Moving past the launchpad
It’s almost two years since Starlink first began onboarding customers for its breakthrough journey into space broadband. Since then, it’s added almost a million subscribers who are getting their broadband from a growing fleet of almost 3,000 satellites hovering in Low Earth Orbit.
However, there have been reports of turbulence. Stories emerged during the summer of Starlink customers seeing a sharp decline in (previously impressive) average download speeds and increased unreliability. Those anecdotal reports were given added weight when Starlink announced it was imposing a soft download cap, to prevent a minority of heavy downloaders from hogging the available bandwidth.
SamKnows, of course, doesn’t rely on anecdotal evidence. It’s constantly measuring the real-time performance of broadband providers around the world, including Starlink, detecting even minute changes in performance and reliability. Has SamKnows spotted any serious drop-off in the performance of Starlink as the company has continued to pile customers onto the network? Has reliability suffered?
We’ve reviewed the latest data and spoken to SamKnows founder Sam Crawford to find out what’s really going on with the Starlink service. Plus, we explore the different ways in which space broadband will be reaching consumers and business customers in the future.
Raw download speeds
Daily distribution of download speeds with upper and lower interval bounds
Coping with growth
Any broadband provider that rapidly expands its user base is going to face challenges when it comes to capacity. For Starlink, those challenges are substantially greater than they would be for a regular fibre broadband provider. For Starlink to increase capacity, it needs to launch more satellites into Low Earth Orbit and increase the number of ground stations serving those satellites. The good news for Starlink customers is that the company has been doing both.
“Starlink has seen quite a lot of growth in its subscriber base,” said SamKnows founder Sam Crawford. “It has almost tripled its subscriber base this year alone, from a couple of hundred thousand users to, in September, about 700,000 – which is pretty impressive. It has to be getting close to a million now.”
“But at the same time, it’s also been launching a lot of new satellites – it’s north of 3,000 satellite launches now – and opening additional ground stations. So it has been bolstering capacity while also greatly increasing its subscriber base.”
Has Starlink managed to increase capacity to keep pace with that rapid increase in subscribers? The SamKnows performance data suggests the company has – by and large – maintained a consistent level of performance, despite the reports to the contrary.
“We’ve seen in the measurements that it’s definitely more apparent there have been periods of congestion,” said Sam Crawford. “You can see that in the throughput figures. The speeds tend to be a bit more erratic, the confidence intervals have increased, and the latency confidence intervals have also increased.
“But in the past couple of months in particular, we’ve seen marked improvements, and so it looks like Starlink has brought on some additional capacity. In general, aside from increasing confidence intervals, the actual averages – both in terms of throughput and latency – are pretty much the same. They’ve barely changed for a year, which is quite impressive given that Starlink has increased its subscriber base more than threefold. Some users are indeed seeing far worse performance – there are probably areas of significant congestion – but, on average, Starlink is holding up pretty well.”
Raw upload speeds
Daily distribution of upload speeds with upper and lower interval bounds
To manage those congestion issues that Sam Crawford highlighted, Starlink recently imposed a soft data cap in some regions to prevent a minority of customers hogging bandwidth. The company has called this system Priority Access.
Customers on the Standard plan, for example, have a Priority Access data limit of 1TB per month. Only data consumed between the peak hours of 7am and 11pm count towards that limit. Customers who stray over that limit are reduced to the so-called Basic Access plan for the remainder of their billing cycle. Starlink doesn’t put a precise figure on Basic Access bandwidth, but states that customers “may experience slower speeds and reduced performance compared to Priority Access”, with services such as streaming video most likely to be affected. Customers can pay $0.25 per GB of data for additional Priority Access if they can’t cope with the reduced speeds.
Sam Crawford says it’s too early to see the impact of the cap in SamKnows’ measurements, but that the “generous” 1TB cap is unlikely to have a serious impact on performance for most customers.
“This is the same for every ISP that has an access network that can be oversubscribed – it has a small proportion of users that are probably using a disproportionately large amount of traffic. This is basically about making sure that the few don’t spoil it for the many, and I don’t think it will have a huge amount of difference on network performance. But I think it will help with that long tail, so where there are areas of significant congestion, it will help reduce the impact on people who are suffering.”
Webpage fetch time
Split by target – (seconds) lower is better
Detecting the dips
Starlink is unlike almost any other broadband service. Dropouts are more likely than with a fibre connection, because you’re relying on a direct line- of-sight signal between your satellite receiver on the ground and one of thousands of satellites flying 550km above the planet at roughly 17,000mph. Not surprisingly, it’s a little more choppy than a chain of fibre optic cables, but still remarkably stable given the sheer physics involved.
