Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:02,002 --> 00:00:06,072
Wireless networks have become almost
commonplace in our homes and businesses.
2
00:00:06,239 --> 00:00:09,776
And we've almost come to expect
that when we walk into a restaurant
3
00:00:09,776 --> 00:00:13,880
or a conference room, that there will be
a wireless network available to use.
4
00:00:14,280 --> 00:00:14,914
The standards
5
00:00:14,914 --> 00:00:19,119
for these wireless networks come from an
I Tripoli Land Man Standards Committee.
6
00:00:19,119 --> 00:00:23,356
This is the IO2 committee
and the wireless networking
7
00:00:23,356 --> 00:00:26,826
part of this committee
is the 802 11 standard.
8
00:00:27,293 --> 00:00:29,896
But as you're probably aware,
there are many different
9
00:00:29,896 --> 00:00:30,930
wireless standards.
10
00:00:30,930 --> 00:00:35,068
And in this video we'll step through
each one of those 802.11 standards
11
00:00:35,435 --> 00:00:40,273
instead of referring to these as 802
11 wireless networks.
12
00:00:40,273 --> 00:00:43,910
You'll often
see this abbreviated as a Wi-Fi network.
13
00:00:44,044 --> 00:00:48,214
This is a trademark from the Wi-Fi
Alliance, who's responsible for testing
14
00:00:48,214 --> 00:00:51,985
the interoperability of all of these
different wireless devices.
15
00:00:53,119 --> 00:00:56,356
The first standard we'll look at
is the one from the very beginning.
16
00:00:56,356 --> 00:00:58,358
It's the 802.11 eight.
17
00:00:58,358 --> 00:01:01,361
This is one of the very
first wireless standards that was released
18
00:01:01,361 --> 00:01:04,364
back in October of 1999.
19
00:01:04,431 --> 00:01:09,235
It's a standard that operates exclusively
in the five gigahertz frequency range.
20
00:01:09,502 --> 00:01:13,239
It can use other frequency ranges
with special licensing,
21
00:01:13,339 --> 00:01:15,775
although these days you don't often
see very many.
22
00:01:15,775 --> 00:01:19,879
802.11
eight networks still around the 802.11.
23
00:01:19,913 --> 00:01:23,216
A wireless standard operates at 54mbps.
24
00:01:23,249 --> 00:01:27,353
And although this doesn't seem very fast
now, back in 1999
25
00:01:27,353 --> 00:01:30,457
when this was first released,
that was a great deal of speed
26
00:01:30,557 --> 00:01:34,094
on a network that suddenly was able
to operate wirelessly.
27
00:01:34,527 --> 00:01:37,964
Because we are operating at five gigahertz
frequencies,
28
00:01:37,964 --> 00:01:41,334
we don't tend to have the same range
as lower frequencies
29
00:01:41,334 --> 00:01:46,473
such as the 2.4GHz range
that's used by 802.11 b.
30
00:01:46,639 --> 00:01:50,376
With these higher frequencies,
the objects around us tend to absorb
31
00:01:50,376 --> 00:01:55,949
the signals, whereas with radio 2.11 B
they tend to bounce off of those devices.
32
00:01:55,949 --> 00:02:01,187
And therefore we get a little bit
more distance from a 2.4GHz base network.
33
00:02:01,387 --> 00:02:06,126
As I mentioned, it's not common
to see 802.11 A and use these days.
34
00:02:06,326 --> 00:02:09,062
And very often
this will be a type of network
35
00:02:09,062 --> 00:02:13,366
that has already been upgraded
to a much faster and newer standard.
36
00:02:14,501 --> 00:02:15,001
At about the
37
00:02:15,001 --> 00:02:18,171
same time that 802.11 A was released,
38
00:02:18,304 --> 00:02:22,809
the I also finalized the 802.11
B standard.
39
00:02:23,042 --> 00:02:25,411
This is not an upgrade to the A.
