<s>
SensorThings	B-Device
API	I-Device
is	O
an	O
Open	O
Geospatial	O
Consortium	O
(	O
OGC	O
)	O
standard	O
providing	O
an	O
open	O
and	O
unified	O
framework	O
to	O
interconnect	O
IoT	B-Operating_System
sensing	O
devices	O
,	O
data	O
,	O
and	O
applications	O
over	O
the	O
Web	O
.	O
</s>
<s>
It	O
is	O
an	O
open	O
standard	O
addressing	O
the	O
syntactic	O
interoperability	O
and	O
semantic	O
interoperability	O
of	O
the	B-Operating_System
Internet	I-Operating_System
of	I-Operating_System
Things	I-Operating_System
.	O
</s>
<s>
It	O
complements	O
the	O
existing	O
IoT	B-Operating_System
networking	O
protocols	O
such	O
CoAP	B-Device
,	O
MQTT	B-Application
,	O
HTTP	B-Protocol
,	O
6LowPAN	B-Protocol
.	O
</s>
<s>
While	O
the	O
above-mentioned	O
IoT	B-Operating_System
networking	O
protocols	O
are	O
addressing	O
the	O
ability	O
for	O
different	O
IoT	B-Operating_System
systems	O
to	O
exchange	O
information	O
,	O
OGC	O
SensorThings	B-Device
API	I-Device
is	O
addressing	O
the	O
ability	O
for	O
different	O
IoT	B-Operating_System
systems	O
to	O
use	O
and	O
understand	O
the	O
exchanged	O
information	O
.	O
</s>
<s>
As	O
an	O
OGC	O
standard	O
,	O
SensorThings	B-Device
API	I-Device
also	O
allows	O
easy	O
integration	O
into	O
existing	O
Spatial	O
Data	O
Infrastructures	O
or	O
Geographic	B-Application
Information	I-Application
Systems	I-Application
.	O
</s>
<s>
OGC	O
SensorThings	B-Device
API	I-Device
has	O
two	O
parts	O
:	O
(	O
1	O
)	O
Part	O
I	O
-	O
Sensing	O
and	O
(	O
2	O
)	O
Part	O
II	O
-	O
Tasking	O
.	O
</s>
<s>
OGC	O
SensorThings	B-Device
API	I-Device
Part	O
I	O
-	O
Sensing	O
was	O
released	O
for	O
public	O
comment	O
on	O
June	O
18	O
,	O
2015	O
.	O
</s>
<s>
The	O
OGC	O
Technical	O
Committee	O
(	O
TC	O
)	O
approves	O
start	O
of	O
electronic	O
vote	O
on	O
December	O
3	O
,	O
2015	O
,	O
and	O
the	O
SensorThings	B-Device
API	I-Device
Part	O
I	O
-	O
Sensing	O
passed	O
the	O
TC	O
vote	O
on	O
February	O
1	O
,	O
2016	O
.	O
</s>
<s>
In	O
2019	O
the	O
SensorThings	B-Device
API	I-Device
was	O
also	O
published	O
as	O
a	O
United	O
Nation	O
's	O
ITU-T	O
Technical	O
Specification	O
.	O
</s>
<s>
OGC	O
SensorThings	B-Device
API	I-Device
Part	O
II	O
-	O
Tasking	O
Core	O
was	O
released	O
for	O
public	O
comment	O
on	O
February	O
20	O
,	O
2018	O
,	O
and	O
it	O
passed	O
the	O
TC	O
vote	O
on	O
June	O
1	O
,	O
2018	O
.	O
</s>
<s>
The	O
for	O
the	O
SensorThings	B-Device
API	I-Device
Part	O
II	O
-	O
Tasking	O
Core	O
was	O
published	O
online	O
on	O
January	O
8	O
,	O
2019	O
.	O
</s>
<s>
The	O
Tasking	O
Core	O
Discussion	O
paper	O
provides	O
15	O
JSON	B-General_Concept
examples	O
showing	O
how	O
SensorThings	B-Device
API	I-Device
Part	O
II	O
-	O
Tasking	O
Core	O
can	O
be	O
used	O
.	O
</s>
<s>
SensorThings	B-Device
API	I-Device
is	O
designed	O
specifically	O
for	O
resource-constrained	O
IoT	B-Operating_System
devices	O
and	O
the	O
Web	O
developer	O
community	O
.	O
</s>
<s>
It	O
