1 00:00:04,160 --> 00:00:07,160 Speaker 1: Get in touch with technology with tech Stuff from how 2 00:00:07,240 --> 00:00:13,920 Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff. 3 00:00:13,960 --> 00:00:17,320 Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer at 4 00:00:17,320 --> 00:00:21,159 Speaker 1: how Stuff Works in I love all things tech, and 5 00:00:21,320 --> 00:00:26,840 Speaker 1: one of the most pervasive modern technologies today is WiFi, 6 00:00:27,160 --> 00:00:30,880 Speaker 1: which is fascinating since as a standard, it just had 7 00:00:30,880 --> 00:00:34,040 Speaker 1: its twenty first birthday not long ago. The original WiFi 8 00:00:34,080 --> 00:00:38,800 Speaker 1: standard was released in nine seven, but the development of 9 00:00:38,880 --> 00:00:41,640 Speaker 1: WiFi stretches back further than that, and I thought it 10 00:00:41,760 --> 00:00:44,440 Speaker 1: might be interesting to trace that history and get to 11 00:00:44,479 --> 00:00:47,040 Speaker 1: know more about the tech that lets us set up 12 00:00:47,360 --> 00:00:51,479 Speaker 1: a local coffee shop situation, you know, to catch up 13 00:00:51,520 --> 00:00:55,440 Speaker 1: on emails. How, how did that come to pass, and 14 00:00:55,560 --> 00:00:58,920 Speaker 1: how does it actually work? Well. Decades before there was 15 00:00:58,960 --> 00:01:02,680 Speaker 1: a WiFi standard, there was a Lohan net. Back in 16 00:01:02,720 --> 00:01:06,800 Speaker 1: the late nineteen sixties, computer scientists and students at the 17 00:01:06,920 --> 00:01:09,600 Speaker 1: University of Hawaii. We're trying to come up with a 18 00:01:09,600 --> 00:01:13,160 Speaker 1: way that would let students on the various Hawaiian islands 19 00:01:13,480 --> 00:01:17,039 Speaker 1: communicate with the main frame computer on the Oahu campus 20 00:01:17,080 --> 00:01:20,760 Speaker 1: at the university. Their work was concurrent with the work 21 00:01:20,920 --> 00:01:23,880 Speaker 1: of BBN, a company that was working on our bonnet 22 00:01:24,520 --> 00:01:27,319 Speaker 1: and our ponette, you may remember, was the predecessor to 23 00:01:27,360 --> 00:01:30,199 Speaker 1: the Internet. The purpose of our ponet was to find 24 00:01:30,200 --> 00:01:35,160 Speaker 1: out ways to connect remote computers together, remote computers that 25 00:01:35,200 --> 00:01:37,800 Speaker 1: were working on different computer architectures, and have a way 26 00:01:37,840 --> 00:01:41,640 Speaker 1: that they can meaningfully communicate with each other. Well, this 27 00:01:41,760 --> 00:01:44,360 Speaker 1: was happening around the same time. Now, one thing the 28 00:01:44,400 --> 00:01:46,520 Speaker 1: group wanted to do was take advantage of a special 29 00:01:46,520 --> 00:01:50,760 Speaker 1: way to send data between computers called packet switching. M 30 00:01:50,760 --> 00:01:54,640 Speaker 1: I T had developed packet switching back in nineteen sixty five, 31 00:01:54,800 --> 00:01:58,720 Speaker 1: so it was still a relatively new technology when the 32 00:01:58,760 --> 00:02:00,800 Speaker 1: folks over at the University of Why You decided to 33 00:02:00,840 --> 00:02:04,400 Speaker 1: try and create their own Aloha net. So what exactly 34 00:02:04,520 --> 00:02:07,680 Speaker 1: is packet switching and why is it so important and 35 00:02:07,800 --> 00:02:11,320 Speaker 1: how networks send information? Well, let's say you want to 36 00:02:11,360 --> 00:02:15,000 Speaker 1: transfer a large file from one computer to another, a 37 00:02:15,080 --> 00:02:20,079 Speaker 1: really big one. Let's say that it's maybe several gigabytes 38 00:02:20,120 --> 00:02:22,959 Speaker 1: in size, which today is a pretty big file. Back 39 00:02:22,960 --> 00:02:25,240 Speaker 1: in the days of nine that would have been an 40 00:02:25,280 --> 00:02:29,440 Speaker 1: unimaginably huge file. But let's stick with it. Now. Let's 41 00:02:29,480 --> 00:02:32,160 Speaker 1: say you're trying to send that file over a network. 42 00:02:32,680 --> 00:02:35,800 Speaker 1: The bandwidth of that network might limit how large a 43 00:02:35,840 --> 00:02:40,040 Speaker 1: file you'd be able to send. In other words, your connections, 44 00:02:40,120 --> 00:02:44,800 Speaker 1: your routers, your switches, your buses, if they have a 45 00:02:44,919 --> 00:02:47,840 Speaker 1: limit on how much information can pass through at one time, 46 00:02:48,560 --> 00:02:52,200 Speaker 1: that might mean that you can't send that file. It's 47 00:02:52,240 --> 00:02:55,680 Speaker 1: just too big to fit through the pipes. If you 48 00:02:55,760 --> 00:02:59,400 Speaker 1: want to have kind of a poor analogy, but a 49 00:03:00,000 --> 00:03:03,160 Speaker 1: physical analogy, imagine that you have a very narrow road 50 00:03:03,720 --> 00:03:07,280 Speaker 1: and you're driving a really wide truck, and you're really 51 00:03:07,280 --> 00:03:10,480 Speaker 1: wide truck is actually too wide for the narrow road. Well, 52 00:03:10,680 --> 00:03:12,200 Speaker 1: looks like you're gonna have to find another way to 53 00:03:12,200 --> 00:03:14,280 Speaker 1: get your truck to the other side of that road. 54 00:03:14,880 --> 00:03:17,400 Speaker 1: That's kind of what I'm talking about here. So packet 55 00:03:17,440 --> 00:03:21,280 Speaker 1: switching was a way to make this more manageable, to 56 00:03:22,200 --> 00:03:25,800 Speaker 1: allow files to transfer across a network in a way 57 00:03:25,840 --> 00:03:31,840 Speaker 1: that did not overly stress the infrastructure. Essentially, packet switching 58 00:03:31,840 --> 00:03:36,240 Speaker 1: works by dividing files up into chunks of data called packets. 