian Agreement

New

ASIA
INTER-ASIAN AFFAIRS

Conference Agrees To Set Up Asian News System
(WEEKEND, 11 Dec 77). .cececcecccccccecnsccceeeccceeeves 3

INDONESIA

Address to Nongovernment Broadcasters Meeting
(Jakarta Domestic Service, 15 Dec 77)..cccccccccecccces 5

SRI LANKA

Country To Join Undersea Communications System
(Patrick Cruez; CEYLON DAILY NEWS, 12 Dec 77).....2.00- 7

EASTERN EUROPE
INTERNATIONAL AFFAIRS

Briefs
GDR-CSSR Radio Accord 9

-a- [III - INT - 140]



The main functions of the service processor are:

{a.] . Maintenance programs and diagnosis for definite location of breakdowns.
{(b.] Signaling and collection of processed alarms.

[c.] Statistics on breakdown data.

[d.] Statistics on traffic data and other significant parameters.

[e.] Configuration and reconfiguration for the switching area.

{f.] Variation of the routing plan.

[g.] Rating and other administrative services.

2. The Peripheral Exchange

Studies for designing the PROTEO system were started in 1969 on the basis of
the peripheral exchange, because it forms the most repetitive unit in the sys-
tem.

The floor plan for a PROTEO switching center for 30,000 users (figure 2) shows
the number of CT used. Design tests or this unit were especially interesting,
because not only the technological problems pertaining to it were tackled and
solved, but also problems of perfecting manufacturing methods suitable for a
completely electronic telecommunications system. Then it must be noted that
the peripheral exchance is the unit that performs integration of the switch-
ing and transmission methods and of the voice and data services.

The design of the peripheral exchange was also based on experience acquired
in the production of two PABX [Private Automatic Branch Exchange] prototypes
using the TDM-PAM technique. One of them is in actual operation at present
as a private exchange in the business area of Castelletto.

The block diagram of the peripheral exchange is shown in figure 3. Users are
connected to the connection network (RC) (dial and multifrequency pushbutton)

and also PCM and low frequency connections.

The connection network is controlledby two cabled logic preprocessors (UCL)
operating with time division. Their main functions are:

{a.] Interface between line signaling and signaling on a common channel
(toward CC).

[b.] User and connection scanning.
{c.] Assignment and maintenance of connections.

{d.] Performance of tests on the connection network.

41


PCM transmission between peripheral terminals and transit network.
Signaling on.common channel.

Recorded program control.

Integrated data transmission.

New services for users.

Centralized structure for maintenance and operation.

The system accomplishes complete integration, both in technique (switching and
transmission) and in services (voice, data, pictures).

1.1.

j ——— cr
co o #2
——_ (1)
see (2)

Figure 1. General diagram of the PROTEO system.
Key: 1. data lines; 2. PCM connections; 3. to the traditional
network and to other PROTEO areas

The PROTEO Peripheral Exchange

The peripheral exchange (CT) is the unit to which all the users served by the
system are connected. Each CT switches local traffic, while outside traffic
is routed through PCM connections toward the transit network.

39


NORWAY

EDITORIAL APPLAUDS NRK DECISIONS ON NORDSAT
Oslo AFTENPOSTEN in Norwegian 7 Nov 77 p 2
(Unsigned editorial: "Nordic Television"]

[Text] Are we to have satellite television in Norway? Lars Korvald,
Chairman of the Christian People's Party, has doubts about the Norwegian
Broadcasting Corporation's agreement to Norwegian participation in trial
broadcasts on a Nordic level. He is in doubt as to whether the elected rep-
resentatives of the people really want Nordic television in Norwegian homes,
and if the representatives do not wan. it, there is no need for test broad-
casts, Korvald concludes,

In itself it would be all right if Norway could make a sovereign decision

as to whether satellite television broadcasts should be received in Norwegian
homes, But to say that this cultural offering will not take place if our
elected representatives say no, is a pure over-simplification of the actual
situation. A "no" from Korvald will not stop the television signals from
passing through the air to the thousands of antenna units and receivers

which can be simply installed, And if there should be no Norwegian prohibi-
tion, we can be sure that in the future there will be no lack of opportunities
to look at other countries' television programs on one's own receiver.

