<s>
An	O
open-access	B-Architecture
network	I-Architecture
(	O
OAN	O
)	O
refers	O
to	O
a	O
horizontally	O
layered	B-Application
network	B-Architecture
architecture	I-Architecture
in	O
telecommunications	O
,	O
and	O
the	O
business	O
model	O
that	O
separates	O
the	O
physical	O
access	O
to	O
the	O
network	O
from	O
the	O
delivery	O
of	O
services	O
.	O
</s>
<s>
There	O
are	O
two	O
different	O
open-access	B-Architecture
network	I-Architecture
models	O
:	O
the	O
two	O
-	O
and	O
three-layer	O
models	O
.	O
</s>
<s>
Towards	O
the	O
end	O
of	O
the	O
twentieth	O
century	O
,	O
with	O
the	O
rise	O
of	O
packet	B-Protocol
switching	I-Protocol
—	O
as	O
used	O
on	O
the	O
Internet	O
—	O
and	O
IP-based	B-Protocol
and	O
wireless	O
technologies	O
,	O
it	O
became	O
possible	O
to	O
design	O
,	O
build	O
,	O
and	O
operate	O
a	O
single	O
high	O
performance	O
network	O
capable	O
of	O
delivering	O
hundreds	O
of	O
services	O
from	O
multiple	O
,	O
competing	O
providers	O
.	O
</s>
<s>
Regardless	O
of	O
whether	O
the	O
two	O
-	O
or	O
three-layer	O
model	O
is	O
used	O
,	O
an	O
open-access	B-Architecture
network	I-Architecture
fundamentally	O
means	O
that	O
there	O
is	O
an	O
"	O
organisational	O
separation	O
"	O
of	O
each	O
of	O
the	O
layers	O
.	O
</s>
<s>
In	O
the	O
three-layer	O
OAN	O
model	O
the	O
physical	O
layer	O
—	O
the	O
fiber	B-Architecture
or	O
wireless	O
infrastructure	O
—	O
is	O
owned	O
by	O
one	O
company	O
,	O
the	O
operations	O
and	O
maintenance	O
of	O
the	O
network	O
and	O
the	O
provision	O
of	O
services	O
is	O
run	O
by	O
a	O
second	O
company	O
,	O
and	O
the	O
retail	O
service	O
providers	O
provide	O
the	O
third	O
layer	O
.	O
</s>
<s>
The	O
OAN	O
concept	O
is	O
appropriate	O
for	O
both	O
fiber	B-Architecture
and	O
WiFi	O
access	O
networks	O
,	O
especially	O
where	O
exclusivity	O
cannot	O
be	O
allowed	O
.	O
</s>
<s>
Open	O
access	O
networks	O
are	O
also	O
viewed	O
as	O
a	O
feasible	O
way	O
of	O
deploying	O
next-generation	B-Architecture
broadband	I-Architecture
networks	O
in	O
low	O
population	O
density	O
areas	O
where	O
service	O
providers	O
cannot	O
obtain	O
a	O
sufficient	O
return	O
on	O
investment	O
to	O
cover	O
the	O
high	O
costs	O
associated	O
with	O
trenching	O
,	O
right-of-way	O
encroachment	O
permits	O
,	O
and	O
the	O
requisite	O
network	O
infrastructure	O
.	O
</s>
<s>
In	O
the	O
US	O
,	O
open	O
access	O
networks	O
like	O
municipality	O
owned	O
The	O
Wired	O
Road	O
in	O
Virginia	B-Application
have	O
been	O
able	O
to	O
attract	O
both	O
local	O
and	O
regional	O
service	O
providers	O
quickly	O
.	O
</s>
<s>
New	O
Zealand	O
,	O
Australia	O
and	O
Singapore	O
also	O
have	O
open-access	B-Architecture
networks	I-Architecture
based	O
on	O
fiber	B-Architecture
to	I-Architecture
the	I-Architecture
home	I-Architecture
.	O
</s>
<s>
Australia	O
also	O
has	O
the	O
recently	O
formed	O
government	O
owned	O
corporation	O
NBN	O
Co	O
,	O
who	O
are	O
creating	O
the	O
National	O
Broadband	O
Network	O
to	O
provide	O
open-access	O
fiber	B-Architecture
to	I-Architecture
the	I-Architecture
node	I-Architecture
at	O
one	O
gigabit	O
per	O
second	O
for	O
more	O
than	O
ninety-three	O
percent	O
of	O
homes	O
and	O
businesses	O
in	O
the	O
country	O
,	O
and	O
fixed	B-General_Concept
wireless	I-General_Concept
and	O
satellite	O
technologies	O
with	O
a	O
minimum	O
speed	O
of	O
twelve	O
megabits	O
per	O
second	O
to	O
the	O
remainder	O
of	O
the	O
population	O
.	O
</s>
