Right. We're going to dive into Wireless Protocols. I have these divided into long-range wireless communication protocols. Also, they're sometimes known as Low-Power Wide-Area Networks, you may see this acronym LPWAN. Also known as, aka Low-Power Networks (LPN), aka Small-Cell Networks (SCN). Though we've got cellular. We got one called LoRa, It's also known as LoRaWAN, wide area network, Ingenu, WiMAX. The other category are short-range wireless communication protocols. You got ANT+, Bluetooth Smart, ZigBee, WiFi, we're all really familiar with that one, Near Field Communications, EnOcean, Wireless Hart, Z-Wave and, something called 6LoWPAN. I'm not sure how people pronounce it Six Lo WPAN, or, there it is. We'll see that the 6LoWPAN is the basis for actually a couple of these other ones. So diving into the long-range wireless protocols. We've got Cellular; GSM, and 4G/LTE currently. You know who are the players in the US are, the range is anywhere from five to 30 kilometers. This seems like a bit of a stretch to me. I have AT&T, I get one bar at my house. I've called and complained a few times and they say, "We'll see if we can do something," and then, "We're going to reboot some piece of equipment, cell tower nearest to you," and they wanted me to power cycle my phone and, " Is it any better now?" "No." The speeds, when I was in Denver I ran this download test and I got 28 megabits per second down and 6.5 megabits per second up. Tell me your name again. Greg. Greg. So, Greg ran, he has Verizon, so he ran the SpeedOf.Me test. Because whoever I had run this, they were only getting 4.9 and 1.8 megabits. Interestingly enough, Greg reported 5.6 megabits per second down and 10 megabits per second up. I just found that interesting. Usually, it's the other way around because we're consumers of information, so that would just happen to be the rates today. Cellular - 5G, probably heard about this. This is a work in progress. No one really knows today, according to my understanding, exactly what 5G is going to encompass. But it's actively being worked on, there's a very nice video that we'll watch here in a second, that IEEE Spectrum put together that talks about the work and the different technologies that are coming together to enable 5G. Every new generation of wireless networks delivers faster speeds and more functionality to our smartphones. 1G brought us the very first cell phones, 2G let us text for the first time, 3G brought us online and 4G delivered the speeds that we enjoy today. But as more users come online, 4G networks have just about reached the limit of what they're capable of at a time when users want even more data for their smartphones and devices. Now we're headed towards 5G, the next generation of wireless. It will be able to handle a thousand times more traffic than today's networks and it'll be up to ten times faster than 4G/LTE. Just imagine downloading an HD movie in under a second and then let your imagination run wild. 5G will be the foundation for Virtual Reality, autonomous driving, the Internet of Things and, stuff we can't even yet imagine. But what exactly is a 5G network? The truth is, experts can't tell us what 5G actually is because they don't even know yet. But right now there are five brand new technologies emerging as a foundation of 5G: Millimeter Waves, Small Cells, Massive MIMO, Beamforming and, Full Duplex. First up, technology number one, Millimeter Waves. Your smartphone and other electronic devices in your home, use very specific frequencies on the radio frequency spectrum, typically those under six gigahertz. But these frequencies are starting to get more crowded. Carriers can only squeeze so many bits of data on the same amount of radio frequency spectrum. As more devices come online, we're going to start to see slower service and more dropped connections. The solution is to open up some new real estate. So researchers are experimenting with broadcasting on shorter millimeter waves, those that fall between 30 and 300 gigahertz. This section of spectrum has never been used before for mobile devices and opening it up means more bandwidth for everyone. But there is a catch, millimeter waves can't travel well through buildings or other obstacles and they tend to be absorbed by plants and rain. To get around this problem, we'll need technology number two, Small Cell Networks. Today's wireless networks rely on large high-powered cell towers to broadcast their signals over long distances, but remember higher frequency millimeter waves have a harder time traveling through obstacles, which means if you move behind one, you lose your signal. Small Cell Networks would solve that problem using thousands of low-power mini base stations. These base stations would be much closer together than traditional towers, forming a sort of relay team to transmit signals around obstacles. This would be especially useful in cities, as a user move behind an