<s>
In	O
communication	O
networks	O
,	O
cognitive	B-Architecture
network	I-Architecture
(	O
CN	O
)	O
is	O
a	O
new	O
type	O
of	O
data	B-Architecture
network	I-Architecture
that	O
makes	O
use	O
of	O
cutting	O
edge	O
technology	O
from	O
several	O
research	O
areas	O
(	O
i.e.	O
</s>
<s>
machine	O
learning	O
,	O
knowledge	O
representation	O
,	O
computer	B-Architecture
network	I-Architecture
,	O
network	O
management	O
)	O
to	O
solve	O
some	O
problems	O
current	O
networks	O
are	O
faced	O
with	O
.	O
</s>
<s>
Cognitive	B-Architecture
network	I-Architecture
is	O
different	O
from	O
cognitive	B-Protocol
radio	I-Protocol
(	O
CR	O
)	O
as	O
it	O
covers	O
all	O
the	O
layers	O
of	O
the	O
OSI	O
model	O
(	O
not	O
only	O
layers	O
1	O
and	O
2	O
as	O
with	O
CR	O
)	O
.	O
</s>
<s>
The	O
first	O
definition	O
of	O
the	O
cognitive	B-Architecture
network	I-Architecture
was	O
provided	O
by	O
Theo	O
Kanter	O
in	O
his	O
doctoral	O
research	O
at	O
KTH	O
,	O
The	O
Royal	O
Institute	O
of	O
Technology	O
,	O
Stockholm	O
,	O
including	O
a	O
presentation	O
in	O
June	O
1998	O
of	O
the	O
cognitive	B-Architecture
network	I-Architecture
as	O
the	O
network	O
with	O
memory	O
.	O
</s>
<s>
Theo	O
was	O
a	O
student	O
of	O
Chip	O
Maguire	O
who	O
also	O
was	O
advising	O
Joe	O
Mitola	O
,	O
the	O
originator	O
of	O
cognitive	B-Protocol
radio	I-Protocol
.	O
</s>
<s>
This	O
is	O
the	O
earliest	O
publication	O
of	O
the	O
concept	O
cognitive	B-Architecture
network	I-Architecture
,	O
since	O
Kantor	O
published	O
a	O
bit	O
later	O
.	O
</s>
<s>
Cognitive	B-Protocol
radio	I-Protocol
,	O
Kantor	O
's	O
cognitive	B-Architecture
networks	I-Architecture
,	O
and	O
IBM	O
's	O
autonomic	O
networks	O
provided	O
the	O
foundation	O
for	O
the	O
parallel	O
evolution	O
of	O
cognitive	B-Architecture
wireless	I-Architecture
networks	I-Architecture
and	O
other	O
cognitive	B-Architecture
networks	I-Architecture
.	O
</s>
<s>
In	O
2004	O
,	O
Petri	O
Mahonen	O
,	O
currently	O
at	O
RWTH	O
,	O
Aachen	O
,	O
and	O
a	O
member	O
of	O
Mitola	O
's	O
doctoral	O
committee	O
organized	O
the	O
first	O
international	O
workshop	O
on	O
cognitive	B-Architecture
wireless	I-Architecture
networks	I-Architecture
at	O
Dagstuhl	O
,	O
Germany	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
EU	O
's	O
E2R	O
and	O
E3	O
programs	O
developed	O
cognitive	B-Architecture
network	I-Architecture
theory	O
under	O
the	O
rubric	O
of	O
self*	O
-	O
self	O
organizing	O
networks	O
,	O
self-aware	O
networks	O
,	O
and	O
so	O
forth	O
.	O
</s>
<s>
One	O
of	O
the	O
attempts	O
to	O
define	O
the	O
concept	O
of	O
cognitive	B-Architecture
network	I-Architecture
was	O
made	O
in	O
2005	O
by	O
Thomas	O
et	O
al	O
.	O
</s>
<s>
The	O
concept	O
of	O
large	O
scale	O
cognitive	B-Architecture
network	I-Architecture
was	O
further	O
made	O
in	O
2008	O
by	O
Song	O
,	O
where	O
such	O
Knowledge	O
Plan	O
is	O
clearly	O
defined	O
for	O
large	O
scale	O
wireless	B-General_Concept
networks	I-General_Concept
as	O
the	O
knowledge	O
about	O
the	O
availability	O
of	O
radio	O
spectrum	O
and	O
wireless	O
stations	O
.	O
</s>
<s>
This	O
definition	O
of	O
CN	O
seems	O
to	O
be	O
incomplete	O
since	O
it	O
lacks	O
knowledge	O
which	O
is	O
an	O
important	O
component	O
of	O
a	O
cognitive	B-Application
system	I-Application
as	O
discussed	O
in	O
,	O
and	O
.	O
</s>
<s>
)	O
;	O
(	O
2	O
)	O
a	O
cognition	O
loop	O
which	O
uses	O
artificial	B-Application
intelligence	I-Application
techniques	O
inside	O
its	O
states	O
(	O
learning	O
