AFAL 10, 1989

PO WEEK NAPPLIGATIOM DEVELO

e Development of ISDN Is Proceeding Worldwide

tribution. A full, commercial ISDN that

Network
(ISDN).

ISDN is devel-
oping rapidly
across Europe,
North America
and Japan. Bach
country is ata

different, stage of
development,
ranging from a
basic design
phase to pilot and full commercial im-
plementation. In a number of countries,
ISDN is still a technology-led develop-
ment. As yet, however, there isn't a uni:
versal demand for ISDN services. There-
fore, the pressure to implement ISDN of-
ten comes from network operators, not.

users.

— The way ISDN is being implemented
in various parts of the world differs, in-
variably reflecting the regulatory envi-

ment of each country. Basically

ISDN in North America

Unlike that in Europe, the telecommu-
nications environment in North America

development of ISDN "islands" and the
installation of an ISDN overlay network.
In an island strategy, certain key net:
work centers (normally corresponding
to highvtraffic urban areas) are convert-
ed to ISDN by installing ISDN-compati-

— ple switching, signalling and transmis-

sion eguipment covering a specific geo-
graphic area. This allows the operator
to offer limited ISDN facilities during
the early stages of development, ex-
panding these services as more islands
are installed and ISDN interworking be-
tween islands is established.
The overlay approach, on the other
hand, involves setting up an entirely

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network expansion programs converting
existing analog switching and transmis-
sion eguipment to digital. All major Eu-

ropean countries are installing ISDN ei- .

ther as pilot or commercial network ser-
vices. The European Community is
actively involved in promoting ISDN
Cand telecommunications services in
general) in each of the member coun-
tries. This is being done primarily
through the creation of a single Europe-
wide market for telecommunications
eguipment and an action program for
the installation of ISDN.

The aim of creating a single European
market for telecommunications eguip-

ISDN
(those in

covers all the main business and popula-
tion centers is not expected to be in op-
eration until the early 19905.

In Japan, ISDN is evolving guite dif-
ferently. Although competition is gradu-
ally being introduced into the provision
of both domestic and international tele-
communications services, the Japanese
approach to ISDN is part of a wide, gov-
ernment-sponsored national technology
project. This project is called the Infor-
mation Network System CINS), and it
encompasses a wide range of technolo-
gies and applications—from fiber optics
to video and fifth-generation computers.

Among current ISDN plans and imple-
mentations, Japan's INS project is one of
the most ambitious and far-reaching.
The fundamental difference between
INS and other ISDNS lies not in the tech-
nology but in the nature of the project
itself. INS forms a major part of a gov-
ernment-sponsored initiative to take Ja-
pan into the "Information Age" as
guickly and as coherently as possible.

Also included in the INS project are
the current research activities on fifth-
generation computer systems. When
completed, these activities will provide
a number of additional computing fea-
INS and Standards

'The basic channel structure of INS,
unlike that of the CCITT, was made up
of one 64K-bps channel, one 16K-bps
channel for voice or data and one 8K-
bps signalling channel (64--16--8). ;

As INS becomes more generally avail-
able, this non-ISDN-standard channel
structure is being replaced with the con-
a a CCITT channel

e. In addition, INS i
ticaHber based broadband conununica
tions into the network for a variety of

video applications. ;

During the early 1990s, ISDN services
will be available in one form or zima

| in every major city and business cen €

the United States. Although