<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
(	O
Bluetooth	B-General_Concept
LE	I-General_Concept
,	O
colloquially	O
BLE	O
,	O
formerly	O
marketed	O
as	O
Bluetooth	B-General_Concept
Smart	I-General_Concept
)	O
is	O
a	O
wireless	B-General_Concept
personal	I-General_Concept
area	I-General_Concept
network	I-General_Concept
technology	O
designed	O
and	O
marketed	O
by	O
the	O
Bluetooth	B-Protocol
Special	O
Interest	O
Group	O
(	O
Bluetooth	B-Protocol
SIG	O
)	O
aimed	O
at	O
novel	O
applications	O
in	O
the	O
healthcare	O
,	O
fitness	O
,	O
beacons	B-General_Concept
,	O
security	O
,	O
and	O
home	O
entertainment	O
industries	O
.	O
</s>
<s>
It	O
is	O
independent	O
of	O
classic	B-Protocol
Bluetooth	I-Protocol
and	O
has	O
no	O
compatibility	O
,	O
but	O
Bluetooth	B-Protocol
Basic	O
Rate/Enhanced	O
Data	O
Rate	O
(	O
BR/EDR	O
)	O
and	O
LE	O
can	O
coexist	O
.	O
</s>
<s>
The	O
original	O
specification	O
was	O
developed	O
by	O
Nokia	O
in	O
2006	O
under	O
the	O
name	O
Wibree	B-General_Concept
,	O
which	O
was	O
integrated	O
into	O
Bluetooth	B-Protocol
4.0	O
in	O
December	O
2009	O
as	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
.	O
</s>
<s>
Compared	O
to	O
Classic	B-Protocol
Bluetooth	I-Protocol
,	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
is	O
intended	O
to	O
provide	O
considerably	O
reduced	O
power	O
consumption	O
and	O
cost	O
while	O
maintaining	O
a	O
similar	O
communication	O
range	O
.	O
</s>
<s>
Mobile	O
operating	O
systems	O
including	O
iOS	B-Application
,	O
Android	B-Application
,	O
Windows	B-Protocol
Phone	I-Protocol
and	O
BlackBerry	B-Application
,	O
as	O
well	O
as	O
macOS	B-Application
,	O
Linux	B-Application
,	O
Windows	B-Application
8	I-Application
,	O
Windows	B-Operating_System
10	I-Operating_System
and	O
Windows	B-Application
11	I-Application
,	O
natively	O
support	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
.	O
</s>
<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
is	O
distinct	O
from	O
the	O
previous	O
(	O
often	O
called	O
"	O
classic	O
"	O
)	O
Bluetooth	B-Protocol
Basic	O
Rate/Enhanced	O
Data	O
Rate	O
(	O
BR/EDR	O
)	O
protocol	O
,	O
but	O
the	O
two	O
protocols	O
can	O
both	O
be	O
supported	O
by	O
one	O
device	O
:	O
the	O
Bluetooth	B-Protocol
4.0	O
specification	O
permits	O
devices	O
to	O
implement	O
either	O
or	O
both	O
of	O
the	O
LE	O
and	O
BR/EDR	O
systems	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
uses	O
the	O
same	O
2.4	O
GHz	O
radio	O
frequencies	O
as	O
classic	B-Protocol
Bluetooth	I-Protocol
,	O
which	O
allows	O
dual-mode	O
devices	O
to	O
share	O
a	O
single	O
radio	O
antenna	O
,	O
but	O
uses	O
a	O
simpler	O
modulation	B-Application
system	O
.	O
</s>
<s>
In	O
2011	O
,	O
the	O
Bluetooth	B-Protocol
SIG	O
announced	O
the	O
Bluetooth	B-General_Concept
Smart	I-General_Concept
logo	O
so	O
as	O
to	O
clarify	O
compatibility	O
between	O
the	O
new	O
low	O
energy	O
devices	O
and	O
other	O
Bluetooth	B-Protocol
devices	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Smart	I-General_Concept
Ready	O
indicates	O
a	O
dual-mode	O
