<s>
Digital	B-Protocol
enhanced	I-Protocol
cordless	I-Protocol
telecommunications	I-Protocol
(	O
Digital	B-Protocol
European	I-Protocol
cordless	I-Protocol
telecommunications	I-Protocol
)	O
,	O
usually	O
known	O
by	O
the	O
acronym	O
DECT	B-Protocol
,	O
is	O
a	O
standard	O
primarily	O
used	O
for	O
creating	O
cordless	O
telephone	O
systems	O
.	O
</s>
<s>
This	O
forced	O
development	O
of	O
a	O
variation	O
of	O
DECT	B-Protocol
called	O
DECT	B-Protocol
6.0	O
,	O
using	O
a	O
slightly	O
different	O
frequency	O
range	O
,	O
which	O
makes	O
these	O
units	O
incompatible	O
with	O
systems	O
intended	O
for	O
use	O
in	O
other	O
areas	O
,	O
even	O
from	O
the	O
same	O
manufacturer	O
.	O
</s>
<s>
DECT	B-Protocol
has	O
almost	O
completely	O
replaced	O
other	O
standards	O
in	O
most	O
countries	O
where	O
it	O
is	O
used	O
,	O
with	O
the	O
exception	O
of	O
North	O
America	O
.	O
</s>
<s>
DECT	B-Protocol
was	O
originally	O
intended	O
for	O
fast	O
roaming	O
between	O
networked	O
base	O
stations	O
,	O
and	O
the	O
first	O
DECT	B-Protocol
product	O
was	O
Net3	B-General_Concept
wireless	O
LAN	O
.	O
</s>
<s>
However	O
,	O
its	O
most	O
popular	O
application	O
is	O
single-cell	O
cordless	O
phones	O
connected	O
to	O
traditional	O
analog	O
telephone	O
,	O
primarily	O
in	O
home	O
and	O
small-office	O
systems	O
,	O
though	O
gateways	B-Application
with	O
multi-cell	O
DECT	B-Protocol
and/or	O
DECT	B-Protocol
repeaters	O
are	O
also	O
available	O
in	O
many	O
private	O
branch	O
exchange	O
(	O
PBX	O
)	O
systems	O
for	O
medium	O
and	O
large	O
businesses	O
,	O
produced	O
by	O
Panasonic	O
,	O
Mitel	O
,	O
Gigaset	O
,	O
Cisco	O
,	O
Grandstream	O
,	O
Snom	O
,	O
Spectralink	O
,	O
and	O
RTX	O
.	O
</s>
<s>
DECT	B-Protocol
can	O
also	O
be	O
used	O
for	O
purposes	O
other	O
than	O
cordless	O
phones	O
,	O
such	O
as	O
baby	O
monitors	O
and	O
industrial	O
sensors	O
.	O
</s>
<s>
The	O
ULE	O
Alliance	O
's	O
DECT	B-Protocol
ULE	O
and	O
its	O
"	O
HAN	O
FUN	O
"	O
protocol	O
are	O
variants	O
tailored	O
for	O
home	O
security	O
,	O
automation	O
,	O
and	O
the	B-Operating_System
internet	I-Operating_System
of	I-Operating_System
things	I-Operating_System
(	O
IoT	B-Operating_System
)	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
standard	O
includes	O
the	O
generic	O
access	O
profile	O
(	O
GAP	O
)	O
,	O
a	O
common	O
interoperability	O
profile	O
for	O
simple	O
telephone	O
capabilities	O
,	O
which	O
most	O
manufacturers	O
implement	O
.	O
</s>
<s>
GAP-conformance	O
enables	O
DECT	B-Protocol
handsets	O
and	O
bases	O
from	O
different	O
manufacturers	O
to	O
interoperate	O
at	O
the	O
most	O
basic	O
level	O
of	O
functionality	O
,	O
that	O
of	O
making	O
and	O
receiving	O
calls	O
.	O
</s>
<s>
Japan	O
uses	O
its	O
own	O
DECT	B-Protocol
variant	O
,	O
J-DECT	O
,	O
which	O
is	O
supported	O
by	O
the	O
DECT	B-Protocol
forum	O
.	O
</s>
<s>
The	O
New	O
Generation	O
DECT	B-Protocol
(	O
NG-DECT	O
)	O
standard	O
,	O
marketed	O
as	O
CAT-iq	O
by	O
the	O
DECT	B-Protocol
Forum	O
,	O
provides	O
a	O
common	O
set	O
of	O
advanced	O
capabilities	O
for	O
handsets	O
and	O
base	O
stations	O
.	O
</s>
<s>
CAT-iq	O
allows	O
interchangeability	O
across	O
IP-DECT	B-Protocol
base	O
stations	O
and	O
handsets	O
from	O
different	O
manufacturers	O
,	O
while	O
maintaining	O
backward	O
compatibility	O
with	O
GAP	O
equipment	O
.	O
</s>
<s>
It	O
also	O
requires	O
mandatory	O
support	O
for	O
wideband	B-Algorithm
audio	I-Algorithm
.	O
</s>
<s>
DECT-2020	O
New	O
Radio	O
,	O
marketed	O
as	O
NR+	O
(	O
New	O
Radio	O
plus	O
)	O
,	O
is	O
a	O
5G	O
data	O
transmission	O
