JPRS ID: 10139 WORLDWIDE REPORT TELECOMMUNICATIONS POLICY, RESEARCH AND DEVELOPMENT

• Document Type: CREST
• Collection: JPRS
• Document Number (FOIA) /ESDN (CREST): CIA-RDP82-00850R000400070054-1
• Release Decision: RIF
• Original Classification: U
• Document Page Count: 16
• Document Creation Date: November 1, 2016
• Sequence Number: 54
• Content Type: REPORTS

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL USE ONLI'
JPRS L/10139
25 Nov~mber 1981
- Warldwide Re ort
p
= TELECOMMUNICATIONS POLICY,
RE~EARCH AND DEVELOPMENT
(F4U0 16/81)
Fg~$ FOREIGN BROADCAST INFORMATION SERVICE
FOR OFFICIAL USE ONI.Y
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
NOTE
JPRS publications contain information primarily from foreign
_ me~aspapers, periodicals and books, but also from news agency
tYansmissions and broadcasts. Materials from foreign-language
sources are translated; those from English-language sources
are ~ranscribed or reprinted, with the original phrasing and
other characteristics retained.
Headlines, editorial reports, and material enclosed in brackets
_ [J are supplied by JPRS. Processing indicators such as [Text]
or [Excerpt] in the first line of each item, or foll.owing the
last line of a brief, indicate how the original information was
_ processed. Where no processing indicator is given, the infor-
mation was summarized or extracted.
Unfamiliar names rendered phonetically or translitexated are
enclosed in parentheses. Words or names preceded by a ques-
tion mark and enclosed in parentheses were not clear in the
original but have been supplied as appropriate in contzxt.
Other unattributed parenthetical notes within the body ~f an
- item originate with the source. Times within items are as
given by source.
The contents of this publication in no way represent the poli-
cies, views or attitudes of the L'.S. Government.
COPYRIGHT LAWS AND REGULATIONS GOVERNING OWNERSHIP OF
MATERIALS REPRODUCED HEREIN REQUIRE THAT DISSE~IINATION
OF THIS PUBLICATION BE RESTRICTi:D FOR OFFICIAL USE 0~1LY.
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL USE ONLY
JPRS I,/10139
`l5 November 1981
WORLDWIDE REPORT
TELECOMMUNICATIONS POLICY, RE SEARCH AND DEVELOPMENT
(FOUO 16/ 81)
_ CONTENTS
ASIA
JAPAN
Concealed Image Transmissian Method Developed
(NIKKAN KOGYO SHIl~IBUN, 21 Sep 8T) 1
- WEST EUROPE
ITALY
Mod~zl~r Equipment for Packet Switched Data Networks
(N. Corsi, L. Musumeci; ELETTRONYCA E TEI,EC(A~iUNICAZIONI,
May-Jun 81) 5
. '
- a - [III - WW - ~.4C FOUO]
FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL USE ONLY
JAPAN
CONCEALED IMAGE fRANSMISSION METHOD DEVELOPED
Tokyo NTlQC~'~N KOGYO SHIMBUN in Japanese 21 Sep 81 p 3 ,
[Text] New Secure Communication Method Developed by Professor Tominaga et al of
Waseda University; Industrial Espio~nage Throws Up Hands
- In the field of facsimile, which is one of the three "divine objects" of OA (~office
automation), a new m.eth~~i of communication developed for the purpose of "keeping
things secret" has been the topic of conversation recently. As the amount of in-
formation in society increases, many problems are expected to crop up. That :~s,
there is urgent need f or trazsmission of confidential documents by means of
facsimile transmission, for measurPS to counter the theft of documents and "eaves-
dropping" on microwave millimeter wave transmission, and for protection of images
, (documents) transmitted which are of value to a third party. A new concealed
image transmission method ~-?as been developed by a research group headed by ProFessor
' Hideyoshi Tominaga, Department of Electronic Communication, Faculty of Science and
Technology, Waseda University. '~e "concealed image transmission method" developed
by this ~roug uaes a formae that may be called a"hidden image" conversi~n method.
