Starlink’s high-speed satellite Internet: What’s the catch?

Image of Starlink satellites taken in April 2020, by Jud McCranie on Wikimedia Commons.

You may have heard about Starlink from SpaceX. You may even have been lucky enough to be outside at the right time to see one of these 'string of pearls' events.

What you're seeing below is not the final mesh of satellites, its what you see after a rocket ejects a cluster of satellites as they are on the way to their low earth orbit (LEO).

It's causing concern among the sky-watching community because of the high impact it has on the visibility of stars in the night sky, astrophotography and the pleasure of watching the heavens above.

But I'm not writing today about disgruntled star-watchers. Instead, I'd like to discuss some potential challenges ahead when LEO satellite Internet services (such as Starlink's) are rolled out more broadly.

Yes, it's fast, and it's potentially a great solution for remote areas

This isn't some future delivery, this is a viable, fast, and most importantly, low-round-trip-time (RTT) method of doing high-bandwidth Internet from almost anywhere. If you are somebody who lives outside a core city high-speed broadband footprint, this is good news.

When satellite broadband was discussed in the past, it was not an attractive choice. It was sometimes the least-worst option for people who lived beyond the footprint of a wired (or fibred) or wireless land-radio link.

The reason was the delay - traditional satellite services came at a huge delay (half a second, or 500ms RTT), which caused all kinds of problems, especially when using voice transmission and interactive networking. LEO satellite Internet providers like Starlink get around delay issues thanks to their low orbit.

Why is Starlink faster than traditional satellite broadband?

Starlink is different to the typical satellite broadband options of the past. It's LEO. The distance has been reduced so much from Geosynchronous Earth Orbit (GEO), which is 35,000kms out in space, to just 150 to 200kms. The effect on delay is transformative because this is all about the speed of light - you can't defy the laws of physics about the speed of light in space.

GEO ends up taking 500ms, while LEO ends up with around 50ms.

If you're trying to do the maths here and compare the distances with the speed of light, bear in mind that it won't add up perfectly.

The 500ms is overwhelmingly the RTT to space. The 50ms, on the other hand, includes other processes such as encoding overheads, multiple hops, and various things that are included in the bigger figure for GEO.

The bandwidth provided by these LEO satellites is really very good… for now. Starlink, unfortunately, runs the risk of being a victim of its own success.

The catch: The more people using it in an area, the slower it gets

Surprisingly, in both Australia and New Zealand, people on the fringes of cities are hooking up too. It's not just being used for remote areas.

Starlink is now being seen as a way to get high-speed Internet when the normal terrestrial high-speed Internet is within view, but alas, not quite at your door.

What's the problem? If it's high-speed Internet, why should just out-of-the-way places get it? People on the fringes of cities who don't have good fibre options would understandably want to access to high-speed satellite Internet.

The catch here is that the bandwidth is at its best while you are the only person in the footprint using it at the time. It's a classic 'early adopter' situation. The more people who take up service in your location, and take a beam from the LEO system at the same time as you, in the same place as you, the more it has to be chopped up into smaller units to share out. This is called 'multiplexing' and the only fair outcome in the end is for roughly equal shares. So, if you get 100mbit throughput now, by the time five of your neighbours come on stream, it probably won't be 100mbit any more. It might still peak at 100, but it may also only be 25. Fair's fair.

This means the suburban fringe of cities is where the nuances of signing up to Starlink need to be considered. If you live just outside the city, on the fringe of the broadband deployment area, perhaps in the suburban outskirts of Bangkok, or Sydney, or Auckland, or maybe on a hobby farm in the countryside in America (but not too far from the nice deli and the supermarkets) you are going to be closer to your neighbours than the people who live in really remote areas like farms and villages in isolated communities. It's these isolated areas that get the biggest advantage from Starlink.

If this was about intermittent use by mobile devices, this might not matter.

But if this ends up being about a semi-permanent hookup to the Starlink network in urban fringes, then two things are going to happen:

Firstly, you won't get the bandwidth you hoped for initially, because you're too close to your neighbours.

But this also flows on to a second, very serious thing to consider. What happens if the people who make decisions on building infrastructure decide 'well, there's Starlink, so do we need to build broadband to these fringe areas?'.

In that scenario, the capital investment needed to bring terrestrial broadband to your door may not arrive because it may be assumed you have good enough bandwidth from the LEO satellite. In which case, lacking broadband, more people in this fringe area would sign up to get Starlink, thus making it slower.

It's a catch-22. The better that LEO satellite Internet is, the more this risk could grow.

The views expressed by the authors of this blog are their own and do not necessarily reflect the views of APNIC. Please note a Code of Conduct applies to this blog.

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