40
00:02:25,411 --> 00:02:28,081
Instead,
this is a completely different standard
41
00:02:28,081 --> 00:02:31,551
that operates with different frequencies
and different speeds.
42
00:02:31,751 --> 00:02:35,054
802.11 B operates in the 2.4GHz range,
43
00:02:35,054 --> 00:02:40,126
and its maximum speed is 11mbps,
which is certainly much slower
44
00:02:40,160 --> 00:02:43,263
than the 54mbps we were able to get.
45
00:02:43,263 --> 00:02:46,399
With 8 or 2 dot 11 A
so why would we choose
46
00:02:46,399 --> 00:02:49,502
the slower
11 megabit per second wireless standard
47
00:02:49,602 --> 00:02:53,072
when a 54 megabits
standard already was available?
48
00:02:53,239 --> 00:02:56,876
In many cases, this is associated
with the frequency in use.
49
00:02:57,110 --> 00:03:00,213
As I mentioned earlier, 2.4GHz frequencies
50
00:03:00,213 --> 00:03:03,550
tend to bounce off of devices
instead of being absorbed,
51
00:03:03,783 --> 00:03:08,588
and therefore we get a bit longer
distance in 2.4GHz networks.
52
00:03:08,855 --> 00:03:11,824
This, of course, will depend
on the type of environment.
53
00:03:11,824 --> 00:03:13,326
If you're in a warehouse,
54
00:03:13,326 --> 00:03:17,397
you may choose 802.11 A
because there's so much open space.
55
00:03:17,630 --> 00:03:20,200
But if you're in an office
setting with a lot of people in desks,
56
00:03:20,200 --> 00:03:24,337
you may choose to 11 b
because that frequency works a lot better
57
00:03:24,337 --> 00:03:25,672
in that environment.
58
00:03:25,672 --> 00:03:30,009
One challenge we have with this 2.4GHz
range is that wireless
59
00:03:30,009 --> 00:03:33,680
networks are not the only devices
that can use those frequencies.
60
00:03:33,913 --> 00:03:37,350
It's very common to see things like baby
monitors, cordless phones,
61
00:03:37,483 --> 00:03:39,085
or even the Bluetooth standard.
62
00:03:39,085 --> 00:03:42,121
Take advantage of 2.4GHz frequencies.
63
00:03:42,388 --> 00:03:45,992
This means that we could have frequency
conflicts when trying to communicate
64
00:03:45,992 --> 00:03:50,363
using all of these devices
simultaneously in one single area.
65
00:03:50,730 --> 00:03:55,368
It's also difficult to find 802.11
B networks that might still be operating.
66
00:03:55,501 --> 00:03:57,804
And if you do run into an 802.
67
00:03:57,804 --> 00:04:02,041
11 B network, it's probably because
you're upgrading it to a newer version.
68
00:04:03,276 --> 00:04:04,544
One of the first upgrades
69
00:04:04,544 --> 00:04:09,782
available to these 2.11 B networks
was the standard for Android 2.11 G.
70
00:04:10,016 --> 00:04:15,521
This was released in the June 2003
timeframe, and just like 802.11 B
71
00:04:16,089 --> 00:04:20,226
2.11 G also operates in the 2.4GHz range.
72
00:04:20,560 --> 00:04:25,231
The reason that this was such a useful
upgrade for folks running Android 2.11 B
73
00:04:25,365 --> 00:04:30,403
was that we increase the speed on the
G standard to 54mbps,
74
00:04:30,570 --> 00:04:34,140
which is about the same
as we found with 802.11 A.
75
00:04:34,474 --> 00:04:38,845
This data 2.11 G standard is backwards
compatible with the B standard.
76
00:04:39,012 --> 00:04:42,215
That means that we could upgrade
our access point to the 802.
77
00:04:42,215 --> 00:04:46,953
11 G, and still continue
to use our B devices on the same network.
