1 00:00:00,090 --> 00:00:00,923 In this lesson, 2 00:00:00,923 --> 00:00:03,120 we're going to cover wireless standards. 3 00:00:03,120 --> 00:00:04,560 Now, the wireless standards we use today 4 00:00:04,560 --> 00:00:06,720 for our Wi-Fi networks are actually codified 5 00:00:06,720 --> 00:00:10,350 in the 802.11 standard as set forth by the Institute 6 00:00:10,350 --> 00:00:14,700 of Electrical and Electronics Engineers, known as the IEEE. 7 00:00:14,700 --> 00:00:17,370 Now, the 802.11 standard defines the technology 8 00:00:17,370 --> 00:00:19,800 that we use for wireless local area network communications 9 00:00:19,800 --> 00:00:21,210 like Wi-Fi. 10 00:00:21,210 --> 00:00:23,250 Over the years, these standards have evolved 11 00:00:23,250 --> 00:00:24,180 to meet the growing needs 12 00:00:24,180 --> 00:00:26,220 for faster wireless data transfer speeds 13 00:00:26,220 --> 00:00:28,740 and for more reliable wireless networks. 14 00:00:28,740 --> 00:00:30,000 So in this lesson, 15 00:00:30,000 --> 00:00:33,030 we're going to take a look at the various 802.11 standards, 16 00:00:33,030 --> 00:00:36,150 like wireless a, wireless b, wireless g, 17 00:00:36,150 --> 00:00:39,990 wireless n, wireless ac, and wireless ax. 18 00:00:39,990 --> 00:00:42,090 Now, as we move through this lesson, I'm going to provide you 19 00:00:42,090 --> 00:00:44,190 with a lot of facts and figures about each 20 00:00:44,190 --> 00:00:46,020 of these different wireless standards. 21 00:00:46,020 --> 00:00:49,290 You need to memorize the standard's name such as wireless a, 22 00:00:49,290 --> 00:00:51,150 as well as the frequency band it utilizes, 23 00:00:51,150 --> 00:00:52,680 like 2.4 gigahertz, 24 00:00:52,680 --> 00:00:54,660 five gigahertz, or six gigahertz, 25 00:00:54,660 --> 00:00:57,090 as well as the maximum speed and the maximum distance 26 00:00:57,090 --> 00:01:00,120 or range for each of these different wireless standards. 27 00:01:00,120 --> 00:01:03,090 All right, with that said, let's go ahead and get started. 28 00:01:03,090 --> 00:01:05,280 Now, first, we have wireless a. 29 00:01:05,280 --> 00:01:08,190 Wireless a operates in the five gigahertz band at a speed 30 00:01:08,190 --> 00:01:10,740 of up to 54 megabits per second with a range 31 00:01:10,740 --> 00:01:12,660 of around 35 meters. 32 00:01:12,660 --> 00:01:16,560 Wireless a, or more formally the 802.11a standard 33 00:01:16,560 --> 00:01:18,180 required radios that were more expensive 34 00:01:18,180 --> 00:01:20,580 to build and manufacturer at the time they came out 35 00:01:20,580 --> 00:01:22,140 in the late 1990s, 36 00:01:22,140 --> 00:01:24,090 but it did give us a good amount of speed 37 00:01:24,090 --> 00:01:26,910 since they operate at 54 megabits per second. 38 00:01:26,910 --> 00:01:29,340 Unfortunately though wireless a was pretty expensive 39 00:01:29,340 --> 00:01:31,500 to procure and install, so only business users 40 00:01:31,500 --> 00:01:33,210 really ended up using it. 41 00:01:33,210 --> 00:01:35,490 Now, because wireless a wasn't gaining much traction 42 00:01:35,490 --> 00:01:37,440 in the retail markets due to its cost, 43 00:01:37,440 --> 00:01:39,510 manufacturers developed a new standard known 44 00:01:39,510 --> 00:01:42,510 as wireless b or 802.11b 45 00:01:42,510 --> 00:01:43,800 to create something that was cheaper 46 00:01:43,800 --> 00:01:45,630 and easier to manufacture. 