<s>
Network	B-General_Concept
Protocol	I-General_Concept
Virtualization	I-General_Concept
or	O
Network	O
Protocol	O
Stack	O
Virtualization	B-General_Concept
is	O
a	O
concept	O
of	O
providing	O
network	O
connections	O
as	O
a	O
service	O
,	O
without	O
concerning	O
application	O
developer	O
to	O
decide	O
the	O
exact	O
communication	O
stack	O
composition	O
.	O
</s>
<s>
Network	B-General_Concept
Protocol	I-General_Concept
Virtualization	I-General_Concept
(	O
NPV	O
)	O
was	O
firstly	O
proposed	O
by	O
Heuschkel	O
et	O
al	O
.	O
</s>
<s>
in	O
2015	O
as	O
a	O
rough	O
sketch	O
as	O
part	O
of	O
a	O
transition	B-General_Concept
concept	O
for	O
network	O
protocol	O
stacks	O
.	O
</s>
<s>
NPV	O
has	O
been	O
further	O
investigated	O
as	O
a	O
central	O
element	O
of	O
LPWAN	B-General_Concept
Internet	B-Operating_System
of	I-Operating_System
Things	I-Operating_System
(	O
IoT	B-Operating_System
)	O
scenarios	O
.	O
</s>
<s>
In	O
this	O
context	O
,	O
NPV	O
becomes	O
a	O
very	O
successful	O
and	O
flexible	O
tool	O
to	O
accomplish	O
the	O
deployment	O
and	O
management	O
of	O
constrained	O
sensors	O
,	O
actuators	O
and	O
controllers	O
in	O
massive	O
IoT	B-Operating_System
access	O
networks	O
.	O
</s>
