In this episode of Allies in Innovation, host Mikkel Svold talks with Andreas Stren, lecturer at the University of Applied Sciences Wiener Neustadt, and Alexander Spaniol, RF engineer at Terma. They break down how SDR shifts control from hardware to software, enables remote updates, faster adjustments to mission demands, and better risk management.
They also get into real-world SDR use cases, cybersecurity challenges, and why the tech could be a game-changer for ground stations and smaller space operators.
If you’re into the current or future space communication systems, this one’s worth a listen.
In this episode, you'll learn about:
- Key benefits of software-defined radio in space missions.
- How SDR enhances flexibility and re-configurability for satellites.
- Overcoming SDR challenges: radiation effects and cybersecurity.
- The role of virtualization in satellite communication solutions.
- Future prospects: cost-effective and accessible ground stations.
Episode Content
00:00 Introduction to Software-Defined Radio and Guests
00:47 What is Software-Defined Radio (SDR)?
01:43 Transition from Hardware to Software-Defined Systems
03:15 Advantages of Reduced Hardware in Space Missions
05:39 Flexibility and Reconfigurability in SDR Applications
08:12 Risks and Challenges of Using SDRs in Space
12:33 Cybersecurity Concerns in Software-Defined Systems
14:07 Connection Between SDR and Virtualization
16:22 Cost-Effectiveness of Virtualized Ground Stations
17:22 Educational Impact of SDR in Aerospace Training
28:42 Future Trends in SDR for Communication Services
Production
This podcast is brought to you by Terma.
This podcast is produced by Montanus.
Episode Transcript
Mikkel Svold (00:00):
Hello, and welcome to Allies in Innovation. NASA, they write that you have five things you need more than anything when you enter space. You need a system to live and breathe. If you, of course, send humans up there, you need propulsion power, you need the ability to hold off heat. We mentioned that in the last episode on space here on the podcast, and you need radiation protection, that was also mentioned on the last episode. And then you need constant communication because if you don't have communication, you lose navigation and you lose the satellite or the mission altogether.
(00:47):
So, that last one is the focus of today's episode. And luckily for me once again, I have Andreas Stren in the virtual studio with me. Welcome back to you, Andreas.
Andreas Stren (00:58):
Hello, nice to see you again.
Mikkel Svold (01:00):
You're still the lecturer of aerospace and engineering program at the University of Applied Sciences in Wiener, Neustadt. And with us also we have Alexander Spaniol, who is the radio frequency engineer at Terma. Welcome to you.
Alexander Spaniol (01:14):
Hello. Thank you.
Mikkel Svold (01:16):
I think since the topic here is software-defined radio, because that's what we are talking about today, the communication between Earth and whatever mission that we have out there, if it's a satellite, or if it's someone on Mars, software-defined radio, for me, and for the listeners outside this deep space industry, what is a software-defined radio or SDR?
Alexander Spaniol (01:43):
So, software-defined radios are used to communicate with the satellite and our ground stations. So, from the ground station to the satellite, and, of course, also from the satellite to the ground station.
(01:58):
And what is the special point about software-defined radio? In the past, we, most of the time, had hardware defined radios, and nowadays, we are using software-defined radios. But what does that mean? Software-defined radio is the kind of radio communication system where we have components that additionally relied on hardware, for example, modulators and demodulators, signal processors, frequency mixers, up-link, up-converters, down-converters, and so on. They were implemented in hardware. And nowadays, we do that in software.
(02:34):
And this combination of reconfigurable hardware with this powerful software makes this radio as software defined radio. So, we try to get as much as possible into software to get all the benefits from there and try to rely as less as possible on the actual hardware itself.
Mikkel Svold (02:56):
And what does this... I know we touched on this in the last episode with you guys as well, but what does this actually mean to the hardware? Because you say that you needed modulators and you need frequency... I don't know all the words, all the equipment. Don't you still need that?
Alexander Spaniol (03:15):
Of course, you need it, but the thing is the hardware itself, you don't longer need it because what you're actually doing you're receiving the signal. Most of the times, click then have hardware or component that attenuates your signals, but let's say, it makes it stronger and then you directly digitize it. So, you have your analog to digital converter, so you make this analog waveform and digital signal just by making samples out of it.
(03:47):
And then you have it in software, and everything else is then done software. And that's what we do in software, therefore we do not longer need any hardware. For example, modulation, demodulation frequency, mixing, the up-conversion, down-conversion, and so on, that is no longer needed to have this physical component.
