Hi, Nakul, I really like the discussion around the security aspect. I think it's really interesting, and now I'm trying to figure out a way to connect two dots together starting from the beginning of the class. One thing is the non-standalone. I think that strikes me as you're building something on top of the other thing, like 5G on top of 4G, would that impact any security vulnerability concern here? That's a good question. To answer that, let's go back to something we discussed previously. What is network security about? It is about ensuring the security of data when it is in transit, as well as the security of data when it is being stored. Now in an NSA network, as you may recall, the wireless channel may be provided by 5G, but the ultimate core network is provided by 4G, meaning that the data transmission is taken care of by 5G, whereas data storage is taken care of by 4G. 3GPP, the standardizations body has instituted well-defined algorithms to go over the security of data when it is in transit, over 5G wireless network and security of data when it is being stored inside the 4G core network. Even though you see two different technologies co-mingling with each other, both of them have their own well-defined security algorithms so that the end-to-end security of data, including transmission and storage is ensured at the end of the day. The fact that it is provided by two different technologies doesn't quite compromise the security of the underlying data, as long as the basic due diligence of ensuring the robustness and security has been done by the operators, and operators usually are very good about that. As long as the end-to-end security has been ensured, it wouldn't make a difference if your wireless channel is 5G but your ultimate core network is 4G. How about massive IoT and security? I can imagine massive IoT is connecting so many devices and would that expose you to more vulnerability in that case? That's another good question, and I have to say I like how you're thinking because that tells me you are trying to put two things together, meaning that you are really getting a hang of the things that we have been discussing so far, so I take it as a good sign. As to your question about whether massive IoT would be somewhat difficult to implement in face of security, well, I see what might make you think that way. That is, for example, when we buy a phone, we have to manually insert the SIM card inside and that is when your phone becomes active. One might think that, hey, if we have 1 million devices in a given factory as a part of our massive IoT or private network, would somebody need to insert SIM cards into those million devices in order to ensure their functionality and their security? Well, the answer is not quite, that is not how security will work in scalable paradigm like massive IoT. One of the ways it will work is that instead of there being an external agent of security like SIM card, when the devices are manufactured and configured and provisioned for the first time, that is when some of the fundamental security keys will be programmed into the device itself. They may be hardware keys or software keys, or a combination thereof, but those devices will likely come with some form of keys. When such a device that has been pre-configured with an initial key boots up in the coverage of your private network, it will communicate with a certain component in your private 5G network, and using communication with that component, the end-to-end 5G security framework will have been established on top of some of the initial keys that have already been configured. Now, granted I'm simplifying things here a little for the sake of the discussion, but this approach is actually being used more and more. One name for this approach is called Zero-Touch Onboarding, in that you onboard a device without it ever being touched after it is manufactured. One real life example of this is that these days, some companies give you their authorized devices like a laptop or a tablet or a phone, and the moment you boot that device up on a corporate campus, it automatically connects to a Wi-Fi network. You don't have to pick a Wi-Fi network and enter a password anymore, your laptop or tablet or your device in general, automatically does that for you. That is one form of Zero-Touch Onboarding in real life, and how does that happen? Well, because it is an authorized device issued to you by the company, it already has some form of software and hardware keys in the device. When the device boots up, it communicates with the Network Security agent, and via that agent, the end-to-end security framework is completely established without you having to ever enter a Wi-Fi password on that device. This is one way how the scalability problem will be solved to ensure security in a massive IoT network. Thank you so much, Nicole, for spoiling me with all your insightful answers for all of my question that I have throughout the day. I feel like a really learned so much from the fundamental throughout the whole history of wireless communication to now 5G, and I learned so much about how 5G actually work in real life. Thank you again for sharing your knowledge and your experience with me and our audience as well. Thank you for having me here. It was a pleasure being with you and all the audience members here today. I hope this class was useful to you. I can already tell that you were able to grasp some of the, not just simple, but some of the advanced fundamentals as well. Put two and two together and that clearly reflected in the insightful questions you were asking towards the end. I hope this class was useful to you, and as importantly, I hope that this class was useful to all of our listeners today as well. I hope that this class serves as a good starting point. It serves to wet everybody's curiosity on 5G. I hope this class encourages them to learn more and more about 5G, which is a technology that everybody says is going to change everything, but nobody really takes the time to explain how. I hope that this class was useful to everybody as the building block of their further understanding of the 5G technological ecosystem overall.
