Radio transmissions are governed by the speed of light, and LEO networks are one seventeenth of the distance to conventional geostationary satellites, which beam broadcast signals. That gives them the potential to deliver data.
LEO satellites are now much cheaper than they were before. Reusable rockets and advances in radio boffinry – and the build-out and capabilities of mobile networks – mean that many more LEO satellites can be launched. More satellites will be launched in the next two years than ever have been.
The best known of these is the Starlink venture by SpaceX, the company founded by Tesla Motors Chief Executive Elon Musk, which went live to UK consumers earlier this year. About 1,800 Starlink units have been launched, but that’s only the start; 12,000 have been approved by the US regulator, the Federal Communications Commission, and Starlink has applied for more than 30,000 in total.
Another company, OneWeb, has now resumed its launch programme after an investment from the UK Government rescued it from bankruptcy. OneWeb has launched a third of its fleet and is just moving from partial to commercial coverage. Kuiper Systems, backed by Jeff Bezos, founder and former Chief Executive of Amazon, has permission from the FCC for 3,236 LEO satellites, but has yet to launch the first of these.
Rather than selling direct to consumers, OneWeb is targeting businesses, including mobile operators, and governments.
“While Starlink are targeting retail consumers, OneWeb are more focussed on business services, business connectivity, and on high reliability and low latency applications, like mission critical communications,” explains the Satellite Catapult’s Director of Ubiquitous Connectivity Kieran Arnold.
That’s also the path taken by Canada’s Telesat fleet. Telesat launched a demonstration satellite in 2018 and plans to install 288 in all.
Whatever the business model favoured by the constellation owner, it’s all about data: each satellite is designed to deliver fast internet. Rural users who until now have been deprived of data connections will be able to get them, and many more residents will be able to swap their slow, unreliable connections for fast, efficient links. Mobile networks are central to this, as they will integrate the new infrastructure behind the scenes, without the consumer having to upgrade their phone. (Iridium’s LEO network required a hefty, £2,000 phone that wouldn’t work on any other network).
The first users who will connect to the new generation of LEO satellites have already been sent their do-it-yourself kits. The work to integrate 4G or 5G mobile networks with the new capabilities of the satellites is already taking place.
“What this is enabling – and none of the incumbents should see this as a threat – is 100 per cent coverage of fast internet for anyone who wants it,” says Adam Beaumont, founder and Chief Executive of aql, and a member of the UK5G Advisory Board.
“That’s the powerful statement; nobody’s been able to say that in the past. They’ve been fretting over 4G, or fibre not-spots, and the cost of commitment to fill that 3 per cent which is not served at all, which is a nigh-on-impossible task. Now there’s an operator who can.”
But until now, the economics didn’t add up. “If you have just five users a week driving down a road, it’s not going to be worth that investment for any operator,” notes Howard Benn, Head of Standards and Industrial Affairs at Samsung Electronics.
This problem has bedevilled successive governments. Satellite changes this. It becomes feasible to think about the expense of a mobile base station, which requires power and backhaul to talk to other base stations on the network. Unlike expensive fibre or line-of-sight microwave, satellite doesn’t discriminate, and the large up-front capital expenditure is being handled by the satellite constellation owners.
The economic case
for boosting the connectivity of a village, or a street that’s a mile from the market square, is also improved. Covid-19 lockdowns have prompted many to consider working outside metropolitan areas. But poor connectivity (rather than no connectivity at all) is frequently cited as one of the biggest factors that deters businesses from locating in or just outside Britain’s market towns. So the combination of LEO satellites and 5G promises to be a major contribution to the government’s levelling-up agenda, narrowing the disparities between high-bandwidth cities and the towns outside.
In 2019, only about 40 per cent of rural users who took part in a poll had a broadband connection that was faster than 2Mbps, way below the government’s minimum standard of 10Mbps download speed, and far below the 64Mbps national average download speed that Ofcom found in 2020. US analyst Craig Moffett estimated recently that with a typical 10:1 oversubscription ratio, Starlink could serve 700,000 users at its full speed of 100 Mbps.
Beaumont’s aql acquired 4G mobile operator BlueWave in 2014 and gained experience of building 4G in rural areas and of connecting ferries and ships. For this it began to integrate geostationary satellites into its service. On the Isle of Man today BlueWave is at the cutting edge, catching the signals of a major constellation and making them usable for everyday phone users.
“We now have first-hand experience of using satellites for 5G backhaul,” Beaumont says: “aql built out a ground station, which you can think of as a receiver and relay station for the signals from the satellite, and we got this to talk to our 5G network.”