Secrets can be kept and certificatinn (confirmation of document exchange) can be
accomplished conyeniently by this new method. It has caught the attention of many,
be~a.use development of such eoftware enables tha confidential management of various
"documents" according to their importance even after the 0A document management has
entered the paperless age.
Documents and Images Protected, Jumbled Transmission, Sharp Rece~tion
Facsimile transmission is a m,ethod of transmitting images such as documents by
electranic means ~ver a distance to a receiver. The original document that is to
be transmitted is scanned with a light, and the black and white density of the
image is converted into electiic signals. At the receiving end, the electric
signals are cenvcrted back into the corresponding image. However., facaimi3.e equip-
ment used in an office is ahared by many for economic reason~s and ia used for
transmitting various types of documents including both confidential documents anc~
open letters. Under such circumstances, if a document that must be kept secret can
be transmitted with ~umbled signals which can only be decoded by the rightful re-
ceiver with a certain key into a clear image (document), then the confidentiality
~ of the document can de maintained.
1
FOR Or r i~IAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000440070054-1
FOR OFFIC'4AL US~ (3NLY �
There,are many applications of this meth~d. For exaiaple, it can be programmed to
_ detect whether the seal of electronic mail has heen Lroken by a third party or not,
o-r only a portion of the document.such as the signature may be concealed by the
jtu-nbleo signals so that only the rightful receiver is able to reproduce the .
signature. Thus, the transmission of dacuments Hhich cauld be of value to a third
' party, such as tickets, entrance ttckets, and checks, can also be carried out, and
"many other new uses may crup up," says Professor Tominaga.
_ 'The basic princi.ple of the method is as follows: the arrangement of the image
(letter) point and the arrangement of black and white are ~ixed up so that the re-
ar.range3 signals have the appearance of a~amming signal. The change in arrange-
~nent can be acccnaplished by changing the order of scan lines according to a random
iiumber generator and repeating this pattern periodically. In an ac.tual machine,
ttiis becor,ies part of the logic in3ide the shirt register before codification.
1'he decoding key used by the receiver for reproduction of the image consists of the
same random number gener.ator. With this key, a register logic which is the reverse
of the transmitter is created so that the scan lines are restored to their original
arrange~;ent .
'fhere are infinite variations of this rearrang~ment schemes and if the period of
random number generation is increased, the proc~ss required to decode it also in-
creases proportionately. However, the standard proposed by the CCITT (Consultative
Committee for Intercia~ion31 Telephone and Telegraph) is ce.ntered around a technol-
ogy wttich is aimed at shortening the f ascimile codification of the image information
In order to imrpove the circuit efficiency. A technology in which the random number
~;eneration is made more co~nplex runs counter to the effor4 to make codification more
ef.ficient. Therefore, the problem is h~w tu rp~oncile these two. That is, the
algorism for arrangement change must be decided by the codification efficiency and
the content of the document.
The method for arrangement change may be varied according to the degree oi secrecy
desired, One oi the methods ie called shuffling. The original manuscript (Figure
_ a) is shuffled into random order by a single acan line as in shuffling ~ deck ot
cards (Figure B); or points may be rearrnnged on the same scan line (Figure C);
or points may be rearranged Uetween different sc~n lines (Figure Dj; or blocks may
be rearran~ed as a unit. [Figurea not reproduced~~ This pracesa of randomly chang-
ing the arrarigement is called acrambling. The scrambled signals appear to a third
party as nottiing but noise, .
c:oncealed image transmission is a method of transmieaion of a more advanced degree
tFian the scrambled signals. The aignals transmitted by this method consist of the
:;cr~mbled signala of a confidential document superimposed on the normal aignals
of an ordinary document. Unlesa on~e knows the decoding key, the signals appear
to tiirn as an ordinary transmisaion with garbles. "As the algorith for removal of
bar.blF.d inform.ation in order to improve the image becomes more coaimonplace in the
future, thP unsuspecting third party will thraw away a large quantity of concealed
images disguished da garbles," say~ Pro�essor Tominaga.