protocol	O
which	O
meets	O
ITU-R	O
IMT-2020	O
requirements	O
for	O
ultra-reliable	O
low-latency	O
and	O
massive	O
machine-type	O
communications	O
,	O
and	O
can	O
co-exist	O
with	O
earlier	O
DECT	B-Protocol
devices	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
standard	O
was	O
developed	O
by	O
ETSI	O
in	O
several	O
phases	O
,	O
the	O
first	O
of	O
which	O
took	O
place	O
between	O
1988	O
and	O
1992	O
when	O
the	O
first	O
round	O
of	O
standards	O
were	O
published	O
.	O
</s>
<s>
Named	O
Digital	B-Protocol
European	I-Protocol
Cordless	I-Protocol
Telephone	I-Protocol
at	O
its	O
launch	O
by	O
CEPT	O
in	O
November	O
1987	O
;	O
its	O
name	O
was	O
soon	O
changed	O
to	O
Digital	B-Protocol
European	I-Protocol
Cordless	I-Protocol
Telecommunications	I-Protocol
,	O
following	O
a	O
suggestion	O
by	O
Enrico	O
Tosato	O
of	O
Italy	O
,	O
to	O
reflect	O
its	O
broader	O
range	O
of	O
application	O
including	O
data	O
services	O
.	O
</s>
<s>
DECT	B-Protocol
is	O
recognized	O
by	O
the	O
ITU	O
as	O
fulfilling	O
the	O
IMT-2000	O
requirements	O
and	O
thus	O
qualifies	O
as	O
a	O
3G	B-Architecture
system	O
.	O
</s>
<s>
Within	O
the	O
IMT-2000	O
group	O
of	O
technologies	O
,	O
DECT	B-Protocol
is	O
referred	O
to	O
as	O
IMT-2000	O
Frequency	O
Time	O
(	O
IMT-FT	B-Protocol
)	O
.	O
</s>
<s>
DECT	B-Protocol
was	O
developed	O
by	O
ETSI	O
but	O
has	O
since	O
been	O
adopted	O
by	O
many	O
countries	O
all	O
over	O
the	O
World	O
.	O
</s>
<s>
The	O
original	O
DECT	B-Protocol
frequency	O
band	O
(	O
1880	O
–	O
1900MHz	O
)	O
is	O
used	O
in	O
all	O
countries	O
in	O
Europe	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
the	O
Federal	O
Communications	O
Commission	O
in	O
2005	O
changed	O
channelization	O
and	O
licensing	O
costs	O
in	O
a	O
nearby	O
band	O
(	O
1920	O
–	O
1930MHz	O
,	O
or	O
1.9GHz	O
)	O
,	O
known	O
as	O
Unlicensed	O
Personal	O
Communications	O
Services	O
(	O
UPCS	O
)	O
,	O
allowing	O
DECT	B-Protocol
devices	O
to	O
be	O
sold	O
in	O
the	O
U.S.	O
with	O
only	O
minimal	O
changes	O
.	O
</s>
<s>
These	O
channels	O
are	O
reserved	O
exclusively	O
for	O
voice	O
communication	O
applications	O
and	O
therefore	O
are	O
less	O
likely	O
to	O
experience	O
interference	O
from	O
other	O
wireless	O
devices	O
such	O
as	O
baby	O
monitors	O
and	O
wireless	B-General_Concept
networks	I-General_Concept
.	O
</s>
<s>
The	O
New	O
Generation	O
DECT	B-Protocol
(	O
NG-DECT	O
)	O
standard	O
was	O
first	O
published	O
in	O
2007	O
;	O
it	O
was	O
developed	O
by	O
ETSI	O
with	O
guidance	O
from	O
the	O
Home	B-Application
Gateway	I-Application
Initiative	O
through	O
the	O
DECT	B-Protocol
Forum	O
to	O
support	O
IP-DECT	B-Protocol
functions	O
in	O
home	O
gateway/IP	O
-PBX	O
equipment	O
.	O
</s>
<s>
The	O
ETSI	O
TS	O
102	O
527	O
series	O
comes	O
in	O
five	O
parts	O
and	O
covers	O
wideband	B-Algorithm
audio	I-Algorithm
and	O
mandatory	O
interoperability	O
features	O
between	O
handsets	O
and	O
base	O
stations	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
Forum	O
maintains	O
the	O
CAT-iq	O
trademark	O
and	O
certification	O
program	O
;	O
CAT-iq	O
wideband	B-Algorithm
voice	I-Algorithm
profile	O
1.0	O
and	O
interoperability	O
profiles	O
2.0/2.1	O
are	O
based	O
on	O
the	O
relevant	O
parts	O
of	O
ETSI	O
TS	O
102	O
527	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
Ultra	O
Low	O
Energy	O
(	O
DECT	B-Protocol
ULE	O
)	O
standard	O
was	O
announced	O
in	O
January	O
2011	O
and	O
the	O
first	O
commercial	O
products	O
were	O
launched	O
later	O
that	O
year	O
by	O
Dialog	O
Semiconductor	O
.	O
</s>
<s>
Like	O