78
00:04:47,387 --> 00:04:51,724
And although 2.11 G operates at higher
speeds, it still suffers
79
00:04:51,724 --> 00:04:56,029
from the same frequency conflicts
that we have with the hundred 2.11 B
80
00:04:56,195 --> 00:05:00,600
because all of these devices
will be using 2.4GHz frequencies.
81
00:05:01,768 --> 00:05:03,369
In 2009, a new
82
00:05:03,369 --> 00:05:07,440
standard was released
that effectively upgraded 802.11 A,
83
00:05:07,473 --> 00:05:12,345
B, and G to a new version of 802 11 N.
84
00:05:12,679 --> 00:05:16,482
As you probably noticed,
it can be confusing to keep track of all
85
00:05:16,482 --> 00:05:18,751
of these different letters and numbers.
86
00:05:18,751 --> 00:05:24,290
So instead of using
the standard name of 802.11 A or 802.11 G,
87
00:05:24,390 --> 00:05:28,227
we're now referring to these standards
as Wi-Fi standards.
88
00:05:28,394 --> 00:05:33,066
So 802 11 in
can also be called Wi-Fi four.
89
00:05:33,299 --> 00:05:38,338
Technically speaking, 802.11
A, B, and G could also be called Wi-Fi
90
00:05:38,338 --> 00:05:39,672
one, two, or three,
91
00:05:39,672 --> 00:05:44,177
but because those standards are so old
and indeed difficult to find implemented
92
00:05:44,177 --> 00:05:48,014
on anyone's networks
these days, we are starting with Wi-Fi
93
00:05:48,014 --> 00:05:51,017
four as the standards
for this numbering scheme.
94
00:05:51,451 --> 00:05:54,721
Because 802.11 N, or Wi-Fi four,
95
00:05:54,721 --> 00:05:57,724
is designed to upgrade 802.11 A,
96
00:05:57,757 --> 00:06:02,595
B, and G, this standard is able to operate
at both five gigahertz
97
00:06:02,829 --> 00:06:07,800
and 2.4GHz simultaneously,
if your access point supports that.
98
00:06:08,067 --> 00:06:11,337
We also have more bandwidth available
for each individual channel.
99
00:06:11,337 --> 00:06:13,940
We can have up to 40MHz channel widths.
100
00:06:13,940 --> 00:06:15,575
And what this really means is we're able
101
00:06:15,575 --> 00:06:19,545
to transfer much more data
at the same time over this network.
102
00:06:19,979 --> 00:06:22,815
If you do have a wireless access point
that's able to use
103
00:06:22,815 --> 00:06:26,486
those 40MHz channel widths
and it has four antennas on it,
104
00:06:26,586 --> 00:06:30,289
you can get a maximum
theoretical throughput from 2.11
105
00:06:30,289 --> 00:06:33,292
N of 600mbps,
106
00:06:33,393 --> 00:06:38,531
which is obviously a large improvement
over a 2.11 A, B, or G.
107
00:06:39,165 --> 00:06:43,703
The Sata 2.11 N standard also introduced
a new form of communication
108
00:06:43,703 --> 00:06:49,142
for wireless networks called Mimo,
or multiple input multiple output.
109
00:06:49,342 --> 00:06:52,412
This means the devices
can transfer much more information
110
00:06:52,412 --> 00:06:56,282
simultaneously between the end
station and the access point.
111
00:06:57,350 --> 00:06:59,218
In January of 2014, we
112
00:06:59,218 --> 00:07:04,223
introduced 802.11 AC,
which we now refer to as Wi-Fi five,
113
00:07:04,524 --> 00:07:09,128
and this was another improvement
over the previous standard of radio 2.11.
114
00:07:09,128 --> 00:07:13,533
In Wi-Fi five operates
exclusively in the five gigahertz range,
115
00:07:13,566 --> 00:07:20,072
so unlike 802.11 in, there is no 2.4GHz
available in Wi-Fi five.
116
00:07:20,306 --> 00:07:24,343
We can also use much more of that wireless
spectrum simultaneously,
117
00:07:24,343 --> 00:07:29,982
because 2.11 AC will support up
to 160MHz of a channel bandwidth.
