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The Future of Wireless Networks with Luiz DaSilva

Luiz DaSilva joined Virginia Tech’s “Curious Conversations” to chat about the evolution of wireless networks, the importance of advancing the next generation of wireless, and the critical role the Commonwealth Cyber Initiative (CCI) is playing in that advancement.

About DaSilva

DaSilva is the Bradley Professor of Cybersecurity in the Bradley Department of Electrical and Computer Engineering and the Executive Director of the Commonwealth Cyber Initiative. His research interests include wireless networks, with a focus on networks of adaptive and cognitive radios, and the application of game theory to network resource management.

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Travis Williams (00:43.361)

I guess to start, I'm really curious when folks talk about 5G, 6G, next G, what are we talking about?

Luiz DaSilva (00:59.834)

Okay, so the G stands for generation, right? So, these are different generations of wireless networks. So about every 10 years, we get a new generation. And usually that means a big step in terms of the capabilities of the network. And that drives the kind of application that we can have on our cell phones. So if you think back, depending on how old people are, they will remember the first generation or they may not. Right. So this, we're talking about the 80s here and those really big phones like the size of a brick. Those are analog phones, of course, just for voice. Right. So, and then about 10 years later, there was a second generation which really made cell phones popular. So, the prices went way down.

Like I couldn't afford the first-generation phone. I remember them, but I didn't own one. But then the second generation was much, much more widespread. And then that became digital. So instead of analog, we started seeing text messaging as well as voice. And then another 10 years, third generation, you get a little bit more web browsing, for example, some some more data in addition to voice. Then the fourth generation is where the smartphones really became popular. So completely new set of apps, right? So all of a sudden we were using apps for all kinds of things. And then we're now in the fifth generation or 5G. So there are no technical specifications that go along with each of these generations that then enable a new set of features.

Travis Williams (02:59.293)

Yeah, that's fascinating that you mentioned the big cell phones because I think I only saw those on TV. 

Luiz DaSilva (03:04.29)

Okay, good. Yeah, you're too young to remember those. But yeah, people used to carry them around with huge briefcases because you had to carry also the battery, right, so which was also large.

Travis Williams (03:20.497)

Yeah, we had a car phone that was in a bag that stayed in our car. And I don't remember us ever using it.

Luiz DaSilva (03:22.994)

Exactly. Yeah. So that's, yeah, that's the only time that I actually had access to a first-generation phone was when I rented a car. I remember when I was in Chicago and it came with a car phone. And I thought that was really exciting and different. It would still be a bit expensive to use it. So I don't think I used it to make any calls. But yeah, those were first generation.

Travis Williams (03:51.265)

Well, that's really cool. Well, what makes advancing to the next generation of this technology, what makes it so important both for us as individuals, but also us as a society?

Luiz DaSilva (04:04.354)

Well, what we have seen is that wireless networks have enabled all kinds of new uses, new apps, new ways in which we relate to each other. So to some extent, it happens without our really being completely aware that it's happening. But when you look back, the kinds of things that you can do with your phone now and...and how reliant on your phone you are is something that's kind of snuck up on us. Right. So, but now it's really part of our critical infrastructure. So without them, we are kind of not able to perform a lot of very basic functions. And every generation has enabled a new set of applications. Sometimes we will talk about killer apps. Right. So what's the...That's the killer app for a generation. It's the thing that will happen that wasn't available before. And we're not very good at predicting what those killer apps are in advance. But when we look back, we can see that the network has transitioned from being something that we use primarily for voice calls, so traditional phone calls, to something where voice calls are actually the least of our uses. For the network, but now we can do all kinds of things. We can pay for things using our phones, we can monitor our health, we can just do all kinds of things. And as we evolve, we're now in the fifth generation and starting to talk about what comes next, then the expectation is that there will be another family of applications that could be enabled. No one knows exactly what those applications will be, but we speculate on things like AR, VR, so virtual reality and augmented reality, right? So having that really be widespread, and that requires a lot more of the network that may come in 6G.

Luiz DaSilva (06:26.046)

maybe a better sense of presence when we interact remotely. So right now we're interacting at the distance and we're doing that over a screen in 2D and so on. But you can imagine that you could project a 3D version of you and I would interact with you virtually with more of a sense of presence, feeling it a little bit more like we were in the same room.

So those are some of the applications. Gaming, for example, which already is an application, but next generation of gaming could be enabled by a new set of a new network and then a generation of networks.