59 00:03:36,680 --> 00:03:38,440 Speaker 1: You can think of them as like envelopes that have 60 00:03:38,640 --> 00:03:41,120 Speaker 1: letters inside of them, and each letter is part of 61 00:03:41,120 --> 00:03:44,760 Speaker 1: a file that you're sending across the Internet. Packets contain 62 00:03:44,800 --> 00:03:47,520 Speaker 1: a little extra information in them in addition to the 63 00:03:47,560 --> 00:03:51,480 Speaker 1: file itself. That information includes data about the computer that 64 00:03:51,760 --> 00:03:55,480 Speaker 1: was sending the file the computer that's supposed to receive 65 00:03:55,560 --> 00:03:58,360 Speaker 1: the file, so kind of like the return address and 66 00:03:58,400 --> 00:04:02,320 Speaker 1: the send address, those two things would be included, and 67 00:04:02,360 --> 00:04:05,720 Speaker 1: also how that particular chunk of data fits in with 68 00:04:05,880 --> 00:04:08,960 Speaker 1: the rest of the information that's being sent. So you 69 00:04:08,960 --> 00:04:10,920 Speaker 1: can also think of it as sort of like instructions 70 00:04:10,920 --> 00:04:13,440 Speaker 1: on how to put a puzzle back together. So if 71 00:04:13,440 --> 00:04:16,880 Speaker 1: I go with the mail analogy, as in like postal mail, 72 00:04:17,680 --> 00:04:20,240 Speaker 1: every single piece of information is a piece of a puzzle, 73 00:04:20,800 --> 00:04:23,159 Speaker 1: and with that piece of a puzzle, I include a 74 00:04:23,160 --> 00:04:25,440 Speaker 1: little bit of instructions about where that piece fits. I 75 00:04:25,520 --> 00:04:28,600 Speaker 1: might say this piece is the bottom right corner of 76 00:04:28,640 --> 00:04:32,279 Speaker 1: the puzzle, and then the envelope has the address that 77 00:04:32,360 --> 00:04:34,840 Speaker 1: I'm sending from and the address I'm sending to. Well, 78 00:04:34,880 --> 00:04:38,080 Speaker 1: that's kind of like a packet of data. In packet switching, 79 00:04:38,120 --> 00:04:41,360 Speaker 1: you send these smaller, more manageable chunks of data across 80 00:04:41,360 --> 00:04:44,440 Speaker 1: a network. The chunks may or may not follow the 81 00:04:44,480 --> 00:04:47,200 Speaker 1: same pathway to get to their destination. They may not 82 00:04:47,279 --> 00:04:50,440 Speaker 1: all go through the exact same nodes across the Internet. 83 00:04:51,120 --> 00:04:53,720 Speaker 1: The neat thing is they can all split up and 84 00:04:53,760 --> 00:04:58,040 Speaker 1: take different pathways, and typically you have duplicate packets journeying 85 00:04:58,080 --> 00:05:01,520 Speaker 1: to the destination to help ensure that the full file 86 00:05:01,760 --> 00:05:04,920 Speaker 1: arrives where it needs to go. Otherwise the file will 87 00:05:04,920 --> 00:05:07,200 Speaker 1: be corrupt because it will be missing a piece of 88 00:05:07,240 --> 00:05:09,520 Speaker 1: the puzzle. Once the packets get to the right computer, 89 00:05:09,920 --> 00:05:13,760 Speaker 1: they get reassembled into whatever the original file was, whether 90 00:05:13,800 --> 00:05:17,400 Speaker 1: it's a text file, an image video, whatever it might be. 91 00:05:18,279 --> 00:05:20,720 Speaker 1: The team at the University of Hawaii wanted to use 92 00:05:20,880 --> 00:05:26,120 Speaker 1: packet switching technology coupled with radio transmissions in order to 93 00:05:26,240 --> 00:05:30,120 Speaker 1: send information from the main frame and to receive information 94 00:05:30,200 --> 00:05:33,720 Speaker 1: from students across the island chain. They decided to create 95 00:05:33,720 --> 00:05:37,719 Speaker 1: a system that would transmit information using radio signals that 96 00:05:37,760 --> 00:05:42,520 Speaker 1: were in the ultra high frequency or UHF range. UHF, 97 00:05:42,560 --> 00:05:46,840 Speaker 1: apart from being a hilarious weird Al Yankovic movie, is 98 00:05:47,120 --> 00:05:51,680 Speaker 1: a range of radio signals that fall into the spectrum 99 00:05:51,720 --> 00:05:54,200 Speaker 1: that at the low end is at three hundred mega 100 00:05:54,240 --> 00:05:57,520 Speaker 1: hurts and at the upper end is at three giga hurts. 101 00:05:57,800 --> 00:06:00,360 Speaker 1: Now it hurts is a unit that refers to one 102 00:06:00,440 --> 00:06:03,920 Speaker 1: cycle per second. I've talked about this recently, but it's 103 00:06:03,960 --> 00:06:06,880 Speaker 1: always good to go over this again. Now imagine that 104 00:06:07,120 --> 00:06:11,640 Speaker 1: a radio wave is a long sign wave with smooth, 105 00:06:11,880 --> 00:06:15,719 Speaker 1: even peaks and valleys, and they just repeat over and 106 00:06:15,760 --> 00:06:17,320 Speaker 1: over and over again. Now, if you were to take 107 00:06:17,360 --> 00:06:20,320 Speaker 1: an arbitrary point, such as the peak of the wave, 108 00:06:20,839 --> 00:06:24,400 Speaker 1: and measure it to the next peak over, you would 109 00:06:24,400 --> 00:06:29,000 Speaker 1: have one wavelength of that radio wave. Radio waves travel 110 00:06:29,040 --> 00:06:31,840 Speaker 1: at the speed of light, regardless of wavelength, if it's 111 00:06:31,839 --> 00:06:34,520 Speaker 1: a short wavelength or a long wavelength. So if you 112 00:06:34,560 --> 00:06:37,839 Speaker 1: know how long a wavelength is for a radio wave, 113 00:06:38,240 --> 00:06:40,880 Speaker 1: you know how many radio waves will pass a given 114 00:06:40,920 --> 00:06:43,560 Speaker 1: point in space every second, because you already know the 115 00:06:43,680 --> 00:06:46,840 Speaker 1: speed at which they will travel. A three hundred mega 116 00:06:46,880 --> 00:06:50,839 Speaker 1: Hurts radio wave will have three hundred million waves pass 117 00:06:50,960 --> 00:06:54,360 Speaker 1: through a given point in space per second. A three 118 00:06:54,440 --> 00:06:59,080 Speaker 1: giga Hurts radio wave will have three billion radio waves 119 00:06:59,120 --> 00:07:02,840 Speaker 1: pass that same point per second. The three gig Hurts 120 00:07:02,880 --> 00:07:06,279 Speaker 1: waves clearly have to be smaller than the mega Hurts 121 00:07:06,279 --> 00:07:08,400 Speaker 1: ones because they're all traveling at the same speed. So 122 00:07:08,440 --> 00:07:11,280 Speaker 1: the only way you can cram more wavelengths past the 123 00:07:11,360 --> 00:07:16,160 Speaker 1: point per second is by decreasing the wavelength. The radio 124 00:07:16,200 --> 00:07:18,800 Speaker 1: spectrum as a whole, by the way, starts all the 125 00:07:18,840 --> 00:07:23,560 Speaker 1: way down at three hurts meaning only three extremely long 126 00:07:23,720 --> 00:07:27,120 Speaker 1: radio waves would pass a given point in space every second, 127 00:07:27,600 --> 00:07:29,960 Speaker 1: and it goes all the way up to three terra hurts, 128 00:07:30,000 --> 00:07:33,520 Speaker 1: which is equivalent to three thousand giga hurts or three 129 00:07:33,680 --> 00:07:38,200 Speaker 1: thousand billion cycles per second. So while UHF stands for 130 00:07:38,280 --> 00:07:42,240 Speaker 1: ultra high frequency, it's nowhere near the top of the spectrum. 131 00:07:42,720 --> 00:07:47,320 Speaker 1: Aloha net relied on to such frequencies in the UHF range. 