DECT	B-Protocol
,	O
DECT	B-Protocol
ULE	O
standard	O
uses	O
the	O
1.9GHz	O
band	O
,	O
and	O
so	O
suffers	O
less	O
interference	O
than	O
Zigbee	B-Protocol
,	O
Bluetooth	B-Protocol
,	O
or	O
Wi-Fi	O
from	O
microwave	O
ovens	O
,	O
which	O
all	O
operate	O
in	O
the	O
unlicensed	O
2.4GHz	B-Algorithm
ISM	B-Algorithm
band	I-Algorithm
.	O
</s>
<s>
DECT	B-Protocol
ULE	O
uses	O
a	O
simple	O
star	O
network	O
topology	O
,	O
so	O
many	O
devices	O
in	O
the	O
home	O
are	O
connected	O
to	O
a	O
single	O
control	O
unit	O
.	O
</s>
<s>
A	O
new	O
low-complexity	O
audio	O
codec	O
,	O
LC3plus	O
,	O
has	O
been	O
added	O
as	O
an	O
option	O
to	O
the	O
2019	O
revision	O
of	O
the	O
DECT	B-Protocol
standard	O
.	O
</s>
<s>
DECT-2020	O
New	O
Radio	O
protocol	O
was	O
published	O
in	O
July	O
2020	O
;	O
it	O
defines	O
a	O
new	O
physical	O
interface	O
based	O
on	O
cyclic	B-Device
prefix	I-Device
orthogonal	B-Protocol
frequency-division	I-Protocol
multiplexing	I-Protocol
(	O
CP-OFDM	B-Device
)	O
capable	O
of	O
up	O
to	O
1.2Gbit/s	O
transfer	O
rate	O
with	O
QAM-1024	O
modulation	O
.	O
</s>
<s>
The	O
updated	O
standard	O
supports	O
multi-antenna	O
MIMO	O
and	O
beamforming	B-Algorithm
,	O
FEC	O
channel	O
coding	O
,	O
and	O
hybrid	O
automatic	B-Error_Name
repeat	I-Error_Name
request	I-Error_Name
.	O
</s>
<s>
Direct	O
communication	O
between	O
end	O
devices	O
is	O
possible	O
with	O
a	O
mesh	B-Architecture
network	I-Architecture
topology	O
.	O
</s>
<s>
In	O
October	O
2021	O
,	O
DECT-2020	O
NR	O
was	O
approved	O
for	O
the	O
IMT-2020	O
standard	O
,	O
for	O
use	O
in	O
Massive	O
Machine	O
Type	O
Communications	O
(	O
MMTC	O
)	O
industry	O
automation	O
,	O
Ultra-Reliable	O
Low-Latency	O
Communications	O
(	O
URLLC	O
)	O
,	O
and	O
professional	O
wireless	O
audio	O
applications	O
with	O
point-to-point	O
or	O
multicast	O
communications	O
;	O
the	O
proposal	O
was	O
fast-tracked	O
by	O
ITU-R	O
following	O
real-world	O
evaluations	O
.	O
</s>
<s>
The	O
new	O
protocol	O
will	O
be	O
marketed	O
as	O
NR+	O
(	O
New	O
Radio	O
plus	O
)	O
by	O
the	O
DECT	B-Protocol
Forum	O
.	O
</s>
<s>
OFDMA	O
and	O
SC-FDMA	O
modulations	O
were	O
also	O
considered	O
by	O
the	O
ESTI	O
DECT	B-Protocol
committee	O
.	O
</s>
<s>
OpenD	O
is	O
an	O
open-source	O
framework	O
designed	O
to	O
provide	O
a	O
complete	O
software	O
implementation	O
of	O
DECT	B-Protocol
ULE	O
protocols	O
on	O
reference	O
hardware	O
from	O
Dialog	O
Semiconductor	O
and	O
DSP	O
Group	O
;	O
the	O
project	O
is	O
maintained	O
by	O
the	O
DECT	B-Protocol
forum	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
standard	O
originally	O
envisaged	O
three	O
major	O
areas	O
of	O
application	O
:	O
</s>
<s>
The	O
enterprise	O
PABX	O
market	O
had	O
some	O
success	O
,	O
and	O
all	O
the	O
major	O
PABX	O
vendors	O
have	O
offered	O
DECT	B-Protocol
access	O
options	O
.	O
</s>
<s>
The	O
public	O
access	O
application	O
did	O
not	O
succeed	O
,	O
since	O
public	O
cellular	O
networks	O
rapidly	O
out-competed	O
DECT	B-Protocol
by	O
coupling	O
their	O
ubiquitous	O
coverage	O
with	O
large	O
increases	O
in	O
capacity	O
and	O
continuously	O
falling	O
costs	O
.	O
</s>
<s>
There	O
has	O
been	O
only	O
one	O
major	O
installation	O
of	O
DECT	B-Protocol
for	O
public	O
access	O
:	O
in	O
early	O
1998	O
Telecom	O
Italia	O
launched	O
a	O
wide-area	O
DECT	B-Protocol
network	O
known	O
as	O
"	O
Fido	O
"	O
after	O
much	O
regulatory	O
delay	O
,	O
covering	O
major	O
cities	O
in	O
Italy	O
.	O
</s>
<s>
DECT	B-Protocol
has	O
been	O
used	O
for	O
wireless	B-Architecture
local	I-Architecture
loop	I-Architecture