One can lament the arrival of this opportunity within the foreseeable future,
but it cannot be overlooked, In years to come, it is highly probably that
television programs will come from various countries, specifically directed
to "uncovered" television markets. The question will be whether the Nordic
countries will see themselves in a position to meet the demands of a world-
wide television society in time, whether they will participate through a
Nordic program offering which, we are fully convinced, will be able to com-
pete with most of what is offered, including more commercially orientated
types of programs,

Nordic satellite television will naturally require fundamental consideration

of program policy, But a joint Nordic project would be no hindrance to the
development of a national media policy. We think it is strange that the

64


INTERNATIONAL AFFAIRS

BRIEFS

GDR-CSSR RADIO ACCORD--Prague--A protocol was signed in Prague on Friday
on radio cooperation between the GDR anditthe €SSR in 1978 and 1979 by the
chairman of the GDR State Committee for Radio and Rudi Singer, and the
director general of Czech Radio, Jan Risko. The document provides for the
expansion of cooperation in radio between the two states by exchanging
information and material for all types of program. In the joint preparation
of programs on the economic cooperation between the two countries, special
attention is to be given to the important anniversaries and jubilees, in
particular to:the 30th anniversary of the victory of the Czech workers in
1949 and the 30th anniversary of the founding of the GDR. [Text] [East
Berlin ADN International Service in German 1630 GMT 16 Dec 77 LD]

cso: 5500



In July 1973, the exchange was installed at Settimo Milanese (Milan) and field
trials were started immediately in collaboration with the SIP,

This location offered the advantage of introducing the PROTEO exchange as an
exchange for peripheral traffic in the polycentric network of Milan, giving
an opportunity to tackle problems connected.to interfacing with various tra-
ditional methods.

OD seiner in cane Ps: 6...

| CASTELLETTO
|

Tt
Nr te 0
SUL Canali 6

Figure 10. Introduction of the peripheral exchange in the Settimo Milanese
network.

Key: 1. field trial; 2. Milan; 3. maintenance center; 4. traditional ex-
change; 5. center; 6. low frequency; 7. data channels

Figure 10 shows the configuration of the trial. The PROTEO exchange is con-
nected as follows:

[a.] By means of two PCM systems with the main exchange in Milan Center.

[b.] By means of two 15-connection low-frequency lines with the Settimo Mi- -
lanese step-by-step exchange.

{c.] By means of a PCM system with a rural subexchange (CRM).
The PROTEO CT is controlled by the CD about 4 kilometers away, located near

the Castelletto laboratories, to make a thorough test of the problems of ope-
ration and maintenance raised by an unsupervised decentralized exchange.

51


Table 5
[Malfunctions]
Number of interventions

Unit total replacements repairs others

Subscriber group 29 28 1
Low-frequency connection group 1 1 -- --
PCM connection group 4 - 1 3
Timer - -- -- -
25-hertz generator 1 . -- 1 --
Medium-frequence digit re-

ceiver group - -- -- --
Test unit 1 -- 1
UCL 4 -- 4 -
cD 8 - -- 8
Total 48 29 8 11

Figure 12. Repair time distribution.
Key: 1. number of breakdowns; 2. nor-
mal log distribution; 3. repair time

An automatic control cycle, lasting 30 seconds, consisted of tests on the fol-
lowing units:

user and line circuit boards (4 jacks) (35 tests each)
2 connection groups (20 tests each)
1 medium-frequency digit receiver (15 tests each)
1 tone generator ( 4 tests each)
1

UCL switching program section

57


Beirut-Cyprus-Greece-Marseilles cables, and later the al-'Arbaniyah
ground station will place our international communications system at a
higher level than that of 1974.

"I take this opportunity of conveying to you, for myself and in the name

of all the Telegraph and Telephone personnel, as well as all the specialists
who contributed to the overhaul of this center, our most sincere wishes

for Lebanon to continue its progress to peace and prosperity under your
leadership."