device	O
compatible	O
with	O
both	O
classic	O
and	O
low	O
energy	O
peripherals	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Smart	I-General_Concept
indicates	O
a	O
low	O
energy-only	O
device	O
which	O
requires	O
either	O
a	O
Smart	O
Ready	O
or	O
another	O
Smart	B-Device
device	I-Device
in	O
order	O
to	O
function	O
.	O
</s>
<s>
With	O
the	O
May	O
2016	O
Bluetooth	B-Protocol
SIG	O
branding	O
information	O
,	O
the	O
Bluetooth	B-Protocol
SIG	O
began	O
phasing	O
out	O
the	O
Bluetooth	B-General_Concept
Smart	I-General_Concept
and	O
Bluetooth	B-General_Concept
Smart	I-General_Concept
Ready	O
logos	O
and	O
word	O
marks	O
and	O
reverted	O
to	O
using	O
the	O
Bluetooth	B-Protocol
logo	O
and	O
word	O
mark	O
in	O
a	O
new	O
blue	O
color	O
.	O
</s>
<s>
The	O
Bluetooth	B-Protocol
SIG	O
identifies	O
a	O
number	O
of	O
markets	O
for	O
low-energy	O
technology	O
,	O
particularly	O
in	O
the	O
smart	O
home	O
,	O
health	O
,	O
sport	O
,	O
and	O
fitness	O
sectors	O
.	O
</s>
<s>
low	O
power	O
requirements	O
,	O
operating	O
for	O
"	O
months	O
or	O
years	O
"	O
on	O
a	O
button	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
compatibility	O
with	O
a	O
large	O
installed	B-Operating_System
base	I-Operating_System
of	O
mobile	O
phones	O
,	O
tablets	O
,	O
and	O
computers	O
.	O
</s>
<s>
The	O
company	O
began	O
developing	O
a	O
wireless	O
technology	O
adapted	O
from	O
the	O
Bluetooth	B-Protocol
standard	O
which	O
would	O
provide	O
lower	O
power	O
usage	O
and	O
cost	O
while	O
minimizing	O
its	O
differences	O
from	O
Bluetooth	B-Protocol
technology	I-Protocol
.	O
</s>
<s>
The	O
results	O
were	O
published	O
in	O
2004	O
using	O
the	O
name	O
Bluetooth	B-Protocol
Low	O
End	O
Extension	O
.	O
</s>
<s>
After	O
further	O
development	O
with	O
partners	O
,	O
in	O
particular	O
Logitech	O
and	O
within	O
the	O
European	O
project	O
MIMOSA	O
,	O
and	O
actively	O
promoted	O
and	O
supported	O
by	O
STMicroelectronics	O
since	O
its	O
early	O
stage	O
,	O
the	O
technology	O
was	O
released	O
to	O
the	O
public	O
in	O
October	O
2006	O
with	O
the	O
brand	O
name	O
Wibree	B-General_Concept
.	O
</s>
<s>
After	O
negotiations	O
with	O
Bluetooth	B-Protocol
SIG	O
members	O
,	O
an	O
agreement	O
was	O
reached	O
in	O
June	O
2007	O
to	O
include	O
Wibree	B-General_Concept
in	O
a	O
future	O
Bluetooth	B-Protocol
specification	I-Protocol
as	O
a	O
Bluetooth	B-Protocol
ultra	O
low	O
power	O
technology	O
.	O
</s>
<s>
The	O
technology	O
was	O
marketed	O
as	O
Bluetooth	B-General_Concept
Smart	I-General_Concept
and	O
integration	O
into	O
version	O
4.0	O
of	O
the	O
Core	O
Specification	O
was	O
completed	O
in	O
early	O
2010	O
.	O
</s>
<s>
The	O
first	O
smartphone	O
to	O
implement	O
the	O
4.0	O
specification	O
was	O
the	O
iPhone	B-Operating_System
4S	I-Operating_System
,	O
released	O
in	O
October	O
2011	O
.	O
</s>
<s>
A	O
number	O
of	O
other	O
manufacturers	O
released	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
Ready	O
devices	O
in	O
2012	O
.	O
</s>
<s>
The	O
Bluetooth	B-Protocol
SIG	O
officially	O
unveiled	O
Bluetooth	B-Protocol
