<s>
Real-time	B-Protocol
communication	I-Protocol
(	O
RTC	O
)	O
is	O
a	O
category	O
of	O
software	O
protocols	O
and	O
communication	O
hardware	O
media	O
that	O
gives	O
real-time	O
guarantees	O
,	O
which	O
is	O
necessary	O
to	O
support	O
real-time	O
guarantees	O
of	O
real-time	B-General_Concept
computing	I-General_Concept
.	O
</s>
<s>
Real-time	B-Protocol
communication	I-Protocol
protocols	O
are	O
dependent	O
not	O
only	O
on	O
the	O
validity	O
and	O
integrity	O
of	O
data	O
transferred	O
but	O
also	O
the	O
timeliness	O
of	O
the	O
transfer	O
.	O
</s>
<s>
Real-time	B-Protocol
communication	I-Protocol
systems	O
are	O
generally	O
understood	O
as	O
one	O
of	O
two	O
types	O
:	O
Hard	O
Real-Time	O
(	O
HRT	O
)	O
and	O
Soft	O
Real-Time	O
(	O
SRT	O
)	O
.	O
</s>
<s>
The	O
difference	O
between	O
a	O
hard	O
and	O
soft	O
real-time	B-Protocol
communication	I-Protocol
system	O
is	O
the	O
consequences	O
of	O
incorrect	O
operation	O
.	O
</s>
<s>
Safety-critical	B-Application
systems	I-Application
capable	O
of	O
causing	O
catastrophic	O
consequences	O
upon	O
a	O
fault	O
,	O
such	O
as	O
aircraft	O
fly-by-wire	O
systems	O
,	O
are	O
designated	O
as	O
hard	O
real-time	O
,	O
whereas	O
non-critical	O
but	O
ideally	O
real-time	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
hotel	O
reservation	O
systems	O
,	O
are	O
designated	O
as	O
soft	O
real-time	O
.	O
</s>
<s>
The	O
designation	O
of	O
a	O
real-time	B-Protocol
communication	I-Protocol
system	O
as	O
hard	O
or	O
soft	O
has	O
significant	O
influence	O
on	O
its	O
design	O
.	O
</s>
<s>
Hard	O
real-time	B-Protocol
communication	I-Protocol
systems	O
are	O
frequently	O
electromechanically	O
linked	O
to	O
a	O
physical	O
mechanism	O
,	O
often	O
one	O
that	O
interfaces	O
directly	O
with	O
people	O
or	O
property	O
,	O
which	O
often	O
contributes	O
to	O
or	O
defines	O
the	O
potential	O
danger	O
of	O
a	O
fault	O
.	O
</s>
<s>
Due	O
to	O
their	O
safety-critical	B-Application
nature	O
,	O
the	O
communication	O
protocols	O
defined	O
in	O
a	O
hard	O
real-time	B-General_Concept
system	I-General_Concept
generally	O
must	O
be	O
deterministic	B-Protocol
.	O
</s>
<s>
Hard	O
real-time	B-Protocol
communication	I-Protocol
systems	O
are	O
particularly	O
common	O
in	O
the	O
transportation	O
,	O
industrial	O
,	O
and	O
medical	O
sectors	O
.	O
</s>
<s>
Common	O
applications	O
include	O
control	O
systems	O
,	O
automotive	B-Device
controllers	I-Device
,	O
medical	O
devices	O
,	O
and	O
critical	O
safety	O
systems	O
such	O
as	O
airbag	O
firing	O
computers	O
.	O
</s>
<s>
The	O
spacecraft	O
communication	O
network	O
SpaceWire	B-Architecture
supports	O
real-time	B-Protocol
communication	I-Protocol
.	O
</s>
<s>
Time-Triggered	B-Protocol
Ethernet	I-Protocol
supports	O
real-time	O
synchronous	O
communication	O
in	O
complex	O
multi-hop	O
Ethernet	O
networks	O
.	O
</s>
<s>
Unlike	O
hard	O
real-time	B-Protocol
communication	I-Protocol
systems	O
,	O
soft	O
real-time	B-Protocol
communication	I-Protocol
systems	O
generally	O
do	O
not	O
have	O
the	O
capacity	O
to	O
cause	O
catastrophic	O
harm	O
upon	O
a	O
fault	O
,	O
which	O
allows	O
for	O
non-deterministic	O
,	O
less	O
rigorous	O
network	B-Architecture
infrastructure	I-Architecture
.	O
</s>
<s>
This	O
allows	O
soft	O
real-time	B-Protocol
communication	I-Protocol
systems	O
to	O
operate	O
over	O
consumer	O
networks	O
such	O
as	O
residential	O
internet	O
connections	O
and	O
cellular	O
networks	O
.	O
</s>
<s>
A	O
large	O
amount	O
of	O
soft	O
real-time	B-General_Concept
systems	I-General_Concept
are	O
telecommunications	O
products	O
such	O
as	O
VOIP	B-Application
systems	I-Application
and	O
certain	O
video	B-Application
calling	I-Application
platforms	O
such	O
as	O
Discord	B-Application
and	O
Google	B-Protocol
Meet	I-Protocol
.	O
</s>
<s>
Data	O
transmitted	O
over	O
a	O
soft	O
real-time	B-Protocol
communication	I-Protocol
system	O
is	O
not	O
stored	O
in	O
a	O
centralized	O
server	O
,	O
and	O
peers	O
are	O
connected	O
directly	O
to	O
one	O
another	O
rather	O
than	O
through	O
a	O
server	O
,	O
although	O
intermediary	O
connecting	O
nodes	O
between	O
peers	O
are	O
allowed	O
when	O
a	O
direct	O
link	O
cannot	O
be	O
established	O
.	O
</s>
<s>
WebRTC	B-Protocol
,	O
an	O
open-source	B-License
real-time	B-Protocol
communication	I-Protocol
framework	B-Architecture
for	O
mobile	O
applications	O
and	O
web	O
browsers	O
,	O
is	O
the	O
current	O
most	O
prominent	O
implementation	O
of	O
real-time	B-Protocol
communication	I-Protocol
in	O
the	O
web-oriented	O
telecommunications	O
space	O
.	O
</s>