47 00:01:45,630 --> 00:01:47,700 To accomplish this, wireless b moved 48 00:01:47,700 --> 00:01:49,620 into the 2.4 gigahertz band 49 00:01:49,620 --> 00:01:50,970 because those radios that worked 50 00:01:50,970 --> 00:01:53,430 within the 2.4 gigahertz band were much cheaper 51 00:01:53,430 --> 00:01:54,720 to manufacture than the ones 52 00:01:54,720 --> 00:01:57,270 that were supporting the five gigahertz band. 53 00:01:57,270 --> 00:01:59,940 In fact, the 2.4 gigahertz frequency band 54 00:01:59,940 --> 00:02:01,200 was already being commonly used 55 00:02:01,200 --> 00:02:03,600 by a lot of household devices that we use today, 56 00:02:03,600 --> 00:02:06,960 including security cameras, walkie-talkies, baby monitors, 57 00:02:06,960 --> 00:02:09,060 microwaves, and many others. 58 00:02:09,060 --> 00:02:12,150 This made the radios in the 802.11b wireless devices 59 00:02:12,150 --> 00:02:13,527 much cheaper and easier to get, 60 00:02:13,527 --> 00:02:17,040 and it led to widespread adoption of Wi-Fi throughout homes, 61 00:02:17,040 --> 00:02:18,900 businesses, and schools. 62 00:02:18,900 --> 00:02:20,610 Now, using this cheaper chip set 63 00:02:20,610 --> 00:02:22,110 and the way the frequencies work, 64 00:02:22,110 --> 00:02:24,510 this actually slowed down our networks all the way down 65 00:02:24,510 --> 00:02:26,460 to 11 megabits per second, 66 00:02:26,460 --> 00:02:28,980 which today sounds extremely slow, 67 00:02:28,980 --> 00:02:31,140 but all the way back in the late 1990s 68 00:02:31,140 --> 00:02:32,220 when this was released, 69 00:02:32,220 --> 00:02:33,840 this was actually still considered pretty fast 70 00:02:33,840 --> 00:02:35,310 for most home users. 71 00:02:35,310 --> 00:02:38,940 Wireless b supported a maximum range around 140 meters, 72 00:02:38,940 --> 00:02:41,730 which was significantly longer than the 35 meters provided 73 00:02:41,730 --> 00:02:43,530 by wireless a networks. 74 00:02:43,530 --> 00:02:46,530 Now, the third one we have is what's known as wireless g. 75 00:02:46,530 --> 00:02:49,860 Wireless g, also known as the 802.11g standard, 76 00:02:49,860 --> 00:02:52,380 operates in the 2.4 gigahertz band, 77 00:02:52,380 --> 00:02:55,770 but it can operate at speeds of up to 54 megabits per second 78 00:02:55,770 --> 00:02:58,410 and a range of about 140 meters. 79 00:02:58,410 --> 00:03:00,810 Basically, wireless g provided the same speed 80 00:03:00,810 --> 00:03:03,090 and distance as the more expensive wireless a, 81 00:03:03,090 --> 00:03:05,340 but it uses the same cheaper frequency band 82 00:03:05,340 --> 00:03:07,710 as the wireless b standard, which made it cheaper 83 00:03:07,710 --> 00:03:10,080 and easier to install for most users. 84 00:03:10,080 --> 00:03:12,090 Eventually, users demanded faster 85 00:03:12,090 --> 00:03:14,940 and faster wireless networking speeds as more smartphones 86 00:03:14,940 --> 00:03:16,530 and tablets were entering the market. 87 00:03:16,530 --> 00:03:19,410 So in response to that, a new standard was developed, 88 00:03:19,410 --> 00:03:21,750 and this brings us to the fourth wireless standard we have, 89 00:03:21,750 --> 00:03:25,020 which is known as wireless n, 802.11m, 90 00:03:25,020 --> 00:03:29,520 or Wi-Fi 4 since it was the fourth generation of Wi-Fi. 91 00:03:29,520 --> 00:03:30,870 Now, to reach these higher speeds 92 00:03:30,870 --> 00:03:33,030 that our users were demanding, the wireless networks 93 00:03:33,030 --> 00:03:35,790 had to switch back over to the five gigahertz band. 94 00:03:35,790 --> 00:03:37,710 By operating in the five gigahertz band, 95 00:03:37,710 --> 00:03:40,740 users could get speeds of up to 600 megabits per second 96 00:03:40,740 --> 00:03:43,590 and cover a distance of about 35 meters. 