as	O
a	O
substitute	O
for	O
copper	O
pairs	O
in	O
the	O
"	O
last	O
mile	O
"	O
in	O
countries	O
such	O
as	O
India	O
and	O
South	O
Africa	O
.	O
</s>
<s>
The	O
first	O
data	O
application	O
for	O
DECT	B-Protocol
was	O
Net3	B-General_Concept
wireless	O
LAN	O
system	O
by	O
Olivetti	O
,	O
launched	O
in	O
1993	O
and	O
discontinued	O
in	O
1995	O
.	O
</s>
<s>
A	O
precursor	O
to	O
Wi-Fi	O
,	O
Net3	B-General_Concept
was	O
a	O
micro-cellular	O
data-only	O
network	O
with	O
fast	O
roaming	O
between	O
base	O
stations	O
and	O
520kbit/s	O
transmission	O
rates	O
.	O
</s>
<s>
Data	O
applications	O
such	O
as	O
electronic	O
cash	O
terminals	O
,	O
traffic	O
lights	O
,	O
and	O
remote	O
door	O
openers	O
also	O
exist	O
,	O
but	O
have	O
been	O
eclipsed	O
by	O
Wi-Fi	O
,	O
3G	B-Architecture
and	O
4G	B-Architecture
which	O
compete	O
with	O
DECT	B-Protocol
for	O
both	O
voice	O
and	O
data	O
.	O
</s>
<s>
DECT	B-Protocol
6.0	O
is	O
a	O
North	O
American	O
marketing	O
term	O
for	O
DECT	B-Protocol
devices	O
manufactured	O
for	O
the	O
United	O
States	O
and	O
Canada	O
operating	O
at	O
1.9GHz	O
.	O
</s>
<s>
The	O
"	O
6.0	O
"	O
does	O
not	O
equate	O
to	O
a	O
spectrum	O
band	O
;	O
it	O
was	O
decided	O
the	O
term	O
DECT	B-Protocol
1.9	O
might	O
have	O
confused	O
customers	O
who	O
equate	O
larger	O
numbers	O
(	O
such	O
as	O
the	O
2.4	O
and	O
5.8	O
in	O
existing	O
2.4GHz	B-Algorithm
and	O
5.8GHz	O
cordless	O
telephones	O
)	O
with	O
later	O
products	O
.	O
</s>
<s>
The	O
term	O
was	O
coined	O
by	O
Rick	O
Krupka	O
,	O
marketing	O
director	O
at	O
Siemens	O
and	O
the	O
DECT	B-Protocol
USA	O
Working	O
Group	O
/	O
Siemens	O
ICM	O
.	O
</s>
<s>
In	O
North	O
America	O
,	O
DECT	B-Protocol
suffers	O
from	O
deficiencies	O
in	O
comparison	O
to	O
DECT	B-Protocol
elsewhere	O
,	O
since	O
the	O
UPCS	O
band	O
(	O
1920	O
–	O
1930MHz	O
)	O
is	O
not	O
free	O
from	O
heavy	O
interference	O
.	O
</s>
<s>
Before	O
1.9GHz	O
band	O
was	O
approved	O
by	O
the	O
FCC	O
in	O
2005	O
,	O
DECT	B-Protocol
could	O
only	O
operate	O
in	O
unlicensed	O
2.4	O
GHz	O
and	O
900MHz	O
Region	O
2	O
ISM	B-Algorithm
bands	I-Algorithm
;	O
some	O
users	O
of	O
Uniden	O
WDECT	O
2.4GHz	B-Algorithm
phones	O
reported	O
interoperability	O
issues	O
with	O
Wi-Fi	O
equipment	O
.	O
</s>
<s>
European	O
DECT	B-Protocol
products	O
may	O
not	O
be	O
used	O
in	O
the	O
United	O
States	O
and	O
Canada	O
,	O
as	O
they	O
likewise	O
cause	O
and	O
suffer	O
from	O
interference	O
with	O
American	O
and	O
Canadian	O
cellular	O
networks	O
,	O
and	O
use	O
is	O
prohibited	O
by	O
the	O
Federal	O
Communications	O
Commission	O
and	O
Industry	O
Canada	O
.	O
</s>
<s>
DECT	B-Protocol
8.0	O
HD	O
is	O
a	O
marketing	O
designation	O
for	O
North	O
American	O
DECT	B-Protocol
devices	O
certified	O
with	O
CAT-iq	O
2.0	O
"	O
Multi	O
Line	O
"	O
profile	O
.	O
</s>
<s>
Cordless	O
Advanced	O
Technology	O
—	O
internet	O
and	O
quality	O
(	O
CAT-iq	O
)	O
is	O
a	O
certification	O
program	O
maintained	O
by	O
the	O
DECT	B-Protocol
Forum	O
.	O
</s>
<s>
It	O
is	O
based	O
on	O
New	O
Generation	O
DECT	B-Protocol
(	O
NG-DECT	O
)	O
series	O
of	O
standards	O
from	O
ETSI	O
.	O
</s>
<s>
NG-DECT/CAT	O
-iq	O
contains	O
features	O
that	O
expand	O
the	O
generic	O
GAP	O
profile	O
with	O
mandatory	O
support	O
for	O
high	O
quality	O
wideband	B-Algorithm
voice	I-Algorithm
,	O
enhanced	O
security	O
,	O
calling	O
party	O
identification	O
,	O
multiple	O
lines	O
,	O
parallel	O
calls	O
,	O
and	O
similar	O
functions	O
to	O
facilitate	O
VoIP	B-Application
calls	I-Application
through	O
SIP	B-Application
and	O
H.323	B-Protocol