132 00:07:47,400 --> 00:07:51,000 Speaker 1: One frequency was used for outgoing signals from the main 133 00:07:51,000 --> 00:07:54,240 Speaker 1: frame to the other computers, so the main computer would 134 00:07:54,240 --> 00:07:58,320 Speaker 1: send signals out over one frequency to students, but the 135 00:07:58,360 --> 00:08:01,040 Speaker 1: other frequency was used by the other computers to send 136 00:08:01,040 --> 00:08:04,000 Speaker 1: messages back to the main frame, so the students machines 137 00:08:04,400 --> 00:08:07,000 Speaker 1: would use a different frequency. So you had kind of 138 00:08:07,000 --> 00:08:09,320 Speaker 1: two channels in a way. You had the outgoing and 139 00:08:09,360 --> 00:08:12,840 Speaker 1: the incoming. But this created a possible problem. There could 140 00:08:12,960 --> 00:08:15,840 Speaker 1: come an instance in which more than one computer was 141 00:08:15,880 --> 00:08:18,680 Speaker 1: trying to communicate with the main frame at the same time, 142 00:08:19,080 --> 00:08:21,520 Speaker 1: and when that happened, the signals were said to quote 143 00:08:21,560 --> 00:08:25,400 Speaker 1: unquote collide with one another. It's sort of like trying 144 00:08:25,440 --> 00:08:28,360 Speaker 1: to have multiple people talk over a single radio channel. 145 00:08:28,400 --> 00:08:30,840 Speaker 1: Only one person can speak at a time. If multiple 146 00:08:30,880 --> 00:08:35,400 Speaker 1: people try it's just a mess. So alohan Net adopted 147 00:08:35,400 --> 00:08:37,640 Speaker 1: a strategy in which the main frame would send out 148 00:08:37,679 --> 00:08:41,560 Speaker 1: a received signal whenever an incoming message came in without 149 00:08:41,559 --> 00:08:44,480 Speaker 1: a collision. It was essentially saying, I am confirming that 150 00:08:44,559 --> 00:08:46,880 Speaker 1: I got your message, and that would tell the sending 151 00:08:46,880 --> 00:08:49,560 Speaker 1: computer that the message got through, and if the sending 152 00:08:49,600 --> 00:08:53,120 Speaker 1: computer did not get such a response, it would attempt 153 00:08:53,160 --> 00:08:57,199 Speaker 1: to send the packets of data again at a randomly 154 00:08:57,320 --> 00:09:02,000 Speaker 1: determined time interval. That random interval was meant to decrease 155 00:09:02,080 --> 00:09:06,160 Speaker 1: the possibility that another collision would occur because obviously more 156 00:09:06,200 --> 00:09:08,600 Speaker 1: than one computer is involved in this, and if both 157 00:09:08,679 --> 00:09:12,280 Speaker 1: computers tried to send the exact same data packets at 158 00:09:12,360 --> 00:09:15,040 Speaker 1: the same time intervals over and over again, you're just 159 00:09:15,040 --> 00:09:18,720 Speaker 1: gonna keep getting collisions. This time, there would be the 160 00:09:18,760 --> 00:09:20,720 Speaker 1: hope that there would be no collisions because you would 161 00:09:20,760 --> 00:09:24,520 Speaker 1: have this somewhat random time interval that is spacing things 162 00:09:24,559 --> 00:09:27,920 Speaker 1: out a little bit. Now. In its original configuration, alohan 163 00:09:28,040 --> 00:09:31,160 Speaker 1: that was not terribly efficient. It had a throughput rate 164 00:09:31,280 --> 00:09:35,439 Speaker 1: of just eighteen percent and most of the bandwidth went unused, 165 00:09:35,760 --> 00:09:38,720 Speaker 1: and so the team needed to come up with a fix. First, 166 00:09:39,000 --> 00:09:42,160 Speaker 1: they tried the old time sharing route. Time sharing is 167 00:09:42,200 --> 00:09:45,840 Speaker 1: when you have several terminals connected to a centralized computer. 168 00:09:46,360 --> 00:09:49,280 Speaker 1: The computer can only work on one set of instructions 169 00:09:49,320 --> 00:09:52,000 Speaker 1: at a time, and so users have to wait a 170 00:09:52,120 --> 00:09:56,040 Speaker 1: turn to access the computers processing power and memory and etcetera. 171 00:09:56,240 --> 00:09:59,960 Speaker 1: But computers work really fast and so frequently it would 172 00:10:00,000 --> 00:10:02,600 Speaker 1: feel like you were working on a mainframe in real 173 00:10:02,679 --> 00:10:05,600 Speaker 1: time at the same time as everybody else, though in 174 00:10:05,640 --> 00:10:08,120 Speaker 1: fact the computer is actually rushing to complete one set 175 00:10:08,120 --> 00:10:11,280 Speaker 1: of instructions before starting on the next one. The problem 176 00:10:11,320 --> 00:10:14,439 Speaker 1: with time sharing over radio network was that the computers 177 00:10:14,480 --> 00:10:17,800 Speaker 1: had to follow a schedule of when they could send packets, 178 00:10:18,320 --> 00:10:20,319 Speaker 1: so if it wasn't their time to send a packet, 179 00:10:20,360 --> 00:10:22,320 Speaker 1: they had to wait and so and meant that there 180 00:10:22,320 --> 00:10:25,360 Speaker 1: were wasted cycles since sometimes the computer had nothing to 181 00:10:25,440 --> 00:10:29,800 Speaker 1: send and so those scheduled transmission times would go unused. However, 182 00:10:29,920 --> 00:10:32,880 Speaker 1: this did increase the throughput rate for a Looha net, 183 00:10:32,920 --> 00:10:36,400 Speaker 1: so it improved things a little bit. The team decided 184 00:10:36,520 --> 00:10:39,400 Speaker 1: to try a different approach to improve the system further, 185 00:10:39,760 --> 00:10:43,360 Speaker 1: and they designed instructions so that client machines, the ones 186 00:10:43,480 --> 00:10:47,040 Speaker 1: that are sending request to the centralized computer, would monitor 187 00:10:47,120 --> 00:10:50,080 Speaker 1: the traffic on the radio channel to determine when the 188 00:10:50,160 --> 00:10:53,040 Speaker 1: channel was free. So essentially they're listening for the quiet spots, 189 00:10:53,480 --> 00:10:56,320 Speaker 1: and then the client machine would send packets over that 190 00:10:56,480 --> 00:10:59,760 Speaker 1: radio channel. The packets were actually smaller at this point, 191 00:11:00,080 --> 00:11:03,360 Speaker 1: which would allow for more gaps between packets, and that 192 00:11:03,400 --> 00:11:06,600 Speaker 1: would allow other computers to slip other packets in. So 193 00:11:06,640 --> 00:11:11,200 Speaker 1: while the messages appear to be consistent and continuous, in 194 00:11:11,280 --> 00:11:13,880 Speaker 1: fact it's a bunch of tiny little puzzle pieces, and 195 00:11:13,920 --> 00:11:16,920 Speaker 1: occasionally there's enough of a gap for other puzzle pieces 196 00:11:16,960 --> 00:11:19,600 Speaker 1: to sneak in, and the centralized computer would just sort 197 00:11:19,679 --> 00:11:23,240 Speaker 1: everything based upon the meta information on the packets. This 198 00:11:23,280 --> 00:11:27,800 Speaker 1: approach got the name Carrier Sense Multiple Access or c 199 00:11:28,280 --> 00:11:32,120 Speaker 1: s m A. The system continued to monitor collisions as well, 200 00:11:32,559 --> 00:11:36,720 Speaker 1: so it's full name was c s m A DASH 201 00:11:36,960 --> 00:11:41,440 Speaker 1: c D or Carrier Since Multiple Access with Collision Detection. 