WEBVTT 1 00:00.000 --> 00:05.000 When it comes to wireless communications, we can have all kinds of different 2 00:05.000 --> 00:05.840 wireless devices 3 00:05.840 --> 00:08.600 out there that have nothing to do with networking. 4 00:08.600 --> 00:11.840 For example, we might have wireless TV remotes. 5 00:11.840 --> 00:13.960 We have wireless video game controllers. 6 00:13.960 --> 00:18.470 We even have things like Bluetooth that maybe sounds like it's wireless 7 00:18.470 --> 00:19.520 networking, but 8 00:19.520 --> 00:23.360 yeah, it's for transmitting data, but all of these things transmit data. 9 00:23.360 --> 00:27.550 So when we're talking about actual wireless networking, we are going to use a 10 00:27.550 --> 00:28.200 phrase that 11 00:28.200 --> 00:31.360 we refer to as Wi-Fi. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 11 00:28.200 --> 00:31.360 we refer to as Wi-Fi. 12 00:31.360 --> 00:35.070 Wi-Fi, it looks like an abbreviation, but believe it or not, it stands for 13 00:35.070 --> 00:35.760 absolutely 14 00:35.760 --> 00:36.760 nothing. 15 00:36.760 --> 00:41.550 It was named in an era where we had this concept of audio called "hi-fi," which 16 00:41.550 --> 00:41.760 stood 17 00:41.760 --> 00:46.440 for "hi-fidelity," but when the organization now known as the Wi-Fi Alliance 18 00:46.440 --> 00:47.040 created this 19 00:47.040 --> 00:50.800 term, they didn't say, "Hey, it stands for wireless fidelity." 20 00:50.800 --> 00:54.900 They just wanted it to be a marketable term, and that's what they came up with, 21 00:54.900 --> 00:55.680 and it worked 22 00:55.680 --> 00:58.800 as what we all used today. 23 00:58.800 --> 01:05.000 Now the Wi-Fi Alliance builds the concept of Wi-Fi as a way of making a set of WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 23 00:58.800 --> 01:05.000 Now the Wi-Fi Alliance builds the concept of Wi-Fi as a way of making a set of 24 01:05.000 --> 01:05.920 standards 25 01:05.920 --> 01:07.680 for us to follow. 26 01:07.680 --> 01:10.560 So they do standards testing, for example. 27 01:10.560 --> 01:15.410 So if I have a Wi-Fi device, that means that I can communicate with other Wi-Fi 28 01:15.410 --> 01:16.400 devices. 29 01:16.400 --> 01:20.040 These days, we actually have numbers associated with it, for example. 30 01:20.040 --> 01:25.220 As of the moment of this recording, the most recent version of Wi-Fi is Wi-Fi 6 31 01:25.220 --> 01:26.000 , and kind 32 01:26.000 --> 01:31.500 of this Wi-Fi 6E, which gives us access to additional frequencies for WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 32 01:26.000 --> 01:31.500 of this Wi-Fi 6E, which gives us access to additional frequencies for 33 01:31.500 --> 01:33.040 communication. 34 01:33.040 --> 01:37.860 We also have Wi-Fi 4 and Wi-Fi 5 that came before it, and then we have old 35 01:37.860 --> 01:38.960 legacy versions 36 01:38.960 --> 01:40.560 of Wi-Fi as well. 37 01:40.560 --> 01:46.320 But either way, this Wi-Fi standards-based testing is not itself the definition 38 01:46.320 --> 01:46.720 of the 39 01:46.720 --> 01:47.720 technology. 40 01:47.720 --> 01:52.760 The definition of the technology is created by the IEEE, which creates our 41 01:52.760 --> 01:54.040 Ethernet standards, 42 01:54.040 --> 02:01.280 802.3 and all of these, and they created wireless Ethernet as the 802.11 spec. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 42 01:54.040 --> 02:01.280 802.3 and all of these, and they created wireless Ethernet as the 802.11 spec. 43 02:01.280 --> 02:06.760 And so we see 802.11 as the original definition of Wi-Fi networking, and then 44 02:06.760 --> 02:08.440 from there we see 45 02:08.440 --> 02:10.200 additional letters being added. 46 02:10.200 --> 02:19.140 For example, they had 802.11 A and 802.11 B and G and AC and AX, and all these 47 02:19.140 --> 02:20.120 letters and 48 02:20.120 --> 02:25.490 numbers combining together is why we really prefer to just use the term Wi-Fi 6 49 02:25.490 --> 02:26.880 , for example, 50 02:26.880 --> 02:28.880 or Wi-Fi 5. 