The PTT Minister
Farid Raphael

Press Conference

Accompanied by the Director General for Telephones, Mr Remi Chami, and
the Director General for Information, Mr Charles Rizq, the Minister
held a press conference to make the following statements:

"Ten months ago, when I took over at the PIT Ministry, I realized the
extent of the damages: regional communications cut off, transmission centers
destroyed, telex center out of order, the international communication

lines reduced to the Beirut-Marseilles cable, whose output had dropped
considerably, several centers destroyed (Sinnael-Fil, 'Alayh, Tammana,
Biskinta, Jubb Jannin, Ra's Ba'Lbakk), the others suffering from lack of
maintenance, lack of individual parts, and disorders caused by the events.
In all [it was] a network seriously damaged by the fighting (in Beirut,
more than 60,000 out of 160,000 lines out of order), to such an extent

that in certain areas, overhauling was equivalent to the installation of a
new network. Now, even before the events, the administration had not

been able to evolve either with regard to the requirements or the installed
equipment: the routine methods and shortage of cadres set restrictions

on its action and aroused continuous complaints from the public.

"This same administration, who more than any other State administration,
suffered through the events, having even lost its offices, part of its
documents, all its stock of equipment and spare parts, deprived of means
of tran: port (30 vehicles retained out of 260) had the duty to rectify the
situation."

Repairs

"We had assigned priority to a program of repairs of the damages, devoting
to the international communications sector the attention it merited.

"In the area of local communications, we restored regional communications
(Tripoli, Sidon, Zahlah, 'Alayh, Juniyah, Brummana, Bikfaya...), restored
nearly 70 percent of the damaged network, permitting the connection of
close to 45,000 subscriber lines in Beirut and its suburbs, put back
into service 2,000 lines of the 'Alayh exchange, temporarily

il



ie

BIBLIOGRAPHIC DATA |?- Report No. R
SHEET JPRS 70432

3. Recipient's Accession No.

4. Title and Subtitle

TRANSLATIONS ON TELECOMMUNICATIONS POLICY, RESEARCH
AND DEVELOPMENT, No. 26

5. Report Date
6 January 1978

6.

7. Author(s)

8. Performing Organization Rept.
jo.

9. Performing Organization Name and Address

Joint Publications Research Service
1000 North Glete Road

Arlington, Virginia 22201

10. Project/Task/Work Unit No.

11. Contract/Grant No.

12. Sponsoring Organization Name and Address

As above

13. Type of Report & Period
Covered

15. Supplemencary 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. Coverage will be worldwide with focus

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

17. Key Words and Document Analysis. Ie. Descriptors

Worldwide
Computers
Satellite Communications

Electronics and Electrical Engineering
Telecommunications
Telemetry

17b. Identifiers ‘Open-Ended Terms

Ve. COSATI Field/Group Q9B, C, F, 17B, 22B

18. Availability Statement

Unlimited Availability
Sold by NTIS -

Springfield, Virginia 22151

19. Security Class (This

> 69
BO. Security carers BR 22. Price

Page
incLA SIFIED

Zi. No. of Pages

FORM NTIS-35 (REV. 3-72)

THIS FORM MAY BE REPRODUCED

USCOMM-DG 14952-P72



In the case of six-digit user numbering, the most suitable solution is the one
in figure 6. If the number of new-technique lines is made proportional to the
number of old-technique lines for each first digit, it is not necessary either
to expand or change the old-technique group selectors (8) (9). The same pro-
cedure can be observed also for five-digit decades, but, in this case, there
is the disadvantage that entering at the III SG (group selectors) level means
entering toward a group of only about 1,000 user lines (in other words, small
capacity entering lines are made in a first phase). A similar criterium may
also be adopted in networks with six and seven digits, but with an output at
the III SG level and an input at the IV SG level. In fact, in these networks ,
an available decade can normally be found not at the second but at the third
digit. In Italy, that occurs in the cities of Rome and Milan.

A study of the large local networks has been made by means of a simulation
model prepared expressly for this purpose. The following input data may be
varied in this model:

{a.]| The number of existing exchanges and their capacity.

[b.] The number of new-technique lines under expansion for each exchange
(also in new locations) and the routing plans.

[c.] The cost of transits under old and new technique, the cost of analog-
digital converters and of junction lines.

The study indicated, among other things, how, for traffic from the old tech-
nique to the new, it is advisable to differentiate the direction by means of
the old II SG instead of immediately requesting a new technique transit. For
traffic from the new technique to the old, it has likewise been found advan-
tageous to avoid an excessive subdivision of entering lines and, instead, to
make a further transit under the new technique close to the destination ex-
change.

The results of the study have been verified, taking into account developments
up to the year 2000 for two actual cases: the Brescia network and the decade 3
part of the Turin network.

3.2. Minor Local Networks

Networks with athree-digit district code and normally five-digit user number-
ing are taken up here. Six-digit user numbers can also be used, however.