Reproduction of this concealed image is achieved by turning it over so to speak,
th.at is, by interchanging the poaition of ar~ apparent image on the fror.t with the
2
FOR OFF(CIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R400404070054-1
FOR OFFICIAI. USE ONLY
! f~ ~~y~ � I
;L+1
j'~~~,~~ t:;
i~~~:~i:': '
r
i t
~s,k~ ~ i
Y ~
. , ~ af ~ ~ 1
~ _
i..r ~ ~ ~ ; ~ ~ G/ ~ ~ ~
` , ~
r? , i ~
~^'~1 . ~ 1~ ~
~ l~ .i-~ ~ ~ ~
. . J~~! ~
1` ~ ~ { r1� ~ :
_ ~ ~ ~..~Y ,
' ' ~ ~
' [Drawing] To tranamit a manuscript (1) by means
- =~iJ= of concealed tranemission, (2) is superimposed
on (1) and transmitted; the output of this
transmission is shown in (3).
" .
, , zr,~~:) ~
j ~ ^~i-.~r':: �1 ~
~ ' _ ; . : ,1
, f, ; a 1;, .
. ~ ~
: ; ~
~
r i' �~S ~ , ~
\ �:v,.` ` . ~
~,rr''~\
.1
~ l
~.~~'t"...,,_:
Z ~
. .
~
~
.~~lia '
11~J~
~ I i J .
S~
1~r'1Mry ~ ~ .
' { ~ ~ ~ ~e
~ ,~,ti ~ �
f ' ~~1.
. ~ _ ~
~ ~
. r
~ ~
_ ~r
:;y~. , ~ � = ~ ,
,~9".^i. `i... 3~ ~
=G=
3
FOR OFFIC[AL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000440070054-1
FUR nFFfC1.4L iJSE ONLY
hidden image on tiie back. ihus, by reversing the arrangement.order of the front
and the back, the image on the front becomes scrasbled while the image on the back
, bec~nes unscramble~d. The concealed image may c~nsist of a superposition of several
~ sheets of images or ~just a singl.e sheet. In the case of a single sheet of i.mage,
the key section of the document such as the signature m2y be scrambled and sc~ttered
in the form of garbles somewhere in the document.
Certification may be cited as another effective application of th~ concealed image
transmission method. Certification is a process of confirming receipt of a docu-
ment by the receiver. An additional scrambled image is superimposed onto the
scrambled signals of the docu~?ent which is being transmitted. After the rightful
receiver has decoded ths scrambl~d signals with an appropriate key, the reproduced
additional im.age is then sent back to the original sender. Thus, certification can
be carried out smoothly if the sender and the receiver make arrangements beforehand.
The high speed f.acsimile machines used today are standardized by the CCITT ae G-III
(Group_III). The neYt generation of G-IV facsimile machines reporGtdly will be
facsimil.e machines with an internal memory. The purpose of having a memory is to
increase the effective utilization of the circuit and to transmit a larger volume
at a higher speed. With the mem.ory function available, the technique of superimpos-
ing several imagzs which is essential in the concealed image method can be intro-
duced easily and the application of software for confidential transmission can be
accomplished. Furthermore, in the future, when all documents and information are
stored in the comp~iter memory and the so-called "paperless office" is a reality,
the equipment itself can be shared by everyone, with the confident~al and non-
confidential documents intermixed. In such circumstances, the document management
can be easily carried out by takint appropriate secret protection measures in ac-
cordance with r.he degree of confidentiality. Meanwhile, communication by such
means as microwave and millimeter wave is expected to gro~w in the future because
of the low equipment cost per circuit. Aaide from military secret communications,
ather users of coum~unications via electronic waves are beginnix~g to attach impor-
tance to the concealed communication technique.
