<s>
Winlink	B-Protocol
,	O
or	O
formally	O
,	O
Winlink	B-Protocol
Global	O
Radio	B-Protocol
Email	I-Protocol
(	O
registered	O
US	O
Service	O
Mark	O
)	O
,	O
also	O
known	O
as	O
the	O
Winlink	B-Protocol
2000	I-Protocol
Network	O
,	O
is	O
a	O
worldwide	O
radio	O
messaging	O
system	O
that	O
uses	O
amateur-band	O
radio	O
frequencies	O
and	O
government	O
frequencies	O
to	O
provide	O
radio	O
interconnection	O
services	O
that	O
include	O
email	O
with	O
attachments	O
,	O
position	O
reporting	O
,	O
weather	O
bulletins	O
,	O
emergency	O
and	O
relief	O
communications	O
,	O
and	O
message	O
relay	O
.	O
</s>
<s>
Winlink	B-Protocol
networking	O
started	O
by	O
providing	O
interconnection	O
services	O
for	O
amateur	O
radio	O
(	O
also	O
known	O
as	O
ham	O
radio	O
)	O
.	O
</s>
<s>
The	O
system	O
used	O
to	O
employ	O
multiple	O
central	O
message	O
servers	O
around	O
the	O
world	O
for	O
redundancy	O
,	O
but	O
in	O
2017	O
–	O
2018	O
upgraded	O
to	O
Amazon	B-Application
Web	I-Application
Services	I-Application
that	O
provides	O
a	O
geographically-redundant	O
cluster	O
of	O
virtual	O
servers	O
with	O
dynamic	O
load	B-Application
balancers	I-Application
and	O
global	O
content-distribution	B-Operating_System
.	O
</s>
<s>
Gateway	O
stations	O
have	O
operated	O
on	O
sub-bands	O
of	O
HF	B-Algorithm
since	O
2013	O
as	O
the	O
Winlink	B-Protocol
Hybrid	O
Network	O
,	O
offering	O
message	O
forwarding	O
and	O
delivery	O
through	O
a	O
mesh-like	O
smart	O
network	O
whenever	O
Internet	O
connections	O
are	O
damaged	O
or	O
inoperable	O
.	O
</s>
<s>
During	O
the	O
late	O
1990s	O
and	O
late	O
2000s	O
,	O
it	O
increasingly	O
became	O
what	O
is	O
now	O
the	O
standard	O
network	O
system	O
for	O
amateur	O
radio	B-Protocol
email	I-Protocol
worldwide	O
.	O
</s>
<s>
Additionally	O
,	O
in	O
response	O
to	O
the	O
need	O
for	O
better	O
disaster	O
response	O
communications	O
in	O
the	O
mid	O
to	O
later	O
part	O
of	O
the	O
2000s	O
,	O
the	O
network	O
was	O
expanded	O
to	O
provide	O
separate	O
parallel	O
radio	B-Protocol
email	I-Protocol
networking	O
systems	O
for	O
MARS	O
,	O
UK	O
Cadet	O
,	O
Austrian	O
Red	O
Cross	O
,	O
the	O
US	O
Department	O
of	O
Homeland	O
Security	O
SHARES	O
HF	B-Algorithm
Program	O
,	O
and	O
other	O
groups	O
.	O
</s>
<s>
E-mail	O
via	O
high	B-Algorithm
frequency	I-Algorithm
(	O
HF	B-Algorithm
)	O
can	O
be	O
used	O
nearly	O
everywhere	O
on	O
the	O
planet	O
,	O
and	O
is	O
made	O
possible	O
by	O
connecting	O
an	O
HF	B-Algorithm
single	B-Device
sideband	I-Device
(	O
SSB	O
)	O
transceiver	O
system	O
to	O
a	O
computer	O
,	O
modem	B-Application
interface	O
,	O
and	O
appropriate	O
software	O
.	O
</s>
<s>
The	O
HF	B-Algorithm
modem	B-Application
technologies	O
include	O
PACTOR	B-Device
,	O
Winmor(deprecated )	O
,	O
ARDOP	O
,	O
Vara	O
HF	B-Algorithm
,	O
and	O
Automatic	B-Device
Link	I-Device
Establishment	I-Device
(	O
ALE	B-Device
)	O
.	O
</s>
<s>
VHF/UHF	O
protocols	O
include	O
AX.25	B-Protocol
Packet	O
and	O