202 00:11:42,400 --> 00:11:46,199 Speaker 1: Now I've got more to say about the evolution toward WiFi, 203 00:11:46,240 --> 00:11:48,960 Speaker 1: but before I go further, let's take a quick break 204 00:11:49,080 --> 00:11:59,800 Speaker 1: to thank our sponsor Aloha. Nette was up and running 205 00:12:00,040 --> 00:12:02,640 Speaker 1: by nineteen seventy one, but it would still be more 206 00:12:02,640 --> 00:12:06,120 Speaker 1: than twenty years before we'd see the first WiFi standard 207 00:12:06,360 --> 00:12:09,320 Speaker 1: get unveiled. He could be fourteen years before I have 208 00:12:09,360 --> 00:12:12,680 Speaker 1: another big moment to talk about in the evolution toward WiFi. 209 00:12:13,320 --> 00:12:17,559 Speaker 1: That moment happened in nineteen five when the United States 210 00:12:17,640 --> 00:12:21,840 Speaker 1: Federal Communications Commission, or FCC changed the rules about the 211 00:12:21,920 --> 00:12:27,000 Speaker 1: radio spectrum. Every country has rules about which frequency bands 212 00:12:27,080 --> 00:12:30,600 Speaker 1: in the radio spectrum may be used for specific applications. 213 00:12:30,880 --> 00:12:34,120 Speaker 1: For example, in the United States, AM radio has all 214 00:12:34,200 --> 00:12:38,080 Speaker 1: frequencies between five thirty five killer hurts and one thousand, 215 00:12:38,200 --> 00:12:42,640 Speaker 1: six hundred five killer hurts. No other technology is allowed 216 00:12:42,679 --> 00:12:47,000 Speaker 1: to use those radio frequencies. This prevents various technologies from 217 00:12:47,040 --> 00:12:50,600 Speaker 1: interfering with one another. If you didn't have restrictions on 218 00:12:50,679 --> 00:12:54,640 Speaker 1: who could use which frequency, then whatever frequency was the 219 00:12:54,720 --> 00:12:58,800 Speaker 1: strongest had the greatest UH energy behind it in any 220 00:12:58,800 --> 00:13:01,840 Speaker 1: given area would win out and it would be chaos. 221 00:13:02,400 --> 00:13:05,520 Speaker 1: And so the United States divvied up the radio spectrum 222 00:13:05,520 --> 00:13:09,760 Speaker 1: for specific uses, which included not only communications technology but 223 00:13:09,840 --> 00:13:13,959 Speaker 1: also stuff like microwave ovens. Say what, and by the way, 224 00:13:14,000 --> 00:13:17,120 Speaker 1: this is not just the US. Other countries also have 225 00:13:17,240 --> 00:13:20,679 Speaker 1: done this, But it's because technology like microwave ovens can 226 00:13:20,800 --> 00:13:25,280 Speaker 1: generate radio frequencies of their own, not to communicate, but 227 00:13:25,520 --> 00:13:28,520 Speaker 1: that can be a byproduct of their operations. So the 228 00:13:28,600 --> 00:13:33,800 Speaker 1: United States FCC mandated that manufacturers of microwaves and other 229 00:13:34,120 --> 00:13:38,160 Speaker 1: technologies that create these radio waves make sure their products 230 00:13:38,200 --> 00:13:42,080 Speaker 1: only generated radio frequencies within specific bands in order to 231 00:13:42,120 --> 00:13:45,520 Speaker 1: avoid creating interference for other technology. So it's not like 232 00:13:45,559 --> 00:13:48,959 Speaker 1: the US specifically said, hey, let's set aside the slice 233 00:13:48,960 --> 00:13:52,000 Speaker 1: of radio frequency spectrum so that microwaves can talk to 234 00:13:52,040 --> 00:13:54,920 Speaker 1: one another. In staid, they said, hey, let's make sure 235 00:13:54,920 --> 00:13:59,520 Speaker 1: all microwave oven manufacturers be certain that their ovens only 236 00:13:59,559 --> 00:14:02,880 Speaker 1: generate radio frequencies in this slice so that the ovens 237 00:14:02,920 --> 00:14:06,240 Speaker 1: don't interfere with communications equipment. In other words, they set 238 00:14:06,280 --> 00:14:08,760 Speaker 1: aside a certain slice of the radio spectrum and said 239 00:14:09,120 --> 00:14:11,679 Speaker 1: this is your playground. You can create stuff that creates 240 00:14:11,760 --> 00:14:14,800 Speaker 1: radio frequencies in this range, and that shouldn't mess up 241 00:14:14,880 --> 00:14:19,440 Speaker 1: anything that's on either side of that frequency range. These bands, 242 00:14:19,560 --> 00:14:22,760 Speaker 1: the ones set aside for equipment that can generate radio 243 00:14:22,800 --> 00:14:27,120 Speaker 1: waves but aren't necessarily communication tech, are called I S 244 00:14:27,320 --> 00:14:31,120 Speaker 1: M bands. The I s M stands for Industrial, Scientific, 245 00:14:31,200 --> 00:14:36,080 Speaker 1: and Medical. These bands cover several different separate groups of frequencies, 246 00:14:36,160 --> 00:14:38,960 Speaker 1: but two of them include the two point four giga 247 00:14:39,000 --> 00:14:41,640 Speaker 1: Hurts to two point five gig Hurts band and the 248 00:14:41,760 --> 00:14:44,920 Speaker 1: five point seven to five gig Hurts to five point 249 00:14:45,000 --> 00:14:48,280 Speaker 1: eight seven five giga Hurts bands. These are going to 250 00:14:48,320 --> 00:14:51,480 Speaker 1: be very important for our discussions on WiFi. Now again 251 00:14:51,560 --> 00:14:55,280 Speaker 1: we look at five, when the FCC decided it would 252 00:14:55,320 --> 00:14:59,040 Speaker 1: open up three I s M bands to unlicensed use 253 00:14:59,480 --> 00:15:01,600 Speaker 1: that would in flude the two point four giga Hurts 254 00:15:01,600 --> 00:15:04,160 Speaker 1: and the five point seven to five gig Hurts bands. 