Travis Williams (07:11.313)

Yeah, so when we talk about trying to create a new network, a better operating network, and just so that we can see what's possible, are we mostly talking about speed? Is it speed and data?

Luiz DaSilva (07:23.374)

That's a great question. So traditionally, it has been mostly speed. So how many bits we can transmit per second. So that has been the main metric that differentiates one generation from another. And that has a lot of consequences. 

So now you can download a high quality video over your phone. Whereas 20 years ago, that would not have been really possible. It would take forever. We'll probably time out and so on. So it wouldn't even work. So every generation has enabled a new, among other things, but higher bit rates, so higher bandwidth. So now, this is about to change. So there are other metrics that now are becoming more and more important. So one of them is latency or delay.

So the speed with which you can actually transmit information. That becomes important for some sort of application. So if you can imagine industry automation, for example, robots in a factory manufacturing plant, if you control them over the cellular network, then you need very low latency, very low delay because the control loops that will control a robot require that sort of immediate reaction. Or if you imagine autonomous vehicles that being controlled by a wireless network or via a wireless network, you need very short delays to be able to react in time. So delay becomes more and more important metric. And another metric gaining in importance is reliability. So how much you can rely on the network being there when you need it. So sometimes you'll hear things like four nines or five nines and that just means 99.99% probability of the network being available when you need it. That's four nines or 99.999%, that would be five nines.

And so if you use the network for applications that are mission critical, that involve cyber physical systems, so components that have a mechanical part to them, then you need a network to be extremely reliable because a failure could result in a serious accident that could impact someone's health or someone's life.

Travis Williams (10:16.069)

Yeah, imagine especially for something like defense applications, that would be really critical.

Luiz DaSilva (10:21.482)

Yeah, so in the defense realm, as you also automate cyber-physical systems like drones and vehicles and so on, you're starting to deal with things that have a physical instantiation. And therefore, any failure could have a physical consequence. So it's a little bit different from when transmission of video, for example. So as we're doing now, if we lose this video, it will be a bummer, but it will not cause really serious consequences. Yeah.

Travis Williams (11:03.645)

We will survive, I do believe. Excuse me. Well, I know that one of the things that you all have at CCI is a testbed. And I'm curious, I hear a lot about testbeds, and I'm curious, kind of broadly, what is a testbed?

Luiz DaSilva (11:22.342)

So in general, a testbed is a facility that allows you to test new technologies. So it can mean different things in different fields. So if you're working with transportation systems, like VTTI does, a testbed facility may be something like a smart road, where you can test vehicles for safety, et cetera. When we are talking about 5G and wireless and 6G, et cetera, and the CCI testbed, we actually have more than one. But we have one primary one that's based at Virginia Tech. And that is a wireless network that allows us to experiment with new technologies. And since CCI is really about cybersecurity,

We need to have research facilities, test facilities, that allow our researchers to also break things. So they need to be able to see what happens if there is an attack, if there is a cyber attack, if there is, in our case, for example, a fake base station would be an example of that. So what if someone installs a base station that provider and tries to collect your data that way and to make you connect to this false base station. So we need to actually experiment with that and test what happens. How do you circumvent any vulnerabilities and how do you deal with attacks? So we have our test bed facilities, which allow us to either include a new technology that's not part of the current network and test it before it gets absorbed into the next generation, for example, and it allows us to test for things like cyber attacks.

Travis Williams (13:28.841)

That's cool. So do you get to come up with some of like the role playing where you get to play the bad guy and try to break in?

Luiz DaSilva (13:35.23)

Sure, yeah, we can do that since it's not a production facility, right? So it's not a network that's supporting real users, like the Division of IT at Virginia Tech has its networks that supports all of us. But the testbed facility is not supporting real users. So we get to play the bad guys so that we can then see how we avoid any...any attacks, any malicious activity on them.

Travis Williams (14:05.749)

That sounds like a lot of fun.

Luiz DaSilva (14:07.486)

It is, so it can be. And it's one of the things that the researchers do and one of the powerful things that you can do if you have really significant research facilities and test facilities.

Travis Williams (14:26.813)

Yeah, I was going to ask you what makes CCI's test bed or maybe test beds unique.

Luiz DaSilva (14:33.278)

Yeah, so one thing that's really unique is that we have an indoor component, which is quite sophisticated by itself. But we are now deploying an outdoor component. And the outdoor component is in Blacksburg. The indoor component is in Arlington, both in Virginia Tech facilities. And this combination of the two is really unusual.

