LEO Constellation Revolution Observed at Satellite 2024 

5 mins read

This year, in March, was my first visit to the annual Satellite conference and exhibition, held in Washington D.C. I was there as part of the Calnex Solutions exhibition team, where we were showing how our network emulation solutions could be applied in LEO and GEO Satcomms environments. Straight off, one of my colleagues who has been there before, commented on just how much the event had grown in recent years.    

While Satellite 2024 is a general-purpose satellite show, with everything from antennas to positioning and launch solutions, perhaps, unsurprisingly, the hot topic was the emergence, and potential dominance, of low earth orbit (LEO) satellite constellations and their impact on Satcoms. Some are even describing it as being a revolution. 

The LEO satellite industry is promising to change the world with multi-megabits (100-200+ megabits) per second of data transfer. 

These are throughputs unheard of in the GEO Satcoms industry. In addition, perhaps the biggest bugbear of GEO Satcoms – huge latencies –  are also an order of magnitude better in LEO. We’re talking 10-40ms here (vs 600ms+ for GEO), although in LEO these latencies change, in detail, rapidly because the satellites are moving so fast. To give you an idea, we’re talking of satellites that will orbit the Earth in around 90 minutes, so they go from horizon to horizon really quickly (in just a few minutes depending on where you are located). Think of it like the Sun, that they rise and set. What that means is that network conditions are changing rapidly over a single satellite path. 

And when we talk about LEO constellations, obviously, it’s all the big players like Eutelsat OneWeb and SpaceX Starlink and to a lesser extent the original LEO constellation, still very much present, Iridium.  Other providers include Telesat and, in the pipeline with launches planned in 2024 is Amazon Project Kuiper.  All these players have ambitions to have hundreds, even thousands of satellites offering global coverage. So, there’s a great deal of excitement about the future of (LEO) Satcoms. 

However, as well as the major LEO constellation providers, we met a few companies /governments planning to launch small constellations. An Argentinian organization, associated with the government is looking to launch a single LEO satellite proof-of-concept trial, which will overpass Argentina. If successful, the plan is to expand this to four and it gives you an idea of how small constellations are being considered to provide coverage to certain parts of the country that wouldn’t otherwise have a good network service. It’s interesting how people are looking to LEO satellites to achieve coverage in what we might think of as rural or non-urban regions, because who would install 5G towers up in the middle of nowhere? The answer is nobody in a conventional manner, due to the backhaul issues (connection of the towers to a core network).  But LEO Satcoms may even come to the rescue here – see (5G Backhaul) later.

Perception versus reality – Most LEO Satcoms connections still only are terminal to satellite to ground

If you look at the images used by the LEO satellite providers to market their solutions, not unreasonably, you would believe that the satellites in their constellations are not only connecting with devices (terminals) on the ground but also with each other. Well, the reality right now, is that isn’t the case, with most LEO Satcoms connections still being terminal to satellite to ground. The pictures are ahead of their time.  Certainly, the goal is to have the satellites transmit directly to each other in what is being called the “Space Segment”.  

Having said that, change is coming with Starlink launching around a hundred or so, of what might be termed “Mark II” satellites with inter-satellite links. These can transfer data between each other at hundreds of gigabits per/second. It’s almost like a fiber cable in space, but obviously without cable. They are laser driven – point the laser at the other satellite and transmit along the laser beam. What’s interesting is that the beam isn’t kept as tightly focused as you might expect.  They allow it to widen slightly, so that it could fall approximately onto the antenna on the other satellite. However, this type of interconnected satellite is really just at the beginning of its life. 

Over time, this approach could do away with the need for lots of ground stations, which even the likes of Starlink are currently reliant on to deliver their service, but it definitely isn’t going to happen overnight. 

So, I mentioned earlier that you’d never stick a 5G cell tower in the middle of nowhere because of the Ground Segment issue – how will it be connected (backhauled) to the ISPs core network?  But what if the backhaul was performed through LEO Satcoms? Now we’re talking, right?  Yes, and that is a development is happening right now. 

Another development that also seemed to be creating significant interest at Satellite 2024 was 5G services coming directly from LEO satellites. Equipped with advanced modems (eNodeBs), these satellites act like cell phone towers but operate in space. The objective is to offer users a seamless cellular experience, particularly in areas currently underserved by traditional cellular networks. 

There was significant interest in the new LEO Satcoms capabilities from the military, and we expected that. From the WEST 2024 show (San Diego), where we exhibited at a month earlier, we were reminded that the US Navy has been dealing with very low speed circuits which are insufficient for its needs and is turning to commercial services such as Starlink to fulfill some of its needs across oceans. Trials are currently under way and the vision is to achieve, onboard, bandwidth not much less than can be delivered from shore-based networks. This isn’t a case of displacing Immarsat Government’s long standing CBSP (Commercial Broadband Satellite Program) which was renewed in 2022 for another 10 years, more a case of complementing it. It certainly sounds interesting.

Several seasoned Satellite 2024 attendees told me that had we come to the show the year before, we would have found it considerably smaller and quieter. What has changed the situation is the coming of age of LEO satellite networks. These really are transforming the Satcoms landscape and we know that the GEO Satcoms industry, which has been long established, is clearly very worried about the emergence of LEO satellite services. Some have even defined it as the satellite industry’s “Blackberry verses Apple” moment. We will have to wait and see – Satellite 2025 promises to be interesting!

The latest release (V2024.04) of the Calnex NE-ONE network emulator range now provides enhanced Moving Objects functionality to create realistic test environments involving fast moving objects, such as LEO satellite constellations, aircraft in flight, vehicles on the move or train journeys. 

These include:  

  • Drop-Down selection of different LEO (i.e.Starlink/OneWeb/Iridium/) service plan data  
  • Support for Moving Objects e.g. Vehicles, Aircraft, Trains and LEO Satellites etc, via: 
  • Network Variables Functionality: Automates dynamic changes in network impairment values, and network routing over time 
  • Moving Objects Table-based Value Changes: Import tables of different network parameter values to run and control tests in rapidly changing network conditions