118
00:07:30,550 --> 00:07:34,153
This translates into more channels
that can be used simultaneously,
119
00:07:34,153 --> 00:07:35,488
and therefore more data
120
00:07:35,488 --> 00:07:38,958
that can be transferred over
that wireless network simultaneously.
121
00:07:39,192 --> 00:07:42,795
This standard also changes
how information is transferred over
122
00:07:42,795 --> 00:07:43,830
that wireless network.
123
00:07:43,830 --> 00:07:47,633
We refer to this as signaling modulation,
and this also increased
124
00:07:47,633 --> 00:07:51,404
the amount of data that was able
to be transferred at any particular time.
125
00:07:51,871 --> 00:07:57,543
This newer 2.11 AC standard not only uses
multiple input multiple output,
126
00:07:57,777 --> 00:08:03,216
but increases the capabilities
of that Mimo by adding multi-user Mimo
127
00:08:03,349 --> 00:08:06,586
so multiple users
could be communicating over
128
00:08:06,586 --> 00:08:10,022
multiple input and multiple outputs
simultaneously.
129
00:08:10,289 --> 00:08:14,460
This standard supports up
to eight of those multi-user Mimo streams,
130
00:08:14,460 --> 00:08:18,331
which translates into a maximum total
throughput of nearly
131
00:08:18,331 --> 00:08:21,868
seven gigabits
per second for Android 2.11 AC.
132
00:08:22,502 --> 00:08:27,473
We mentioned earlier that 802.11 AC
operates only in the five gigahertz band,
133
00:08:27,640 --> 00:08:30,776
but if you look at access points
that may be available to buy,
134
00:08:30,877 --> 00:08:35,281
you'll see some of them say
that they are 802.11 AC access points
135
00:08:35,481 --> 00:08:39,218
that operate at five gigahertz and 2.4GHz.
136
00:08:39,452 --> 00:08:43,289
In those cases, the communication
that's occurring at 2.4GHz
137
00:08:43,456 --> 00:08:46,792
is actually using the 802.11 N standard,
138
00:08:46,959 --> 00:08:50,363
and anything at five
gigahertz is using the AC standard.
139
00:08:51,531 --> 00:08:53,199
The upgrade to 802.11
140
00:08:53,199 --> 00:08:57,003
AC arrived in February of 2021
with the 802.
141
00:08:57,003 --> 00:09:01,207
11 a X standard,
or what we call the Wi-Fi six standard.
142
00:09:01,541 --> 00:09:06,479
This is a standard that operates at either
five gigahertz frequencies or 2.4GHz
143
00:09:06,479 --> 00:09:10,816
frequencies, and on some access points
can use both of those simultaneously.
144
00:09:11,017 --> 00:09:14,787
The standard also supports many different
channel widths, so we can have bandwidths
145
00:09:14,787 --> 00:09:18,624
of 20, 40, 80 and 160MHz
146
00:09:18,658 --> 00:09:21,661
for people
communicating on that wireless network.
147
00:09:21,894 --> 00:09:26,198
If we look at the standards
for 8 to 11 acts, we can get a total
148
00:09:26,198 --> 00:09:30,436
throughput per channel
of about 1.2 gigabits per second.
149
00:09:30,736 --> 00:09:33,873
This is a relatively small increase
in throughput when you compare it
150
00:09:33,873 --> 00:09:37,043
to other improvements in the standards
through the years,
151
00:09:37,243 --> 00:09:41,314
but there is a difference in how
this particular version was designed.
152
00:09:41,514 --> 00:09:45,851
8.2. 11 Ax was designed to solve
some of the problems we have with
153
00:09:45,885 --> 00:09:49,922
using these wireless networks in areas
where there are a large number of people.
154
00:09:50,022 --> 00:09:54,327
So if you're at a sporting event
or a trade show, you may find it difficult
155
00:09:54,327 --> 00:09:57,330
sometimes to communicate
over these wireless networks.
