<s>
In	O
computing	O
,	O
cache	B-General_Concept
algorithms	O
(	O
also	O
frequently	O
called	O
cache	B-General_Concept
replacement	O
algorithms	O
or	O
cache	B-General_Concept
replacement	O
policies	O
)	O
are	O
optimizing	O
instructionsor	O
algorithmsthat	O
a	O
computer	B-Application
program	I-Application
or	O
a	O
hardware-maintained	O
structure	O
can	O
follow	O
in	O
order	O
to	O
manage	O
a	O
cache	B-General_Concept
of	O
information	O
stored	O
on	O
the	O
computer	O
.	O
</s>
<s>
When	O
the	O
cache	B-General_Concept
is	O
full	O
,	O
the	O
algorithm	O
must	O
choose	O
which	O
items	O
to	O
discard	O
to	O
make	O
room	O
for	O
the	O
new	O
ones	O
.	O
</s>
<s>
Due	O
to	O
the	O
inherent	O
caching	B-General_Concept
capability	O
of	O
nodes	O
in	O
Information-centric	B-Protocol
networking	I-Protocol
ICN	O
,	O
the	O
ICN	O
can	O
be	O
viewed	O
as	O
a	O
loosely	O
connect	O
network	O
of	O
caches	B-General_Concept
,	O
which	O
has	O
unique	O
requirements	O
of	O
Caching	B-General_Concept
policies	O
.	O
</s>
<s>
Unlike	O
proxy	O
servers	O
,	O
in	O
Information-centric	B-Protocol
networking	I-Protocol
the	O
cache	B-General_Concept
is	O
a	O
network	O
level	O
solution	O
.	O
</s>
<s>
Therefore	O
,	O
it	O
has	O
rapidly	O
changing	O
cache	B-General_Concept
states	O
and	O
higher	O
request	O
arrival	O
rates	O
;	O
moreover	O
,	O
smaller	O
cache	B-General_Concept
sizes	O
further	O
impose	O
different	O
kind	O
of	O
requirements	O
on	O
the	O
content	O
eviction	O
policies	O
.	O
</s>
<s>
In	O
particular	O
,	O
eviction	O
policies	O
for	O
Information-centric	B-Protocol
networking	I-Protocol
should	O
be	O
fast	O
and	O
lightweight	O
.	O
</s>
<s>
Various	O
cache	B-General_Concept
replication	O
and	O
eviction	O
schemes	O
for	O
different	O
Information-centric	B-Protocol
networking	I-Protocol
architectures	O
and	O
applications	O
are	O
proposed	O
.	O
</s>
<s>
The	O
Time	O
aware	O
Least	O
Recently	O
Used	O
(	O
TLRU	O
)	O
is	O
a	O
variant	O
of	O
LRU	O
designed	O
for	O
the	O
situation	O
where	O
the	O
stored	O
contents	O
in	O
cache	B-General_Concept
have	O
a	O
valid	O
life	O
time	O
.	O
</s>
<s>
The	O
algorithm	O
is	O
suitable	O
in	O
network	O
cache	B-General_Concept
applications	O
,	O
such	O
as	O
Information-centric	B-Protocol
networking	I-Protocol
(	O
ICN	O
)	O
,	O
Content	B-Operating_System
Delivery	I-Operating_System
Networks	I-Operating_System
(	O
CDNs	O
)	O
and	O
distributed	O
networks	O
in	O
general	O
.	O
</s>
<s>
In	O
the	O
TLRU	O
algorithm	O
,	O
when	O
a	O
piece	O
of	O
content	O
arrives	O
,	O
a	O
cache	B-General_Concept
node	O
calculates	O
the	O
local	O
TTU	O
value	O
based	O
on	O
the	O
TTU	O
value	O
assigned	O
by	O
the	O
content	O
publisher	O
.	O
</s>
<s>
Once	O
the	O
local	O
TTU	O
value	O
is	O
calculated	O
the	O
replacement	O
of	O
content	O
is	O
performed	O
on	O
a	O
subset	O
of	O
the	O
total	O
content	O
stored	O
in	O
cache	B-General_Concept
node	O
.	O
</s>
<s>
The	O
Least	O
Frequent	O
Recently	O
Used	O
(	O
LFRU	O
)	O
cache	B-General_Concept
replacement	O
scheme	O
combines	O
the	O
benefits	O
of	O
LFU	O
and	O
LRU	O
schemes	O
.	O
</s>
<s>
LFRU	O
is	O
suitable	O
for	O
'	O
in	O
network	O
 '	O
cache	B-General_Concept
applications	O
,	O
such	O
as	O
Information-centric	B-Protocol
networking	I-Protocol
(	O
ICN	O
)	O
,	O
Content	B-Operating_System
Delivery	I-Operating_System
Networks	I-Operating_System
(	O
CDNs	O
)	O
and	O
distributed	O
networks	O
in	O
general	O
.	O
</s>
<s>
In	O
LFRU	O
,	O
the	O
cache	B-General_Concept
is	O
divided	O
into	O
two	O
partitions	O
called	O
privileged	O
and	O
unprivileged	O
partitions	O
.	O
</s>