Finally, this group plan to present a paper describing their results at rhe "Inter-
- national Symposium on Image and Document Communications" in Paris in November.
COPYRIGHT: Nikkan Kogyo Shimbunsha, 1981
9113
CSO: ~~106/11
_ ~
FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000440070054-1
FOR OFF[CIAL USE ONLY
ITALY
MODULAR EQUIPMENT FOR PACKET SWITCHED DATA I~ETWORKS
Turin ELETTRONICA E TELECOMMUNICA'LIONI in Italian May-Jun 81 pp 126-130
_ [Article by N. Corsi and L. Musumeci*]
[Test] Summary--Modular Equipment for Packet Switched Data Networks. This paper
- points out the basic choices for ~he design of network equi~ment to be used in pack-
et switched networks. Considering the wide range of system requirements, the ap-
proach based on the availability of modular blocks has been chosen and investigated.
The paper shows how it is possible to interconnect the building blocks in order to
best fulfill network requirements. A packet adapter concentrator (ACP) for X28 and
X25 data traffic has been developed and tested. The ACP is a single processor
equipment based on a general purpose CPU and dedicated communication units. The ACP
is described in more detail from the hardware and eoftware point of view.
1. Introduction
The first Public Data Pl~twoxks, based on the packet-switching technique, went into
service in the second hHlf of the 1970's. The atandardization activity successfully
carried out by the concerned interna~ional organisms, particularly by the ISO (In-
ternational Standard [as published] Organization) and by the ICCTT (International
Consultative Committee for Telegraphy and Telephony), has made it possible to obtain
a range of Recommendations that have created the premises for having ava:ilable, in
the near future, a world-level Data Network, like what has come about for the tele-
phone service and the telex service.
The~e decidedly positive results have led several Adminietrations in Europe to adopt
the packet technique for constructing Data Networks, to be opened to public service
in the beginning of the 1980's.
~
The packet networks furnish "Virtual Circuits" that can be defined as logical asso-
ciations between pairs of terminals, by means of which it ia possible to exchange,
through the network, packet-structured data information.
* Doctor of Engineering Norberto Corsi of the CSELT (Telecommunications Research
dnd Study Center), Turin; Doctor of Engineering Luigi Musumeci of ITALTEL. Type-
scri.pt received 12 February 1981. Paper presented to the 28th International Com-
munications Conference of Genoa.
5
FOR OFFIC[AL USE ONLY
~
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000440070054-1
FOR O~'F[CIAL USE ONL4'
1'he characteristics of the virtual circuits are defined by Recommendation X25. ~ao
basic communication services are offered in partir_ular by means of virtual circuits:
1) Virtual Calling, by which, and analogously to wnat happens in cireuit switching~
a virtual circuit is temporarily established between two terminals by means of
exchange of suitable signaling packets wiCh the network.
i
2) Permanent Virtual Circuit, by which two terminals are permanenrly associated
through a virtual circuit. This service is similar to that offered by means of
~ dedicated connections of point-to-point type.
While on the one hand there is a growing demand for data services, on the other
hand, u5ers are having to cope with problems today relative to exchange of informa-
tion between t~rminals hav~ng different formata, codes, transmission speecis, etc.
Because of its intrinsic ~lature, which involves "store and forward," the packet-
switching technique seems to be the most flexible, in terms both of performance
- characteristics and cost, �or solving these problems.
_ This article describes how, starting with appropriately chosen modular structures,
_ it is possible to construct the network equipmenC necessary for providing a packet-
switching service open to the ongoing technologic~l development and to the use re-
quirements in terms of new applications.
The soiutions described make reference to the results of studies and experimentation
carried out in colla.boration between the CSELT and ITALTEL.
2. Network Configuration
In the Data Network, the essential functions to be performed are those of concentra-
tion and switching. In a3dition to khese, it is also neceasary to take into account
the functions of management and control, which make i~ possible to keep, in time,
the available resourcns at a high level of efficiency and to manage the d~velopment
oL the network in a coordinated manner.