Some of these networks have already reached saturations of five-digit number-
ing and six-digit developments are in progress or are being scheduled. For
these kinds of networks, the most suitable methods of introduction are still
the ones described for large networks.

In most cases, however, the field of numbering is far from saturation, ‘in part

also because of the small number of dependent rural networks. Consequently,
one or two first digits are already available, or are easily made available.

32



ITALY

TECHNIQUES USED IN INTRODUCING TIME-DIVISION SWITCHING SYSTEMS

Milan TELECOMUNICAZIONI in Italian Nos 60-61 Sep-Dec 76 pp 3-12

[Article by Paolo de Ferra, of the STET-Telephone Financing Company, and Ad-
meto De Giovanni, of the SIP (Italian Telephone Operating Company), originally
presented to the International Switching Symposium, Kyoto, October 1976]

[Text]

The aim of this paper is to point out the main aspects of
introducing time-division (TD) switching systems into ex-
isting telecommunications networks. The first part deals
with the essential features and technical-economic prin-
ciples pertaining to both local and transit time-division
switching systems. In the second part, problems and para-
meters concerning the adoption of new time-division switch-
ing systems for large local networks are discussed. Then
special problems concerning rural and long-distance networks
are taken up and possible solutions are pointed out. The
third part deals with the use of time-division systems in
existing step-by-step local networks of different sizes.
Some general guidelines are obtained from an analysis of
representative models and actual cases. The fourth part
takes up features pertaining to the introduction of sup-
plementary telephone services and synchronous data ser-
vice. In the conclusion, the most significant guidelines
for facilitating the introduction of new time-division
systems are summarized.

1. Introduction

Today, a constantly increasing number of administrations and constructors are
tending to adopt time-division digital switching in place of space-division
switching for 4-wire switchboards in the long distance network. In fact, for
many reasons it can be believed that digital switching will be competitive at
any rate in that sector. In Italy, considerable interest has already been
shown for many years in digital techniques and recently the Ministry of Post
and Telecommunications has scheduled experimentation with various digital
transit exchanges in its own long distance network.

20



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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-
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original but have been supplied as appropriate in context.
Other unattributed parenthetical notes within the body of an
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A.) In rural areas, traffic interest is oriented more toward long distances.
Moreover, the distances between rural exchanges and the respective higher level
exchanges make PCM transmission competitive of itself. Therefore, digital
switching sytems are subject to smaller burdens in comparison with their use
in large networks.

B.) Within a ruralarea the burdens pertaining to traffic between the new and
the old technique may be smaller. For example, local connections can be made

by means of low-cost converters (for example, PAM/low frequency instead of
PCM/low frequency).

Cc.) In small networks (more than in large ones) an exchange is often replaced
for reasons of saturation of locals. In those cases, an entirely new-technique
exchange will be installed, without interconnection problems or burdens.

wKI@TM ly oy
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oe (5)

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Figure 4. Routing for rural areas.
Key: 1. transit center; 2. PCM lines; 3. rural exchange;
4. last selection existing lines; 5. last selection new lines;

6. overflows; 7. transit network; 8. decentralized transit
network

A typical connection diagram between a relatively large rural exchange and a

higher level transit center is shown in figure 4. All the following can be
observed:

28



9. De Giovanni, A.; Segre, F; and Maggi, F. “Problems of Insertion of the
PROTEO System in Networks," TELECOMUNICAZIONI, Nos 54-55, March June 1975.

10. Decina, M., and Ferra, P. de. "Prospects for Techniques and Services In-
tegration into the Italian Telecommunication Network," Paper No 243, ISS,
Monaco, September 1974.

11. Mossotto, C.; Musumeci, I.; and Pietromarchi, A. "Technical Requirements
for Digital Data Switching in PCM Exchanges," to be presented in this
symposium.