5	O
on	O
16	O
June	O
2016	O
during	O
a	O
media	O
event	O
in	O
London	O
.	O
</s>
<s>
One	O
change	O
on	O
the	O
marketing	O
side	O
is	O
that	O
the	O
point	O
number	O
was	O
dropped	O
,	O
so	O
it	O
is	O
now	O
just	O
called	O
Bluetooth	B-Protocol
5	O
(	O
and	O
not	O
Bluetooth	B-Protocol
5.0	O
or	O
5.0	O
LE	O
like	O
for	O
Bluetooth	B-Protocol
4.0	O
)	O
.	O
</s>
<s>
On	O
the	O
technical	O
side	O
,	O
Bluetooth	B-Protocol
5	O
will	O
quadruple	O
the	O
range	O
by	O
using	O
increased	O
transmit	O
power	O
or	O
coded	O
physical	O
layer	O
,	O
double	O
the	O
speed	O
by	O
using	O
optional	O
half	O
of	O
the	O
symbol	O
time	O
compared	O
to	O
Bluetooth	B-Protocol
4.x	O
,	O
and	O
provide	O
an	O
eight-fold	O
increase	O
in	O
data	O
broadcasting	O
capacity	O
by	O
increasing	O
the	O
advertising	O
data	O
length	O
of	O
low	O
energy	O
Bluetooth	B-Protocol
transmissions	O
compared	O
to	O
Bluetooth	B-Protocol
4.x	O
,	O
which	O
could	O
be	O
important	O
for	O
IoT	B-Operating_System
applications	O
where	O
nodes	O
are	O
connected	O
throughout	O
a	O
whole	O
house	O
.	O
</s>
<s>
An	O
'	O
advertising	O
packet	O
 '	O
in	O
Bluetooth	B-Protocol
parlance	O
is	O
the	O
information	O
that	O
is	O
exchanged	O
between	O
two	O
devices	O
before	O
pairing	O
,	O
i.e.	O
</s>
<s>
For	O
example	O
,	O
advertising	O
packets	O
allow	O
a	O
device	O
to	O
display	O
to	O
the	O
user	O
the	O
name	O
of	O
another	O
Bluetooth	B-Protocol
device	O
before	O
pairing	O
with	O
it	O
.	O
</s>
<s>
Bluetooth	B-Protocol
5	O
will	O
increase	O
the	O
data	O
length	O
of	O
this	O
advertising	O
packet	O
.	O
</s>
<s>
The	O
length	O
of	O
this	O
packet	O
in	O
Bluetooth	B-Protocol
4.x	O
was	O
31	O
bytes	O
(	O
for	O
broadcast	O
topology	O
)	O
.	O
</s>
<s>
The	O
Bluetooth	B-Protocol
SIG	O
released	O
Mesh	O
Profile	O
and	O
Mesh	O
Model	O
specifications	O
officially	O
on	O
18	O
July	O
2017	O
.	O
</s>
<s>
Mesh	O
specification	O
enables	O
using	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
for	O
many-to-many	O
device	O
communications	O
for	O
home	O
automation	O
,	O
sensor	B-Architecture
networks	I-Architecture
and	O
other	O
applications	O
.	O
</s>
<s>
Borrowing	O
from	O
the	O
original	O
Bluetooth	B-Protocol
specification	I-Protocol
,	O
the	O
Bluetooth	B-Protocol
SIG	O
defines	O
several	O
profiles	B-General_Concept
–	O
specifications	O
for	O
how	O
a	O
device	O
works	O
in	O
a	O
particular	O
application	O
–	O
for	O
low	O
energy	O
devices	O
.	O
</s>
<s>
A	O
device	O
may	O
contain	O
implementations	O
of	O
multiple	O
profiles	B-General_Concept
.	O
</s>
<s>
The	O
majority	O
of	O
current	O
low	O
energy	O
application	O
profiles	B-General_Concept
are	O
based	O
on	O
the	O
Generic	O
Attribute	O
Profile	O
(	O
GATT	O
)	O
,	O
a	O
general	O
specification	O
for	O
sending	O
and	O
receiving	O
short	O
pieces	O
of	O
data	O
,	O
known	O
as	O
attributes	O
,	O
over	O
a	O
low	O
energy	O
link	O
.	O
</s>
<s>
The	O
Bluetooth	B-Protocol
mesh	O
profile	O
is	O
an	O
exception	O
to	O
this	O
rule	O
,	O
being	O
based	O
on	O
the	O
General	O
Access	O
Profile	O
(	O
GAP	O
)	O
.	O
</s>