Generally speaking, the concentration function is carried out in the peripheral part
of the network so as to achieve savings in the transmission lines. This functi~n is
often associated with that of adaptation of the nonpacket terminals; this makes it
- possible to transfer into the accesa network the heavy task of support of the vari-
ous protocols and thus to lighten the ;.oad on the nodes with which it is most con-
venient to interface with unified protocols of type X25.
'fhe nodes--both terminals and transit nodes--provide for switching the packets and
directing them to the destination requested in accordance with the routing strategy
chosen.
The management and control philosophy depends fundamentally on the dimensions of the
network and on its architecture. In the context of a public netwerk with broad geo-
graphical coverage and organized in at least a two-level hierarchy, it is considered
more advantageous to go with a hierarchical structure, in which various peripheral
centers are available, coordinated by one or two primary centers positioned at the
highest level of the network. In short, the control and management functions pro-
6
FUR OFF[C[AL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL ~JSE ONLY
vide for gathering and transporting to the center the data for carrying out the op-
erations of charging, continual testing of the state of~the network, gathering of
data for statistics, and signaling of breakdowns occurring in the equipment.
~1~ 0 UTENTI A PACCHETTO ~X25~
~2~ UTCNTI START-STOP ~X26~
1
~M ACp
c,y
~Q
P
" LGM 9~,
a 4
" NCP
Q NLP
9 NCP NGP u
n Q.
~o
L~
q~P
~M p~P
�6fi
- Figure 1. General structure of the network referred to. ACP = Packet Adapter Con-
centrator; NCP = Packet-Switching Node; CM = Maintenance Center; CGM = Management
and Maintenance Center.
Key:
1. Packet users 2. Start-stop uaers
CPU M
IPA IPA IPA IPS
UNITA D~ INTERfACtIA ~1~
Kf7
Figure 2. Monoprocessur structure. CPU = Central Procesaing Unit; M= Memory;
_ IPA = Asynchronous Prot~cols Interface; IPS = Synchronous Protocols Interface.
Key:
1. Interface units
7
FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
F(iR OFFICIAL USE ONLY
In addition, the r~anagement cen[ers are capable of carrying out operations re~ative
to topological change:~ and network reconfiguration owing to breakdowns and over-
loads.
- Figure 1 shows the reference-network st~ ~ure. _ equipment c~~nsidered can be
classified as follows:
1) Packet Adapter Concentrators (ACP), normally placed in the access networic and to
which the user linPS are connected;
2) Packet-Switching Nodes (NCP): term.nat witches or transit switches for the pur-
pose of being able to construct differen. network structures;
3) peripheral Maintenance Centers (CM) and prim., Management and Maintenance Cen-
ters (^C:N).
3. Structure of the Network Equipment
A structure-design objective for achieving the functions requi~ ~ic ~-switch-
ing ner.works should provide for a single "syatem" with such flexibiii~y ..s to be
able to configure all the necessary items of equipment with the capacity desired.
The technical and economic advantage resulting from a solution of this type is in-
deed quite obvious.
The present state of the technology, which has introduced the microprucessor on a
vast scale and has enormously reduced the cost of inemories, has made this approach
possible. The availability of processing units at extremely low cost r~as oriented
design ~c:�~ard objectives such as:
a) functional modularity, for the construction of distributed and therefore flexible
systems;
- b) modularity of the processing capacity, for con~truction of economically viab!e
systems, of uoth small and large dimensions;
c) :riodulari.ty of the reliability assignable to the systems, by providing them with
ttie quantity of redundance required by the degree of service of the particular
application.
In short, the technical solution that meets with greatest favor today provides for
development of units based on microproces~ors specialized for handling particular
= functions (for example, managemer.t of a particular protocol, switching of individual
packets, etc) and interconnected in a wide variety of configurations.
In our case, the aforesaid units constitute the "basic subsystems," comprising a
process~r, the memory related to it, and the associated terminals and interfaces
(Figure 2).