51 02:28.880 --> 02:32.920 And when Wi-Fi 7 comes out, which is possibly out by the time you watch this, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 51 02:28.880 --> 02:32.920 And when Wi-Fi 7 comes out, which is possibly out by the time you watch this, 52 02:32.920 --> 02:33.560 it's going 53 02:33.560 --> 02:38.280 to be based on another 802.11 specification. 54 02:38.280 --> 02:44.250 Now any wireless communication is going to need to choose which frequencies 55 02:44.250 --> 02:45.160 that we're 56 02:45.160 --> 02:46.840 going to transmit on. 57 02:46.840 --> 02:52.360 So frequencies for transmission, which is usually abbreviated as TX like this, 58 02:52.360 --> 02:52.920 we're going 59 02:52.920 --> 02:56.480 to need to decide what frequencies to transmit on. 60 02:56.480 --> 03:00.610 For example, if I have an access point and I have a wireless device here, if WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 60 02:56.480 --> 03:00.610 For example, if I have an access point and I have a wireless device here, if 61 03:00.610 --> 03:01.480 one is speaking 62 03:01.480 --> 03:04.780 a really high frequency and one is speaking a very low frequency, they can't 63 03:04.780 --> 03:05.440 communicate 64 03:05.440 --> 03:06.720 with one another. 65 03:06.720 --> 03:11.630 They have to perfectly match the frequencies that they want to communicate on, 66 03:11.630 --> 03:12.400 otherwise 67 03:12.400 --> 03:16.160 they're not going to be able to hear the other person speak. 68 03:16.160 --> 03:18.880 And so we have to match those frequencies, we have to decide which frequencies 69 03:18.880 --> 03:19.160 we're 70 03:19.160 --> 03:20.160 going to use. 71 03:20.160 --> 03:25.190 And again, every wireless form of communication gets to choose which 72 03:25.190 --> 03:26.800 frequencies to use, and 73 03:26.800 --> 03:29.600 there are many that are available to choose from. 74 03:29.600 --> 03:35.800 From a Wi-Fi perspective, we have three primary bands that are a range or a WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 74 03:29.600 --> 03:35.800 From a Wi-Fi perspective, we have three primary bands that are a range or a 75 03:35.800 --> 03:38.160 collection of frequencies. 76 03:38.160 --> 03:44.840 We have the 2.4 GHz band, and so these are our bands that we're listing out 77 03:44.840 --> 03:45.240 here. 78 03:45.240 --> 03:47.360 We have the 2.4 GHz band. 79 03:47.360 --> 03:53.910 We have the 5 GHz band, actually let's write it down here, 5 GHz, and we have 80 03:53.910 --> 03:55.360 the 6 GHz 81 03:55.360 --> 03:56.360 band. 82 03:56.360 --> 04:01.300 This is brand new, when I mentioned Wi-Fi 6E, that is the first time we ever WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 82 03:56.360 --> 04:01.300 This is brand new, when I mentioned Wi-Fi 6E, that is the first time we ever 83 04:01.300 --> 04:02.120 had access 84 04:02.120 --> 04:04.840 to the 6 GHz band. 85 04:04.840 --> 04:10.310 Now the 2.4 GHz band, this was the original band, it was very, very small and 86 04:10.310 --> 04:11.160 didn't give 87 04:11.160 --> 04:13.960 us many frequencies to be able to use. 88 04:13.960 --> 04:20.550 The 5 GHz band expanded on this, so we have lots of bands, but it's also very 89 04:20.550 --> 04:21.280 busy, it's 90 04:21.280 --> 04:25.300 borrowing a lot of frequencies that are supposed to be reserved for other 91 04:25.300 --> 04:26.080 purposes. 92 04:26.080 --> 04:31.560 And so it can be a little bit complicated as far as which channels we can use, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 92 04:26.080 --> 04:31.560 And so it can be a little bit complicated as far as which channels we can use, 93 04:31.560 --> 04:32.400 and that's 94 04:32.400 --> 04:34.640 going to vary by region. 