<s>
Wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
(	O
WLL	O
)	O
,	O
is	O
the	O
use	O
of	O
a	O
wireless	O
communications	O
link	O
as	O
the	O
"	O
last	B-Protocol
mile	I-Protocol
/	O
first	O
mile	O
"	O
connection	O
for	O
delivering	O
plain	O
old	O
telephone	O
service	O
(	O
POTS	O
)	O
or	O
Internet	O
access	O
(	O
marketed	O
under	O
the	O
term	O
"	O
broadband	O
"	O
)	O
to	O
telecommunications	O
customers	O
.	O
</s>
<s>
Other	O
terms	O
for	O
this	O
type	O
of	O
access	O
include	O
broadband	O
wireless	O
access	O
(	O
BWA	O
)	O
,	O
radio	O
in	O
the	O
loop	O
(	O
RITL	B-Architecture
)	O
,	O
fixed-radio	B-Architecture
access	I-Architecture
(	O
FRA	O
)	O
,	O
fixed	B-Architecture
wireless	I-Architecture
access	I-Architecture
(	O
FWA	O
)	O
and	O
metro	B-Architecture
wireless	I-Architecture
(	O
MW	O
)	O
.	O
</s>
<s>
Fixed	B-Architecture
wireless	I-Architecture
terminal	I-Architecture
(	O
FWT	O
)	O
units	O
differ	O
from	O
conventional	O
mobile	O
terminal	O
units	O
operating	O
within	O
cellular	O
networks	O
such	O
as	O
GSM	O
in	O
that	O
a	O
fixed	B-Architecture
wireless	I-Architecture
terminal	I-Architecture
or	O
desk	O
phone	O
will	O
be	O
limited	O
to	O
an	O
almost	O
permanent	O
location	O
with	O
almost	O
no	O
roaming	O
abilities	O
.	O
</s>
<s>
Services	O
are	O
split	O
between	O
licensed	O
commonly	O
used	O
by	O
carriers	O
and	O
telcos	O
and	O
unlicensed	O
services	O
more	O
commonly	O
deployed	O
by	O
home	O
users	O
and	O
wireless	B-General_Concept
ISPs	I-General_Concept
(	O
WISPs	O
)	O
.	O
</s>
<s>
Then	O
,	O
the	O
point-to-point	O
microwave	O
solution	O
was	O
referred	O
to	O
as	O
,	O
"	O
LAN	B-General_Concept
extension	O
over	O
microwave	O
"	O
,	O
thereafter	O
,	O
"	O
wireless	O
backhaul	O
,	O
"	O
and	O
it	O
was	O
exclusively	O
deployed	O
for	O
enterprise	O
and	O
government	O
clients	O
.	O
</s>
<s>
Following	O
the	O
release	O
of	O
wi-fi	O
IEEE	O
802.11	O
,	O
licensed	O
point-to-point	O
microwave	O
became	O
an	O
addition	O
tool	O
for	O
wireless	B-General_Concept
internet	I-General_Concept
service	I-General_Concept
providers	I-General_Concept
(	O
WISP	O
)	O
and	O
ISPs	O
to	O
close	O
the	O
Digital	O
divide	O
.	O
</s>
<s>
In	O
2017	O
,	O
a	O
company	O
called	O
Climate	O
Resilient	O
Internet	O
,	O
LLC	O
,	O
formed	O
to	O
develop	O
a	O
new	O
standard	O
and	O
certification	O
for	O
point-to-point	O
microwave	O
(	O
"	O
fixed	B-Application
wireless	O
"	O
)	O
for	O
enterprise	O
and	O
government	O
resilience	O
to	O
extreme	O
weather	O
,	O
grid	O
outages	O
and	O
terror	O
attacks	O
.	O
</s>
<s>
Multichannel	O
multipoint	O
distribution	O
service	O
(	O
MMDS	O
)	O
and	O
local	O
multipoint	O
distribution	O
service	O
(	O
LMDS	O
)	O
were	O
the	O
first	O
true	O
multipoint	O
services	O