It takes advantage of resources that we have at Virginia Tech. For example, we hold spectrum licenses that cover two counties in Virginia, including Montgomery County, so we can actually deploy a test bed outdoors using our own spectrum. So spectrum that we have access to. That's quite unusual for universities. Only a handful of universities hold their own spectrum.

And then we, in the case of our CCI XG testbed, we have invested since the beginning on something called OpenRAN, Open Radio Access Networks, which is a big focus in terms of innovation in the wireless space. So there is, for example, the Chips and Science Act devotes quite a bit of funding for the development of these open radio access networks. And since we have been developing those networks as part of our test bed for three years now, I think we are very, very well positioned in that space. So very few universities would have anything comparable.

Travis Williams (16:17.205)

What do you gain by having a test bed outside? What element does that add to the testing?

Luiz DaSilva (16:24.135)

You get to test with more, I would say, credibility, closer to how a real network really works, right? So, real networks work indoors and outdoors, but large-scale network deployments that you have by large operators like AT&T or Verizon or T-Mobile.

They primarily are set up outdoors and they provide coverage both indoors and outdoors, but the base stations that you see when you drive around are all outdoors. So first to test some ideas in an environment that's closer to a real cellular network, that outdoor component is actually quite important.

Travis Williams (17:15.721)

Wow, that's fascinating. Well, I was gonna ask you how the testbed, what role it was playing in helping us overcome some of these challenges in developing the technology for the next G for whatever's coming next.

Luiz DaSilva (17:30.11)

Yeah, so every new technology that takes a while, right? So to transition from an idea that may come even from theory all the way into a commercial deployment. The process of developing a new generation of technology for wireless networks can take about 10 years, from the visioning of the network all the way to commercial deployment.

So for example, right now we're already talking about the vision for 6G, that's for the next generation. So what role does the testbed play? Well, before you can convince the community as a whole and the standardization bodies, for example, which will ultimately determine what technologies will be embraced by a generation of networks.

you have to be able to test, right? So to show that they actually work, to show that the technology scales, and to show that the performance that you can obtain is what you would expect. And that's usually done by a process of a combination of some theoretical work, simulation, and then testing in the field. So that...capability of being able to actually test technologies and show, okay, we can show it works, not just in a simulation, not just because the equations work out, but also, we can actually build this and show it working, have a proof of concept. That's an important part. That's what really makes people stop and take notice and say, okay, now I believe that this new idea, we will actually work in practice.

Travis Williams (19:24.165)

Yeah, that makes a lot of sense to me. And I think that you all have different partners that have come in and want to use these facilities. Is there a specific way that folks that might listen to this that want to know more? Where should they go to find out more?

Luiz DaSilva (19:38.13)

Sure, so if they want to find out more about CCI in general, so go to So cyber initiative, just one word,.org. That's our main site, so you can navigate to the part of the site that talks specifically about testbed. Yeah, we have partnered with universities, of course. CCI itself is...a consortium of more than 42 universities and colleges across Virginia. And some of those universities also host part of the testbed, by the way. So Mason, ODU, and VCU all have components that integrate into the XG testbed. So we partner in different ways. So for example, we partner with operators like AT&T, with vendors, with small businesses in different ways. So sometimes we do research for them. So we have a research contract. Sometimes we join forces and go after some opportunity that might exist. For example, the federal government has some calls for research projects. So some of them are a partnership between universities like Tech and some of the industry that's relevant to wireless networks in the case of the topic that we're talking about today. We are also building what's called a university industry research center to bring together a number of partners that are interested in the development of this technology alongside several of the universities in CCI. So there are many ways in which together. Sometimes it's actually providing students with the opportunity to do experiential learning. So we do a lot of internships where we place students in companies so that they actually learn by doing, by working alongside professionals in those companies. So there are many, many ways to work with us. I would say, you know, start from our website and then...

Luiz DaSilva (22:03.158)

reach out to us and then we'll see how we can match the interests. It depends on the company and the institution that wants to part.

Travis Williams (22:14.577)

Well, that's awesome. Well, thank you so much for talking to me. I greatly appreciate it. You know, we've come a long way from the days of the big Zach Morris cell phone. So we've come a long way since the days of the big Zach Morris cell phone. So that's exciting. I hope maybe next time we talk, maybe we can talk in 3D.

Luiz DaSilva (22:29.506)

Yeah, I think that would be nicer than just Zoom, right? So I think we would all appreciate the move from the traditional 2D to 3D in our remote interactions. Thank you, Travis.