95 04:34.640 --> 04:42.110 The 6 GHz is not only lots, and I mean lots of frequency real estate, but it 96 04:42.110 --> 04:43.320 also is very 97 04:43.320 --> 04:44.320 free. 98 04:44.320 --> 04:49.090 It had been reserved, nothing else had been using it before Wi-Fi was allowed 99 04:49.090 --> 04:49.800 to use this 100 04:49.800 --> 04:50.800 space. 101 04:50.800 --> 04:54.510 And so yes, we do have to decide, and this happens on a per country and per 102 04:54.510 --> 04:56.040 region basis, 103 04:56.040 --> 05:01.510 but ultimately when frequencies are opened up for use, that means that we can WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 103 04:56.040 --> 05:01.510 but ultimately when frequencies are opened up for use, that means that we can 104 05:01.510 --> 05:02.320 now use them 105 05:02.320 --> 05:05.640 and otherwise they're typically reserved. 106 05:05.640 --> 05:10.220 In fact, because 2.4 GHz was one of the very first sets of frequencies that was 107 05:10.220 --> 05:10.720 opened 108 05:10.720 --> 05:15.690 up, when I say that it was the original frequency, that's great, but it was 109 05:15.690 --> 05:16.840 also very, very 110 05:16.840 --> 05:18.160 busy. 111 05:18.160 --> 05:24.790 Lots and lots of devices out there that are non-Wi-Fi, meaning microwaves and 112 05:24.790 --> 05:25.600 what I said 113 05:25.600 --> 05:30.000 about earlier about wireless TV remotes and wireless video game controllers, a WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 114 05:30.000 --> 05:30.600 lot of those 115 05:30.600 --> 05:36.160 will use 2.4 GHz because hey, it was around back then. 116 05:36.160 --> 05:39.360 And so that's going to make it a lot more difficult for Wi-Fi to coexist with 117 05:39.360 --> 05:40.080 those types of 118 05:40.080 --> 05:42.080 devices. 119 05:42.080 --> 05:47.520 Now we can start to think of frequencies as sort of this wireless real estate. 120 05:47.520 --> 05:51.910 I really like to think of it this way, because if I, for example, want to build 121 05:51.910 --> 05:52.880 a home, 122 05:52.880 --> 05:57.880 I might have 3 different plots of land that are available. 123 05:57.880 --> 06:01.240 And I might go out and say, "Hey, I want this plot of land. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 123 05:57.880 --> 06:01.240 And I might go out and say, "Hey, I want this plot of land. 124 06:01.240 --> 06:02.800 I want to use this plot of land." 125 06:02.800 --> 06:03.800 Except guess what? 126 06:03.800 --> 06:07.730 Somebody already has a house on that lot, meaning that that's already been 127 06:07.730 --> 06:08.440 claimed. 128 06:08.440 --> 06:13.320 I can't build a house on that same plot of land. 129 06:13.320 --> 06:16.760 So I can't actually use that, but I could use one of these two. 130 06:16.760 --> 06:20.320 And so I go out and I choose this and I build my house here. 131 06:20.320 --> 06:24.870 And if somebody else shows up in the same space and wants to build a house 132 06:24.870 --> 06:26.000 right here, well, 133 06:26.000 --> 06:30.080 they're going to have to choose the last available spot. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 133 06:26.000 --> 06:30.080 they're going to have to choose the last available spot. 134 06:30.080 --> 06:32.360 And so they will have to build over here. 135 06:32.360 --> 06:33.920 Well, frequencies the same way. 136 06:33.920 --> 06:39.800 If I have 3 devices all here trying to communicate with maybe another device up 137 06:39.800 --> 06:40.560 here on their 138 06:40.560 --> 06:44.560 own, you know, that is all in the same physical space. 139 06:44.560 --> 06:46.200 Maybe these are all in the same room. 140 06:46.200 --> 06:51.080 Well, I might choose one frequency. 141 06:51.080 --> 06:53.200 Let's just call it frequency one here to communicate up to this device. 142 06:53.200 --> 06:57.660 Well, when this one shows up or these two show up to communicate, if they try 143 06:57.660 --> 06:58.600 to communicate 144 06:58.600 --> 07:02.720 on the same frequency, it's going to cause a lot of problems. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 144 06:58.600 --> 07:02.720 on the same frequency, it's going to cause a lot of problems. 145 07:02.720 --> 07:06.160 And that's a Roman numeral one, by the way, not a capital I. 146 07:06.160 --> 07:07.840 I'm trying to count here. 147 07:07.840 --> 07:10.800 So frequency one is already claimed. 148 07:10.800 --> 07:14.200 So I'm going to have to use frequency two. 149 07:14.200 --> 07:16.320 And that's going to have to be a different frequency. 150 07:16.320 --> 07:19.920 Maybe it's a much lower frequency than frequency one. 151 07:19.920 --> 07:23.440 And then same thing over here when this set shows up, if they want to be able 152 07:23.440 --> 07:24.240 to communicate 153 07:24.240 --> 07:27.090 freely with one another, they're going to have to choose another frequency, 154 07:27.090 --> 07:27.640 which maybe 155 07:27.640 --> 07:31.520 is a much higher frequency communication. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 155 07:27.640 --> 07:31.520 is a much higher frequency communication. 156 07:31.520 --> 07:36.710 In one physical area, once a frequency has been claimed, we really have to be 157 07:36.710 --> 07:37.280 careful 158 07:37.280 --> 07:40.400 about trying to use or share that. 159 07:40.400 --> 07:44.680 It's usually best if we just find a new frequency that we can use because again 160 07:44.680 --> 07:46.040 , each frequency 161 07:46.040 --> 07:49.920 is itself the concept of real estate. 162 07:49.920 --> 07:54.440 Now we can expand this further to look at the fact that when we're 163 07:54.440 --> 07:56.160 communicating, when 164 07:56.160 --> 08:02.070 I do a transmission and a reception, I could use a single frequency if I wanted WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 164 07:56.160 --> 08:02.070 I do a transmission and a reception, I could use a single frequency if I wanted 165 08:02.070 --> 08:02.640 to. 166 08:02.640 --> 08:08.130 I could communicate between these two devices, pick one frequency and just 167 08:08.130 --> 08:09.240 transmit all of 168 08:09.240 --> 08:12.040 my information on the one frequency. 169 08:12.040 --> 08:15.680 The problem is that there's usually other devices around that are communicating 170 08:15.680 --> 08:16.760 what happens 171 08:16.760 --> 08:19.920 if these two devices are using the exact same frequency. 172 08:19.920 --> 08:25.070 Well, as we're going to explore later, if we have the same frequency in the 173 08:25.070 --> 08:26.000 same space, 174 08:26.000 --> 08:27.840 this is going to cause problems. 175 08:27.840 --> 08:31.600 This is called wireless interference. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 175 08:27.840 --> 08:31.600 This is called wireless interference. 176 08:31.600 --> 08:37.450 And we've all, as engineers in the networking space, probably talked about or 177 08:37.450 --> 08:38.800 heard of wireless 178 08:38.800 --> 08:39.800 interference. 179 08:39.800 --> 08:43.710 A lot of us have experienced it, sometimes even in our own houses, that we have 180 08:43.710 --> 08:44.240 wireless 181 08:44.240 --> 08:48.480 devices interfering with one another, and that's the same concept. 182 08:48.480 --> 08:55.440 So usually, instead of saying, "Hey, we're going to use a single frequency," we 183 08:55.440 --> 08:56.640 want to 184 08:56.640 --> 08:59.960 use instead many frequencies. 185 08:59.960 --> 09:01.920 So we're not going to use a single frequency. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 185 08:59.960 --> 09:01.920 So we're not going to use a single frequency. 186 09:01.920 --> 09:05.280 We're actually going to use many frequencies at once and spread our 187 09:05.280 --> 09:07.280 communications across 188 09:07.280 --> 09:08.720 those different frequencies. 