The fundamental compone!~t was chosen in accordance with the criterion of being able
to develop the ACP equipment with a single subsystem and to use a large number of
. subsystems, appropriately interconnected, for higher-level fu~ctions and greater
- traffic capacity. This is because of the fact that it was considered advantageous
to exploit the economy and efficiency of single-processor structures in the peri-
pheral area of the network where the traffic is less concentrated.
8
FOR OFF[CIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-44850R000400070054-1
FOR OFFICIAL USE ONLY
As rebards the Central F'rocessing Unit adopted, producte of the PDP 11 family of mi-
croproceasors were der_ided on, while the Interface Units for the various lir~e termin-
, ations were specially designed for the purpose. This structure makes it possible to
manage up to 64 user terminals, with a mixed traffic of characters and packete up to
40 packets/sec (on the assumption that each packet is made up of 64 characters).
This modularity permits a vast range of applications in the peripheral area of the
Data Network. Interconnection of several subsysteme (modules provided with CPU,
memories, and appropriate interfaces) makes it possible to obtain increasingly com-
plex structures so as to construct equipment that can be used as terminal nodes and
as transit nodes for processing capacitiea of several hundred packets per second.
SCOM
' C PU M
~
CPU M
M
INT
SPL 1
CPU M CPU M
M M
INT SCOI SPL2 INT
CPU M
M
INT
SPL n
~d9e
Figure 3. Multiprocessor structure. SCOM = Communication Subsystem; SCOL = Subsys-
tem for Management of Connections; SPL = Subsystem for Handling Line Protocols;
INT = Line Interface.
The most important aspect in the designing of a system of this type (multiprocessor)
xs to assign the functions to be carried out to the varioua subaystems in such a way
as to optimize the traffic handled. In particular, in order to achieve, within ac-
captable limits, a linear growth of traffic capacity mana~eable with the growth of
the number of subsystems involved, it is necessary to keep the processPS with a high
degree of information exchange within the subsystem itself as much as possible.
Figure 3 presents the block diagram of a multiprocessor structure whose subsystems
can be reduced to the following three types�
9
FOR OFF[CIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL USE ONLY
1) Subsystems for Handling the Line Protocols (SPL): it is obviously necessary to
use a lar.ge number af SPL's, witt~ the load distributed uniformly so as to opti-
mize the ul-ilization of the available resources.
2) Subsystem for Management of Connections and for control and management of the
network (SCOL). These functions are not critical from the point of view of pro-
cessing capacity, but they do require considerable memory capacity and can be
- centralized in a single subsystem.
3) Communication Subsystem (SCOM) Lor interconnection of the SPL's with one another
and with the SCOL subsystem. This fun~tion can be fulfilled in a satisfactory
- manner through the use of a processor-type ccntrol. This solution was considered
an efficient one by compar~son with oCher i..~thods such as the use of a global
common memory, which entails excessive access ~~nflicts when the traffic is high,
or the use of the common-bus TDM technique, which involves a rather complex logic
in the individual SPL's.
In order to ensure high availability of the system, redundance elements must neces-
sarily be introduced; in particular:
1) full duplication, of the "hot stand-by" type, of the centralized subsystems (SCOL
and SCOPf) ;
2) SPL-subsvstems redundancy of the n+ 1 type.
Redundancy between the duplicated subsystems is provided for by mearis of parallel
interfaces directly connected for transfer of synchronization and exchange messages.
The interconnection of the SPL and SCOL subsystems with the communication subsystem
(SCOM) is by means of exchange of packets on a common memory. The duplicated struc-
tures are connected to the unduplicated subsystems throiigh appropriate bus switches
of very high reliability.
4. First Yrototypes
The deFinition of the structure described above was achieved by use of the results
of t}~e following work:
1) simulation af the procedures in increasingly complex structures;
2) development of the most important modules o� the software structure;
- 3) fabrication of the ACP, which, as atated eartier, constitutes the basic subsystem
of the architecture proposed.
