You mentioned some browsing or the data transmissions. Is 5G, mostly for data transmission, uploading, downloading, or can we use it for phone calls as well? Good catch. I do realize that we did not talk much about voice calls. But to answer your question at a higher level, yes, 5G absolutely will support ability to make and receive voice calls. Just that as you correctly pointed out, the focus is on facilitating high-speed throughput and certain other unique cases. How can 5G support voice calls if the focus is on high-speed data? Well, there are two prominent approaches that network operators can follow. One is that, if your phone has both 4G and 5G capabilities, then when you want to make a voice call, your network will silently transfer your phone from 5G to 4G. I'm simplifying things here a bit for the sake of the discussion. But think of it this way, that the network will silently transfer your phone from 5G connection to a 4G connection, you will make or receive your voice call, and once that voice call is complete, the network will automatically and silently bring your phone back to a 5G connection from a 4G connection. You as the end-user, don't have to do anything to that end that is completely transparent and seamless to you. Your network works that magic with your phone in the background. That is one approach, Technical term for that is a Fallback. The another approach is or would be that off voice capabilities in the native 5G network. Although that sounds pretty simple on paper in theory, in practice, it's a little difficult to implement because providing voice service requires many different considerations in the network as compared to providing a data service. Just like taking care of a baby requires many different consideration than taking care of a teenager. In technical language, those are called quality of service, and there are certain components that need to be deployed in the network in order to provide that voice service. Until 5G gets to that point where in those additional components can be deployed, some operators might prefer the Fallback approach that I mentioned earlier, whereas certain other operators can choose to deploy the voice framework as well as the data framework act the same time, so that on Day 1 the users will have access to both 5G data as well as 4G voice at the same time. But as I mentioned, doing so that as it deploying both at the same time is not exactly easy. It's not a cheap either, it takes a few quarters worth of planning and maybe a few million dollars worth of investment, to make that dream a reality. Although that may not happen on Day 1, that dream is earned far away, it will definitely happen in the near future. To answer your question, yes 5G will definitely support voice no matter what network. But beyond your knowledge, how exactly your phone will facilitate that voice call, differs between two schools of our network operators. Wow. That does sound magical. Another thing that you mentioned is the futuristic use cases that LTE technology might not be able to meet those requirements, and I'm just wondering, what was the thing that's missing before and how 5G can help to fill the gap? That's another insightful question. If you take a broader view, you will find many differences between how 5G is designed versus how 4G is designed. But at the end of the day, boils down to certain key metrics that every network is judged by. For example, individual users speeds or throughput, as we engineers like to call it, and the capacity of the overall network. We saw that some of the 5G use cases will require individual users speeds upwards of one gigabits per second. Even in typical conditions, which LTE in its current design cannot guarantee that all the times. The flip side of the coin would be what kind of speeds the network gets by aggregating traffic from all the users. We have also seen that the network will require few terabits per second of speed, and LTE once again, is not fully designed to do that in all conditions, so that is one aspect. Another aspect, and you may have guessed about it already, the aspect of latency. We saw that some of the 5G or modern use cases will require latency, as low as one millisecond end-to-end, whereas LTE with sparing you the details, I can tell you that LTE clearly was not designed to give you end-to-end latency of one millisecond. For the technologically oriented, I can tell that LTE gives about four milliseconds one way latency between your phone and the cell phone tower, so you can tell that is a fundamental limitation which prevents LTE from serving applications that require something like one millisecond end-to-end latency. For massive IoT, we saw that coverage is of paramount importance. In that every nook and cranny of the network, you would need to carefully cover that with 5G network coverage because you would never know where a 5G IoT device would be deployed. As I mentioned earlier, 5G has certain mechanisms to make sure that every proverbial nook and cranny of the network, maybe a word which LTE wasn't exactly designed to do. Another aspect could be a connection density. Once again, put it in and to massive IoT. LTE may have been designed for, let's say, allowing x number of users to talk to the network at a time, but we now know that with the advent of massive IoT, we are going to far exceed that number. You might have 5x or 10x, the number of users trying to talk to the network at the same time and LTE paradigm wasn't designed to be that scalable in its current structure. That is another limitation that we can see for which 4G or even Wi-Fi will not cut it anymore. We even need to move to a new technology which is 5G. To summarize, factors like individual user speeds and network capacity, latency of your connection, the density of connections that the network can support in a given geographical region, and the coverage requirements that you might have for different services. Those are some of the factors that make it inevitable for us to move from 4G to 5G. Now, one question that might have already arise on in your mind is, okay, this sounds good on paper that 5G promises a lot of things. But how exactly 5G is going to achieve those promises that it has made? How exactly will find you keep the promises that have been made on behalf of 5G by 3 GPP and IMT and ITU? Well, that is where we get start getting into the design or operational details of 5G. That metrics are discussion about some of the technically detailed aspects of 5G, something like massive MIMO or beamforming. But don't let it scare you. We are going to discuss that at a sufficiently high level with some friendly examples and analogies in the subsequent modules.