97 00:03:43,590 --> 00:03:45,600 Now, this allowed for really fast networks, 98 00:03:45,600 --> 00:03:48,270 but the problem was this newer five gigahertz spectrum 99 00:03:48,270 --> 00:03:51,540 wasn't compatible with all the existing 802.11b 100 00:03:51,540 --> 00:03:53,550 and g devices that were already out there. 101 00:03:53,550 --> 00:03:55,170 So a lot of people were resistant 102 00:03:55,170 --> 00:03:57,900 to buying wireless n at first when it came out. 103 00:03:57,900 --> 00:03:59,970 Now, by this time, the prices had actually come down 104 00:03:59,970 --> 00:04:02,160 because five gigahertz radios had gotten cheaper 105 00:04:02,160 --> 00:04:04,710 to manufacture, but this backwards compatibility 106 00:04:04,710 --> 00:04:06,150 was a big issue. 107 00:04:06,150 --> 00:04:07,620 So to overcome this, 108 00:04:07,620 --> 00:04:10,050 manufacturers started making hybrid devices 109 00:04:10,050 --> 00:04:12,360 that were marketed under the name wireless n, 110 00:04:12,360 --> 00:04:13,920 and these type of wireless access points 111 00:04:13,920 --> 00:04:16,230 actually had two sets of radios in them, 112 00:04:16,230 --> 00:04:18,300 one for the 2.4 gigahertz spectrum 113 00:04:18,300 --> 00:04:19,709 for backwards compatibility, 114 00:04:19,709 --> 00:04:22,350 and one for the new five gigahertz spectrum that was used 115 00:04:22,350 --> 00:04:23,910 for those faster speeds. 116 00:04:23,910 --> 00:04:27,480 This way, if you had an older 802.11b or g device, 117 00:04:27,480 --> 00:04:28,313 you could connect it 118 00:04:28,313 --> 00:04:30,720 to the slower 2.4 gigahertz spectrum radio 119 00:04:30,720 --> 00:04:33,483 that provided speeds of around 300 megabits per second 120 00:04:33,483 --> 00:04:36,810 at a distance of up to around 70 meters in range. 121 00:04:36,810 --> 00:04:39,570 Now, wireless n also introduced another new technology 122 00:04:39,570 --> 00:04:41,430 for us known as MIMO, 123 00:04:41,430 --> 00:04:43,740 and this increases your data transfer speeds. 124 00:04:43,740 --> 00:04:46,020 Now, MIMO stands for the multiple-input 125 00:04:46,020 --> 00:04:47,670 and multiple-output, which means 126 00:04:47,670 --> 00:04:49,920 that your access point can actually use multiple antennas 127 00:04:49,920 --> 00:04:52,770 to send and receive data at faster speeds than it could 128 00:04:52,770 --> 00:04:54,300 with a single antenna. 129 00:04:54,300 --> 00:04:55,980 This data is essentially being split 130 00:04:55,980 --> 00:04:58,140 across multiple antennas, and which received, 131 00:04:58,140 --> 00:05:01,050 it's going to be multiplexed back into a single data stream 132 00:05:01,050 --> 00:05:03,450 for processing and use by your computer. 133 00:05:03,450 --> 00:05:05,970 This is why you'll often see wireless n access points 134 00:05:05,970 --> 00:05:09,540 having one, two, three or even five antennas on them 135 00:05:09,540 --> 00:05:11,130 because the more antennas they had, 136 00:05:11,130 --> 00:05:14,250 the more data transfer they could support simultaneously. 137 00:05:14,250 --> 00:05:17,160 Now, the fifth type we had is known as wireless ac, 138 00:05:17,160 --> 00:05:21,390 which is also known as 802.11ac or Wi-Fi 5 139 00:05:21,390 --> 00:05:23,970 because it's the fifth generation of Wi-Fi. 140 00:05:23,970 --> 00:05:26,790 Wireless ac operates exclusively inside 141 00:05:26,790 --> 00:05:29,070 of the five gigahertz spectrum, and technically, 142 00:05:29,070 --> 00:05:32,190 it does not have any backwards compatibility support. 