156
00:09:57,363 --> 00:10:01,067
With radio 2.11 Ax,
we introduced a new form of communicating
157
00:10:01,067 --> 00:10:06,339
called orthogonal Frequency
Division, Multiple Access, or OFDM.
158
00:10:06,339 --> 00:10:10,242
A this takes a type of communication
that we've used for some time
159
00:10:10,242 --> 00:10:14,747
on our cellular networks,
and brings it into the world of 802.11.
160
00:10:14,914 --> 00:10:18,217
This allows us to put 811
networks in places
161
00:10:18,217 --> 00:10:22,088
with large numbers of people,
and be able to communicate without a huge
162
00:10:22,088 --> 00:10:25,091
loss in efficiency
over those wireless networks.
163
00:10:25,858 --> 00:10:28,527
So here's
the summary of these different standards.
164
00:10:28,527 --> 00:10:33,265
2.11 A operated on five gigahertz
frequencies and did not have Mimo support.
165
00:10:33,532 --> 00:10:38,004
Its maximum theoretical throughput
per stream was 54mbps.
166
00:10:38,004 --> 00:10:39,372
And in the case of 802.
167
00:10:39,372 --> 00:10:42,241
11 A, we only had one stream to work with.
168
00:10:42,241 --> 00:10:45,878
So with a maximum throughput up 54mbps,
169
00:10:46,278 --> 00:10:49,615
82.11 b operated in the 2.4GHz range,
170
00:10:49,782 --> 00:10:54,086
and it operated at a maximum
throughput at 11mbps.
171
00:10:54,387 --> 00:10:57,156
As the upgrade to 802.11 B
172
00:10:57,156 --> 00:11:00,893
hundred 2.11 G also operated at 2.4GHz
173
00:11:01,027 --> 00:11:04,530
and had a maximum throughput of 54mbps.
174
00:11:04,897 --> 00:11:06,298
If you run into an 802.
175
00:11:06,298 --> 00:11:11,570
11 inch network, you can operate at either
5 or 2.4 gigahertz frequency ranges,
176
00:11:11,837 --> 00:11:16,742
and can use up to four separate streams
of multiple input and multiple output.
177
00:11:17,009 --> 00:11:21,647
This gives us a total
throughput per stream of 150mbps,
178
00:11:21,814 --> 00:11:25,551
or a maximum throughput of 600mbps.
179
00:11:25,584 --> 00:11:30,556
Overall, 802.11
AC is a five gigahertz technology only.
180
00:11:30,556 --> 00:11:34,393
It supports eight downloadable
streams of multi-user, multi-room
181
00:11:34,393 --> 00:11:40,833
input multi-output at 867mbps
for each stream, making a total
182
00:11:40,833 --> 00:11:46,806
theoretical throughput maximum of 6.9
gigabits per second and 802.
183
00:11:46,806 --> 00:11:51,444
11 access operates
at both five gigahertz and 2.4GHz.
184
00:11:51,777 --> 00:11:56,582
It also supports eight streams,
but the multi-user Mimo in Ax supports
185
00:11:56,582 --> 00:12:00,152
eight download and upload streams
simultaneously.
186
00:12:00,352 --> 00:12:04,957
That gives us a maximum theoretical
throughput per stream of 1.2 gigabits
187
00:12:04,957 --> 00:12:08,894
per second, and a maximum theoretical
throughput of all streams
188
00:12:09,061 --> 00:12:11,597
at 9.6 gigabits per second.
189
00:12:12,865 --> 00:12:13,132
If you
190
00:12:13,132 --> 00:12:16,402
purchase an access point,
bring it home and plug it in.
191
00:12:16,535 --> 00:12:20,206
You'll probably get a range of
about 40 to 50m.
192
00:12:20,206 --> 00:12:22,775
If you're using the built in antennas.