obstacle, his smartphone would automatically switch to a new base station and better range of his device, allowing him to keep his connection. Next up, technology number three, Massive MIMO. MIMO stands for Multiple Input Multiple Output. Today's 4G base stations have about a dozen ports for antennas that handle all cellular traffic, but massive MIMO base stations can support about 100 ports, this could increase the capacity of today's networks by a factor of 22 or more. Of course, massive MIMO comes with its own complications. Today's cellular antennas broadcast information in every direction at once and all of those crossing signals can cause serious interference, which brings us to technology number four, Beamforming. Beamforming is like a traffic signaling system for cellular signals. Instead of broadcasting in every direction, it would allow a base station to send a focus stream of data to a specific user. This precision prevents interference and it's way more efficient. That means stations could handle more incoming and outgoing data streams at once. Here's how it works, say you're in a cluster of buildings and you're trying to make a phone call, your signal is ricocheting off of surrounding buildings and crisscrossing with other signals from users in the area. A massive MIMO base station receives all of these signals and keeps track of the timing and the direction of their arrival. It then uses signal processing algorithms to triangulate exactly where each signal is coming from and plots the best transmission route back through the air to each phone. Sometimes, it'll even bounce individual packets of data in different directions off of buildings or other objects to keep signals from interfering with each other. The result is a coherent data stream sent only to you, which brings us to technology number five, Full Duplex. If you've ever used a walkie-talkie, you know that in order to communicate, you have to take turns talking and listening. That's kind of a drag. Today's cellular base stations have that exact same holdup. A basic antenna can only do one job at a time, either transmit or receive. This is because of a principle called, reciprocity, which is the tendency for radio waves to travel both forward and backward along the same frequency. To understand this, it helps to think of a wave like a train loaded up with data, the frequency it's traveling on is like the train track and, if there's a second train trying to go in the opposite direction on the same track, you're going to get some interference. Up until now, the solution has been to have the trains take turns or to put all the trains on different tracks or frequencies. But you can make things a lot more efficient by working around reciprocity. Researchers have used silicon transistors to create high-speed switches that halt the backward role of these waves. It's kind of like a signalling system that can momentarily reroute two trains so that they can get past each other. That means there's a lot more getting done on each track, a whole lot faster. We're still working out many of the kinks with Millimeter Waves, Small Cell Networks, Massive MIMO, Beamforming and Full Duplex. In fact, all of 5G is still a work in progress. It will likely include other new technologies too, and, making all of these systems work together will be a whole other challenge. But if experts can figure that out, ultrafast 5G service could arrive in the next five years. Are there any RF engineering students in the class? Have RF background? I'm not sure if that's a good thing or a bad thing. So I want backup. So, I worked in a satellite communications company for a spell and I learned just enough about Beamforming to be dangerous on a digital logic hardware design engineering in RF is somewhat mystical to me. I'm going to draw a cartoon of what I think happens and I think it's fascinating and I just wanted to share that with you. So don't take this as a absolute, a fact. This is, as I said, interpret what I'm about to tell you from the perspective that I'm a digital hardware engineer and not an analog RF. Personally known formally. As I understand it, the way Beamforming works is there's a series of antenna elements. So think of these as little surfaces that will transmit RF energy. They're driven by say solid-state power amplifiers or something to drive the RF energy. By sending a stream of analog signals or data to these amplifiers, but then becomes analog at this point, but offsetting their timing just a little bit. It sets up regions of positive reinforcement and cancellation and the net result is they can change the direction based on how the set of signals are arriving at these antenna elements so that they can transform a beam often in this direction and then they can adjust the phase relationship of the signals coming into these antenna elements and then later transmit off at another different direction. I thought it was pretty cool.