Mikkel Svold (04:05):
So, now you just basically need a really powerful antenna that can receive all kinds of communication.
Alexander Spaniol (04:14):
Yes.
Mikkel Svold (04:14):
And what sorts of communication are we talking? Is it just the fact that it can do my FM radio can do multiple frequencies? Is that what we're talking, or...
Alexander Spaniol (04:24):
Yes. More or less, it is exactly that we are talking to. We have a radio frequency front end. Of course, this radio frequency front end, we cannot have one antenna that receives, let's say, 10 megahertz frequencies and up to six or 10 gigahertz. That's not possible. That, of course, needs to be suitable for your frequency range. But when you have that, your antenna will receive the signal, then you are already more or less fine to go with software defined radio, but digitizing it.
Andreas Stren (04:51):
Also, advantage would be that, for example, two different antennas can be handled by the same software defined radio, whereas in the past you needed two full systems. So, you can integrate many antennas into one software defined radio, for example. And so just switch them.
Mikkel Svold (05:16):
Okay. So, I can see... Okay, fair enough. You don't need all the hardware equipment on board, the satellite on board, the rover, or whatever you are talking to. You don't need the hardware. But other than the space-saving exercise, why is this a good way? Why is it a good approach?
Andreas Stren (05:39):
We touched it a little bit in the last episode. The environmental impacts are always driving the requirement for missions that are out of the atmosphere. So, if we have less parts that we need to take with us, there is less risk any part is failing.
Mikkel Svold (06:03):
And the environment here, we are talking, actually like the NASA bullets. So, we have, you need to be able to hold off heat, and you need to be radiation resistant, and all this. So, that's the environment considerations that you're thinking.
Andreas Stren (06:16):
Yes, and the hardware parts that are essential or were essential, I would say, always needed own testing procedure and needed to survive for sometimes decades. And the software defined radio using lesser parts also have a lesser risk of failing.
Alexander Spaniol (06:42):
I think that question there, what you should also answer is the other thing about disadvantages of creating software defined radio here into the, in our case space industry, into communication with the satellite is that we, for example, have the big advantage of the flexibility and the re-configurability of the software defined radios. Why? We already have talked about that we are going to replace hardware components in order to do that software.
(07:09):
And the big difference between a hardware first component, is that the software is that we can update, we can rewrite, we can debug it on the software, and we can also do that, for example, when the satellite is up into the orbit because for hardware, to exchange it, we would need a human there to do that. And that's more or less not possible. But with software, we can do that.
(07:34):
So, we can change, for example, our frequency. Here, software defined radio, Andreas has already mentioned it, we have the possibility of receiving several frequencies because we have such a broad bandwidth that we can receive with such an SDR, and we can also receive two signals at the same time and process it if we want to do that. Modulators, demodulators, in the past when we talk about hardware defined radio architectures, they have data designed for a specific data rate for a specific frequency and the specific modulation scheme. With software defined radio, you can change it like you want to.
Mikkel Svold (08:12):
But why would you want to change it?
Alexander Spaniol (08:15):
Why you want to change it? There can be several reasons for that.
(08:18):
For example, if you have a satellite mission, you always have to go, and it may be possible that, for example, start with low orbit, then you increase, increase, increase your orbit, you get more fire away, for example, for the earth. And the requirements on the communication, they change. For example, you need to transmit telemetry or you have your tele-command or your telemetry of the satellite, and this link between satellite and earth and requirements so that they can change, of course, with the orbit.
(08:53):
So, you may need to change your data rate, you may shift your frequency because you have disturbances hit down on earth in that frequency you decided to have your down-link or up-link of the satellite. And with software defined radio you can ship modulation. There are several different modulation schemes. With software defined radio, you can change them as you want to, and different modulation schemes have different advantages and disadvantages. But there you always, of course, have to deep dive into your specific application, what suits the best for you.
Mikkel Svold (09:27):
And Andreas, I know there are some risks, there must be some risks also connected to having a software defined system at all. Can you maybe talk a little bit about that?
Andreas Stren (09:36):
Yes. As you already mentioned, the NASA bullet points for the environmental impacts or requirements, I would say, is that raising the amount of software and reducing the amount of hardware parts, we talked about the advantages.
(09:58):
The disadvantages would be that digital systems react differently to radiation than hardware systems do. So, to compensate for that would be building redundant systems where two SDRs are, for example, next to each other, or maybe three depending on your designing process. And you can always rely on that at least one of them works. And the impact of radiation comes in two forms. There's one that is called a total ionizing dose. That's something commonly known, like rats or measuring with a Geiger counter or something like that. But there is something most people don't know about radiation. There's high energy particles all around in space. Space is not empty. And if this high energetic particles hit, for example, a computer chip, they can induce a so-called single event effect that makes a one to a zero or the other way around, and then your program needs to handle that. This would be...