protocols	I-Protocol
.	O
</s>
<s>
CAT-iq	O
allows	O
any	O
DECT	B-Protocol
handset	O
to	O
communicate	O
with	O
a	O
DECT	B-Protocol
base	O
from	O
a	O
different	O
vendor	O
,	O
providing	O
full	O
interoperability	O
.	O
</s>
<s>
CAT-iq	O
2.0/2.1	O
feature	O
set	O
is	O
designed	O
to	O
support	O
IP-DECT	B-Protocol
base	O
stations	O
found	O
in	O
office	O
IP-PBX	O
and	O
home	B-Application
gateways	I-Application
.	O
</s>
<s>
The	O
DECT	B-Protocol
standard	O
specifies	O
a	O
means	O
for	O
a	O
portable	O
phone	O
or	O
"	O
Portable	O
Part	O
"	O
to	O
access	O
a	O
fixed	O
telephone	O
network	O
via	O
radio	O
.	O
</s>
<s>
A	O
gateway	B-Application
is	O
then	O
used	O
to	O
connect	O
calls	O
to	O
the	O
fixed	O
network	O
,	O
such	O
as	O
public	O
switched	O
telephone	O
network	O
(	O
telephone	O
jack	O
)	O
,	O
office	O
PBX	O
,	O
ISDN	B-Protocol
,	O
or	O
VoIP	B-Application
over	O
Ethernet	O
connection	O
.	O
</s>
<s>
Typical	O
abilities	O
of	O
a	O
domestic	O
DECT	B-Protocol
Generic	O
Access	O
Profile	O
(	O
GAP	O
)	O
system	O
include	O
multiple	O
handsets	O
to	O
one	O
base	O
station	O
and	O
one	O
phone	O
line	O
socket	O
.	O
</s>
<s>
Handsets	O
can	O
in	O
many	O
cases	O
be	O
used	O
as	O
intercoms	O
,	O
communicating	O
between	O
each	O
other	O
,	O
and	O
sometimes	O
as	O
walkie-talkies	B-Application
,	O
intercommunicating	O
without	O
telephone	O
line	O
connection	O
.	O
</s>
<s>
DECT	B-Protocol
operates	O
in	O
the	O
1880	O
–	O
1900MHz	O
band	O
and	O
defines	O
ten	O
frequency	O
channels	O
from	O
1881.792MHz	O
to	O
1897.344MHz	O
with	O
a	O
band	O
gap	O
of	O
1728kHz	O
.	O
</s>
<s>
DECT	B-Protocol
operates	O
as	O
a	O
multicarrier	O
frequency-division	O
multiple	O
access	O
(	O
FDMA	O
)	O
and	O
time-division	O
multiple	O
access	O
(	O
TDMA	O
)	O
system	O
.	O
</s>
<s>
This	O
means	O
that	O
the	O
radio	B-Algorithm
spectrum	I-Algorithm
is	O
divided	O
into	O
physical	O
carriers	O
in	O
two	O
dimensions	O
:	O
frequency	O
and	O
time	O
.	O
</s>
<s>
DECT	B-Protocol
uses	O
time-division	O
duplex	O
(	O
TDD	O
)	O
,	O
which	O
means	O
that	O
down	O
-	O
and	O
uplink	O
use	O
the	O
same	O
frequency	O
but	O
different	O
time	O
slots	O
.	O
</s>
<s>
DECT	B-Protocol
also	O
provides	O
frequency-hopping	B-Protocol
spread	I-Protocol
spectrum	I-Protocol
over	O
TDMA/TDD	O
structure	O
for	O
ISM	B-Algorithm
band	I-Algorithm
applications	O
.	O
</s>
<s>
If	O
frequency-hopping	B-Protocol
is	O
avoided	O
,	O
each	O
base	O
station	O
can	O
provide	O
up	O
to	O
120	O
channels	O
in	O
the	O
DECT	B-Protocol
spectrum	O
before	O
frequency	O
reuse	O
.	O
</s>
<s>
Each	O
timeslot	O
can	O
be	O
assigned	O
to	O
a	O
different	O
channel	O
in	O
order	O
to	O
exploit	O
advantages	O
of	O
frequency	B-Protocol
hopping	I-Protocol
and	O
to	O
avoid	O
interference	O
from	O
other	O
users	O
in	O
asynchronous	O
fashion	O
.	O
</s>
<s>
DECT	B-Protocol
allows	O
interference-free	O
wireless	O
operation	O
to	O
around	O
outdoors	O
.	O
</s>
<s>
DECT	B-Protocol
performs	O
with	O
fidelity	O
in	O
common	O
congested	O
domestic	O
radio	O
traffic	O
situations	O
.	O
</s>
<s>
It	O
is	O
generally	O
immune	O
to	O
interference	O
from	O
other	O
DECT	B-Protocol
systems	O
,	O
Wi-Fi	O
networks	O
,	O
video	O
senders	O
,	O
Bluetooth	B-Protocol
technology	I-Protocol
,	O
baby	O
monitors	O
and	O
other	O
wireless	O
devices	O
.	O
</s>
<s>
ETSI	O
standards	O
documentation	O
ETSI	O
EN	O
300	O
175	O
parts	O
1	O
–	O
8	O
(	O
DECT	B-Protocol
)	O
,	O
ETSI	O
EN	O
300	O
444	O
(	O
GAP	O
)	O
and	O
ETSI	O
TS	O
102	O
527	O
parts	O
1	O
–	O
5	O
(	O
NG-DECT	O
)	O
prescribe	O
the	O