193
00:12:22,775 --> 00:12:24,577
If you're working
in a corporate environment
194
00:12:24,577 --> 00:12:27,980
and you want to connect to buildings
together with radio 2.11,
195
00:12:28,114 --> 00:12:31,484
then obviously that type of antenna
is not going to work.
196
00:12:31,684 --> 00:12:34,553
Instead, you'll need
some fixed directional antennas,
197
00:12:34,553 --> 00:12:38,591
and you may need to increase
the overall signal strength of the 802.
198
00:12:38,591 --> 00:12:39,959
11 signal.
199
00:12:39,959 --> 00:12:41,560
In our offices and homes,
200
00:12:41,560 --> 00:12:46,332
we have signals that might be bouncing
or be absorbed by the things around us.
201
00:12:46,532 --> 00:12:49,635
When we're sending a signal
between buildings, there's usually not
202
00:12:49,635 --> 00:12:53,239
much in the way that would cause
the signal to bounce or be absorbed.
203
00:12:53,439 --> 00:12:57,076
We would use very directional antennas
like this Yagi antenna,
204
00:12:57,276 --> 00:13:00,846
to be able to have a very focused point
to point connection
205
00:13:00,846 --> 00:13:05,017
between an antenna on one building
and the antenna on the other building.
206
00:13:05,985 --> 00:13:09,021
If you're planning to set up a long range
fixed wireless network,
207
00:13:09,054 --> 00:13:12,691
make sure you look at the rules
and regulations in your area.
208
00:13:12,958 --> 00:13:15,294
Wireless networks
have their own complexities
209
00:13:15,294 --> 00:13:18,364
associated with them,
and when you layer on local
210
00:13:18,364 --> 00:13:22,201
and federal rules and regulations
regarding wireless communication,
211
00:13:22,434 --> 00:13:26,005
it provides some additional challenges
to the implementation.
212
00:13:26,372 --> 00:13:30,442
If you're using a wireless service
that's transmitting to your home,
213
00:13:30,442 --> 00:13:34,013
or you're trying to connect different
wireless services between buildings,
214
00:13:34,146 --> 00:13:37,316
you may want to look to see
what frequencies are available to use.
215
00:13:37,516 --> 00:13:40,653
You may have 2.4 and five gigahertz
frequencies available
216
00:13:40,653 --> 00:13:44,123
natively in the standard,
but there may be other frequencies
217
00:13:44,123 --> 00:13:48,060
available that you can apply for,
which might provide you some advantages
218
00:13:48,060 --> 00:13:52,865
over using the busier 2.4GHz
or five gigahertz frequencies.
219
00:13:53,098 --> 00:13:57,102
You'll need to check with the 82.11
standards, and see what options
220
00:13:57,102 --> 00:14:00,105
might be available for the type of network
that you're installing.
221
00:14:00,739 --> 00:14:04,210
Not only are there rules and regulations
about what frequencies you can use
222
00:14:04,210 --> 00:14:05,644
and where you can use them,
223
00:14:05,644 --> 00:14:09,481
there are also regulations
about how much of this signal can be sent.
224
00:14:09,715 --> 00:14:12,151
There are different regulations
on whether these signals
225
00:14:12,151 --> 00:14:15,221
will be inside of the building
or outside of a building. So
226
00:14:15,221 --> 00:14:18,691
make sure you know all of the differences
when you're installing the network.
227
00:14:19,258 --> 00:14:22,161
And ultimately,
you'll need to install an antenna outside.
228
00:14:22,161 --> 00:14:24,830
If you're receiving a signal
from a service provider
229
00:14:24,830 --> 00:14:27,099
or you connecting two buildings together.
230
00:14:27,099 --> 00:14:31,136
Installing antennas outside
have their own set of safety requirements,
231
00:14:31,136 --> 00:14:35,541
not only in where you install the antenna,
and that it's not near any power source,
232
00:14:35,708 --> 00:14:38,711
but you'll also have to make sure
that the antenna is protected.
233
00:14:38,777 --> 00:14:41,247
Case. It happens to be hit by lightning.