Mikkel Svold (11:32):
Yeah, so it's basically easier for that particle to, I'm going to say push the digital system from what... Digital is always one or zero, right? So, push that one over.
Andreas Stren (11:44):
Yes.
Mikkel Svold (11:44):
Like a domino.
Andreas Stren (11:45):
Yes. And that's, for example, a new requirement that came up with SDRs that these single event effects don't disturb the operation.
Mikkel Svold (12:01):
And what about... Does it also pose flanks? I'm thinking like cyber security-wise, we just had an interview on cyber security and, of course, these for Terma, and obviously all defense and space, all that interconnection there is there, cyber is a very important topic. So, what kind of requirements does it set to you? And as a software defined or a software specialist?
Alexander Spaniol (12:33):
Security is one of the biggest topics because Germany, we are here to secure people by our technology that we do, that we make, and cyber security, especially for the software defined architectures. And now in this talk, especially for software defined radio is, of course, a big topic.
Mikkel Svold (12:52):
Is it something you can build in? Can you design your software so that it's unhackable?
Alexander Spaniol (12:58):
Yeah, it's something that you can build in. You have to build it in because you need this security. Everything is within software. And when someone, let's say, hacks into your system, then we will have a big problem because they can easily speak and hijack your satellite. So, cyber security, things like using authentication, encryption, and so on, that is something that we always implemented all our systems at Terma. For sure, also in software defined radio, and our modems.
Andreas Stren (13:32):
Also, as already mentioned, if, for example, if, we hope not, a security layer fails, it's interchangeable by uploading a new version.
Mikkel Svold (13:51):
Yes, you can update your firewall, basically. Yeah. Okay. You mentioned in the last episode virtualization, and I think we just touched a little bit upon it in the last episode, but I think it would be good to revisit that.
(14:07):
How are software defined radio and virtualization, how is that connected? And can you maybe just again say a little bit about what virtualization is, Alexander?
Alexander Spaniol (14:18):
Yeah. Virtualization, really that's a hot topic, or quite a topic, and especially also for us at Terma. Virtualization basically means that when you have something, for example, let's look at the software defined radio, you have a signal, and what we actually do with the software defined radio we bring it from this analog domain to our digital domain. So, we have it digitally available.
(14:44):
And by having it digitally available and making, let's say, virtualization, so, for example, bring it up in the cloud, then we are able to use that from different locations. Where I can bring up here two examples, we can talk about, for example, a software defined radio as part of our radio frequency special checkout equipment. As we know, when we have spacecraft, it is for sure tested before it's launched. And within this manufacturing assembly integration testing circuit, we have the testing of our communication module. And by, for example, in this equipment, having software defined radio, we are able to have all these hardware components that are within such systems. Like, for example, spectrum analyzers, we have power sensors, we have signal generators, we have up and down converters, all really expensive hardware components in such test systems. And bringing software defined radio in such a system, we are able to do most of these things in software.
Mikkel Svold (16:16):
So, you don't need that expensive hardware at all.
Alexander Spaniol (16:18):
You don't need this expensive hardware at all because you're already in the digital domain, and you can further process your signal in a digital domain.
Mikkel Svold (16:22):
Yeah, so you have a digital twin of that.
Alexander Spaniol (16:27):
Yeah, yeah, exactly that, especially when you're speaking then about the operational things. But in testing here, you are then able with this virtualization that you provide them this to your customers. So, you may, for example, no longer be required to have this big rack directly at the customer. You can have it placed, for example, a wrong rack in the laboratory, let's say, for example, at Terma, by virtualizing and having this interface or have it hosted in the cloud, customers can book it and use it because it's already digitized. You have the cloud, and nowadays, the tech, the network that is required, the speeds, the latency, it's there and it's possible.
Mikkel Svold (17:10):
It sounds like a huge cost-saver.
Alexander Spaniol (17:13):
Yes, it is.
Mikkel Svold (17:15):
Yeah. What does that mean for you, Andreas? When you said that the university, what does that mean? This is a completely different way of working.
Andreas Stren (17:22):
Well, it is a completely other way of working, but it has the same impact. For example, we had an educational satellite named Pegasus. It was launched 2017 and re-entered not long ago. It was in orbit six years. It was a big achievement for us. But the thing is it was a hardware-defined radio on there, and our equipment was built up only for this specific mission. And at the end of the mission actually, the whole setup of the ground station equipment was obsolete. And together we are planning a new mission called Climb that raises also complexity because we want to change our orbit.