follows	O
REST	B-Protocol
principles	O
,	O
the	O
JSON	B-General_Concept
encoding	O
,	O
and	O
the	O
OASIS	O
OData	B-Application
protocol	O
and	O
URL	O
conventions	O
.	O
</s>
<s>
Also	O
,	O
it	O
has	O
an	O
MQTT	B-Application
extension	O
allowing	O
users/devices	O
to	O
publish	B-Operating_System
and	I-Operating_System
subscribe	I-Operating_System
updates	O
from	O
devices	O
,	O
and	O
can	O
use	O
CoAP	B-Device
in	O
addition	O
to	O
HTTP	B-Protocol
.	I-Protocol
</s>
<s>
The	O
foundation	O
of	O
the	O
SensorThings	B-Device
API	I-Device
is	O
its	O
data	O
model	O
that	O
is	O
based	O
on	O
the	O
ISO	B-Device
19156	I-Device
(	O
ISO/OGC	O
Observations	B-Device
and	I-Device
Measurements	I-Device
)	O
,	O
that	O
defines	O
a	O
conceptual	O
model	O
for	O
observations	O
,	O
and	O
for	O
features	O
involved	O
in	O
sampling	O
when	O
making	O
observations	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
the	O
SensorThings	B-Device
API	I-Device
provides	O
an	O
interoperable	O
Observation-focus	O
view	O
,	O
that	O
is	O
particularly	O
useful	O
to	O
reconcile	O
the	O
differences	O
between	O
heterogeneous	O
sensing	O
systems	O
(	O
e.g.	O
,	O
in-situ	O
sensors	O
and	O
remote	O
sensors	O
)	O
.	O
</s>
<s>
An	O
IoT	B-Operating_System
device	O
or	O
system	O
is	O
modelled	O
as	O
a	O
Thing	O
.	O
</s>
<s>
The	O
O&M	O
based	O
model	O
allows	O
SensorThings	O
to	O
accommodate	O
heterogeneous	O
IoT	B-Operating_System
devices	O
and	O
the	O
data	O
collected	O
by	O
the	O
devices	O
.	O
</s>
<s>
SensorThings	B-Device
API	I-Device
provides	O
two	O
main	O
functionalities	O
,	O
each	O
handled	O
by	O
a	O
part	O
.	O
</s>
<s>
The	O
Sensing	O
part	O
provides	O
a	O
standard	O
way	O
to	O
manage	O
and	O
retrieve	O
observations	O
and	O
metadata	O
from	O
heterogeneous	O
IoT	B-Operating_System
sensor	O
systems	O
,	O
and	O
the	O
Sensing	O
part	O
functions	O
are	O
similar	O
to	O
the	O
OGC	B-Device
Sensor	I-Device
Observation	I-Device
Service	I-Device
.	O
</s>
<s>
The	O
Tasking	O
part	O
provides	O
a	O
standard	O
way	O
for	O
parameterizing	O
-	O
also	O
called	O
tasking	O
-	O
of	O
task-able	O
IoT	B-Operating_System
devices	O
,	O
such	O
as	O
sensors	O
or	O
actuators	O
.	O
</s>
<s>
The	O
Sensing	O
part	O
is	O
designed	O
based	O
on	O
the	O
ISO/OGC	O
Observations	B-Device
and	I-Device
Measurements	I-Device
(	O
O&M	O
)	O
model	O
,	O
and	O
allows	O
IoT	B-Operating_System
devices	O
and	O
applications	O
to	O
CREATE	B-General_Concept
,	I-General_Concept
READ	I-General_Concept
,	I-General_Concept
UPDATE	I-General_Concept
,	I-General_Concept
and	I-General_Concept
DELETE	I-General_Concept
(	O
i.e.	O
,	O
HTTP	B-Protocol
POST	I-Protocol
,	O
GET	O
,	O
PATCH	O
,	O
and	O
DELETE	O
)	O
IoT	B-Operating_System
data	O
and	O
metadata	O
in	O
a	O
SensorThings	O
service	O
.	O
</s>
<s>
SensorThings	B-Device
API	I-Device
Part	O
I	O
-	O
Sensing	O
defines	O
the	O
following	O
resources	O
.	O
</s>
<s>
As	O
SensorThings	O
is	O