following	O
technical	O
properties	O
:	O
</s>
<s>
32kbit/s	O
G.726	B-Algorithm
ADPCM	O
(	O
narrow	O
band	O
)	O
,	O
</s>
<s>
64kbit/s	O
G.711	B-Algorithm
μ-law/A	O
-law	O
PCM	O
(	O
narrow	O
band	O
)	O
,	O
</s>
<s>
32kbit/s	O
G.729.1	B-Algorithm
(	O
wideband	O
)	O
,	O
</s>
<s>
32kbit/s	O
MPEG-4	B-Algorithm
ER	I-Algorithm
AAC-LD	I-Algorithm
(	O
wideband	O
)	O
,	O
</s>
<s>
Frequency	O
:	O
the	O
DECT	B-Protocol
physical	B-Application
layer	I-Application
specifies	O
RF	O
carriers	O
for	O
the	O
frequency	O
ranges	O
1880MHz	O
to	O
1980MHz	O
and	O
2010MHz	O
to	O
2025MHz	O
,	O
as	O
well	O
as	O
902MHz	O
to	O
928MHz	O
and	O
2400MHz	O
to	O
2483	O
,	O
5MHz	O
ISM	B-Algorithm
band	I-Algorithm
with	O
frequency-hopping	B-Protocol
for	O
the	O
U.S.	O
market	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
physical	B-Application
layer	I-Application
uses	O
FDMA/TDMA	O
access	O
with	O
TDD	O
.	O
</s>
<s>
With	O
high	O
quality	O
connections	O
,	O
2-	O
,	O
4	O
-	O
or	O
8-level	O
differential	O
PSK	O
modulation	O
(	O
DBPSK	O
,	O
DQPSK	O
or	O
D8PSK	O
)	O
,	O
which	O
is	O
similar	O
to	O
QAM-2	O
,	O
QAM-4	O
and	O
QAM-8	O
,	O
can	O
be	O
used	O
to	O
transmit	O
1	O
,	O
2	O
,	O
or	O
3	O
bits	O
per	O
each	O
symbol	O
.	O
</s>
<s>
QAM-16	O
and	O
QAM-64	O
modulations	O
with	O
4	O
and	O
6	O
bits	O
per	O
symbol	O
can	O
be	O
used	O
for	O
user	O
data	O
(	O
B-field	O
)	O
only	O
,	O
with	O
resulting	O
transmission	O
speeds	O
of	O
up	O
to	O
5,068	O
Mbit/s	O
.	O
</s>
<s>
DECT	B-Protocol
provides	O
dynamic	O
channel	O
selection	O
and	O
assignment	O
;	O
the	O
choice	O
of	O
transmission	O
frequency	O
and	O
time	O
slot	O
is	O
always	O
made	O
by	O
the	O
mobile	O
terminal	O
.	O
</s>
<s>
For	O
this	O
purpose	O
,	O
DECT	B-Protocol
devices	O
scan	O
all	O
idle	O
channels	O
at	O
regular	O
30s	O
intervals	O
to	O
generate	O
a	O
received	O
signal	O
strength	O
indication	O
(	O
RSSI	O
)	O
list	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
media	B-Protocol
access	I-Protocol
control	I-Protocol
layer	O
controls	O
the	O
physical	B-Application
layer	I-Application
and	O
provides	O
connection	B-Protocol
oriented	I-Protocol
,	O
connectionless	B-Protocol
and	O
broadcast	B-Operating_System
services	O
to	O
the	O
higher	O
layers	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
data	B-Protocol
link	I-Protocol
layer	I-Protocol
uses	O
Link	O
Access	O
Protocol	O
Control	O
(	O
LAPC	O
)	O
,	O
a	O
specially	O
designed	O
variant	O
of	O
the	O
ISDN	B-Protocol
data	O
link	O
protocol	O
called	O
LAPD	O
.	O
</s>
<s>
This	O
packet	O
only	O
contains	O
64-bit	O
header	O
(	O
A-field	O
)	O
used	O
as	O
a	O
dummy	O
bearer	O
to	O
broadcast	B-Operating_System
base	O
station	O
identification	O
when	O
idle	O
.	O
</s>
<s>
P64	O
(	O
j	O
=	O
640	O
)	O
,	O
P67	O
(	O
j	O
=	O
672	O
)	O
"	O
long	O
slot	O
"	O
,	O
used	O
by	O
NG-DECT/CAT	O
-iq	O
wideband	B-Algorithm
voice	I-Algorithm
and	O
data	O
.	O
</s>
<s>
320	O
bits	O
user	O
data	O
(	O
B-field	O
)	O
:	O
DECT	B-Protocol
payload	O
,	O
i.e.	O
</s>
<s>
The	O
DECT	B-Protocol
network	B-Application
layer	I-Application
always	O
contains	O
the	O
following	O
protocol	O
entities	O
:	O
</s>
<s>
The	O
call	O
control	O
protocol	O
is	O
derived	O
from	O
ISDN	B-Protocol
DSS1	B-Protocol
,	O
which	O
is	O
a	O
Q.931-derived	O
protocol	O
.	O
</s>
<s>
Many	O
DECT-specific	O
changes	O
have	O
been	O
made	O
.	O
</s>
<s>
It	O
includes	O
many	O
elements	O
similar	O
to	O
the	O
GSM	O
protocol	O
,	O
but	O
also	O
includes	O
elements	O
unique	O
to	O
DECT	B-Protocol
.	O
</s>
<s>
Unlike	O
the	O
GSM	O
protocol	O
,	O
the	O