189 09:08.720 --> 09:12.730 So if I have a device here and a device here, I'm going to send one signal that 190 09:12.730 --> 09:13.440 uses a very 191 09:13.440 --> 09:18.370 high frequency, one signal that uses a lower frequency, another one that uses a 192 09:18.370 --> 09:18.920 very low 193 09:18.920 --> 09:20.640 frequency. 194 09:20.640 --> 09:28.150 And because of wireless techniques like OFDM or DSSS, lots of these techniques 195 09:28.150 --> 09:29.200 exist, I 196 09:29.200 --> 09:34.200 can actually send all of these at once. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 196 09:29.200 --> 09:34.200 can actually send all of these at once. 197 09:34.200 --> 09:37.600 And then this wireless device that receives this will split the signals back 198 09:37.600 --> 09:38.280 out and say, 199 09:38.280 --> 09:43.220 "Okay, this signal represented a zero one, this signal represented a zero zero, 200 09:43.220 --> 09:43.640 and this 201 09:43.640 --> 09:49.050 one represented a, well, not a zero zero, but a one one or something like that, 202 09:49.050 --> 09:49.240 and then 203 09:49.240 --> 09:54.840 I can combine this into the data that you had sent to me." 204 09:54.840 --> 09:59.920 Meanwhile, if I hit some level of interference in here, that took out, let's 205 09:59.920 --> 10:01.320 say this middle WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 205 09:59.920 --> 10:01.320 say this middle 206 10:01.320 --> 10:02.320 one. 207 10:02.320 --> 10:06.240 Well, now I don't have the zero zero, but usually I can use some wireless 208 10:06.240 --> 10:07.120 techniques to 209 10:07.120 --> 10:10.240 sort of reestablish what was sent there. 210 10:10.240 --> 10:14.040 Again, much deeper into the wireless world than we have time to get into and 211 10:14.040 --> 10:14.720 well beyond 212 10:14.720 --> 10:20.100 the scope of this course, but at the same time, understand that we can actually 213 10:20.100 --> 10:20.680 repair 214 10:20.680 --> 10:26.220 the information, and this is why we spread our communications across multiple 215 10:26.220 --> 10:27.200 frequencies 216 10:27.200 --> 10:30.460 is to ensure that if we have a little bit of interference, that we don't lose WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 216 10:27.200 --> 10:30.460 is to ensure that if we have a little bit of interference, that we don't lose 217 10:30.460 --> 10:31.200 the entire 218 10:31.200 --> 10:33.440 signal. 219 10:33.440 --> 10:38.600 So this is where the concept of channels come into play. 220 10:38.600 --> 10:43.160 A channel is a range of frequencies. 221 10:43.160 --> 10:52.880 So essentially, I'm going to take my band, let's say this is the 2.4 GHz band, 222 10:52.880 --> 10:53.360 and I can 223 10:53.360 --> 10:55.800 draw out this frequency range. 224 10:55.800 --> 11:04.640 This frequency range starts at about 2.4 GHz and ends at about 2.5 GHz. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 224 10:55.800 --> 11:04.640 This frequency range starts at about 2.4 GHz and ends at about 2.5 GHz. 225 11:04.640 --> 11:09.040 In the middle here, we have these channels, and the channel is itself a range. 226 11:09.040 --> 11:14.600 For example, this group of channels here is part of channel one. 227 11:14.600 --> 11:19.120 And then we have another group of channels here, or group of frequencies called 228 11:19.120 --> 11:19.520 channel 229 11:19.520 --> 11:20.520 two. 230 11:20.520 --> 11:23.470 And you might notice, well, wait a second, they overlap all of these 231 11:23.470 --> 11:24.840 frequencies in here, 232 11:24.840 --> 11:26.680 and that is actually true. 233 11:26.680 --> 11:30.390 So we probably are going to want to look at whatever channel, if I say, well, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 233 11:26.680 --> 11:30.390 So we probably are going to want to look at whatever channel, if I say, well, 234 11:30.390 --> 11:31.200 this is channel 235 11:31.200 --> 11:33.640 three, and this is channel four. 236 11:33.640 --> 11:40.990 Eventually, we're going to get to a channel that starts here and ends over here 237 11:40.990 --> 11:41.320 . 