255 00:15:04,760 --> 00:15:08,720 Speaker 1: Unlicensed use required a couple of technological allowances. One was 256 00:15:08,760 --> 00:15:11,120 Speaker 1: that the transmitters would have to be very low power 257 00:15:11,240 --> 00:15:14,640 Speaker 1: in the one watt range. Another was that gadgets making 258 00:15:14,760 --> 00:15:17,640 Speaker 1: use of that frequency would need a high tolerance to 259 00:15:17,680 --> 00:15:20,440 Speaker 1: interference since other devices were still going to be giving 260 00:15:20,440 --> 00:15:23,840 Speaker 1: off radio waves at those frequencies. Essentially, what the FCC 261 00:15:24,040 --> 00:15:27,160 Speaker 1: was saying is, you can develop technologies that can work 262 00:15:27,160 --> 00:15:29,920 Speaker 1: on these ranges as long as they aren't so powerful 263 00:15:29,960 --> 00:15:32,960 Speaker 1: that they're going to interfere with other technologies, and you 264 00:15:33,000 --> 00:15:35,560 Speaker 1: do it with the understanding that there's already stuff out 265 00:15:35,560 --> 00:15:38,520 Speaker 1: there that's generating radio waves in these frequencies. So whatever 266 00:15:38,560 --> 00:15:41,240 Speaker 1: you create needs to be done in such a way 267 00:15:41,280 --> 00:15:44,960 Speaker 1: that it can tolerate that This decision in set the 268 00:15:44,960 --> 00:15:49,160 Speaker 1: foundation for WiFi, which still would not debut for another decade, 269 00:15:49,200 --> 00:15:51,800 Speaker 1: but that didn't mean there weren't people working on the 270 00:15:51,840 --> 00:15:55,200 Speaker 1: idea in the meantime. One of those people was Vic Hayes. 271 00:15:55,640 --> 00:15:59,840 Speaker 1: Hayes had joined the NCR Corporation in the nineteen seventies. 272 00:16:00,240 --> 00:16:04,560 Speaker 1: In CR, which originally stood for National Cash Register, had 273 00:16:04,600 --> 00:16:08,160 Speaker 1: been involved in various technologies since its founding in the 274 00:16:08,240 --> 00:16:12,080 Speaker 1: late nineteenth century. In CR's goal was to create a 275 00:16:12,160 --> 00:16:15,560 Speaker 1: standard that the company could then use in its own systems. 276 00:16:15,880 --> 00:16:18,200 Speaker 1: The idea was that the standard would allow companies to 277 00:16:18,240 --> 00:16:22,440 Speaker 1: create systems that connected devices like front end retail equipment 278 00:16:22,520 --> 00:16:27,040 Speaker 1: such as cash registers and back end mainframe systems and 279 00:16:27,160 --> 00:16:31,600 Speaker 1: using radio waves instead of cables or other clunky methodologies. 280 00:16:32,000 --> 00:16:34,080 Speaker 1: And they didn't want to go a proprietary route. They 281 00:16:34,080 --> 00:16:36,320 Speaker 1: wanted to create a standard that would work so that 282 00:16:37,200 --> 00:16:42,240 Speaker 1: various O E M companies could create products that used it. 283 00:16:42,560 --> 00:16:45,320 Speaker 1: Hayes had done some work and authoring standards for data 284 00:16:45,360 --> 00:16:49,440 Speaker 1: communications as part of his job previously, and NCR was 285 00:16:49,520 --> 00:16:52,880 Speaker 1: interested in finding an unlicensed use for the two point 286 00:16:52,920 --> 00:16:55,760 Speaker 1: for giga hurts I s M band, n c R 287 00:16:55,840 --> 00:16:58,600 Speaker 1: and a T and T had developed a working predecessor 288 00:16:58,800 --> 00:17:03,760 Speaker 1: to the would essentially evolve into WiFi in nine, and 289 00:17:03,840 --> 00:17:07,359 Speaker 1: that was called wave land. They submitted the design of 290 00:17:07,400 --> 00:17:11,080 Speaker 1: this wireless protocol to the I E E E A 291 00:17:11,240 --> 00:17:16,280 Speaker 1: O two LAND slash MAN Standards Committee. Land, by the way, 292 00:17:16,320 --> 00:17:20,040 Speaker 1: stands for local Area network and MAN for a Municipality 293 00:17:20,119 --> 00:17:23,679 Speaker 1: Area network or Municipal Area network. This led to the 294 00:17:23,720 --> 00:17:26,840 Speaker 1: need to form a new working group within that committee, 295 00:17:27,000 --> 00:17:29,760 Speaker 1: The eight O two Committee to Create a Standard for 296 00:17:29,840 --> 00:17:34,480 Speaker 1: Wireless Networking Communication NCR chose Hayes to head up a 297 00:17:34,520 --> 00:17:38,159 Speaker 1: working group to that effect in nine. The working groups 298 00:17:38,200 --> 00:17:42,200 Speaker 1: designation was a O two point eleven and their goal 299 00:17:42,280 --> 00:17:46,240 Speaker 1: was to create a standard for wireless local area networks. Now, 300 00:17:46,240 --> 00:17:49,159 Speaker 1: a local area network is pretty self explanatory. It's a 301 00:17:49,200 --> 00:17:52,399 Speaker 1: network of computing devices that are locally connected to one another, 302 00:17:52,920 --> 00:17:56,840 Speaker 1: generally contained within a building or maybe a campus of buildings. 303 00:17:57,240 --> 00:18:01,200 Speaker 1: The devices can intercommunicate with one another. A LAND can 304 00:18:01,280 --> 00:18:05,040 Speaker 1: be but doesn't have to be connected to wider networks 305 00:18:05,080 --> 00:18:07,640 Speaker 1: like the Internet, and in the old days, the only 306 00:18:07,680 --> 00:18:11,280 Speaker 1: way you could set up a LAND was to actually 307 00:18:11,280 --> 00:18:14,080 Speaker 1: have physical connections between all the different machines and some 308 00:18:14,160 --> 00:18:17,480 Speaker 1: sort of hub, but NCR wanted to do away with 309 00:18:17,560 --> 00:18:21,280 Speaker 1: those physical connectors and create a standard that manufacturers could 310 00:18:21,359 --> 00:18:25,960 Speaker 1: use to build in wireless communication capabilities directly into their products. 311 00:18:26,680 --> 00:18:30,840 Speaker 1: Hayes had some radio communications background and had previous experience 312 00:18:30,880 --> 00:18:34,600 Speaker 1: helping create communication standards, but still wasn't sure he was 313 00:18:34,640 --> 00:18:37,000 Speaker 1: the right man for the job. As it turned out, 314 00:18:37,040 --> 00:18:40,439 Speaker 1: he absolutely was. He gathered a group of experts together 315 00:18:40,800 --> 00:18:43,520 Speaker 1: and they began to debate what needed to go into 316 00:18:43,520 --> 00:18:47,040 Speaker 1: the standard, and the first big argument was over two 317 00:18:47,080 --> 00:18:53,199 Speaker 1: different modulation strategies, frequency hopping or direct sequence. Both of 318 00:18:53,200 --> 00:18:56,439 Speaker 1: those techniques are meant to use a larger bandwidth for 319 00:18:56,480 --> 00:19:01,000 Speaker 1: transmission than what would otherwise be necessary for the specific 320 00:19:01,160 --> 00:19:05,119 Speaker 1: type of data you're sending back and forth. Frequency hopping 321 00:19:05,200 --> 00:19:09,359 Speaker 1: spread spectrum or f h s S divides a large 322 00:19:09,440 --> 00:19:13,840 Speaker 1: bandwidth into parallel, narrow channels there are large enough to 323 00:19:13,920 --> 00:19:15,919 Speaker 1: hold the data in question. If we go back to 324 00:19:15,960 --> 00:19:19,160 Speaker 1: talking about vehicles