143 00:05:32,190 --> 00:05:35,100 Now, these 802.11ac networks can operate at speeds 144 00:05:35,100 --> 00:05:38,160 of up to 6.9 gigabits per second or more, 145 00:05:38,160 --> 00:05:40,770 which makes them really, really fast. 146 00:05:40,770 --> 00:05:42,540 Now, to achieve this higher speed though, 147 00:05:42,540 --> 00:05:45,600 802.11ac networks had to use a new technology, 148 00:05:45,600 --> 00:05:48,810 and this one is known as MU-MIMO. 149 00:05:48,810 --> 00:05:51,270 Now, this stands for multiple-user, multiple-input, 150 00:05:51,270 --> 00:05:53,610 multiple-output, and it's a newer variation 151 00:05:53,610 --> 00:05:55,620 of the MIMO technology that was developed 152 00:05:55,620 --> 00:05:58,110 for the 802.11n networks. 153 00:05:58,110 --> 00:06:01,680 MU-MIMO is a multi-path wireless communication technology 154 00:06:01,680 --> 00:06:04,380 that allows multiple users to access the wireless network 155 00:06:04,380 --> 00:06:07,200 and access the access point at the same time. 156 00:06:07,200 --> 00:06:09,450 Now, this is different than a regular MIMO connection 157 00:06:09,450 --> 00:06:11,910 where a single user is supported at one time 158 00:06:11,910 --> 00:06:14,220 and then the access point switches between the users 159 00:06:14,220 --> 00:06:16,110 to share the bandwidth across all the users 160 00:06:16,110 --> 00:06:17,730 who are requesting services. 161 00:06:17,730 --> 00:06:20,730 With MIMO, the wireless network acted more like a hub, 162 00:06:20,730 --> 00:06:23,370 but with MU-MIMO, it begins to act more like a switch 163 00:06:23,370 --> 00:06:24,510 and helps to avoid collisions 164 00:06:24,510 --> 00:06:26,520 and congestion, which gives you higher speed 165 00:06:26,520 --> 00:06:28,740 and higher levels of reliability. 166 00:06:28,740 --> 00:06:31,080 Now, the sixth and final wireless standard we have 167 00:06:31,080 --> 00:06:33,150 is what's known as wireless ax 168 00:06:33,150 --> 00:06:36,540 and wireless ax is also known as the 802.11ax, 169 00:06:36,540 --> 00:06:40,440 or Wi-Fi 6 because it is the sixth generation of Wi-Fi. 170 00:06:40,440 --> 00:06:43,740 Now, wireless ax was first introduced back in 2021, 171 00:06:43,740 --> 00:06:45,570 and it can be used in the 2.4 gigahertz 172 00:06:45,570 --> 00:06:49,650 and five gigahertz spectrum under the marketing term Wi-Fi 6 173 00:06:49,650 --> 00:06:52,800 or in a newer and faster six gigahertz spectrum 174 00:06:52,800 --> 00:06:55,830 under the marketing term Wi-Fi 6E, also known 175 00:06:55,830 --> 00:06:59,790 as Wi-Fi 6E enhanced or high efficiency Wi-Fi. 176 00:06:59,790 --> 00:07:02,220 Now, the Wi-Fi 6 and Wi-Fi 6E networks 177 00:07:02,220 --> 00:07:03,360 can actually reach speeds of up 178 00:07:03,360 --> 00:07:08,010 to 9.6 gigabits per second using that MU-MIMO technology. 179 00:07:08,010 --> 00:07:09,720 Also, because these access points 180 00:07:09,720 --> 00:07:11,460 have three different radios inside of it, 181 00:07:11,460 --> 00:07:13,410 including the 2.4 gigahertz band, 182 00:07:13,410 --> 00:07:14,337 the five gigahertz band, 183 00:07:14,337 --> 00:07:16,620 and the six gigahertz band inside of them, 184 00:07:16,620 --> 00:07:18,650 they're going to be fully backwards compatible with all 185 00:07:18,650 --> 00:07:20,760 of the previous versions of wireless networks, 186 00:07:20,760 --> 00:07:25,530 including wireless a, b, g, n, and ac. 187 00:07:25,530 --> 00:07:27,480 Now, for the exam, I want you to remember 188 00:07:27,480 --> 00:07:29,400 that there are different wireless networking standards, 189 00:07:29,400 --> 00:07:34,400 including wireless a, b, g, n, ac and ax. 190 00:07:34,500 --> 00:07:36,570 If it helps you to group them, I want you to remember 191 