238 11:41.320 --> 11:44.720 And in the 2.4 GHz space, that would be channel six. 239 11:44.720 --> 11:51.120 And the last channel over here is channel 11, giving us in the 2.4 GHz space, 240 11:51.120 --> 11:53.680 three non-overlapping 241 11:53.680 --> 11:58.560 channels. 242 11:58.560 --> 12:01.810 And as you might imagine, these non-overlapping channels are going to be the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 242 11:58.560 --> 12:01.810 And as you might imagine, these non-overlapping channels are going to be the 243 12:01.810 --> 12:02.600 ones that we want 244 12:02.600 --> 12:08.440 to use for wireless communications, because if I put a wireless communicator 245 12:08.440 --> 12:09.960 here, and, 246 12:09.960 --> 12:13.420 you know, maybe two devices like this and two devices like this, and they're in 247 12:13.420 --> 12:13.880 the same 248 12:13.880 --> 12:18.380 physical space, and I'm on channel one here and channel two here, there's a lot 249 12:18.380 --> 12:19.320 of overlap 250 12:19.320 --> 12:22.080 of these individual signals in here. 251 12:22.080 --> 12:24.830 And as a result, there's going to be a lot of interference when they're trying 252 12:24.830 --> 12:25.480 to communicate 253 12:25.480 --> 12:26.880 with one another. 254 12:26.880 --> 12:30.200 So we like to choose the non-overlapping channels. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 254 12:26.880 --> 12:30.200 So we like to choose the non-overlapping channels. 255 12:30.200 --> 12:34.160 Now each one of these channels represents roughly 20 MHz. 256 12:34.160 --> 12:41.560 And I say roughly because 2.4 GHz bands a little weird, it uses 22 MHz. 257 12:41.560 --> 12:43.200 The other bands use 20. 258 12:43.200 --> 12:48.560 And so just from an estimate perspective, it's about a 20 MHz channel. 259 12:48.560 --> 12:53.840 And as we see here, if we do some math 2.4 to 2.5 GHz gives us about 100 MHz, 260 12:53.840 --> 12:54.560 we don't 261 12:54.560 --> 12:56.560 get all of that space. 262 12:56.560 --> 13:01.760 And so, you know, out of the 100 is actually a significant chunk of that space. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 262 12:56.560 --> 13:01.760 And so, you know, out of the 100 is actually a significant chunk of that space. 263 13:01.760 --> 13:05.800 And so we actually end closer to 2480. 264 13:05.800 --> 13:09.920 We also have some, you know, channels that we can't use in there. 265 13:09.920 --> 13:14.320 And so for the most part, this is why we see that we've got three of these 20 M 266 13:14.320 --> 13:15.080 Hz channels. 267 13:15.080 --> 13:18.810 Again, there are 22 MHz in this space, which is where we lose some amount of 268 13:18.810 --> 13:19.680 that as well. 269 13:19.680 --> 13:24.430 If there are truly 20 MHz, maybe we could have squeezed a 5th non-overlapping 270 13:24.430 --> 13:25.240 in there. 271 13:25.240 --> 13:29.520 But this is why I again come back to this concept of real estate. 272 13:29.520 --> 13:34.070 These plots of land right here, I can kind of see them here with these channels WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 272 13:29.520 --> 13:34.070 These plots of land right here, I can kind of see them here with these channels 273 13:34.070 --> 13:34.320 . 274 13:34.320 --> 13:37.800 Each one of these channels is a plot of land. 275 13:37.800 --> 13:39.560 It's wireless real estate. 276 13:39.560 --> 13:44.740 If I deploy an access point here on channel 1, it's claiming all of channel 1 277 13:44.740 --> 13:45.520 in that same 278 13:45.520 --> 13:47.120 physical space. 279 13:47.120 --> 13:50.940 So I could deploy another access point here that communicates here, but look at 280 13:50.940 --> 13:51.360 all the 281 13:51.360 --> 13:52.360 overlap. 282 13:52.360 --> 13:58.130 Well, okay, so from a wireless perspective, I need to choose a channel that isn 283 13:58.130 --> 13:58.760 't going 284 13:58.760 --> 14:00.480 to cause interference. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 284 13:58.760 --> 14:00.480 to cause interference. 285 14:00.480 --> 14:05.040 And so maybe I'll choose channel 6 for this access point. 286 14:05.040 --> 14:08.430 I'm building my house on a completely different plot of land, even though I'm 287 14:08.430 --> 14:08.720 in the 288 14:08.720 --> 14:09.880 same physical space. 289 14:09.880 --> 14:13.690 So this is where the analogy breaks down because real estate is a physical 290 14:13.690 --> 14:14.760 concept, whereas 291 14:14.760 --> 14:20.060 this is a radio frequency concept that helps us describe what's happening in 292 14:20.060 --> 14:20.880 the same 293 14:20.880 --> 14:23.360 physical space. 294 14:23.360 --> 14:29.150 So as we see, we don't get a lot of these 20 MHz channels out of the 2.4 GHz 295 14:29.150 --> 14:29.560 band. 296 14:29.560 --> 14:33.400 What's going on with 5 GHz and 6 GHz? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 296 14:29.560 --> 14:33.400 What's going on with 5 GHz and 6 GHz? 297 14:33.400 --> 14:37.120 Well with 5 GHz, notice we don't have a point in here. 298 14:37.120 --> 14:40.720 We're not saying 5.1 GHz or anything like this. 299 14:40.720 --> 14:46.310 We have a lot of real estate inside of the 5 GHz space, but even that said, we 300 14:46.310 --> 14:47.000 don't get 301 14:47.000 --> 14:48.000 all of it. 302 14:48.000 --> 14:49.840 I mentioned there's a lot going on in there. 303 14:49.840 --> 14:55.650 We get roughly half of it, so we can estimate about 500 MHz of that that we get 304 14:55.650 --> 14:55.800 . 305 14:55.800 --> 15:01.490 And if we do some quick math there, 500 divided by the 20, and we get about 25 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 305 14:55.800 --> 15:01.490 And if we do some quick math there, 500 divided by the 20, and we get about 25 306 15:01.490 --> 15:02.160 channels. 307 15:02.160 --> 15:07.760 Which is way more than the 3 that we get with our 2.4 GHz space. 308 15:07.760 --> 15:12.330 And yet we say it's about 25 because depending on where you live in the world, 309 15:12.330 --> 15:13.200 maybe you'll 310 15:13.200 --> 15:16.920 get 25, maybe you'll get 20, maybe you'll get 16. 311 15:16.920 --> 15:20.920 It just depends on the regional authorities and which channels have been made 312 15:20.920 --> 15:21.520 available 313 15:21.520 --> 15:23.480 for Wi-Fi use. 314 15:23.480 --> 15:29.560 The 6 GHz space on the other hand is very large and relatively unused. 315 15:29.560 --> 15:37.800 And we actually get up to 59 of these 20 MHz channels inside of the 6 GHz space WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 315 15:29.560 --> 15:37.800 And we actually get up to 59 of these 20 MHz channels inside of the 6 GHz space 316 15:37.800 --> 15:38.240 . 317 15:38.240 --> 15:40.480 It's an absolutely massive space. 318 15:40.480 --> 15:46.240 It's like breaking new ground, discovering new land in the wireless world. 319 15:46.240 --> 15:51.420 And it's been absolutely huge what we're capable of doing with this 6 GHz space 320 15:51.420 --> 15:51.720 . 321 15:51.720 --> 15:55.600 It's just a matter of making sure our wireless devices can actually communicate 322 15:55.600 --> 15:56.760 at 6 GHz. 323 15:56.760 --> 16:01.340 For right now, most of our devices are going to be communicating either on 2.4 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 323 15:56.760 --> 16:01.340 For right now, most of our devices are going to be communicating either on 2.4 324 16:01.340 --> 16:03.200 GHz or 5 GHz. 325 16:03.200 --> 16:09.240 But as we see more and more devices adopting 6 GHz, we're going to have a lot 326 16:09.240 --> 16:10.440 more freedom 327 16:10.440 --> 16:13.780 to be able to deploy the wireless networks that we want because we're not 328 16:13.780 --> 16:14.720 limited as much 329 16:14.720 --> 16:16.200 by our channel space.