<s>
Ambient	B-Device
backscatter	I-Device
,	O
also	O
known	O
as	O
RF	O
backscatter	B-Algorithm
,	O
uses	O
existing	O
radio	O
frequency	O
signals	O
,	O
such	O
as	O
radio	O
,	O
television	O
and	O
mobile	O
telephony	O
,	O
to	O
transmit	O
data	O
without	O
a	O
battery	O
or	O
power	O
grid	O
connection	O
.	O
</s>
<s>
Later	O
implementation	O
uses	O
Wi-Fi	O
,	O
Bluetooth	B-Protocol
,	O
FM	O
radio	O
and	O
LoRa	B-General_Concept
transmissions	O
.	O
</s>
<s>
There	O
exists	O
technology	O
to	O
extend	O
backscatter	B-Algorithm
communication	O
range	O
up-to	O
3.4	O
kilometers	O
while	O
consuming	O
70	O
μW	O
power	O
at	O
the	O
backscatter	B-Algorithm
tag	O
.	O
</s>
<s>
In	O
2021	O
,	O
researchers	O
integrated	O
RF	O
backscatter	B-Algorithm
with	O
Li-Fi	O
to	O
achieve	O
greater	O
range	O
via	O
PassiveLiFi	O
.	O
</s>