<s>
Bluetooth	B-Protocol
mesh	O
profiles	B-General_Concept
use	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
to	O
communicate	O
with	O
other	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
devices	O
in	O
the	O
network	O
.	O
</s>
<s>
Each	O
device	O
can	O
pass	O
the	O
information	O
forward	O
to	O
other	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
devices	O
creating	O
a	O
"	O
mesh	O
"	O
effect	O
.	O
</s>
<s>
There	O
are	O
many	O
profiles	B-General_Concept
for	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
devices	O
in	O
healthcare	O
applications	O
.	O
</s>
<s>
The	O
Continua	O
Health	O
Alliance	O
consortium	O
promotes	O
these	O
in	O
cooperation	O
with	O
the	O
Bluetooth	B-Protocol
SIG	O
.	O
</s>
<s>
Profiles	B-General_Concept
for	O
sporting	O
and	O
fitness	O
accessories	O
include	O
:	O
</s>
<s>
HOGP	O
(	O
HID	B-General_Concept
over	O
GATT	O
Profile	O
)	O
allowing	O
Bluetooth	O
LE-enabled	O
Wireless	O
mice	O
,	O
keyboards	O
and	O
other	O
devices	O
offering	O
long-lasting	O
battery	O
life	O
.	O
</s>
<s>
Manufacturers	O
of	O
iBeacon	B-General_Concept
devices	O
implement	O
the	O
appropriate	O
specifications	O
for	O
their	O
device	O
to	O
make	O
use	O
of	O
proximity	O
sensing	O
capabilities	O
supported	O
by	O
Apple	O
's	O
iOS	B-Operating_System
devices	I-Operating_System
.	O
</s>
<s>
Relevant	O
application	O
profiles	B-General_Concept
include	O
:	O
</s>
<s>
The	O
time	O
profile	O
allows	O
current	O
time	O
and	O
time	B-Device
zone	I-Device
information	O
on	O
a	O
client	O
device	O
to	O
be	O
set	O
from	O
a	O
server	O
device	O
,	O
such	O
as	O
between	O
a	O
wristwatch	O
and	O
a	O
mobile	O
phone	O
's	O
network	B-Protocol
time	I-Protocol
.	O
</s>
<s>
It	O
introduces	O
LC3	B-General_Concept
as	O
its	O
default	O
codec	O
.	O
</s>
<s>
Compared	O
with	O
standard	O
Bluetooth	B-General_Concept
audio	I-General_Concept
it	O
offers	O
longer	O
battery	O
life	O
.	O
</s>
<s>
In	O
December	O
2020	O
,	O
the	O
Bluetooth	B-Protocol
SIG	O
released	O
a	O
draft	O
specification	O
for	O
a	O
wearable	O
exposure	O
notification	O
service	O
.	O
</s>
<s>
Starting	O
in	O
late	O
2009	O
,	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
integrated	O
circuits	O
were	O
announced	O
by	O
a	O
number	O
of	O
manufacturers	O
.	O
</s>
<s>
These	O
ICs	O
commonly	O
use	O
software	B-Architecture
radio	I-Architecture
so	O
updates	O
to	O
the	O
specification	O
can	O
be	O
accommodated	O
through	O
a	O
firmware	B-Application
upgrade	O
.	O
</s>
<s>
Current	O
mobile	O
devices	O
are	O
commonly	O
released	O
with	O
hardware	O
and	O
software	O
support	O
for	O
both	O
classic	B-Protocol
Bluetooth	I-Protocol
and	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
.	O
</s>
<s>
Windows	B-Application
8	I-Application
and	O
later	O
(	O
Windows	O
7	O
and	O
earlier	O
requires	O
drivers	O
from	O
Bluetooth	B-Protocol
radio	O
manufacturer	O
supporting	O
BLE	O
stack	O
as	O
it	O
has	O
no	O
built-in	O
generic	O
BLE	O
drivers	O
.	O
)	O
</s>
<s>
Android	B-Application
4.3	O
and	O
later	O
.	O
</s>
<s>
Android	B-Application