techniques	O
,	O
decision	O
making	O
techniques	O
,	O
etc	O
.	O
</s>
<s>
Furthermore	O
,	O
in	O
and	O
,	O
a	O
detailed	O
cross-layer	O
network	B-Architecture
architecture	I-Architecture
was	O
proposed	O
for	O
CNs	O
,	O
where	O
CN	O
is	O
interpreted	O
as	O
a	O
network	O
that	O
can	O
utilize	O
both	O
radio	O
spectrum	O
and	O
wireless	O
station	O
resources	O
opportunistically	O
,	O
based	O
upon	O
the	O
knowledge	O
of	O
such	O
resource	O
availability	O
.	O
</s>
<s>
The	O
cross-layer	O
network	B-Architecture
architecture	I-Architecture
of	O
CN	O
in	O
is	O
also	O
named	O
as	O
Embedded	O
Wireless	O
Interconnection	O
(	O
EWI	O
)	O
as	O
opposed	O
to	O
Open	O
System	O
Interconnection	O
(	O
OSI	O
)	O
protocol	O
stack	O
.	O
</s>
<s>
In	O
comparison	O
,	O
traditional	O
wireless	B-General_Concept
networking	I-General_Concept
relies	O
on	O
point-to-point	O
"	O
virtual	O
wired-links	O
"	O
with	O
a	O
predetermined	O
pair	O
of	O
wireless	O
nodes	O
and	O
allotted	O
spectrum	O
.	O
</s>
<s>
This	O
network	B-Architecture
architecture	I-Architecture
also	O
has	O
the	O
following	O
three	O
primary	O
principles	O
:	O
</s>
<s>
According	O
to	O
the	O
functional	O
abstractions	O
,	O
categories	O
of	O
wireless	O
link	O
modules	O
can	O
include	O
:	O
broadcast	O
,	O
unicast	B-Protocol
,	O
multicast	O
,	O
and	O
data	O
aggregation	O
,	O
etc	O
.	O
</s>
<s>
Opportunistic	O
Wireless	O
Links	O
:	O
In	O
realizing	O
the	O
cognitive	O
wireless	B-General_Concept
networking	I-General_Concept
concept	O
,	O
both	O
the	O
occupied	O
spectrum	O
and	O
the	O
participating	O
nodes	O
of	O
an	O
abstract	O
wireless	O
link	O
are	O
opportunistically	O
determined	O
by	O
their	O
instantaneous	O
availabilities	O
.	O
</s>
<s>
High	O
modularity	O
and	O
flexibility	O
could	O
be	O
essential	O
for	O
middleware	B-General_Concept
or	O
application	O
developments	O
.	O
</s>
<s>
EWI	O
is	O
also	O
an	O
organizing-style	O
architecture	O
,	O
where	O
the	O
system	O
layer	O
organizes	O
the	O
wireless	O
link	O
modules	O
(	O
at	O
the	O
wireless	O
link	O
layer	O
)	O
;	O
and	O
peer	O
wireless	O
link	O
modules	O
can	O
exchange	O
module	O
management	O
information	O
by	O
padding	O
packet	B-General_Concept
headers	I-General_Concept
to	O
the	O
system-layer	O
information	O
units	O
.	O
</s>
<s>
Five	O
types	O
of	O
wireless	O
link	O
modules	O
were	O
proposed	O
,	O
including	O
broadcast	O
,	O
peer-to-peer	O
unicast	B-Protocol
,	O
multicast	O
,	O
to-sink	O
unicast	B-Protocol
,	O
and	O
data	O
aggregation	O
,	O
respectively	O
.	O
</s>
<s>
The	O
peer-to-peer	O
unicast	B-Protocol
module	O
can	O
deliver	O
data	O
packets	O
from	O
source	O
to	O
destination	O
over	O
multiple	O
wireless	O
hops	O
.	O
</s>
<s>
The	O
multicast	O
module	O
sends	O
data	O
packets	O
to	O
multiple	O
destinations	O
,	O
as	O
compared	O
to	O
peer-to-peer	O
unicast	B-Protocol
.	O
</s>
<s>
The	O
to-sink	O
unicast	B-Protocol
module	O
can	O
be	O
especially	O
useful	O
in	O
wireless	O
sensor	O
networks	O
,	O
which	O
utilizes	O
higher	O
capabilities	O
of	O
data	O
collectors	O
(	O
or	O
sinks	O
)	O
,	O
so	O
as	O
to	O
achieve	O
better	O
data	O
delivery	O
.	O
</s>
<s>
Two	O
service	B-Protocol
access	I-Protocol
points	I-Protocol
(	O
SAP	O
)	O
are	O
defined	O
on	O
the	O
interface	O
between	O
the	O
system	O
layer	O
and	O
the	O
wireless	O
link	O
layer	O
,	O
which	O
are	O
WL_SAP	O
(	O
Wireless	O
Link	O
SAP	O
)	O
and	O
WLME_SAP	O
(	O
Wireless	O
Link	O
Management	O
Entity	O
SAP	O
)	O
,	O
respectively	O
.	O
</s>