234
00:14:41,247 --> 00:14:44,583
In many cases, it might make more sense
to bring in a third party who has
235
00:14:44,583 --> 00:14:48,921
an expertise in installing these types of
external or outdoor networks.
236
00:14:50,189 --> 00:14:52,458
Another
wireless technology that's widely used
237
00:14:52,458 --> 00:14:56,195
is RFID or radio frequency identification.
238
00:14:56,462 --> 00:14:59,231
If you have an access badge
that unlocks a door by holding it
239
00:14:59,231 --> 00:15:03,836
up to a sensor, it's
probably using RFID inside of that badge.
240
00:15:04,036 --> 00:15:05,371
If you're in manufacturing,
241
00:15:05,371 --> 00:15:08,474
you have an assembly line
or you need to keep track of inventory.
242
00:15:08,507 --> 00:15:13,479
Then you will extensively use RFID,
and we even use RFID at home
243
00:15:13,479 --> 00:15:14,847
to keep track of our pets.
244
00:15:14,847 --> 00:15:18,450
So if we happen to lose that pet,
they can easily be scanned
245
00:15:18,651 --> 00:15:22,021
and that identification information
will be tied back to you
246
00:15:22,054 --> 00:15:24,256
so that your pet can be returned.
247
00:15:24,256 --> 00:15:26,792
This is one type of RFID tag you can see.
248
00:15:26,792 --> 00:15:28,694
This one is designed to be cylindrical,
249
00:15:28,694 --> 00:15:32,498
and you can see how small it is
because it's next to this grain of rice.
250
00:15:32,965 --> 00:15:33,999
If you have an RFID
251
00:15:33,999 --> 00:15:37,970
tag inside of your access badge,
and it's probably a flat one like this,
252
00:15:37,970 --> 00:15:42,041
where the antennas around the outside
and the RFID chip is right in the middle.
253
00:15:42,775 --> 00:15:43,309
As you can see
254
00:15:43,309 --> 00:15:47,479
in these pictures, there's often
no battery inside of these RFID tags.
255
00:15:47,680 --> 00:15:50,249
Instead, this uses radar technology.
256
00:15:50,249 --> 00:15:53,585
As we send signals out,
that signal is being captured
257
00:15:53,585 --> 00:15:57,656
by the antenna that is converted to power,
added to the chip
258
00:15:57,690 --> 00:16:01,427
that effectively powers
and allows this device to transmit back.
259
00:16:01,860 --> 00:16:04,797
Although this is one way to communicate
via RFID,
260
00:16:04,797 --> 00:16:07,800
there are other RFID tags
that do have a power source.
261
00:16:07,900 --> 00:16:11,103
We refer to those
as active or powered RFID.
262
00:16:12,338 --> 00:16:13,439
We've extended the
263
00:16:13,439 --> 00:16:16,642
use of RFID into our mobile phones
264
00:16:16,642 --> 00:16:20,012
and our smartwatches
through the use of NFC.
265
00:16:20,212 --> 00:16:24,383
This is near field communication,
and it's a way for our mobile devices
266
00:16:24,383 --> 00:16:28,620
to be able to have two way conversations
with other devices that we might use.
267
00:16:28,921 --> 00:16:32,925
For example, we might be checking out
at a store and we can use our phone
268
00:16:32,925 --> 00:16:37,997
or our smartwatch to pay for those goods
because we've associated our credit card
269
00:16:37,997 --> 00:16:41,266
with the NFC technology
that's in our devices.
270
00:16:41,800 --> 00:16:46,005
You might also see NFC used
if you need to pair to Bluetooth devices.
271
00:16:46,238 --> 00:16:49,441
And because we often carry our phones
and our smartwatches with us,
272
00:16:49,608 --> 00:16:53,112
we can use NFC to act as an access card
273
00:16:53,278 --> 00:16:57,449
so that we can use our phone to unlock
a door instead of a separate card.
26052
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.