a	O
RESTful	B-Protocol
web	I-Protocol
service	I-Protocol
,	O
each	O
entity	O
can	O
be	O
CREATE	B-General_Concept
,	I-General_Concept
READ	I-General_Concept
,	I-General_Concept
UPDATE	I-General_Concept
,	I-General_Concept
and	I-General_Concept
DELETE	I-General_Concept
with	O
standard	O
HTTP	B-Protocol
verbs	O
(	O
POST	B-Protocol
,	O
GET	O
,	O
PATCH	O
,	O
and	O
DELETE	O
)	O
:	O
</s>
<s>
In	O
addition	O
to	O
the	O
above	O
sensing	O
resources	O
,	O
SensorThings	B-Device
API	I-Device
Part	O
II	O
-	O
Tasking	O
Core	O
defines	O
the	O
following	O
resources	O
:	O
</s>
<s>
In	O
order	O
to	O
reduce	O
the	O
data	O
size	O
transmitted	O
over	O
the	O
network	O
,	O
SensorThings	B-Device
API	I-Device
data	O
array	O
extension	O
allows	O
users	O
to	O
request	O
for	O
multiple	O
Observation	O
entities	O
and	O
format	O
the	O
entities	O
in	O
the	O
dataArray	O
format	O
.	O
</s>
<s>
And	O
the	O
consistent	O
data	O
model	O
mapping	O
gives	O
both	O
a	O
common	O
context	O
to	O
describe	O
the	B-Operating_System
internet	I-Operating_System
of	I-Operating_System
things	I-Operating_System
"	O
.	O
</s>
<s>
A	O
comprehensive	O
evaluation	O
of	O
the	O
SensorThings	B-Device
API	I-Device
is	O
published	O
in	O
.	O
</s>
<s>
SensorThings	B-Device
API	I-Device
was	O
demonstrated	O
in	O
a	O
pilot	O
project	O
sponsored	O
by	O
the	O
Department	O
of	O
Homeland	O
Security	O
Science	O
and	O
Technology	O
Directorate	O
.	O
</s>
<s>
Whiskers	O
is	O
an	O
OGC	O
SensorThings	B-Device
API	I-Device
framework	O
.	O
</s>
<s>
It	O
will	O
have	O
a	O
JavaScript	B-Language
client	O
and	O
a	O
light-weight	O
server	O
for	O
IoT	B-Operating_System
gateway	O
devices	O
(	O
e.g.	O
,	O
Raspberry	O
Pi	O
or	O
BeagleBone	O
)	O
.	O
</s>
<s>
Whiskers	O
aim	O
to	O
foster	O
a	O
healthy	O
and	O
open	O
IoT	B-Operating_System
ecosystem	O
,	O
as	O
opposed	O
to	O
one	O
dominated	O
by	O
proprietary	O
information	O
silos	O
.	O
</s>
<s>
Whiskers	O
aims	O
to	O
make	O
SensorThings	O
development	O
easy	O
for	O
the	O
large	O
and	O
growing	O
world	O
of	O
IoT	B-Operating_System
developers	O
.	O
</s>
<s>
GOST	O
is	O
an	O
open	O
source	O
implementation	O
of	O
the	O
SensorThings	B-Device
API	I-Device
in	O
the	O
Go	B-Application
programming	I-Application
language	I-Application
initiated	O
by	O
Geodan	O
.	O
</s>
<s>
It	O
contains	O
easily	O
deployable	O
server	O
software	O
and	O
a	O
JavaScript	B-Language
client	O
.	O
</s>
<s>
By	O
default	O
sensor	O
data	O
is	O
stored	O
in	O
a	O
PostgreSQL	B-Application
database	O
.	O
</s>
<s>
FROST-Server	O
is	O
an	O
Open	O
Source	O
server	O
implementation	O
of	O
the	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
It	O
is	O
written	O
in	O
Java	O
and	O
can	O
run	O
in	O
Tomcat	B-Language
or	O
Wildfly	O
and	O
is	O
available	O
as	O
a	O
Docker	O
image	O
.	O
</s>
<s>
FROST-Client	O
is	O
a	O
Java	O
client	O
library	O
for	O
communicating	O
with	O
a	O
SensorThings	B-Device
API	I-Device
compatible	O