00:07:36,570 --> 00:07:41,310 that b, g, n and ax all support the 2.4 gigahertz band. 192 00:07:41,310 --> 00:07:44,193 If it's an a, n, ac or ax network, 193 00:07:44,193 --> 00:07:46,860 then it's going to support the five gigahertz band. 194 00:07:46,860 --> 00:07:49,860 And if you're using Wi-Fi 6E inside of the ax standard, 195 00:07:49,860 --> 00:07:52,890 you can now also use the six gigahertz band too. 196 00:07:52,890 --> 00:07:54,360 Now, as you move to newer versions 197 00:07:54,360 --> 00:07:56,070 of the wireless standards, you're going to see 198 00:07:56,070 --> 00:07:57,660 that as your speed goes up, 199 00:07:57,660 --> 00:07:58,950 you're going to see that in general, 200 00:07:58,950 --> 00:07:59,970 the distance you can cover 201 00:07:59,970 --> 00:08:02,490 with a single access point is going to go down. 202 00:08:02,490 --> 00:08:04,290 This is important because on the exam, 203 00:08:04,290 --> 00:08:05,160 you may get questions 204 00:08:05,160 --> 00:08:06,990 about the different frequencies being supported 205 00:08:06,990 --> 00:08:09,450 by a particular standard or their distance. 206 00:08:09,450 --> 00:08:11,490 For example, which of these frequencies 207 00:08:11,490 --> 00:08:13,500 doesn't support five gigahertz? 208 00:08:13,500 --> 00:08:17,340 Wireless a, wireless b, wireless g, or wireless n? 209 00:08:17,340 --> 00:08:20,130 Well, the answer here would be both wireless b 210 00:08:20,130 --> 00:08:22,260 and wireless g because wireless a 211 00:08:22,260 --> 00:08:25,080 and wireless n both support the five gigahertz band, 212 00:08:25,080 --> 00:08:27,450 but wireless b and wireless g only operate 213 00:08:27,450 --> 00:08:29,610 in the 2.4 gigahertz band. 214 00:08:29,610 --> 00:08:30,960 Alternatively, they might try 215 00:08:30,960 --> 00:08:33,090 to make the question a little bit more difficult for you 216 00:08:33,090 --> 00:08:35,490 by asking it in more of a troubleshooting scenario. 217 00:08:35,490 --> 00:08:37,710 For example, let's say you're working 218 00:08:37,710 --> 00:08:40,260 as a network technician and an older laptop is failing 219 00:08:40,260 --> 00:08:42,330 to connect to your wireless ac network. 220 00:08:42,330 --> 00:08:43,679 You check the laptop and you see 221 00:08:43,679 --> 00:08:46,140 that it has a wireless b network card inside of it. 222 00:08:46,140 --> 00:08:47,820 What might be the problem? 223 00:08:47,820 --> 00:08:48,900 Then you'll check the answers 224 00:08:48,900 --> 00:08:50,550 and find that it has something to do with the fact 225 00:08:50,550 --> 00:08:52,170 that there's a frequency mismatch 226 00:08:52,170 --> 00:08:55,080 because wireless ac only supports five gigahertz 227 00:08:55,080 --> 00:08:57,690 and wireless b, that network card in your laptop, 228 00:08:57,690 --> 00:09:01,620 is only going to support 2.4 gigahertz as its frequency band. 229 00:09:01,620 --> 00:09:03,359 Now, the last thing I want to mention for the exam 230 00:09:03,359 --> 00:09:06,390 is that you need to rely only on the information I presented 231 00:09:06,390 --> 00:09:09,210 in this lesson and not what you think is the right answer 232 00:09:09,210 --> 00:09:11,910 because of something you read on a Wi-Fi access point box 233 00:09:11,910 --> 00:09:12,990 at the store. 234 00:09:12,990 --> 00:09:14,040 Now, the box at the store 235 00:09:14,040 --> 00:09:15,930 that you're going to read is going to contain information 236 00:09:15,930 --> 00:09:18,480 that was written by marketers, not technicians, 237 00:09:18,480 --> 00:09:20,760 and they often will mislabel things to make it easier 238 00:09:20,760 --> 00:09:22,170 for consumers to understand, 239 00:09:22,170 --> 00:09:25,290 which helps them make more sales of those wireless devices. 