(18:19):
That is for, I would say, for a university and educational task, pretty hard. We are working on that, but we already changed our ground station to a software defined radio system. And what we can do here, not only that it's more cost-efficient, we can change the communication parameters as Alex mentioned, for example, modulation or frequency, we can change it, and, for example, listen to other educational satellites from other universities around the world. And we can also incorporate it in our courses to show other students, "Hey, that's how you communicate with this satellite, and, for example, let's change the parameters and this is how you talk to this satellite."
(19:17):
And this versatility gives also the students more insight on the differences and how it actually works.
Mikkel Svold (19:29):
I think to be fair, yesterday, when I was researching for this interview, I looked up the notion of communicating with a satellite. So, I looked up in the new and fashionable way of looking things up, so I asked Chat GPT basically, what sorts of communication are we talking about? Is it a, quote-unquote, is it a walkie-talkie communication where you call it up? Like you see in movies, right? You see Armageddon. Oh, I'm old now, right? When it's referred to Armageddon as the one, any movie on space, it's always like a walkie-talkie kind of conversation. You have someone talking one in the other. What kind of communication? Because these, A CubeSat obviously is unmanned, like 99% of all satellites are unmanned, right?
(20:18):
So, what kind of communication? What does it actually look like? Is it text? Is it someone writing, and then there comes text return, or is it coding or what is it?
Andreas Stren (20:27):
May I take this one? So, you always need to think about what information you want to transmit. Okay? If you talk about walkie-talkies, you're talking about an analog signal recording of your voice that needs to be imprinted on the carrier wave. And the carrier is like the frequency where everything happens and then you overlay information onto that. That's what Alex and me are talking about modulation. That's how to pack information on there.
(21:03):
And as going for digital communication, as soon as we are talking digital, we are talking about binary information. And this information can be imprinted on a carrier in very different ways, varying in ways of complexity, or, let's say, information density. And you need to think about, for example, if you use your car key to open up, that's also part of a digital signal imprinted on your key that communicates with the car. So, it's basically everywhere.
Alexander Spaniol (21:54):
Funny note maybe about that, your whole satellite is hardware defined; satellite actually used such a modern chip, which is actually used in this to open up the car.
Andreas Stren (22:04):
Well, we couldn't-
Mikkel Svold (22:06):
Oh really?
Alexander Spaniol (22:07):
What they did at the university is they put it on a platen, 10 by 10 centimeter twice to be redundant. And that was, let's say, more or less...
Andreas Stren (22:17):
I could say we couldn't afford much more, but yeah, it worked.
Alexander Spaniol (22:22):
Yeah. So, that's just a funny side note on that. What I maybe also would like to mention here is you were also asking about if it is like a walkie-talkie communication. So, one is speaking, the other one is listening, and then he answers. Of course, it's possible. For example, the Pegasus satellite from the university, when I remember correctly, that was on half complex communication, we're speaking about half complex when we are either transmitting or receiving. So, that was some kind of walkie-talkie if you want to name it like that.
(22:57):
But nowadays, our larger satellites, they communicate via full-duplex. So, you have for example, an up-link on 2.2 gigahertz and down-link on 2.4 gigahertz. So, while you are up-linking on the one frequency, you directly have your down-link on the other frequency, so you have simultaneous communication with the satellite.
Andreas Stren (23:16):
So, for example, it would be like all three of us talking simultaneously and everyone understands everything. Yeah.
Mikkel Svold (23:27):
Okay. Okay. I think that you need some kind of machine to do that. Yep, yep.
(23:38):
When you look into the future of SDR, what do you see? What's the next step?
Alexander Spaniol (23:48):
Do you want to take that one?
Andreas Stren (23:50):
Yes.
Mikkel Svold (23:51):
Let's ask the guy at the university. You should be the one answering this, Andreas.
Andreas Stren (23:56):
Let's say from the... I will start with the educational part. It's, for me, as I use SDRs to educate people to understand what's actually happening on radio waves all around us. Everyone started to understand it more easily because with the software defined radio, you can visualize what is happening in different ways than using an old hardware spectrum analyzer.
(24:33):
So, basically, that's the first part. So, you can actually see, it's called waterfall diagrams. You can actually see what happens on air on different frequencies all the time simultaneously. Instead of just tuning in onto one special radio show, for example, you optically see several radio shows next to each other.