10,042
cso: 5500

37


Thus, three capacity fields (A, B, C) are shown, each of which indicates the
possibility of the existence of a field of suitability for each technique
(electromechanical, semielectronic and digital). It should be noted, however,
that the drawing is purely for guidance. For example, the existence of field B
is not even proved. At any rate, a basic indication obtained from figure 2 ise
that the greater part of the costs for digital switching in an enalog environ-
ment are due to voice and signaling conversion (2). For this reason, when di-
gital switching exchanges are installed in totally or even only partially di-
gital environments, they become considerably more competitive. Consequently,
it seems predictable for the future that the integrated digital long distance net-
work will finally be extended to the present 2-wire switching exchanges. This
extension finds, however, a limitation in short distance connection in a local
network. On this level, the distribution stages and the user stages form a
single unit with regard to the operations of routing, control, signaling, and
so on. Therefore, a local switching system of the analog type is inevitably
destined to compete with the adoption of digital transit stages in the local
network itself. The basic topic of this paper refers, however, to local sys-
tems designed expressly for digital switching, starting with the first dis-
tribution stage.

Various technical solutions are possible, in these systems, for the user stages,
including the following:

{a.] Space-division switching followea by CODEC [coder-decoder].
[b.] Time-division switching followed by lower cost CODEC.

[c.] Delta coding on the user circuit level followed by digital switching and
delta/PCM converters (3).

[d.] Direct PCM coding by means of integrated components (4).

At any rate, provided the basic local distribution stage is performed with the
digital method, it does not matter which of those solutions is adopted, es-
pecially when future developments in this field are considered. The principal
objective is to obtain substantial economic competitiveness with regard to ana-
leg local exchanges for internal connections. Once this objective has been
evrained, considerable savings will be achieved automatically in connections
between exchanges.

Moreover, adoption of the digital technique in local switching leads to a var-
iation in the equalization of cost between subscriber lines and connection cir-
cuits by lowering to about 1,000 meters the limit of suitability for decentra-
lization of the user stages with regard to transit stages and thus making
savings possible in the subscriber network.

An entirely digital widespread telephone network can be used suitably also for

other services, like data services, for which other savings can also be expected
in this field.

23


SRI LANKA

COUNTRY TO JOIN UNDERSEA COMMUNICATIONS SYSTEM
Colombo CEYLON DAILY NEWS in English 12 Dec 77 pp 1, 5 BK
[By Patrick Cruez]

[Text] Sri Lanka will now become part of a massive undersea cable com-
munication linkup covering five countries in South Asia.

The minister of posts and telecommunications, Mr Shelton Jayasinghe, said
Sri Lanka had indicated its willingness to contribute to the cost of
laying this ASEAM undersea cable linkup connecting this country with Japan,
Hong Kong, Singapore and India.

Mr Jayasinghe said when this 1‘nkup was on the drawing boards 2 years ago
Sri Lanka was to be bypassed. If that was allowed to happen the cable which
would begin from Japan would have gone directly to Madras from Singapore
skipping Sri Lanka.

If that happened a tieup with this massive South Asian telecommunication
link could well have been lost for ever to Sri Lanka.

The linkup with the ASEAN undersea cable was a part of the government's
development plan to bring modern telecommunication systems to the country.
A four-man team of senior engineers was now abroad studying two modern
telecommunication systems.

The United States and France were now using the "Time and Space" System
which was the electronic switching device connecting communications in-
ternally and internationally. Some other countries were linking up with
communication satellites.

Here in Sri Lanka telecommunication development had been so neglected that
what was in existence was the outdated "cross bar" system which was in-
stalled during the colonial era. The ineffectiveness of the cross-bar
system was felt today because although the country needed thousands of
extra telephones the type of cross-bar switchboard currently in use did
not have provision for massive expansion.



5. Conclusions

At this time, both the centralized control and the PROTEO transit network are
undergoing final trials.

A pilot series of the peripheral exchange is under production and acceptance
trials. The wiring method adopted is a modified wire wrap connection and the
entire mechnical structure has been revised, in order to adjust it to the re-
quirements of production.

During 1977, some of these exchanges will be installed in the field. ‘The or-
ganization built for Settimo Milanese is being expanded rapidly for an ade-
quate solution to the problems raised by thak kind of wide-spread installation
of integrated electronic systems. A team of experts has been organized in a
centralized headquarters to analyze the data coming from the field.

This group will act as an interface between the operating agency, the manu-
facturer and the designers with regard to collecting and analyzing data. A
second group will assist the operating agency whenever necessary to perform
research on special breakdowns or to make modifications to the system. A
third centralized group has been provided for handling maintenance of the
software and documentation of the installed systems. A center has been set
up to handle repairs and to administer stores of broken-down parts coming
from the installed systems.

In addition, this center is responsible for analyzing breakdowns and for fur-
nishing data useful for restoring reliability.