and roads, this would be saying, let's 325 00:19:19,200 --> 00:19:22,080 Speaker 1: imagine that you have a really, really wide highway I'm 326 00:19:22,119 --> 00:19:26,240 Speaker 1: talking twenty lanes wide. Uh, and at first you don't 327 00:19:26,240 --> 00:19:31,120 Speaker 1: have any lanes painted in there, it's just an enormous road. Well, 328 00:19:31,280 --> 00:19:34,679 Speaker 1: you could try and use it that way. But frequency 329 00:19:34,680 --> 00:19:38,080 Speaker 1: hopping would allow you to create narrower lanes, lanes that 330 00:19:38,119 --> 00:19:40,400 Speaker 1: are wide enough for a vehicle, so that you could 331 00:19:40,440 --> 00:19:43,639 Speaker 1: have twenty vehicles traveling on there if they all were 332 00:19:43,680 --> 00:19:46,160 Speaker 1: sticking to their own lanes. That's kind of the idea 333 00:19:46,240 --> 00:19:49,639 Speaker 1: behind frequency hopping. The system sends data in a semi 334 00:19:49,760 --> 00:19:53,320 Speaker 1: random way to one of those channels, but that means 335 00:19:53,400 --> 00:19:56,840 Speaker 1: the other channels go unused in the process, and because 336 00:19:56,960 --> 00:19:59,880 Speaker 1: only one channel is in use at any given time, 337 00:20:00,320 --> 00:20:03,720 Speaker 1: you're technically wasting bandwidth equal to the size of the 338 00:20:03,840 --> 00:20:07,480 Speaker 1: channel multiplied by the number of channels minus one channel, 339 00:20:07,480 --> 00:20:10,560 Speaker 1: because you're already using one. So this would be like saying, yeah, 340 00:20:10,600 --> 00:20:13,800 Speaker 1: you have a highway, it's twenty lanes wide. You've painted 341 00:20:13,800 --> 00:20:17,040 Speaker 1: these lanes in there, so you can randomly choose a 342 00:20:17,160 --> 00:20:20,119 Speaker 1: lane between one and twenty and you're fine, But that 343 00:20:20,160 --> 00:20:22,600 Speaker 1: means the other nineteen lanes are going unused. It's not 344 00:20:22,760 --> 00:20:25,840 Speaker 1: an efficient use of space. That was the argument against 345 00:20:26,119 --> 00:20:30,520 Speaker 1: this strategy. Uh, that's obviously inefficient, but it was also 346 00:20:30,640 --> 00:20:34,199 Speaker 1: technically easier to do, and so about half the working 347 00:20:34,200 --> 00:20:37,760 Speaker 1: group wanted to pursue frequency hopping as the modulation methodology 348 00:20:37,760 --> 00:20:41,199 Speaker 1: of choice because while it wasn't efficient, it was easier 349 00:20:41,240 --> 00:20:46,640 Speaker 1: to implement. Direct sequence spread spectrum or d S S 350 00:20:46,640 --> 00:20:51,240 Speaker 1: S introduces pseudo random noise into the signal it sins 351 00:20:51,520 --> 00:20:54,520 Speaker 1: in order to change the phase of the signal itself. 352 00:20:54,560 --> 00:20:58,000 Speaker 1: This creates the digital equivalent of static. It would seem 353 00:20:58,040 --> 00:21:01,400 Speaker 1: to be meaningless information when you received it, but if 354 00:21:01,440 --> 00:21:05,200 Speaker 1: you knew which pseudo random sequence was used to create 355 00:21:05,280 --> 00:21:08,639 Speaker 1: the phase shift, you could reverse that whole process. You 356 00:21:08,680 --> 00:21:13,040 Speaker 1: could d spread the static and extract the meaningful information 357 00:21:13,080 --> 00:21:16,400 Speaker 1: out of it. D S S S is more challenging 358 00:21:16,440 --> 00:21:19,600 Speaker 1: to implement than f H S S, but it also 359 00:21:19,800 --> 00:21:22,000 Speaker 1: is more robust, and so the other half of the 360 00:21:22,040 --> 00:21:25,560 Speaker 1: group wanted to follow that idea. Both of those methodologies 361 00:21:25,560 --> 00:21:28,600 Speaker 1: would allow for multiple devices to communicate across a band 362 00:21:28,640 --> 00:21:32,320 Speaker 1: of frequencies without interfering with one another, and the I 363 00:21:32,560 --> 00:21:35,760 Speaker 1: E E E Rules stated that in order to adopt 364 00:21:35,800 --> 00:21:38,920 Speaker 1: a strategy, you had to secure the support of at 365 00:21:39,000 --> 00:21:42,679 Speaker 1: least seventy of the working group, but each method had 366 00:21:42,720 --> 00:21:46,680 Speaker 1: about of the support. The only solution was to create 367 00:21:46,720 --> 00:21:49,960 Speaker 1: a system that could support both modulation strategies, and so 368 00:21:50,080 --> 00:21:53,640 Speaker 1: that's what the group decided to do. I'll wrap up 369 00:21:53,680 --> 00:21:55,879 Speaker 1: the history of WiFi and give all a low down 370 00:21:55,920 --> 00:21:58,439 Speaker 1: on what the different variations mean in just a second. 371 00:21:58,440 --> 00:22:01,320 Speaker 1: But first let's take another their quick break to thank 372 00:22:01,359 --> 00:22:11,720 Speaker 1: our sponsor. While the working group began to hash out 373 00:22:11,760 --> 00:22:15,440 Speaker 1: the standards that would become fundamental to WiFi, a group 374 00:22:15,520 --> 00:22:20,399 Speaker 1: of engineers, astronauts and astronomers were developing a technique that 375 00:22:20,480 --> 00:22:24,440 Speaker 1: would become just as important. Vick Hayes, whom I mentioned earlier, 376 00:22:24,600 --> 00:22:28,160 Speaker 1: is sometimes called the father of WiFi, but another man, 377 00:22:28,600 --> 00:22:33,840 Speaker 1: John O'Sullivan, also gets that title on occasion. O'Sullivan is 378 00:22:33,880 --> 00:22:38,080 Speaker 1: an electrical engineer, and he focused on radio astronomy. He 379 00:22:38,160 --> 00:22:41,119 Speaker 1: led a team that developed a way to reduce multi 380 00:22:41,240 --> 00:22:46,080 Speaker 1: path interference of radio signals, something that was absolutely necessary 381 00:22:46,160 --> 00:22:48,639 Speaker 1: if you want to have a smooth experience with a 382 00:22:48,720 --> 00:22:52,960 Speaker 1: wireless local area network. His team's work would receive a 383 00:22:53,040 --> 00:22:58,360 Speaker 1: patent credited to the Commonwealth Scientific and Industrial Research Organization 384 00:22:58,920 --> 00:23:02,480 Speaker 1: or c s i r O, which is an Australian 385 00:23:02,560 --> 00:23:05,760 Speaker 1: federal government agency. The really funny thing to me is 386 00:23:05,800 --> 00:23:08,639 Speaker 1: that this research was originally part of an experiment to 387 00:23:08,720 --> 00:23:13,360 Speaker 1: try and detect expanding many black holes. That experiment failed, 388 00:23:13,560 --> 00:23:16,680 Speaker 1: but the technique would end up changing the world once 389 00:23:16,720 --> 00:23:21,159 Speaker 1: incorporated into WiFi. Meanwhile, back in the eight O two 390 00:23:21,160 --> 00:23:25,080 Speaker 1: point eleven Working Group, the standard was getting closer to 391 00:23:25,160 --> 00:23:28,320 Speaker 1: becoming a real thing. The very first version of the 392 00:23:28,359 --> 00:23:34,119 Speaker 1: protocol was unveiled in It had a maximum download speed 393 00:23:34,200 --> 00:23:38,600 Speaker 1: of two megabits per second, which is excruciating lee slow 394 00:23:38,720 --> 00:23:41,920 Speaker 1: these days, and that was only if you could use 395 00:23:42,000 --> 00:23:45,880 Speaker 1: the D S S S approach. Remember, it involved both 396 00:23:45,880 --> 00:23:49,760 Speaker 1: the direct spread and the frequency hopping. If you used 397 00:23:49,840 --> 00:23:53,600 Speaker 1: frequency hopping, you topped out at one megabit per second. 