- Further work will be related to development of nonpacket synchronous protocols, the
making of multiprocessor prototypes, development of remote-management centers. More
detailed information on the ACP already developed is given below.
The ACY is an apparatus composed of a Central Processing Unit (CPU) of general-pur-
pose type and specialized Communication Units which, under the control ef the soft-
ware, carry out the functions of adaptation of the user data to the packet protocol
of Che ne*_work and of concentration of these data at the junctions for connection to
the node.
The ACP was built in two equipment layouts. The first makes it possible to hook up
64 asynchronous lines up to the speed of 1,200 bits/sec, �or a maximum traffic ca-
1G
~ FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1
FOR OFFICIAL USE ONLY
pacity (throughput) of 15 packets/sec; the second makes it possible to hook up 48
- asynchronous lines of the above type and 4 synchronous lines up to the speed of
9,600 bits/sec, for a maximum capacity of 4n packets/sec. Various mixed equipment
layouts are possible, within the limits of the maximum traffic capa:.ities, simply by
variations in the wiring of the apparatus.
L~~ ,~p~,o� cl~
r!CwtORiA ('z>
A DiSCHI
~OS tOC CPU M
- nB wot
ACP a~
ias iva iaa
~
s�
Figure 4. Block diagram of the Packet Adapter Concnetrator (ACP). IOS = Serial In-
put/Output Interface; IOP = Parallel Input/Output Interface; ITB = Bus Interface;
IPS = Synchronous Protocols Interface; IPA = Asynchronous Protocols Interface; WDT =
alarm circuit (Watch-Dog).
Key:
_ 1. Terminal 2. I)isc memory
~ SCMEDUI~TORE
GISTpRC M[MORIII
GESTOPE TE6~PpPo22A2DN1 )
SUPFRVISONE
iH5TRA04TOAf
STORE d C~N~IE X7~ ~
GESTONE 01 C~NAIt %T~~ ~
PROGRAMMI DI CO~+~IlOCA210~It ~
TASS~ZIONE
AIURMI E S1~TISTICYI
INi[RiA~C1A ~?fFATOpE ~
PPp(RAMMI DI SUP/ON'TO
SC1'
Figure 5. The software syatem for Packet-Switching (SCP) of the ACP,
_ Key.
1. Scheduler 7. X25/75 channel manager
2. Memory manager 8. Communication programe
3. Time-sharing manager ~ 9. Charging
4. Supervi_sor 10. Alarms and etatiatice
5. Router 11. Operator interface
6. X2S channel manager 12. Support progrgms
11
- FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/42/09: CIA-RDP82-40854R040400070054-1
FOR OFFLCIAL USE ONLY
Transfer of data between user terminals and ACP is by use of protocols conforming,
- respectively, to Recommendation X28 for asynchronous terminals and Recommendation
X25 for synchronous terminals. For both installations, the connection to the
_ switching node involved is by means of 4 junction lines of synchronous type with
maximum speed of 9,600 bits/sec. Transfer of data between ACP and Node is by use of
a protocol based on Recommendation X75 of the ICCTT.
The following units are shown in the block diagram of the ACP in Figure 4:
1) Central Processing Unit (CPU), for all the data-processing and communications-
management functions. It consists of a Aigital PDP 11/23 miniprocessor that per-
mits interconnection of external units on its own internal bus;
2) Communication Units, for the data input/outpu~ ~tinctions and for the lower-level
processing provided Eor by the protocols. They consist of modules, organized in
4 groups which, by means of appropriate bus extension plates (ITB), are connected
directly to ttie bus of the Central Unit. Each module caii `~rminate 4, 2 or 1
lines or junctions, depending on the type of protocol used on the line and the
- type of access to the central memory. In particular, there are 4-l.ine modules
for asynchronous interfaces, 2-line modules for synchrono;:s interfaces with in-
terrupt access, and 1-line modules for synchronous interfaces with direct memory
access.