for	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
.	O
</s>
<s>
While	O
Europe	O
and	O
the	O
rest	O
of	O
the	O
world	O
developed	O
the	O
3500MHz	O
band	O
for	O
affordable	O
broadband	O
fixed	B-Application
wireless	O
,	O
the	O
U.S.	O
provided	O
LMDS	O
and	O
MMDS	O
,	O
and	O
most	O
implementations	O
in	O
the	O
United	O
States	O
were	O
conducted	O
at	O
2500MHz	O
.	O
</s>
<s>
Most	O
of	O
the	O
growth	O
in	O
long-range	O
radio	O
communications	O
since	O
2002	O
has	O
been	O
in	O
the	O
license-free	O
bands	O
(	O
mostly	O
900MHz	O
,	O
2.4GHz	B-Algorithm
and	O
5.8GHz	O
)	O
.	O
</s>
<s>
Most	O
of	O
the	O
early	O
vendors	O
of	O
license-free	O
fixed	B-Application
wireless	O
equipment	O
such	O
as	O
Adaptive	O
Broadband	O
(	O
Axxcelera	O
)	O
,	O
Trango	O
Broadband	O
,	O
Motorola	O
(	O
Orthogon	O
)	O
,	O
Proxim	O
Networks	O
,	O
Redline	O
Communications	O
and	O
BreezeCom	O
(	O
Alvarion	O
)	O
used	O
proprietary	O
protocols	O
and	O
hardware	O
,	O
creating	O
pressure	O
on	O
the	O
industry	O
to	O
adopt	O
a	O
standard	O
for	O
unlicensed	O
fixed	B-Application
wireless	O
.	O
</s>
<s>
These	O
MAC	B-Protocol
layers	I-Protocol
typically	O
used	O
a	O
15	O
–	O
20MHz	O
channel	O
using	O
direct-sequence	B-Device
spread	I-Device
spectrum	I-Device
and	O
BPSK	O
,	O
CCK	O
and	O
QPSK	O
for	O
modulation	O
.	O
</s>
<s>
These	O
devices	O
all	O
describe	O
the	O
customer	O
premises	O
wireless	O
system	O
as	O
the	O
subscriber	O
unit	O
(	O
SU	O
)	O
,	O
and	O
the	O
operator	O
transmitter	O
delivering	O
the	O
last	B-Protocol
mile	I-Protocol
local	O
loop	O
services	O
as	O
the	O
access	O
point	O
(	O
AP	O
)	O
.	O
</s>
<s>
Originally	O
designed	O
for	O
short-range	O
mobile	B-Application
internet	I-Application
and	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
access	O
,	O
IEEE	O
802.11	O
has	O
emerged	O
as	O
the	O
de	O
facto	O
standard	O
for	O
unlicensed	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
.	O
</s>
<s>
These	O
systems	O
have	O
provided	O
varying	O
results	O
,	O
as	O
the	O
operators	O
were	O
often	O
small	O
and	O
poorly	O
trained	O
in	O
radio	O
communications	O
,	O
additionally	O
802.11	O
was	O
not	O
intended	O
to	O
be	O
used	O
at	O
long	O
ranges	O
and	O
suffered	O
from	O
a	O
number	O
of	O
problems	O
,	O
such	O
as	O
the	O
hidden	B-General_Concept
node	I-General_Concept
problem	I-General_Concept
.	O
</s>
<s>
Providers	O
that	O
had	O
rave	O
reviews	O
when	O
they	O
started	O
faced	O
the	O
prospect	O
of	O
seeing	O
their	O
networks	O
degrade	O
in	O
performance	O
,	O
as	O
more	O
and	O
more	O
devices	O
were	O
deployed	O
using	O
the	O
license-free	O
U-NII	B-Algorithm
(	O
5.3/5.4GHz	O
)	O
and	O
ISM	B-Algorithm
(	O
2.4	O
and	O
5.8GHz	O
)	O
bands	O
and	O
competitors	O
sprung	O
up	O
