<s>
Real-time	B-General_Concept
testing	I-General_Concept
is	O
the	O
process	O
of	O
testing	O
real-time	B-General_Concept
computer	I-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Software	O
testing	O
is	O
performed	O
to	O
detect	O
and	O
help	O
correct	O
bugs	B-Error_Name
(	O
errors	O
)	O
in	O
computer	O
software	O
.	O
</s>
<s>
Static	O
and	O
conventional	O
methods	O
of	O
testing	O
can	O
detect	O
bugs	B-Error_Name
,	O
but	O
such	O
techniques	O
may	O
not	O
ensure	O
correct	O
results	O
in	O
real	O
time	O
software	O
systems	O
.	O
</s>
<s>
Real-time	B-General_Concept
software	I-General_Concept
systems	O
have	O
strict	O
timing	O
constraints	O
and	O
have	O
a	O
deterministic	O
behavior	O
.	O
</s>
<s>
Conventional	O
static	O
way	O
of	O
analysis	O
is	O
not	O
adequate	O
to	O
deal	O
with	O
such	O
timing	O
constraints	O
,	O
hence	O
additional	O
real-time	B-General_Concept
testing	I-General_Concept
is	O
important	O
.	O
</s>
<s>
In	O
this	O
testing	O
,	O
software	O
and	O
hardware	O
are	O
integrated	O
and	O
full	O
range	O
of	O
system	O
tests	O
are	O
conducted	O
to	O
discover	O
errors	O
,	O
if	O
any	O
,	O
during	O
software	O
and	O
hardware	O
interfacing	B-Protocol
.	O
</s>
<s>
Message	B-Application
Sequence	I-Application
Charts	I-Application
is	O
an	O
internationally	O
accepted	O
standard	O
for	O
capturing	O
requirements	O
.	O
</s>
<s>
Specification	B-Application
and	I-Application
Description	I-Application
Language	I-Application
is	O
a	O
standard	O
used	O
for	O
design	O
and	O
analysis	O
.	O
</s>
<s>
TTCN3	B-Protocol
provides	O
a	O
broader	O
applicability	O
,	O
as	O
compared	O
to	O
earlier	O
versions	O
of	O
TTCN	O
,	O
which	O
were	O
primarily	O
focused	O
on	O
OSI	B-Protocol
protocols	I-Protocol
only	O
.	O
</s>
<s>
To	O
accurately	O
capture	O
the	O
real	O
time	O
properties	O
of	O
a	O
given	O
test	O
system	O
and	O
to	O
ensure	O
that	O
requirements	O
and	O
models	O
are	O
used	O
to	O
generate	O
realistic	O
and	O
enforceable	O
timing	O
information	O
,	O
it	O
is	O
essential	O
that	O
the	O
language	O
itself	O
(	O
TTCN-3	B-Protocol
)	O
has	O
a	O
well	O
understood	O
and	O
semantically	O
sound	O
model	O
of	O
time	O
.	O
</s>
<s>
TTCN-3	B-Protocol
is	O
the	O
only	O
currently	O
available	O
,	O
internationally	O
standardized	O
testing	O
language	O
.	O
</s>
<s>
Prior	O
to	O
TTCN3	B-Protocol
,	O
its	O
earlier	O
versions	O
were	O
having	O
limited	O
functionality	O
and	O
limited	O
scope	O
over	O
OSI	O
protocol	O
.	O
</s>
<s>
But	O
,	O
TTCN3	B-Protocol
is	O
an	O
advanced	O
version	O
and	O
has	O
broader	O
applicability	O
.	O
</s>
<s>
Characteristics	O
of	O
TTCN3	B-Protocol
are	O
:	O
</s>
<s>
The	O
reason	O
for	O
using	O
TTCN3	B-Protocol
for	O
real	B-General_Concept
time	I-General_Concept
testing	I-General_Concept
is	O
because	O
of	O
its	O
timers	O
.	O
</s>
<s>
There	O
are	O
no	O
any	O
global	O
kind	O
timers	O
used	O
in	O
TTCN3	B-Protocol
.	O
</s>
<s>
Snapshot	O
Semantics	O
is	O
a	O
technique	O
in	O
TTCN3	B-Protocol
(	O
also	O
in	O
TTCN2	O
)	O
,	O
which	O
deals	O
with	O
the	O
message	O
passed	O
during	O
communication	O
by	O
system	O
to	O
system	O
or	O
implementation	O
under	O
test	O
.	O
</s>