6	O
or	O
later	O
requires	O
location	O
permission	O
to	O
connect	O
to	O
LBE	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
technology	O
operates	O
in	O
the	O
same	O
spectrum	O
range	O
(	O
the	O
2.400	O
–	O
2.4835GHz	O
ISM	B-Algorithm
band	I-Algorithm
)	O
as	O
classic	B-Protocol
Bluetooth	I-Protocol
technology	O
,	O
but	O
uses	O
a	O
different	O
set	O
of	O
channels	O
.	O
</s>
<s>
Instead	O
of	O
the	O
classic	B-Protocol
Bluetooth	I-Protocol
79	O
1-MHz	O
channels	O
,	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
has	O
40	O
2-MHz	O
channels	O
.	O
</s>
<s>
Within	O
a	O
channel	O
,	O
data	O
is	O
transmitted	O
using	O
Gaussian	O
frequency	O
shift	O
modulation	B-Application
,	O
similar	O
to	O
classic	B-Protocol
Bluetooth	I-Protocol
's	O
Basic	O
Rate	O
scheme	O
.	O
</s>
<s>
The	O
bit	O
rate	O
is	O
1Mbit/s	O
(	O
with	O
an	O
option	O
of	O
2Mbit/s	O
in	O
Bluetooth	B-Protocol
5	O
)	O
,	O
and	O
the	O
maximum	O
transmit	O
power	O
is	O
10mW	O
(	O
100mW	O
in	O
Bluetooth	B-Protocol
5	O
)	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
uses	O
frequency	B-Protocol
hopping	I-Protocol
to	O
counteract	O
narrowband	O
interference	O
problems	O
.	O
</s>
<s>
Classic	B-Protocol
Bluetooth	I-Protocol
also	O
uses	O
frequency	B-Protocol
hopping	I-Protocol
but	O
the	O
details	O
are	O
different	O
;	O
as	O
a	O
result	O
,	O
while	O
both	O
FCC	O
and	O
ETSI	O
classify	O
Bluetooth	B-Protocol
technology	I-Protocol
as	O
an	O
FHSS	B-Protocol
scheme	O
,	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
is	O
classified	O
as	O
a	O
system	O
using	O
digital	O
modulation	B-Application
techniques	O
or	O
a	O
direct-sequence	B-Device
spread	I-Device
spectrum	I-Device
.	O
</s>
<s>
range	O
<	O
100	O
m	O
(	O
<33	O
0	O
ft	O
)	O
1	O
–	O
3	O
Mbit/s	O
125	O
kbit/s	O
,	O
500	O
kbit/s	O
,	O
1	O
Mbit/s	O
,	O
2	O
Mbit/s	O
Application	O
throughput	O
,	O
or	O
'	O
goodput	O
 '	O
0.7	O
–	O
2.1	O
Mbit/s	O
0.27	O
–	O
1.37	O
Mbit/sBluetooth	O
5	O
&	O
BLE	O
:	O
Achieving	O
maximum	O
throughput	O
Active	O
slaves	O
7	O
Not	O
defined	O
;	O
implementation	O
dependent	O
Security	O
56/128	O
-bit	O
and	O
application	O
layer	O
user	O
defined	O
128-bit	O
AES	B-Algorithm
in	O
CCM	B-Algorithm
mode	I-Algorithm
and	O
application	O
layer	O
user	O
defined	O
Robustness	O
Adaptive	O
fast	O
frequency	B-Protocol
hopping	I-Protocol
,	O
FEC	B-Error_Name
,	O
fast	O
ACK	B-Protocol
Adaptive	O
frequency	B-Protocol
hopping	I-Protocol
,	O
lazy	O
acknowledgement	B-Protocol
,	O
24-bit	O
CRC	O
,	O
32-bit	O
message	O
integrity	O
check	O
Wake	O
latency	O
(	O
from	O
a	O
non-connected	O
state	O
)	O
Typically	O
100	O
ms	O
6	O
ms	O
Minimum	O
total	O
time	O
to	O
send	O
data	O
(	O
det	O
.	O
</s>
<s>
battery	O
life	O
)	O
0.625	O
ms	O
3	O
ms	O
Voice	O
capable	O
Yes	O
No	O
Network	O
topology	O
Scatternet	B-General_Concept
Scatternet	B-General_Concept
Power	O
consumption	O
1	O
W	O
as	O
the	O
reference	O
0.01	O
–	O
0.50	O
W	O
(	O
depending	O
on	O
use	O
case	O
)	O
Peak	O
current	O
consumption	O
<3	O
0	O
mA	O
<	O
15	O
mA	O
Primary	O
use	O
cases	O
Mobile	O