DECT	B-Protocol
network	O
specifications	O
do	O
not	O
define	O
cross-linkages	O
between	O
the	O
operation	O
of	O
the	O
entities	O
(	O
for	O
example	O
,	O
Mobility	O
Management	O
and	O
Call	O
Control	O
)	O
.	O
</s>
<s>
The	O
architecture	O
presumes	O
that	O
such	O
linkages	O
will	O
be	O
designed	O
into	O
the	O
interworking	O
unit	O
that	O
connects	O
the	O
DECT	B-Protocol
access	O
network	O
to	O
whatever	O
mobility-enabled	O
fixed	O
network	O
is	O
involved	O
.	O
</s>
<s>
DECT	B-Protocol
GAP	O
is	O
an	O
interoperability	O
profile	O
for	O
DECT	B-Protocol
.	O
</s>
<s>
The	O
intent	O
is	O
that	O
two	O
different	O
products	O
from	O
different	O
manufacturers	O
that	O
both	O
conform	O
not	O
only	O
to	O
the	O
DECT	B-Protocol
standard	O
,	O
but	O
also	O
to	O
the	O
GAP	O
profile	O
defined	O
within	O
the	O
DECT	B-Protocol
standard	O
,	O
are	O
able	O
to	O
interoperate	O
for	O
basic	O
calling	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
standard	O
includes	O
full	O
testing	O
suites	O
for	O
GAP	O
,	O
and	O
GAP	O
products	O
on	O
the	O
market	O
from	O
different	O
manufacturers	O
are	O
in	O
practice	O
interoperable	O
for	O
the	O
basic	O
functions	O
.	O
</s>
<s>
The	O
DECT	B-Protocol
media	B-Protocol
access	I-Protocol
control	I-Protocol
layer	O
includes	O
authentication	O
of	O
handsets	O
to	O
the	O
base	O
station	O
using	O
the	O
DECT	B-Protocol
Standard	O
Authentication	O
Algorithm	O
(	O
DSAA	O
)	O
.	O
</s>
<s>
The	O
standard	O
also	O
provides	O
encryption	O
services	O
with	O
the	O
DECT	B-Protocol
Standard	O
Cipher	O
(	O
DSC	O
)	O
.	O
</s>
<s>
The	O
encryption	O
is	O
fairly	O
weak	O
,	O
using	O
a	O
35-bit	O
initialization	B-Algorithm
vector	I-Algorithm
and	O
encrypting	O
the	O
voice	O
stream	O
with	O
64-bit	O
encryption	O
.	O
</s>
<s>
While	O
most	O
of	O
the	O
DECT	B-Protocol
standard	O
is	O
publicly	O
available	O
,	O
the	O
part	O
describing	O
the	O
DECT	B-Protocol
Standard	O
Cipher	O
was	O
only	O
available	O
under	O
a	O
non-disclosure	O
agreement	O
to	O
the	O
phones	O
 '	O
manufacturers	O
from	O
ETSI	O
.	O
</s>
<s>
The	O
properties	O
of	O
the	O
DECT	B-Protocol
protocol	O
make	O
it	O
hard	O
to	O
intercept	O
a	O
frame	O
,	O
modify	O
it	O
and	O
send	O
it	O
later	O
again	O
,	O
as	O
DECT	B-Protocol
frames	O
are	O
based	O
on	O
time-division	O
multiplexing	O
and	O
need	O
to	O
be	O
transmitted	O
at	O
a	O
specific	O
point	O
in	O
time	O
.	O
</s>
<s>
Unfortunately	O
very	O
few	O
DECT	B-Protocol
devices	O
on	O
the	O
market	O
implemented	O
authentication	O
and	O
encryption	O
procedures	O
and	O
even	O
when	O
encryption	O
was	O
used	O
by	O
the	O
phone	O
,	O
it	O
was	O
possible	O
to	O
implement	O
a	O
man-in-the-middle	O
attack	O
impersonating	O
a	O
DECT	B-Protocol
base	O
station	O
and	O
revert	O
to	O
unencrypted	O
mode	O
which	O
allows	O
calls	O
to	O
be	O
listened	O
to	O
,	O
recorded	O
,	O
and	O
re-routed	O
to	O
a	O
different	O
destination	O
.	O
</s>
<s>
After	O
an	O
unverified	O
report	O
of	O
a	O
successful	O
attack	O
in	O
2002	O
,	O
members	O
of	O
the	O
deDECTed.org	O
project	O
actually	O
did	O
reverse	O
engineer	O
the	O
DECT	B-Protocol
Standard	O
Cipher	O
in	O
2008	O
,	O
and	O
as	O
of	O
2010	O
there	O
has	O
been	O
a	O
viable	O
attack	O
on	O
it	O
that	O
can	O
recover	O
the	O
key	O
.	O
</s>
<s>
In	O
2012	O
,	O
an	O
improved	O
authentication	O
algorithm	O
,	O
the	O
DECT	B-Protocol
Standard	O
Authentication	O
Algorithm	O
2	O
(	O
DSAA2	O
)	O
,	O
and	O
improved	O
version	O
of	O
the	O
encryption	O
algorithm	O
,	O
the	O
DECT	B-Protocol
Standard	O
Cipher	O
2	O
(	O
DSC2	O
)	O