around	O
them	O
.	O
</s>
<s>
This	O
approach	O
is	O
generally	O
called	O
"	O
mesh	B-Architecture
networking	I-Architecture
"	O
,	O
which	O
relies	O
on	O
ad	B-Protocol
hoc	I-Protocol
networking	I-Protocol
protocols	O
,	O
however	O
,	O
mesh	O
and	O
ad	B-Protocol
hoc	I-Protocol
networking	I-Protocol
protocols	O
have	O
yet	O
to	O
deliver	O
high-speed	O
low-latency	O
business-class	O
end-to-end	O
reliable	O
local-loop	O
service	O
,	O
as	O
the	O
paths	O
can	O
sometimes	O
traverse	O
exponentially	O
more	O
radio	O
links	O
than	O
a	O
traditional	O
star	O
(	O
AP	O
→	O
SU	O
)	O
topology	O
.	O
</s>
<s>
These	O
include	O
Global	O
System	O
for	O
Mobile	O
Communications	O
(	O
GSM	O
)	O
,	O
time-division	O
multiple	O
access	O
(	O
TDMA	O
)	O
,	O
code-division	B-Protocol
multiple	I-Protocol
access	I-Protocol
(	O
CDMA	B-Protocol
)	O
,	O
and	O
Digital	B-Protocol
Enhanced	I-Protocol
Cordless	I-Protocol
Telecommunications	I-Protocol
(	O
DECT	B-Protocol
)	O
.	O
</s>
<s>
The	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
market	O
is	O
currently	O
an	O
extremely	O
high-growth	O
market	O
,	O
offering	O
Internet	O
service	O
providers	O
immediate	O
access	O
to	O
customer	O
markets	O
without	O
having	O
to	O
either	O
lay	O
cable	O
through	O
a	O
metropolitan	O
area	O
,	O
or	O
work	O
through	O
the	O
ILECs	O
,	O
reselling	O
the	O
telephone	O
,	O
cable	O
or	O
satellite	O
networks	O
,	O
owned	O
by	O
companies	O
that	O
prefer	O
to	O
largely	O
sell	O
direct	O
.	O
</s>
<s>
This	O
trend	O
revived	O
the	O
prospects	O
for	O
local	O
and	O
regional	O
ISPs	O
,	O
as	O
those	O
willing	O
to	O
deploy	O
fixed	B-Application
wireless	O
networks	O
were	O
not	O
at	O
the	O
mercy	O
of	O
the	O
large	O
telecommunication	O
monopolies	O
.	O
</s>
<s>
Due	O
to	O
the	O
enormous	O
quantity	O
of	O
802.11	O
"	O
Wi-Fi	O
"	O
equipment	O
and	O
software	O
,	O
coupled	O
with	O
the	O
fact	O
that	O
spectrum	O
licenses	O
are	O
not	O
required	O
in	O
the	O
ISM	B-Algorithm
and	O
U-NII	B-Algorithm
bands	I-Algorithm
,	O
the	O
industry	O
has	O
moved	O
well	O
ahead	O
of	O
the	O
regulators	O
and	O
the	O
standards	O
bodies	O
.	O
</s>
<s>
CDMA	B-Protocol
(	O
USA	O
)	O
.	O
</s>
<s>
UMTS	B-Protocol
3rd	O
Generation	O
(	O
World	O
)	O
.	O
</s>
<s>
Fixed	B-Application
or	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
:	O
</s>
<s>
IEEE	O
802.11	O
,	O
originally	O
designed	O
for	O
short-range	O
mobile	B-Application
Internet	I-Application
and	O
network	O
access	O
service	O
,	O
it	O
has	O
emerged	O
as	O
the	O
facto	O
standard	O
for	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
.	O
</s>
<s>
WiMAX	O
or	O
IEEE	O
802.16	O
may	O
become	O
the	O
dominant	O
medium	O
for	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
.	O
</s>