phones	O
,	O
gaming	O
,	O
headsets	O
,	O
stereo	O
audio	O
streaming	O
,	O
smart	O
homes	O
,	O
wearables	O
,	O
automotive	O
,	O
PCs	O
,	O
security	O
,	O
proximity	O
,	O
healthcare	O
,	O
sports	O
&	O
fitness	O
,	O
etc	O
.	O
</s>
<s>
More	O
technical	O
details	O
may	O
be	O
obtained	O
from	O
official	O
specification	O
as	O
published	O
by	O
the	O
Bluetooth	B-Protocol
SIG	O
.	O
</s>
<s>
Note	O
that	O
power	O
consumption	O
is	O
not	O
part	O
of	O
the	O
Bluetooth	B-Protocol
specification	I-Protocol
.	O
</s>
<s>
All	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
devices	O
use	O
the	O
Generic	O
Attribute	O
Profile	O
(	O
GATT	O
)	O
.	O
</s>
<s>
The	O
application	B-Application
programming	I-Application
interface	I-Application
offered	O
by	O
a	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
aware	O
operating	O
system	O
will	O
typically	O
be	O
based	O
around	O
GATT	O
concepts	O
.	O
</s>
<s>
Any	O
implementer	O
may	O
pick	O
a	O
random	O
or	O
pseudorandom	O
UUID	O
for	O
proprietary	O
uses	O
,	O
but	O
the	O
Bluetooth	B-Protocol
SIG	O
have	O
reserved	O
a	O
range	O
of	O
UUIDs	O
(	O
of	O
the	O
form	O
)	O
for	O
standard	O
attributes	O
.	O
</s>
<s>
'	O
Long	O
read	O
 '	O
and	O
'	O
Long	O
write	O
 '	O
operations	O
can	O
be	O
used	O
when	O
the	O
length	O
of	O
the	O
characteristic	O
's	O
data	O
exceeds	O
the	O
MTU	B-Protocol
of	O
the	O
radio	O
link	O
.	O
</s>
<s>
This	O
avoids	O
the	O
need	O
for	O
the	O
client	O
to	O
poll	B-General_Concept
the	O
server	O
,	O
which	O
would	O
require	O
the	O
server	O
's	O
radio	O
circuitry	O
to	O
be	O
constantly	O
operational	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
is	O
designed	O
to	O
enable	O
devices	O
to	O
have	O
very	O
low	O
power	O
consumption	O
.	O
</s>
<s>
Several	O
chipmakers	O
including	O
Cambridge	O
Silicon	O
Radio	O
,	O
Dialog	O
Semiconductor	O
,	O
Nordic	O
Semiconductor	O
,	O
STMicroelectronics	O
,	O
Cypress	O
Semiconductor	O
,	O
Silicon	O
Labs	O
and	O
Texas	O
Instruments	O
had	O
introduced	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
optimized	O
chipsets	O
by	O
2014	O
.	O
</s>
<s>
A	O
study	O
by	O
beacon	O
software	O
company	O
Aislelabs	O
reported	O
that	O
peripherals	O
such	O
as	O
proximity	O
beacons	B-General_Concept
usually	O
function	O
for	O
1	O
–	O
2	O
years	O
powered	O
by	O
a	O
1,000	O
mAh	O
coin	B-Algorithm
cell	I-Algorithm
battery	O
.	O
</s>
<s>
This	O
is	O
possible	O
because	O
of	O
the	O
power	O
efficiency	O
of	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
protocol	O
,	O
which	O
only	O
transmits	O
small	O
packets	O
as	O
compared	O
to	O
Bluetooth	B-Protocol
Classic	I-Protocol
which	O
is	O
also	O
suitable	O
for	O
audio	O
and	O
high	O
bandwidth	B-Algorithm
data	O
.	O
</s>
<s>
In	O
contrast	O
,	O
a	O
continuous	O
scan	O
for	O
the	O
same	O
beacons	B-General_Concept
in	O
central	O
role	O
can	O
consume	O
1,000	O
mAh	O
in	O
a	O
few	O
hours	O
.	O
</s>
<s>
Android	B-Application
and	O
iOS	B-Operating_System
devices	I-Operating_System
also	O
have	O
very	O
different	O
battery	O
impact	O
depending	O
on	O