Vara	O
FM	O
.	O
</s>
<s>
In	O
accordance	O
with	O
long	O
standing	O
amateur	O
radio	O
tradition	O
,	O
international	O
guidelines	O
and	O
FCC	O
rules	O
section	O
97.113	O
,	O
hams	O
using	O
the	O
Winlink	B-Protocol
system	O
are	O
advised	O
that	O
it	O
is	O
not	O
appropriate	O
to	O
use	O
it	O
for	O
business	O
communications	O
.	O
</s>
<s>
The	O
Winlink	B-Protocol
system	O
is	O
open	O
to	O
properly	O
licensed	O
amateur	O
radio	O
operators	O
.	O
</s>
<s>
For	O
offshore	O
cruising	O
yachtspeople	O
Winlink	B-Protocol
is	O
widely	O
used	O
as	O
an	O
alternative	O
,	O
or	O
alongside	O
,	O
Sailmail	O
,	O
which	O
is	O
an	O
HF	B-Algorithm
PACTOR	B-Device
based-email	O
system	O
using	O
marine	O
HF	B-Algorithm
frequencies	O
rather	O
than	O
amateur	O
.	O
</s>
<s>
PACTOR-I	B-Device
,	O
WINMOR(deprecated )	O
,	O
ARDOP	O
,	O
,	O
HSMM	O
(	O
WiFi	O
)	O
,	O
AX.25	B-Protocol
packet	O
,	O
D-Star	B-Protocol
,	O
TCP/IP	B-Protocol
,	O
and	O
ALE	B-Device
are	O
non-proprietary	O
protocols	O
used	O
in	O
various	O
RF	O
applications	O
to	O
access	O
the	O
Winlink	B-Protocol
network	O
systems	O
.	O
</s>
<s>
Later	O
versions	O
of	O
PACTOR	B-Device
are	O
proprietary	O
and	O
supported	O
only	O
by	O
commercially	O
available	O
modems	B-Application
from	O
Special	O
Communications	O
Systems	O
GmbH	O
.	O
</s>
<s>
In	O
amateur	O
radio	O
service	O
,	O
AirMail	O
,	O
Winlink	B-Protocol
Express	O
,	O
and	O
other	O
email	O
client	O
programs	O
used	O
by	O
the	O
Winlink	B-Protocol
system	O
,	O
disable	O
the	O
proprietary	O
compression	O
technology	O
for	O
PACTOR-II	B-Device
,	O
PACTOR-III	B-Device
,	O
and	O
PACTOR-IV	B-Device
modems	B-Application
and	O
instead	O
relies	O
on	O
the	O
open	O
FBB	B-Architecture
protocol	O
,	O
also	O
widely	O
used	O
worldwide	O
by	O
packet	B-Application
radio	I-Application
BBS	B-Application
forwarding	O
systems	O
.	O
</s>
<s>
In	O
May	O
1995	O
,	O
the	O
American	O
Radio	O
Relay	O
League	O
(	O
ARRL	O
)	O
privately	O
asked	O
the	O
FCC	O
to	O
change	O
Part	O
97.309(a )	O
to	O
allow	O
fully	O
documented	O
G-TOR	O
,	O
Clover	O
,	O
and	O
original	O
open	O
source	O
PacTOR	B-Device
(	O
Pactor	B-Device
I	O
)	O
modes	O
.	O
</s>
<s>
However	O
,	O
subsequent	O
versions	O
of	O
Pactor	B-Device
contained	O
proprietary	O
compression	O
algorithms	O
that	O
prevent	O
over-the-air	O
interception	O
.	O
</s>
<s>
In	O
spite	O
of	O
FCC	O
rulings	O
and	O
,	O
Winlink	B-Protocol
advocates	O
continue	O
to	O
use	O
the	O
proprietary	O
versions	O
of	O
Pactor	B-Device
and	O
other	O
undocumented	O
data	O
formats	O
that	O
cannot	O
be	O
eavesdropped	O
,	O
and	O
continue	O
to	O
press	O
the	O
FCC	O
for	O
encrypted	O
data	O
transmissions	O
in	O
amateur	O
radio	O
,	O
as	O
exemplified	O
in	O
a	O
Winlink	B-Protocol
petition	O
to	O
the	O
FCC	O
for	O
legalized	O
encryption	O
of	O
the	O
US	O
amateur	O
spectrum	O
while	O
seeking	O
broader	O
spectrum	O
allocations	O
in	O
response	O
to	O
the	O
Puerto	O
Rico	O
hurricanes	O
of	O
2017	O
.	O
</s>
