how will wireless 5g technology handle 1,000 times more data that's what I'm gonna talk about today and my name is Emily Johnson I'm an associate professor and docent at Lynch Apple University in Sweden so what is wireless communication that is what you're using when you're attending information between your mobile phone and an access point in a cellular network like a base station that you can find a rooftop of building or one is Wi-Fi station that you find everywhere in many buildings today and what are these signals that are being sent well that is what is the wireless transmission and the signals are electromagnetic waves that are radiating from one size for the user for example up to one of these devices and this is nothing else than light but at frequencies that our eyes can see but that the antennas in user device and in one of this access point are able to detect its transmitted and information that we're sending is digital information today and these are serious and ones that describes different things it could be text it could be sound could be images or video whatever type of information we're sending we communicate it with wireless communication today and for that reason we have seen a fast traffic growth because nowadays our mobile phone is not only used to do calls but we also do video streaming gaming social networking and new killer applications are showing up all the time so we haven't thought about before that we really want to use when we heard about them and that means that we are consuming more data every month more gigabyte in our subscriptions and for that reason if you look at data for example Ericsson mobility report you can see that the amount of data that we are transmitting wirelessly increases by around 50 percent every year so if we in 2015 we're transmitting 0.7 gigabyte per person per month we will in a few years in 2021 transmit as much at 6.5 gigabyte per personal month and this is split up over all people in the world so some people obviously using more and some much less but this means that if we have an annual increase of 50% it's going to grow very quickly and we will have as much as 1,000 times more data traffic until here 2030 for this also means that even if we have a technology that worked very well today with all the time needs to create a new technology that and improve the old ones so we are able to deliver this much more data traffic Efrat reason we have generations our wireless communications so in Sweden it was around 90 to 1 that the first generation showed up this was an analog technology which meant that you can centrally listen to it in the same way as you listen to radio in your car however in 1991 that was when the first 2g systems showed up and that was based on digital technology as the technology we have today and what it was mainly used to make phone calls then around year 2001 3G shura and one of the new things there was so you can internet on your phone you can make video calls and such things and in 2010 we had realised that ok it is the Internet applications that are the most important ones and therefore the 4G systems arrived and that one was used in particular to do mobile broadband applications and you can see here it's around 10 years time between every generation and that means that until year 2020 we will show our C and new technology showing it and that technology is what we call 5g and today 5 G's under development standardization is going on and prior to that a lot of researchers were discussing what are the new technological components that needs to be added here and what are the goals that we need to have with the system and of course we would like it to be faster before when we are transmitting information we also need to be able to deliver 1,000 times more data and other things we are talking about is that we would like the system to be were robust so we can really trust it as men we are trusting the electrical grid to always work no more coverage problems for example and we also will like the system to be much more energy efficient at least for devices that the man stat so today you might have to charge a mobile phone every day but if you put up a small sensor somewhere that's gonna send a little bit of information now and then you will like its battery to last for perhaps 10 years and that requires a whole new way of building the systems so everything we're talking about here is wireless technology where we are sending a little electromagnetic signals from an antenna to access point to an antenna to cell phone and these waves here you can view it in the following way think about this antenna access point as a flickering light bulb sometimes its arms sometimes it off and at the receiver we have like a camera taking vocalists and detecting when is the flickering turning on the light bulb and when is it off and based on that we can guess what's the 0 or a 1 the way of transmitting that is the basic concept and what we really are doing then is that we make sure that our digital bits information is somehow transmitted as electromagnetic signals and we cannot send everything at once but we are sending a few of them at a time so if this is sequence 0 0 1 0 1 1 0 1 that we would like to convey well then we can split it up into different pieces and transmit one at a time and every time we transmit something like that we are detecting what was transmitted to receiver and these are submissions are going very rapidly so for example it could be microseconds between the transmissions it's an example if you heard about a sinusoid this is one period of that signal and if we would like to convey serous zero we can send that red signal if you would like to convey cr1 we can send a phase shifted version this green signal if you would like to send one one we can have the purple one over here and if you would like to convey one-zero we can send the blue one like this so let me give you an example that but first just notice that the period here of the signal is proportional to one over the bandwidth so the more bandwidth we can let our senior consume the shorter the time will be and in that way the bandwidth is a number of transmissions like this that we can do per second okay so let's make an example this is the sequence a bits that would like to transmit so first 0 0 then we look ok it was this red signal so we cop it and transmit that one then 1 0 we look ok it was the blue signal here that is corresponding to 1 0 1 1 we take the purple one transmit that one after previous once 0 1 that is the green one we caught it so that is 2 procedure we look at with signals that we would like or with sequence of bits we like to transmit we pick the right signal and transmit that one and next time we have 1 1 we take the same purple one next time we have 0 0 we take the same red one representing 0 0 and we continue like that over and over again we can transmit very very long sequences with million of these bits in a short time period so this is a signal what's going to transmit it of course without any color it's just a single letter transmitted the problem is then that what you're going to receive at the other side is often destroyed by noise and distortion so it might look much more like this and therefore the challenge for wireless researchers as myself is how can we transmit as many short intervals like this and let them represent as many different alternatives as possible and still be able to detect from a single look like this what were the actual signals are transmitted that is wireless communication in that row so in the question that I was posting here was how will five you technology handle 1000 it's more data and in order to understand as we need to break down the problem look at increasing the data traffic in a particular area this could be an area one square kilometer or something else the important thing is that within this area we would like to deliver 1,000 times more traffic data and for this problem we can use this following formula that the capacity meaning number of bits per second that we can convey per square kilometer can be divided up into three different factors the first one is the cell density measured in cells per square kilometer so that is the number of small areas that we are dividing this bigger area into and in each area we call it a cell we