<s>
Q15X25	B-Device
is	O
a	O
communications	O
protocol	O
for	O
sending	O
data	O
over	O
a	O
radio	O
link	O
.	O
</s>
<s>
Q15X25	B-Device
is	O
a	O
form	O
of	O
packet	B-Application
radio	I-Application
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
interconnect	O
local	O
VHF	O
AX.25	B-Protocol
packet	O
networks	O
over	O
transcontinental	O
distances	O
.	O
</s>
<s>
Anyone	O
can	O
design	O
or	O
adapt	O
the	O
open-source	B-Application
software	I-Application
to	O
develop	O
their	O
own	O
Q15X25	B-Device
system	O
.	O
</s>
<s>
Q15X25	B-Device
is	O
a	O
digital	O
signal	O
processor-intensive	O
mode	O
designed	O
to	O
pass	O
AX.25	B-Protocol
packets	O
on	O
HF	O
with	O
speed	O
and	O
reliability	O
much	O
greater	O
than	O
traditional	O
HF	O
ARQ	B-Error_Name
modems	O
.	O
</s>
<s>
Q15X25	B-Device
uses	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
(	O
FEC	O
)	O
,	O
and	O
like	O
MT63	B-Device
,	O
uses	O
time	O
-	O
and	O
frequency-interleaving	O
in	O
order	O
to	O
avoid	O
most	O
error	O
sources	O
.	O
</s>
<s>
Linux	B-Application
implementations	O
are	O
usually	O
called	O
"	O
newpsk	B-Device
"	O
or	O
"	O
newqpsk	B-Device
"	O
.	O
</s>
<s>
MixW	O
,	O
a	O
multipurpose	O
communications	O
control	O
and	O
digital	O
modes	O
package	O
on	O
Windows	O
can	O
implement	O
Kiss	O
and/or	O
"	O
TCP/IP	O
over	O
X.25	O
"	O
on	O
either	O
traditional	O
300baud	O
,	O
1200baud	O
and	O
2400baud	O
FSK	O
packet	O
"	O
modems	O
"	O
implemented	O
as	O
DSP	O
via	O
sound	O
card	O
or	O
over	O
Q15X25	B-Device
.	O
</s>
<s>
The	O
"	O
FlexNet	O
"	O
Windows	O
packet	O
software	O
also	O
has	O
a	O
newqpsk	B-Device
/	O
Q15X25	B-Device
option	O
.	O
</s>
<s>
As	O
with	O
any	O
amateur	O
radio	O
transmission	O
,	O
anyone	O
can	O
listen/decode	O
Q15X25	B-Device
transmissions	O
,	O
but	O
an	O
amateur	O
radio	O
operation	O
license	O
is	O
required	O
for	O
transmission	O
.	O
</s>