The soFtware of the ACP equipment group is composed of two systems:
1) the Packet-Switching Software (SCP) system for real-time execution of the networ~
functions residing in the ACP il-self;
2) the Mai.nter~ance system (M) for off-line execution of diagnostic and testing pro-
cedures.
The SCP system (Figure 5), in turn, is designed in terms of three subsystems:
a) Supervisor, for management of the resour~es and coordination of the processes;
b) Communication Programs for traffic management;
c) Support Programs for supervision of the ACP and for network-management functions.
The Supervisor comprises the following modules:
1) ~he Schecluler, which provides for synchronization of the processes and assignment
of the CPU's time to the processes themselves;
2) the Memory Manager, which provides for dyn4.nic assignment of khe memory areas for
temporary memorization of the characters and packets as well as of the data ex-
changed between processes;
3) the Time-Sharing Manager, which provides for management of the meters associated
with the time-sharings put into the ACP.
- The Communication programs comprise: �
1) the Chanr,el Managers: program modules for management of the virtual connections
(Formation and killing) and for control of the data flow through the connection
itself;
2) Lhe Router: program module responsible �or association between input and output
lines for each of the virtual connections required, and depositary o� the config-
uration of the ACP (lines hooked up, in service, out of service, etc).
12
_ FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1

APPROVED FOR RELEASE: 2007/02/49: CIA-RDP82-00850R040400070054-1
F4R OFFiCIAL USE ONLY
The Channel Managers so far developed relate to the X28 protocol for asynchronous
terminals, the X25 protocol for packet terminals, and the X75 protocol for junction
lines: the program modules reproduce, as regards structure also, the typical multi-
leVe3. structure of the recommendations involved. The Channel Managers communicate
with one another through internal interfaces; the mechanism that provides for these
interfaces is a code system to which the managers accede through the Scheduler.
Finally, as regards the Support Programs, the following modules have been provided:
1) the Charging-Block Manager: the data used for generation of the charging blocks
are detected by the Channel Managers and transferred to the Network Management
and Maintenance Center, using a logical chann~l devoted to this purpose;
2) Alarms and Statistics Managers: provid.ea for collecting infarmation on the state
_ of the ACP and forwarding it to the operator (l~cal or remote) or to the Manage-
ment and Maintenance Center;
3) Man-Machine Interface: this module manages the operator-machine dialogue, which
can be both local and remote (from a Maintenance Center [CM] or from the Man-
agement and Maintenance Center [CGM]--see Figure 1).
5. Conclusions
The choices made for constructing equipment to be uaed within the framework of Pack-
et Switched Data Networks have been illustrated. The basic structure, already built
with a single processor, is that which carries out the function of adaptation of
nonpacket terminals and of concentration of tYie data traffic. Multiprocessor struc-
tures can be built, starting with the basic structure, in accordance with the guide-
lines discussed in this paper and with a modular approach, for both th~ hardware and
the software, covering the entire spectrum of functions and capacities required even
by networks of considerable complexity and large dimensions.
BIBLIOGRAPHY
1. ICCTT Recommendations X3, X25, X28, X75; Study Group VII, Geneva, February 1980.
2. Roberts, L.G., "Packet Network Design--The Third Generation," IFIP Congress 77.
3. Kelly, P.T.F., "Public Packet Switched Data Ne~works, International Plans and
Standards," PROCEEDINGS OF IEEE, Vol 66, No 11, November 1978.
4. Halsey, J.R., Hardy, L.E., and Powning, L.F., "Public Data Networks: Their Evo-
lution, Interfaces and Status," ISM SYSTEMS JOURNAL, Vol 18-2, 1979.
5. Micciarelli, A., and Mossotto, C., "Technical Aspects in the Implementation of a
Public Switched Network for Data," International Switching Symposium, Paris,
1979.
COPYRIGHT: 1974 by ERI-EDIZIONI RAI RADIOTELEVISIONE ITALIANA
11257
CSO: 5500/2311 END
~3
FOR OFFICIAL USE ONLY
APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000400070054-1