stole one access point that is taking care of the users in this cell then we have a factor called as spectral efficiency measured in bits per second per Hertz per cell this is a measure of how efficiently each access point can communicate with the users and finally we have the available frequency spectrum measured in Hertz if you multiply these units together you're going to get bits per second per square kilometer which is a good way of checking that the formula this makes sense and the important thing then is that if you would like to achieve a 1,000 times more data traffic then the capacity need to grow with 1,000 times and we have these three different factors that we can improve for example when people start to talk about these type of formulas in 2011 Nokia said we believe that we can reach 1,000 by 10 times more cells ten times higher spectral efficiency and ten times more spectrum ten times ten times ten becomes 1000 is one way of achieving this number another way is something that SK Telecom a South Korean telecom operator suggested that maybe we should have much more cells instead 56 times more cells six times more spectral efficiency and three times more spectrum that was what they believed in and if you multiply those numbers together you get essentially 1,000 which was the point here and what is important is that everyone can have their own opinions about how we much we're going to improve these different factors but everyone agrees on that we need to make improvements in all three of them otherwise there's no chance that we can reach 1,000 so what I'm gonna do now is to go brief a fruit each of the factors and explain how we can make improvements so the first factor higher cell density so as I told you we are dividing an area into cells and that is why we are calling this type of things cellular networks and the phone for cell phones and each cell has an access point located somewhere in it and this access point serves all these users in the cell so they are sending the signals back and forth to each other and what we can do in order to improve the cell density is to simply deploy more access points so if we from the beginning have this many cells then we can have more and more and in that way we comes denser and denser more axons point per square kilometer and that also means that the access point to jus kind of communicate with will be much closer to you and in that way you can also cut down on your transmit power and save energy and the challenge is that the more access point you put up in an area the more potential interference there will be so that means that in order to still deliver the same amount of data in each of the cells when you have a big and the small one we need to deal with interference problem in a particular way and that's one of the challenges when you are building systems like this the next factor is higher spectral efficiency so the spectral efficiency is a measure that comes from information theory and tells us how many bits can we convey per second and per Hertz of communication spectrum and if you look into the formulas from information theory it turns out that it's very challenging to improve the spectral efficiency beyond a certain thing called a channel capacity and what you can do is that you can increase your transmit power and that turns out to be very expensive because every time you were like a double spectral efficiency by increasing power you essentially need 17 times more power to do that doubling is 17 times 17 so this is not real the way you do it what instead do is to try to have many simultaneous transmissions and make sure that each transmission have the same spectral efficiency as before but if you have many of them you multiplex well many of them then you get much more in total in order to do that we need to leave the conventional systems where you have one antenna that is radiating the signals in a predefined manner this could be like in all directions equally or as a spotlight in a particular direction and that is when we use in what we call them I am a technology called multiple impulse multiple output meaning that instead of having one antenna we're gonna have an array or multiple antennas say 100 or 200 and each of them is just small antenna elements and by sending the signals from this in the particular way we are able to direct the signal towards the user and not in other directions so very directly of like having a spotlight that is following you wherever you are and if you do this properly you can send signal to 10 or 20 users at the same time even if they are in the same cell and in that way you will have 10 or 20 times higher spectral efficiency the third factor is more frequency spectrum and how we would do that well remember that the bandwidth was proportional to the number cross mission that we can have per second or you can say that we reduced the time per transmission per serie one that we are sending by having a larger bandwidth and in order to increase a spectrum we will like to find some undo spectrum and the problem is that today old applications are around 300 megahertz up to 5 gigahertz that's where 2g 3G 4G Wi-Fi television broadcasting and also many military applications and other things that is where they are operating and we have already allocated a lot of those resources to different applications and tweetment for example we have 580 megahertz for cellular communications and another 540 megahertz for Wi-Fi if you add up together it's 1 gigahertz and the whole interval here is less than 5 gigahertz what we're using 1/5 of this area so there's no way you can get more than 5 times that in order to get something like that you will need to throw out all other types of applications that there are so that's not really the way to do it but there are actually many other frequencies far above 5 gigahertz and that is what we are looking at today how can we use much higher frequency bands before for communications and that is something called millimeter wave communications because the wavelength is around a millimeter in this balance and we typically talking about 30 gigahertz up to 300 gigahertz the challenges here wouldn't be that the same propagation is very different particular when you have such a short wavelength it doesn't propagate through your hand for example so if you're handing is round your handset and put it towards your ear it'd be very hard for the signal to find a way from your phone even so you need to build this isn't right way and also be able to design new hardware that are able to work in these type of environments and to have such huge bandwidth that's not been done before so that leads me to the summary so the question was how will fight the technology handle 1000 times more data and we had three different factors one was higher cell density and that means that you DISA deploy more access point per square kilometer she shrink the size of each cell I believe that around 1000 times more data can be achieved by having 10 times higher cell density and when it comes to higher spectral efficiency it is the mai-mai technology that's being used for that and that means you direct signal towards users and you serve many use at the same time different directed signals and I believe that you can achieve around 20 times improvement in that and finally more frequency spectrum which leads to more small transmissions per second and more data rate in that way and in order to make large improvements we need to go up to higher frequencies for example this millimeter wave bands from 30 to 300 gigahertz and I believe that five times more there is something that's reasonable to achieve and this 10 times 20 times 5 that's 1,000 just true just my guess I think that everyone had their own opinions in this industry about how you make improvements but everyone agrees on that you need to improve all 3 of them in order to reach 1,000 so if you would like to know more about 5g there's a lotta resources online and for example I have YouTube channel that you can follow for my communication systems group and it can also follow the massive MIMO block on massive MIMO dotnet and there we're writing about the mind technology and different aspects of 5g and I'm Aiman beyond song I'm associate professor in communication systems at Lincoln University thank you