server	O
.	O
</s>
<s>
SensorThings	O
HcDT	O
is	O
a	O
JavaScript	B-Language
charting	O
library	O
for	O
the	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
It	O
is	O
based	O
on	O
the	O
open	O
source	O
Highcharts	B-Application
library	O
and	O
.	O
</s>
<s>
It	O
is	O
a	O
front-end	O
charting	O
library	O
enable	O
developers	O
to	O
connect	O
to	O
datastreams	O
from	O
any	O
OGC	O
SensorThings	B-Device
API	I-Device
service	O
,	O
and	O
display	O
the	O
sensor	O
observations	O
in	O
charts	O
,	O
tables	O
,	O
or	O
dashboard	O
widgets	O
for	O
web	O
applications	O
.	O
</s>
<s>
Mozilla	B-Operating_System
developed	O
a	O
node	O
implementation	O
of	O
the	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
52N	O
SensorThingsAPI	O
is	O
an	O
open	O
source	O
implementation	O
of	O
the	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
Its	O
core	O
features	O
are	O
the	O
interoperability	O
with	O
the	O
implementing	O
the	O
OGC	B-Device
Sensor	I-Device
Observation	I-Device
Service	I-Device
,	O
customizable	O
database	O
mappings	O
and	O
several	O
convenience	O
extensions	O
.	O
</s>
<s>
It	O
can	O
be	O
deployed	O
as	O
a	O
Docker	O
container	O
,	O
inside	O
an	O
Apache	B-Language
Tomcat	I-Language
or	O
as	O
a	O
standalone	O
application	O
.	O
</s>
<s>
OGC	O
SensorThings	B-Device
API	I-Device
is	O
used	O
as	O
the	O
standard	O
interface	O
that	O
interconnects	O
multiple	O
sensors	O
and	O
offers	O
an	O
IoT	B-Operating_System
enabled	O
real-time	O
situational	O
awareness	O
.	O
</s>
<s>
All	O
data	O
are	O
publicly	O
available	O
via	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
Data	O
are	O
published	O
with	O
open	O
standards	O
,	O
including	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
Part	O
of	O
the	O
project	O
is	O
an	O
open	O
source	O
ETL	O
engine	O
to	O
load	O
the	O
project	O
sensor	O
data	O
into	O
an	O
OGC	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
This	O
provides	O
easy-to-use	O
client-side	O
visualisation	O
of	O
Internet-of-Things	B-Operating_System
sensor	O
data	O
from	O
OGC	O
SensorThings	B-Device
API	I-Device
compatible	O
servers	O
.	O
</s>
<s>
is	O
an	O
open	O
source	O
library	O
of	O
custom	O
HTML	O
elements	O
(	O
web	O
components	O
)	O
supporting	O
SensorThings	B-Device
API	I-Device
.	O
</s>
<s>
These	O
elements	O
facilitate	O
the	O
development	O
of	O
HTML	O
applications	O
integrating	O
functionality	O
and	O
data	O
from	O
SensorThings	B-Device
API	I-Device
compatible	O
services	O
.	O
</s>
<s>
It	O
is	O
a	O
modular	O
Java	O
application	O
with	O
Docker-based	O
deployment	O
,	O
implemented	O
according	O
to	O
the	O
15-078r6	O
OGC	O
SensorThings	B-Device
API	I-Device
1.0	O
Implementation	O
Standard	O
.	O
</s>
<s>
SensorThings	B-Device
API	I-Device
provides	O
functions	O
similar	O
to	O
the	O
OGC	B-Device
Sensor	I-Device
Observation	I-Device
Service	I-Device
,	O
an	O
OGC	O
specification	O
approved	O
in	O
2005	O
.	O
</s>