A group specializing in planning system documentation and operator manuals
has been set up. In fact, it has been ascertained that inadequate informa-
tion or imprecise directions to the operators are the most frequent causes of
dangerous actions.

Experience achieved in the field demonstrates the interesting possibilities
offered by this electronic system for both corrective and preventive main-
tenance.

The total repair time ascertained enables us to anticipate low maintenance
costs without sacrificing service quality.

The companies in the STET group are making a great effort to offer, shortly,
a technologically advanced telecommunications system consistent with inter-
national guidelines.

Considerable experience will be acquired from the many systems already in-
stalled in the field, before entering the mass production phase.

59


Figure 5. Circuit board with four user jacks.
2.) Connection Groups

There are 180 connections, divided in six groups of 30 each. A group may con-
sist either of PCM connections, called CODECOM, or low-frequency (BF) connec-
tions used for connecting with electromechanical switchboards.

3.) Digit Receiver Groups (RCF)

They consist of circuits used to detect multifrequency user selection. Each
group is duplicated for reasons of reliability.

4.) Tone Generators
These are the units that send the various tones used to the subscribers.

The main characteristics of the peripheral exchange are described in tables

1, 2 and 3. The PROTEO pheripheral exchange, constructed with the TDM me-
thod, uses all the exceptional capabilities offered by that method and by a
recorder program control, to perform complete supervision of the’ exchange it-
self. The control operations are performed on UCL and RC using the TDM tech-
nique, while first-level diagnosis (location of the unit out of order and its
isolation) uses the recorded program control capability. One or more time in-
tervals (phases) are used to obtain cyclic control over the exchange, depending
on the type of controls required, on the need for reconfiguration and on the
traffic situation.

45


a 4 cc

Figure 6: Testing unit.
Key: 1. testing unit

The block diagram of the monitoring organization is given in figure 6. The
testing unit (GK) includes all the instruments used for supervisory controls
(senders, receivers, analyzers) over RC and UCL and it has full access to each
unit by means of a separate route. Figure 7 shows, as an example, the instru-
ments used for supervisiong the user's connection and lines.

The results of these tests are sent to the central control for proper analysis.
This control notifies the maintenance personnel in case of an alarm.

3. Field Trials of the Peripheral Exchange

A "decentralized control" (CD), capable of supervising one single peripheral
exchange, was designed for the purpose of obtaining a valid field testing with
the peripheral exchange without having a central control, which was developed

only subsequently

This development made it possible to ascertain both the capabilities of the
exchange and the corresponding applicable software to be used subsequently in
the central control.

This choice also offered the possibility of a gradual introduction of the sys-
tem in rural areas with a slow development, in which an immediate installation
of CC and RT may not be immediately economical.

47


fe

LEBANON

PROGRESS IN RESTORING COMMUNICATIONS REPORTED
Beirut L'ORIENT-LE JOUR in French 4 Nov 77 p 2

[Text] In the communications field, Lebanon has exceeded the level reached
in 1974. This is what the PTT [Posts Telegraph and Telephone] Minister,
Mr Farid Raphael, claimed yesterday. In a press conference, he indicated
that in 1978, 80,000 new telephone lines would be laid, and that 4 months
from now, all the telephone exchanges would be working perfectly. He
specified that "the desired quality would not, however, be reached before
1978." Prior to this, Mr Raphael had inaugurated the re-starting of the
al-'Arbaniyah station, which will extend its capacity from 5 to 13
satellite li.es.

Mr Raphael also inaugurated the resumption of the telex service (2,000 lines
which will be allotted between now and next May), addressing the following
telex message to the Head of State:

"Mr President:

"T am happy to address to you the first totally automated telex message,
after the overhaul of the Beirut telex station.

"T am convinced that this normalization of the telex service permitting 2,000
subscribers to exchange their telex communications throughout the world
automatically and in both directions, will provide a very beneficial impetus
to the various sectors of the national economy.

"This return to normal is only one stage of an overall expansion plan

aiming at satisfying, in accordance with your directives, the expansion
needs of this country, and including the installation of 2,000 new lines
during the first half of 1978, and a new electronic center with 575 terminals
in 1979.

"I confirm to you that the operation of this telex center, the automatic
international telephone exchange, and the Beirut-Marseilles, Beirut-Alexandria,

10