(25:01):
And for the future, it doesn't only raises the understanding of this technology, but also, as we had the example of simultaneous communications next to each other, this will intensively rise on parallel communications that are at the same time talking, sending, receiving. So, basically, it'll get louder in the air.
Mikkel Svold (25:39):
And just to get that, why is that a good thing that you can suddenly receive more signals? Is that because its more and more it's machines talking to each other, so it's just the speed of communication is larger, or is it something else?
Andreas Stren (25:59):
The amount of data transmitted per second will rise with this technology. It already did. And also, as we talked about, using one software defined radio for several antennas, for example, gives also more versatility on the other hand. So, you can, for example, receive the same signal with anything speaking.
Alexander Spaniol (26:32):
Maybe also here what you can have, for example, two down-links and two up-links at the same time, also from the same satellite. Of course, there's two antennas, but that, for example, would be possible and depend upon the amount of data you can transfer that. So, maybe also to get a little bit back on the topic from the ground station's point of view or how we see the software defined radio here in the future. Here, always at via Terma, for example, also thinking here, the ground station as a service, since when we have our SDR in place, we have our Terma SDR motor, for example. We can have a browse frequency range, for example, 10 gigahertz to six gigahertz with the various modulation schemes that are used as per the different standards. And that enables you together with the virtualization, we already have talked about virtualization in testing application, but you can also have that for sure in the ground station.
(27:30):
So, you can book a ground station, let's say, as a service, and you use the virtualized or digitized signal. And then you have several, let's say, microservices available because you have, for example, your modulator, de-modulator, e-framer, or even decoding, there are various error correction schemes. If you receive a signal, there for sure will be errors within. And with that, you can correct it. And so you, for example, can book this different microservices and directly get the data from the satellite, for example. So, you don't have to build your own ground station. You can use another general purpose ground station wireless virtual interface. And there, for example, where I see one of the big roles of software defined radio in the future.
Mikkel Svold (28:18):
Yeah. And that not only talks into, of course, the fact that some companies, they may have it as a service that you can buy from them, but obviously, it's also going to enable smaller companies, CubeSats, it's going to enable students to send stuff up without it costing millions and millions of dollars to establish a ground station.
Andreas Stren (28:42):
Yes.
Alexander Spaniol (28:43):
And the university, you hooked up on that topic when I remember correctly because you also had at the universities out as part-
Andreas Stren (28:52):
It already started. We're not speaking about far future. It already started and it is happening right now. So, there's also a large open source community to not only enable individual persons, not only companies or educational institutes. So, everyone can start with it right now and talk to many satellites with a very small budget that more or less demystifies communication as it was within the past decades, because it was always a mystery. How does this work? So, now everyone can do it, look at it. And for the virtualization point of view, for example, for our next mission, we cannot operate our ground station 24/7 with manpower.
(29:55):
So, we use this new technology to be able to access it from anywhere, anytime, if something happens, if you need to react to something. And that is also a benefit that comes with it for our team, for example.
Mikkel Svold (30:19):
So, today we can actually, correct me if I'm wrong, you can actually log onto your satellite communication via a normal laptop.
Andreas Stren (30:27):
Basically, yes.
Mikkel Svold (30:30):
That is pretty cool. I just saw the movie on one of the first Apollo missions. It's a completely different setup.
Andreas Stren (30:39):
Huge.
Mikkel Svold (30:39):
Let's just say that. Buildings upon buildings upon buildings with huge communication rooms and all this, and now it's just a laptop. It looks really cool, the other thing. But this is actually really cool, I think.
(30:59):
Okay. I think let those be the last words for this episode. Thank you so much for joining Alexander Spaniol and Andreas Stren.
Andreas Stren (31:07):
Thank you.
Mikkel Svold (31:07):
Thank you so much.
Alexander Spaniol (31:11):
You're welcome.
Mikkel Svold (31:11):
It was-
Alexander Spaniol (31:13):
Thank you for this opportunity.
Mikkel Svold (31:14):
It was a real pleasure. The pleasure was absolutely on my side. And of course, to you guys out there listening, if you enjoyed this episode, do share it with your friends and colleagues, or whoever you find or might find it interesting. And if you have any questions, reach out to us on podcast@terma.com. That was podcast@terma.com, and there'll be someone in the other end trying to, well, either answer your question or maybe take up that topic that you proposed for the podcast and send it on to me. So, that'll be much appreciated.
(31:49):
I think that's all for me to say now. And the only thing left is to say thank you so much for listening.