<s>
For	O
parallel	B-Operating_System
computing	I-Operating_System
,	O
the	O
interconnection	O
network	O
is	O
the	O
heart	O
of	O
a	O
parallel	B-Operating_System
processing	I-Operating_System
system	O
,	O
and	O
many	O
systems	O
have	O
failed	O
to	O
meet	O
their	O
design	O
goals	O
for	O
the	O
design	O
of	O
their	O
essential	O
components	O
.	O
</s>
<s>
The	O
bandwidth	B-Algorithm
limitation	O
of	O
the	O
electronic	O
interconnects	O
prompted	O
the	O
need	O
for	O
exploring	O
alternatives	O
that	O
overcome	O
this	O
limitation	O
.	O
</s>
<s>
Optics	O
is	O
considered	O
as	O
an	O
alternative	O
that	O
is	O
capable	O
of	O
providing	O
inherentcommunication	O
,	O
parallelism	B-Operating_System
,	O
high	O
connectivity	O
and	O
large	O
bandwidth	B-Algorithm
.	O
</s>
<s>
Therefore	O
,	O
in	O
the	O
construction	O
of	O
very	O
powerful	O
and	O
large	O
multiprocessor	B-Operating_System
systems	O
,	O
it	O
is	O
advantageous	O
to	O
interconnect	O
close	O
processors	O
physically	O
using	O
electronic	O
links	O
and	O
far	O
processors	O
(	O
kept	O
in	O
other	O
package	O
)	O
using	O
optical	O
links	O
.	O
</s>
<s>
Various	O
models	O
of	O
optoelectronic	O
parallel	B-Operating_System
computers	I-Operating_System
have	O
been	O
proposed	O
in	O
recent	O
years	O
.	O
</s>
<s>
The	O
processors	O
are	O
organized	O
in	O
the	O
form	O
of	O
an	O
n	O
×	O
n	O
array	B-Operating_System
of	O
certain	O
groups	O
each	O
containing	O
3n/2	O
nodes	B-Protocol
.	O
</s>
<s>
It	O
can	O
be	O
noted	O
that	O
the	O
entire	O
network	B-Architecture
topology	I-Architecture
is	O
almost	O
regular	O
with	O
an	O
O(log n )	O
diameter	O
.	O
</s>
<s>
Each	O
factor	O
network	O
consists	O
of	O
n	O
leaf	O
nodes	B-Protocol
.	O
</s>