type	O
of	O
scans	O
and	O
the	O
number	O
of	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
devices	O
in	O
the	O
vicinity	O
.	O
</s>
<s>
With	O
newer	O
chipsets	O
and	O
advances	O
in	O
software	O
,	O
by	O
2014	O
both	O
Android	B-Application
and	O
iOS	B-Application
phones	O
had	O
negligible	O
power	O
consumption	O
in	O
real-life	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
use	O
.	O
</s>
<s>
Bluetooth	B-Protocol
5	O
has	O
introduced	O
a	O
new	O
transmission	O
mode	O
with	O
a	O
doubled	O
symbol	O
rate	O
.	O
</s>
<s>
Bluetooth	B-General_Concept
LE	I-General_Concept
has	O
been	O
traditionally	O
transmitting	O
1	O
bit	O
per	O
symbol	O
so	O
that	O
theoretically	O
the	O
data	O
rate	O
doubles	O
as	O
well	O
.	O
</s>
<s>
However	O
,	O
the	O
new	O
mode	O
doubles	O
the	O
bandwidth	B-Algorithm
from	O
about	O
1MHz	O
to	O
about	O
2MHz	O
which	O
makes	O
for	O
more	O
interferences	O
on	O
the	O
edge	O
regions	O
.	O
</s>
<s>
This	O
is	O
an	O
essential	O
difference	O
over	O
Bluetooth	B-Protocol
2	I-Protocol
EDR	O
which	O
also	O
doubled	O
the	O
data	O
rate	O
but	O
was	O
doing	O
that	O
by	O
employing	O
a	O
π/4	O
-DQPSK	O
or	O
8-DPSK	O
phase	B-Device
modulation	I-Device
on	O
a	O
1MHz	O
channel	O
while	O
Bluetooth	B-Protocol
5	O
continues	O
to	O
use	O
just	O
frequency	O
shift	O
keying	O
.	O
</s>
<s>
The	O
traditional	O
transmission	O
of	O
1	O
Mbit	O
in	O
the	O
Bluetooth	B-Protocol
Basic	O
Rate	O
was	O
renamed	O
1M	O
PHY	O
in	O
Bluetooth	B-Protocol
5	O
.	O
</s>
<s>
In	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
every	O
transmission	O
starts	O
on	O
the	O
1M	O
PHY	O
leaving	O
it	O
to	O
the	O
application	O
to	O
initiate	O
a	O
switch	O
to	O
the	O
2M	O
PHY	O
.	O
</s>
<s>
This	O
is	O
designed	O
to	O
facilitate	O
firmware	B-Application
updates	O
where	O
the	O
application	O
can	O
switch	O
back	O
to	O
a	O
traditional	O
1M	O
PHY	O
in	O
case	O
of	O
errors	O
.	O
</s>
<s>
Bluetooth	B-Protocol
5	O
has	O
introduced	O
two	O
new	O
modes	O
with	O
lower	O
data	O
rate	O
.	O
</s>
<s>
These	O
80	O
bits	O
are	O
not	O
FEC	B-Error_Name
encoded	O
as	O
usual	O
but	O
they	O
are	O
sent	O
directly	O
to	O
the	O
radio	O
channel	O
.	O
</s>
<s>
It	O
is	O
followed	O
by	O
a	O
header	O
block	O
(	O
"	O
FEC	B-Error_Name
Block	O
1	O
"	O
)	O
which	O
is	O
always	O
transmitted	O
in	O
S=	O
8	O
mode	O
.	O
</s>
<s>
The	O
Coding	O
Indicator	O
defines	O
the	O
Pattern	O
Mapping	O
used	O
for	O
the	O
following	O
payload	O
block	O
(	O
"	O
FEC	B-Error_Name
Block	O
2	O
"	O
)	O
where	O
S=	O
2	O
is	O
possible	O
.	O
</s>
<s>
The	O
new	O
packet	O
format	O
of	O
Bluetooth	B-Protocol
5	O
allows	O
transmitting	O
from	O
2	O
up	O
to	O
256	O
bytes	O
as	O
the	O
payload	O
in	O
a	O
single	O
burst	O
.	O
</s>
<s>
This	O
is	O
a	O
lot	O
more	O
than	O
the	O
maximum	O
of	O
31	O
bytes	O
in	O
Bluetooth	B-Protocol
4	O
.	O
</s>
<s>
The	O
old	O
transmission	O
packet	O
format	O
,	O
as	O
it	O
continues	O
to	O
be	O
used	O
in	O
the	O
1M	O
PHY	O
and	O
2M	O
PHY	O
modes	O
,	O
has	O
been	O
named	O
"	O
Uncoded	O
"	O
in	O
Bluetooth	B-Protocol
5	O
.	O
</s>
