<s>
In	O
the	O
1980s	O
,	O
the	O
telecommunications	O
industry	O
expected	O
that	O
digital	O
services	O
would	O
follow	O
much	O
the	O
same	O
pattern	O
as	O
voice	O
services	O
did	O
on	O
the	O
public	O
switched	O
telephone	O
network	O
,	O
and	O
conceived	O
an	O
end-to-end	O
circuit	B-Protocol
switched	I-Protocol
service	O
,	O
known	O
as	O
Broadband	B-Protocol
Integrated	I-Protocol
Services	I-Protocol
Digital	I-Protocol
Network	I-Protocol
(	O
B-ISDN	B-Protocol
)	O
.	O
</s>
<s>
Before	O
B-ISDN	B-Protocol
,	O
the	O
original	O
ISDN	O
attempted	O
to	O
substitute	O
the	O
analog	O
telephone	O
system	O
with	O
a	O
digital	O
system	O
which	O
was	O
appropriate	O
for	O
both	O
voice	O
and	O
non-voice	O
traffic	O
.	O
</s>
<s>
Obtaining	O
worldwide	O
agreement	O
on	O
the	O
basic	B-Protocol
rate	I-Protocol
interface	I-Protocol
standard	O
was	O
expected	O
to	O
lead	O
to	O
a	O
large	O
user	O
demand	O
for	O
ISDN	O
equipment	O
,	O
hence	O
leading	O
to	O
mass	O
production	O
and	O
inexpensive	O
ISDN	O
chips	O
.	O
</s>
<s>
However	O
,	O
the	O
standardization	O
process	O
took	O
years	O
while	O
computer	B-Architecture
network	I-Architecture
technology	O
moved	O
rapidly	O
.	O
</s>
<s>
For	O
home	O
use	O
the	O
largest	O
demand	O
for	O
new	O
services	O
was	O
video	O
and	O
voice	O
transfer	O
,	O
but	O
the	O
ISDN	O
basic	B-Protocol
rate	I-Protocol
lacks	O
the	O
necessary	O
channel	O
capacity	O
.	O
</s>
<s>
This	O
led	O
to	O
introduction	O
of	O
B-ISDN	B-Protocol
,	O
by	O
adding	O
the	O
word	O
broadband	B-General_Concept
.	O
</s>
<s>
Although	O
the	O
term	O
had	O
a	O
meaning	O
in	O
physics	O
and	O
engineering	O
(	O
similar	O
to	O
wideband	O
)	O
,	O
the	O
CCITT	O
defined	O
it	O
as	O
:	O
"	O
Qualifying	O
a	O
service	O
or	O
system	O
requiring	O
transmission	O
channels	O
capable	O
of	O
supporting	O
rates	O
greater	O
than	O
the	O
primary	B-Protocol
rate	I-Protocol
"	O
referring	O
to	O
the	O
primary	B-Protocol
rate	I-Protocol
which	O
ranged	O
from	O
about	O
1.5	O
to	O
2	O
Mbit/s	O
.	O
</s>
<s>
Services	O
envisioned	O
included	O
video	B-Application
telephone	I-Application
and	O
video	B-Application
conferencing	I-Application
.	O
</s>
<s>
They	O
included	O
G.707	O
to	O
G.709	O
,	O
and	O
I.121	O
which	O
defined	O
the	O
principal	O
aspects	O
of	O
B-ISDN	B-Protocol
,	O
with	O
many	O
others	O
following	O
through	O
the	O
1990s	O
.	O
</s>
<s>
The	O
designated	O
technology	O
for	O
B-ISDN	B-Protocol
was	O
Asynchronous	O
Transfer	O
Mode	O
(	O
ATM	O
)	O
,	O
which	O
was	O
intended	O
to	O
carry	O
both	O
synchronous	B-Application
voice	O
and	O
asynchronous	O
data	O
services	O
on	O
the	O
same	O
transport	O
.	O
</s>
<s>
The	O
B-ISDN	B-Protocol
vision	O
has	O
been	O
overtaken	O
by	O
other	O
disruptive	O
technologies	O
used	O
in	O
the	O
Internet	O
.	O
</s>
<s>
The	O
term	O
"	O
broadband	B-General_Concept
"	O
became	O
a	O
marketing	O
term	O
for	O
any	O
digital	O
Internet	O
access	O
service	O
.	O
</s>