,	O
both	O
based	O
on	O
AES	O
128-bit	O
encryption	O
,	O
were	O
included	O
as	O
optional	O
in	O
the	O
NG-DECT/CAT	O
-iq	O
suite	O
.	O
</s>
<s>
DECT	B-Protocol
Forum	O
also	O
launched	O
the	O
DECT	B-Protocol
Security	O
certification	O
program	O
which	O
mandates	O
the	O
use	O
of	O
previously	O
optional	O
security	O
features	O
in	O
the	O
GAP	O
profile	O
,	O
such	O
as	O
early	O
encryption	O
and	O
base	O
authentication	O
.	O
</s>
<s>
Various	O
access	O
profiles	O
have	O
been	O
defined	O
in	O
the	O
DECT	B-Protocol
standard	O
:	O
</s>
<s>
Other	O
interoperability	O
profiles	O
exist	O
in	O
the	O
DECT	B-Protocol
suite	O
of	O
standards	O
,	O
and	O
in	O
particular	O
the	O
DPRS	O
(	O
DECT	B-Protocol
Packet	O
Radio	O
Services	O
)	O
bring	O
together	O
a	O
number	O
of	O
prior	O
interoperability	O
profiles	O
for	O
the	O
use	O
of	O
DECT	B-Protocol
as	O
a	O
wireless	O
LAN	O
and	O
wireless	O
internet	O
access	O
service	O
.	O
</s>
<s>
With	O
good	O
range	O
(	O
up	O
to	O
indoors	O
and	O
using	O
directional	O
antennae	O
outdoors	O
)	O
,	O
dedicated	O
spectrum	O
,	O
high	O
interference	O
immunity	O
,	O
open	O
interoperability	O
and	O
data	O
speeds	O
of	O
around	O
500kbit/s	O
,	O
DECT	B-Protocol
appeared	O
at	O
one	O
time	O
to	O
be	O
a	O
superior	O
alternative	O
to	O
Wi-Fi	O
.	O
</s>
<s>
The	O
protocol	O
capabilities	O
built	O
into	O
the	O
DECT	B-Protocol
networking	O
protocol	O
standards	O
were	O
particularly	O
good	O
at	O
supporting	O
fast	O
roaming	O
in	O
the	O
public	O
space	O
,	O
between	O
hotspots	O
operated	O
by	O
competing	O
but	O
connected	O
providers	O
.	O
</s>
<s>
The	O
first	O
DECT	B-Protocol
product	O
to	O
reach	O
the	O
market	O
,	O
Olivetti	O
's	O
Net3	B-General_Concept
,	O
was	O
a	O
wireless	O
LAN	O
,	O
and	O
German	O
firms	O
Dosch	O
&	O
Amand	O
and	O
Hoeft	O
&	O
Wessel	O
built	O
niche	O
businesses	O
on	O
the	O
supply	O
of	O
data	O
transmission	O
systems	O
based	O
on	O
DECT	B-Protocol
.	O
</s>
<s>
However	O
,	O
the	O
timing	O
of	O
the	O
availability	O
of	O
DECT	B-Protocol
,	O
in	O
the	O
mid-1990s	O
,	O
was	O
too	O
early	O
to	O
find	O
wide	O
application	O
for	O
wireless	O
data	O
outside	O
niche	O
industrial	O
applications	O
.	O
</s>
<s>
Whilst	O
contemporary	O
providers	O
of	O
Wi-Fi	O
struggled	O
with	O
the	O
same	O
issues	O
,	O
providers	O
of	O
DECT	B-Protocol
retreated	O
to	O
the	O
more	O
immediately	O
lucrative	O
market	O
for	O
cordless	O
telephones	O
.	O
</s>
<s>
By	O
the	O
time	O
mass	O
applications	O
for	O
wireless	O
Internet	O
had	O
emerged	O
,	O
and	O
the	O
U.S.	O
had	O
opened	O
up	O
to	O
DECT	B-Protocol
,	O
well	O
into	O
the	O
new	O
century	O
,	O
the	O
industry	O
had	O
moved	O
far	O
ahead	O
in	O
terms	O
of	O
performance	O
and	O
DECT	B-Protocol
's	O
time	O
as	O
a	O
technically	O
competitive	O
wireless	O
data	O
transport	O
had	O
passed	O
.	O
</s>
<s>
DECT	B-Protocol
uses	O
UHF	O
radio	O
,	O
similar	O
to	O
mobile	O
phones	O
,	O
baby	O
monitors	O
,	O
Wi-Fi	O
,	O
and	O
other	O
cordless	O
telephone	O
technologies	O
.	O
</s>
<s>
The	O
UK	O
Health	O
Protection	O
Agency	O
(	O
HPA	O
)	O
claims	O
that	O
due	O
to	O
a	O
mobile	O
phone	O
's	O
adaptive	O
power	O
ability	O
,	O
a	O
DECT	B-Protocol
cordless	O
phone	O
's	O
radiation	O
could	O
actually	O
exceed	O
the	O
radiation	O
of	O
a	O
mobile	O
phone	O
.	O
</s>
<s>
A	O
DECT	B-Protocol
cordless	O
phone	O
's	O
radiation	O
has	O
an	O
average	O
output	O
power	O
of	O
10mW	O
but	O
is	O
in	O
the	O
form	O
of	O
100	O
bursts	O
per	O
second	O
of	O
250mW	O
,	O
a	O
strength	O
comparable	O
to	O
some	O
mobile	O
phones	O
.	O
</s>