SamKnows doesn’t do anything differently when measuring the performance of Starlink or any other ISP – they’re all judged on the same performance criteria, using the same methods. But Sam gives us some insight into how SamKnows measures and reports those fluctuations in service, which might explain the reasons that SamKnows measurements differ from the more apocalyptic, anecdotal reports about Starlink’s performance that emerged over the summer.
For example, connection failures don’t affect average speed measurements. “Since the speed test is a measure of how fast or how much bandwidth you can push through the pipe at any time, we don’t include failures in the average – because one failed speed test would drag the average to zero for that period and it wouldn’t make sense.”
“Of course, it’s important not to just paper over the issue of a lack of coverage, because it’s great if you can get 150Mbits/sec for 30 minutes every day, but if for the other 23.5 hours you have no coverage at all, then you’re going to be pretty cheesed off,” said Sam, adding that this was just a hypothetical scenario, not a reflection of Starlink’s performance!
We’re sending a constant stream of traffic and sampling how often packets drop across the entire hour.
“We do have lots of other metrics that capture outages or disconnections,” said Sam. “The most obvious one is a simple packet-loss metric. Our latency and packet-loss metrics run continuously, so we’re not just sampling it, say, every 10 seconds within an hour running some simple pings. We’re sending a constant stream of traffic and sampling how often packets drop across the entire hour. We send packets roughly once every 1.5 seconds.”
When two or more consecutive packets are lost, SamKnows characterises that as an outage. “We show that to the customers in our SamKnows One dashboard. It’s like a time line for the day, with little vertical red bars indicating when outages occur. If you look at a very poor connection, you can just see this little striped pattern of red bars indicating outages – and, obviously, that isn’t a good thing.”
As the chart on this page shows, SamKnows has not measured any serious deterioration in UDP ping latency on the Starlink network over the course of the past year, but it’s just one of the dozens of stability and throughput metrics that the company will continue to measure around the clock for Starlink customers.
Daily distribution of latency with upper and lower interval bounds
Where’s the competition?
Despite some minor turbulence during the summer, Starlink continues to deliver for the vast majority of customers. But what about those potential rivals we mentioned when we first covered space broadband back in the very first issue of SamKnows Spotlight?
OneWeb, the company part- owned by the UK government, already has hundreds of satellites deployed. However, the number is nowhere near as many as Starlink, and they’re at much higher altitudes, which means increased latency among other things. OneWeb’s focus is the business sector, providing connectivity for the military, offshore energy companies and the maritime industries, among others, and so it isn’t really a direct competitor to Starlink. Indeed, it now relies on the rockets of Starlink’s parent company, SpaceX, to launch its satellites.
Starlink’s biggest potential competitor remains Amazon’s Project Kuiper, but it remains a fair distance away from a commercial launch. In October, the company announced it would be launching two prototype satellites – KuiperSat-1 and -2 – into space in early 2023. “Our prototype mission will help us test how the different pieces of our satellite network work together, adding real-world data from space to results from our extensive lab testing, fieldwork and simulation,” the company wrote in a blog post. “We’ll use findings from the mission to help finalise design, deployment, and operational plans for our commercial satellite system, which will provide reliable, affordable broadband to customers around the world.”
Although Starlink has gained first-mover advantage in this market, it isn’t a lost cause for new entrants such as Amazon. After all, the world is a big market, and as Sam Crawford points out, the barriers to switching are low. “It isn’t like there’s any hugely complicated infrastructure or very long- term contracts involved,” said Sam. “They simply have to install a different dish on their home. The first-mover advantage will be beneficial, but I wouldn’t say it’s going to be crucial for Starlink.”
Starlink isn’t resting on its laurels, waiting for Amazon or other competitors to muscle their way into its market. The company has been busy forging new alliances with mobile networks and airlines to help expand the reach of the Starlink service.
In August, Starlink announced a partnership with T-Mobile that aims to fill in the enormous geographical gaps in cellular coverage in the United States. The companies will fit new hardware to Starlink satellites that will effectively create a new mobile network in the sky, using the mid- band spectrum that T-Mobile already owns. This means consumers won’t need to buy new handsets or satellite phones – the vast majority of smartphones already in the market will be compatible.
The two companies claim that this “satellite-to-cellular service will provide nearly complete coverage almost anywhere a customer can see the sky”. This means that areas such as national parks, parts of Alaska, and huge swathes of land where it’s either uneconomical or impossible to install cell towers will benefit from coverage.
However, the bandwidth on offer will be modest, at least to begin. T-Mobile aims to provide text messaging, MMS and enough data for “participating messaging apps” in the first instance, with plans to add voice and full data coverage at a later date. The first services should go live by the end of 2023.
Lots of different techniques have been tried for bringing internet connectivity to planes.