398 00:23:54,280 --> 00:23:56,920 Speaker 1: That didn't exactly cause everyone to throw their cables out 399 00:23:56,920 --> 00:23:59,760 Speaker 1: their respective windows in a fit of joy, but it 400 00:23:59,840 --> 00:24:05,200 Speaker 1: was progress. In ninet, the Working Group released a new protocol, 401 00:24:05,760 --> 00:24:09,760 Speaker 1: and this one was called eight O two dot eleven B. 402 00:24:10,520 --> 00:24:13,320 Speaker 1: It also used D S S S and the two 403 00:24:13,359 --> 00:24:15,840 Speaker 1: point for a gigahertz band, but it was able to 404 00:24:15,880 --> 00:24:19,520 Speaker 1: boost speeds up to eleven megabits per second. While this 405 00:24:19,640 --> 00:24:22,320 Speaker 1: was the second protocol released by the group, it was 406 00:24:22,359 --> 00:24:25,679 Speaker 1: the first to be widely adopted as a wireless local 407 00:24:25,720 --> 00:24:28,840 Speaker 1: area network standard. Chances are, if you were an early 408 00:24:28,880 --> 00:24:33,520 Speaker 1: adopter of wireless technology, this was the standard your computer 409 00:24:33,680 --> 00:24:36,280 Speaker 1: was using, as it was the first that time that 410 00:24:36,320 --> 00:24:40,880 Speaker 1: manufacturers actually embraced this technology when they started making network adapters. 411 00:24:41,400 --> 00:24:45,040 Speaker 1: Later on, the functionality would be built directly onto laptop 412 00:24:45,119 --> 00:24:47,680 Speaker 1: motherboards instead of having to get an adapter that you 413 00:24:47,680 --> 00:24:50,399 Speaker 1: would plug into your laptop. But this was still pretty 414 00:24:50,480 --> 00:24:54,239 Speaker 1: darn slow compared to wired connections. A little later in nine, 415 00:24:55,440 --> 00:24:58,200 Speaker 1: a new methodology launched. It was called eight O two 416 00:24:58,280 --> 00:25:02,320 Speaker 1: point one one A. And yes, these designations are getting 417 00:25:02,320 --> 00:25:05,360 Speaker 1: awfully confusing because the naming standard jumps around a bit. 418 00:25:05,520 --> 00:25:08,919 Speaker 1: We just talked about AT two point eleven B and 419 00:25:08,960 --> 00:25:11,159 Speaker 1: the original one was just called AT two point eleven 420 00:25:11,280 --> 00:25:13,200 Speaker 1: and now we're talking about ATO two point eleven A. 421 00:25:13,960 --> 00:25:16,479 Speaker 1: This one had a couple of major differences from the 422 00:25:16,560 --> 00:25:20,360 Speaker 1: earlier versions. First, it worked on a different band of frequencies. 423 00:25:20,400 --> 00:25:23,520 Speaker 1: Instead of using two point four giga hurts, at two 424 00:25:23,520 --> 00:25:26,880 Speaker 1: point eleven A relied on five giga hurts, And that 425 00:25:26,920 --> 00:25:30,239 Speaker 1: meant the AT two point eleven A standard was not 426 00:25:30,400 --> 00:25:33,199 Speaker 1: compatible with the earlier ones because it was using a 427 00:25:33,240 --> 00:25:36,400 Speaker 1: totally different range of frequencies for communications, so you could 428 00:25:36,440 --> 00:25:41,320 Speaker 1: not use a Dot eleven A device with a Dot 429 00:25:41,320 --> 00:25:44,680 Speaker 1: eleven B device. They talked on different radio frequencies so 430 00:25:44,680 --> 00:25:47,359 Speaker 1: they could not communicate with each other, but it was 431 00:25:47,400 --> 00:25:50,359 Speaker 1: also faster, with the top speed of around fifty four 432 00:25:50,440 --> 00:25:54,080 Speaker 1: megabits per second. In addition, it relied on something called 433 00:25:54,320 --> 00:25:59,200 Speaker 1: orthogonal frequency division multiplexing or o f d M. Now, 434 00:25:59,240 --> 00:26:02,120 Speaker 1: this is a way to in code data across multiple 435 00:26:02,200 --> 00:26:06,919 Speaker 1: carrier frequencies, and maybe someday I'll try to tackle that 436 00:26:07,000 --> 00:26:10,280 Speaker 1: concept in a full episode, but it gets super technical, 437 00:26:10,320 --> 00:26:12,320 Speaker 1: so I'm going to leave it for now because I'm 438 00:26:12,359 --> 00:26:14,240 Speaker 1: running out of time and we still have a couple 439 00:26:14,280 --> 00:26:16,800 Speaker 1: of versions of WiFi we have to touch upon. The 440 00:26:16,840 --> 00:26:20,920 Speaker 1: next one is at two point eleven G. That standard 441 00:26:20,960 --> 00:26:23,600 Speaker 1: debuted in two thousand three, and it uses the two 442 00:26:23,680 --> 00:26:26,040 Speaker 1: point for giga Hurts radio band, so back to two 443 00:26:26,119 --> 00:26:29,760 Speaker 1: point four but like at two point eleven A, it 444 00:26:29,920 --> 00:26:33,240 Speaker 1: also used o f d M, and that would give 445 00:26:33,680 --> 00:26:37,160 Speaker 1: point eleven G a max speed of fifty four megabits 446 00:26:37,200 --> 00:26:39,960 Speaker 1: per second. And because it communicates on the two point 447 00:26:40,000 --> 00:26:42,760 Speaker 1: four giga Hurts range, it is compatible with eight to 448 00:26:42,880 --> 00:26:44,840 Speaker 1: two point eleven B, and so a lot of the 449 00:26:44,840 --> 00:26:48,040 Speaker 1: equipment you could buy, such as a wireless router, would 450 00:26:48,040 --> 00:26:50,639 Speaker 1: have the designation of eight to two point eleven B 451 00:26:50,880 --> 00:26:55,280 Speaker 1: slash G, meaning it could operate across both standards. Also, 452 00:26:55,320 --> 00:26:57,919 Speaker 1: you should know that communication can only go as fast 453 00:26:58,000 --> 00:27:01,560 Speaker 1: as the slowest component involved in the communication. So if 454 00:27:01,600 --> 00:27:04,440 Speaker 1: you had an AT two point eleven B device