240 00:09:25,290 --> 00:09:28,500 So for example, if you're talking about wireless ac, 241 00:09:28,500 --> 00:09:31,830 you need to remember that the wireless ac standard located 242 00:09:31,830 --> 00:09:35,670 in 802.11ac only specifies operation inside 243 00:09:35,670 --> 00:09:37,860 of the five gigahertz frequency band. 244 00:09:37,860 --> 00:09:39,420 But if you go to the store today 245 00:09:39,420 --> 00:09:42,150 and you try to buy a wireless ac access point at the store, 246 00:09:42,150 --> 00:09:43,530 that box is going to tell you 247 00:09:43,530 --> 00:09:45,481 that it supports both five gigahertz 248 00:09:45,481 --> 00:09:48,930 and 2.4 gigahertz bands, and that is actually a lie. 249 00:09:48,930 --> 00:09:50,190 It's simply not true, 250 00:09:50,190 --> 00:09:51,180 and if you remember that, 251 00:09:51,180 --> 00:09:53,400 you're going to get the question wrong on the exam. 252 00:09:53,400 --> 00:09:54,930 The reason is the real truth 253 00:09:54,930 --> 00:09:57,000 is that wireless ac only operates 254 00:09:57,000 --> 00:10:00,030 in the five gigahertz spectrum according to the standard. 255 00:10:00,030 --> 00:10:02,130 When you buy a wireless ac access point 256 00:10:02,130 --> 00:10:03,987 and it says it supports both the five gigahertz 257 00:10:03,987 --> 00:10:06,180 and the 2.4 gigahertz frequencies, 258 00:10:06,180 --> 00:10:07,920 it's actually a wireless access point 259 00:10:07,920 --> 00:10:09,840 with two separate radios in it. 260 00:10:09,840 --> 00:10:13,380 One radio is using the five gigahertz band for wireless ac 261 00:10:13,380 --> 00:10:16,200 as speeds of up to 1,300 megabits per second, 262 00:10:16,200 --> 00:10:19,320 but the other one is using a 2.4 gigahertz radio 263 00:10:19,320 --> 00:10:21,600 that's being used with wireless n at speeds of up 264 00:10:21,600 --> 00:10:23,310 to 300 megabits per second 265 00:10:23,310 --> 00:10:25,740 using a MIMO antenna configuration. 266 00:10:25,740 --> 00:10:28,200 So the bottom line here is that while in real life 267 00:10:28,200 --> 00:10:29,190 it's a lot easier to talk 268 00:10:29,190 --> 00:10:30,900 to your end users about the fact 269 00:10:30,900 --> 00:10:34,020 that wireless ac access points are backwards compatible, 270 00:10:34,020 --> 00:10:35,580 and they support both five gigahertz 271 00:10:35,580 --> 00:10:37,560 and 2.4 gigahertz bands, 272 00:10:37,560 --> 00:10:39,660 if you answer that way on the exam, you're going 273 00:10:39,660 --> 00:10:42,120 to get it wrong because the official standard states 274 00:10:42,120 --> 00:10:45,180 that wireless ac only supports the five gigahertz band 275 00:10:45,180 --> 00:10:46,980 for use in its operations. 276 00:10:46,980 --> 00:10:48,810 According to the official wireless standards, 277 00:10:48,810 --> 00:10:51,600 there are only two dual band standards that we use today: 278 00:10:51,600 --> 00:10:54,030 wireless n and wireless ax. 279 00:10:54,030 --> 00:10:57,930 Wireless n and wireless ax both operate in the 2.4 gigahertz 280 00:10:57,930 --> 00:10:59,760 and five gigahertz frequency bands 281 00:10:59,760 --> 00:11:01,950 per the official 802.11 standards, 282 00:11:01,950 --> 00:11:04,770 and all the others only support a single band, 283 00:11:04,770 --> 00:11:08,250 either 2.4 gigahertz in the case of wireless b and g 284 00:11:08,250 --> 00:11:09,180 and five gigahertz 285 00:11:09,180 --> 00:11:11,973 in the case of wireless a and wireless ac.