communicating 455 00:27:04,480 --> 00:27:07,320 Speaker 1: with an AT two point eleven G device, you could 456 00:27:07,359 --> 00:27:10,200 Speaker 1: only hit speeds about to eleven megabits per second because 457 00:27:10,240 --> 00:27:13,639 Speaker 1: that was the top speed limit for B. So it's 458 00:27:13,720 --> 00:27:15,440 Speaker 1: kind of like a a chain is only as strong 459 00:27:15,480 --> 00:27:18,480 Speaker 1: as its weakest link. The connections are only as fast 460 00:27:18,520 --> 00:27:21,640 Speaker 1: as their slowest point. In two thousand nine, we got 461 00:27:21,640 --> 00:27:25,159 Speaker 1: at two point eleven IN. This standard allowed for the 462 00:27:25,280 --> 00:27:30,000 Speaker 1: use of multiple antennas when transmitting information, which increased speeds 463 00:27:30,119 --> 00:27:34,040 Speaker 1: up to four hundred fifty megabits per second. What's more, 464 00:27:34,400 --> 00:27:37,600 Speaker 1: the eleven N standard could operate across both two point 465 00:27:37,640 --> 00:27:40,760 Speaker 1: four and five giga hurts bands, meaning it could also 466 00:27:40,760 --> 00:27:44,560 Speaker 1: communicate with all the older standards like AT two point 467 00:27:44,600 --> 00:27:47,879 Speaker 1: eleven B, slash G and at two point eleven A. 468 00:27:48,640 --> 00:27:52,040 Speaker 1: Then in two thousand twelve we got at two point 469 00:27:52,080 --> 00:27:56,520 Speaker 1: eleven A C and yes I am crying, thanks for asking. 470 00:27:56,840 --> 00:27:59,520 Speaker 1: This standard operates in the five giga hurts range and 471 00:27:59,560 --> 00:28:02,480 Speaker 1: has ends for speeds in the gigabit realm, which is 472 00:28:02,840 --> 00:28:05,800 Speaker 1: wicked fast. It's also really useful if you've got a 473 00:28:05,880 --> 00:28:09,359 Speaker 1: lot of machines connected within that single wireless land, because 474 00:28:09,359 --> 00:28:11,880 Speaker 1: you've got a lot of bandwidth to play with. Now, 475 00:28:12,000 --> 00:28:16,000 Speaker 1: at ce seen some companies showed off devices that are 476 00:28:16,080 --> 00:28:18,840 Speaker 1: using a new version of WiFi has not yet had 477 00:28:18,880 --> 00:28:22,320 Speaker 1: an official release. It's called eight O two point eleven 478 00:28:22,440 --> 00:28:26,080 Speaker 1: a X, and the devices at ce S were reported 479 00:28:26,119 --> 00:28:29,840 Speaker 1: to have a top data transmission speed of eleven gigabits 480 00:28:29,960 --> 00:28:34,280 Speaker 1: per second, which is really wicked fast. It can operate 481 00:28:34,320 --> 00:28:37,000 Speaker 1: in both the two point four and five giga Hurts bands, 482 00:28:37,040 --> 00:28:42,120 Speaker 1: and it should launch sometime in two thousand nineteen officially. Now, 483 00:28:42,120 --> 00:28:44,600 Speaker 1: there are other versions of the WiFi standard that don't 484 00:28:44,720 --> 00:28:47,560 Speaker 1: use the two point four or five giga Hurts ranges. 485 00:28:47,800 --> 00:28:50,760 Speaker 1: They tend to be for other types of technologies than 486 00:28:50,840 --> 00:28:54,040 Speaker 1: mobile devices and computers. They could be for something like 487 00:28:54,080 --> 00:28:57,520 Speaker 1: an in vehicle network, for example, And I didn't cover 488 00:28:57,560 --> 00:28:59,720 Speaker 1: them because you're not likely to work with them yourself 489 00:28:59,800 --> 00:29:02,440 Speaker 1: in an average setting. But I hope this gives you 490 00:29:02,720 --> 00:29:07,440 Speaker 1: a little more information about WiFi. Maybe in a future episode, 491 00:29:07,440 --> 00:29:10,560 Speaker 1: I'll dive into deeper detail of exactly how WiFi works. 492 00:29:10,880 --> 00:29:13,920 Speaker 1: But you have a general idea it's all about radio frequencies, 493 00:29:14,280 --> 00:29:16,840 Speaker 1: mostly in the two point four gig hurts or five 494 00:29:16,920 --> 00:29:19,840 Speaker 1: giga hurts five point seven to five gig hurts range, 495 00:29:19,880 --> 00:29:24,440 Speaker 1: to be specific, and that it involves various modulation techniques 496 00:29:24,720 --> 00:29:29,360 Speaker 1: so that multiple devices can communicate with a centralized router 497 00:29:29,600 --> 00:29:33,280 Speaker 1: or hub in order to send information with to each 498 00:29:33,320 --> 00:29:36,040 Speaker 1: other and also to the Internet at large. So it's 499 00:29:36,080 --> 00:29:40,120 Speaker 1: been a very useful technology, one that has transformed our 500 00:29:40,160 --> 00:29:45,280 Speaker 1: world in meaningful and difficult to anticipate ways, and I 501 00:29:45,320 --> 00:29:48,600 Speaker 1: suspect the that will continue to be the case. In fact, 502 00:29:48,640 --> 00:29:53,240 Speaker 1: we may even see wireless technologies supersed wired ones to 503 00:29:53,280 --> 00:29:56,920 Speaker 1: the point where people who are using high speed connections 504 00:29:56,960 --> 00:30:01,080 Speaker 1: for their jobs or for stuff like high end gaming 505 00:30:01,520 --> 00:30:04,719 Speaker 1: will choose to go wireless rather than wired, because we 506 00:30:04,760 --> 00:30:07,000 Speaker 1: may eventually get to the point where it's just faster, 507 00:30:07,560 --> 00:30:12,080 Speaker 1: it's just less latency, higher data throughput rates. If that happens, 508 00:30:12,320 --> 00:30:15,280 Speaker 1: it's really a game changer. I hope you guys enjoyed 509 00:30:15,320 --> 00:30:18,280 Speaker 1: this episode. If you have any requests for future topics, 510 00:30:18,280 --> 00:30:21,080 Speaker 1: I should cover here on tech stuff, whether it's a technology, 511 00:30:21,200 --> 00:30:24,200 Speaker 1: maybe it's a person in technology, maybe it's a company, 512 00:30:24,560 --> 00:30:26,360 Speaker 1: or maybe there's someone you would like me to interview 513 00:30:26,440 --> 00:30:28,480 Speaker 1: or have on as a guest host, let me know. 514 00:30:28,680 --> 00:30:31,200 Speaker 1: Send me an email the addresses tech stuff at how 515 00:30:31,280 --> 00:30:33,640 Speaker 1: stuff works dot com, or draw me a line on 516 00:30:33,680 --> 00:30:35,880 Speaker 1: Facebook or Twitter. The handle of both of those is 517 00:30:35,960 --> 00:30:39,239 Speaker 1: tech stuff H s W. Don't forget to follow us 518 00:30:39,240 --> 00:30:43,200 Speaker 1: on Instagram and I'll talk to you again really soon. 519 00:30:48,840 --> 00:30:51,280 Speaker 1: For more on this and thousands of other topics, is 520 00:30:51,280 --> 00:31:02,440 Speaker 1: it how stuff works dot com.