This was not easy, he says: “The amount of engineering to make this happen is absolutely off the scale mind-boggling” but the physics challenges that LEO engineers must overcome are the same challenges that 5G engineers have been solving, for instance with phased array and beam-forming technology.
This means that 5G and satellite are perfect complementary technologies, says Beaumont.
“Combine the satellites with a very resilient last-mile delivery technology such as 5G and you’ve got a very promising new infrastructure. Both LEO and 5G are two low-latency techs that accept step changes in throughput. Then combine that with wind or solar and you can start to deploy connectivity in very hard-to-reach areas.”
The guinea pig for Beaumont’s BlueWave has been Candour Productions, a wildlife video production company based in Leeds. To make it more challenging, Candour sought to film in caves in Ribblesdale, North Yorkshire. And more challenging still, the company wanted to broadcast the results in real time. The Live and Wild project won the support of DCMS as part of its Testbeds and Trials programme.
BT has been using satellites for decades and is exploring what the new LEO satellites can offer. Andy Sutton, Principal Network Architect, told us the company gained insights through EE’s operation of the UK’s emergency services network.
“We had to increase the overall availability of the network so we could achieve resilient transmission to strategic nodes, so they could switch over,” says Sutton. “What’s the most sensible and most viable way of achieving that? Having looked through the options we opted for satellite for resilience, plus the ability to deploy some specialist capabilities such as rapid response vehicles. And for times during upgrades, or a temporary outage, or vandalism during the early days of Covid.
“However, there’s a finite capacity and it covers a large geographical area. Capacity isn’t cheap on geostationary satellites. We use backhaul today - I’d suggest in the UK we’re ahead of the game.”
The LEO satellites create some new problems, says Sutton – for instance, they move very fast, increasing the Doppler effect – but their close proximity to Earth solves other traditional satellite problems, such as poor latency. There’s no need to use compression, for example. “From consumer trials of Starlink, the latency seems to be manageable,” he says.
Although it’s early days in the integration of 5G backhaul and satellite, both Sutton and Beaumont offer the opinion that availability of this technology would have made a significant difference in the early days of 2020’s coronavirus lockdown. For instance, Sutton explains that satellite kicks in when a base station is down, meaning that home workers would not have faced dropped connections, and lack of maintenance staff would have been less of a problem.
Security is another advantage of the new satellite infrastructure. The UK Space Agency’s Head of Telecommunications Strategy, Mike Rudd, explains:
“An internet connection from the UK to Australia can travel via a number of routes, but not all of those are necessarily benign. Traffic is moving through regions where there’s no ability to inspect the cable, or to control any junctions on your circuit, so there’s a lot of scope and opportunity for bad practice. Satellite is inherently more secure.”
There are real-world, DCMS-supported examples of how this can work, such as in rural Dorset. The Satellite Catapult’s Arnold says it is “the only county without a motorway – the geography of the Jurassic coast, for example, is horrendous”. This results in sparse rural communities living in the shadow of radio masts, as they do in many parts of the UK. The ideal place to put the masts would be out at sea, but that would be costly and impractical.
The 5G Rural Dorset programme, supported by the Satellite Applications Catapult, is exploring ways to use satellites to improve coverage, with benefits for offshore and onshore communities and organisations.
Better coverage means augmenting the reliability of networks so that they reach the five nines – 99.999 uptime – meaning fewer dropped calls for consumers. Coverage is so poor in Dorset, he says, that councils can’t use cashless machines in car parks, which means they have to employ car park attendants.
Maritime workers were among the first satellite users – the US predecessor to the global positioning system was opened up for ships to gain accurate positioning in 1967. Today’s internet of things infrastructure means that small sensors, such as those that trace shipping containers, can be tracked more accurately by reliable and ubiquitous broadband over satellite.
“The large constellations give you that ability for persistent connectivity – particularly at northern latitudes, which you don’t get with a geostationary satellite,” explains Rudd.
Arnold says the question that remains is how to get the link down to Earth. To answer that, the European Space Agency recently opened a 5G Hub at the Harwell Science and Innovation Campus in Oxfordshire. It’s hosting companies from the 5G ecosystem, satellite and terrestrial operators, and equipment providers, to test new services. It’s part of the strategic-programme-line 5G programme. One example at Harwell is an O2 initiative with the UK’s Space Agency, called the Darwin SatCom Lab, which is exploring industrial, IoT and automotive cases.
Another specific industrial IoT project will benefit rail users. SODOR, the island satellites for digitisation of railways project, is an initiative inspired by the Reverend Wilbert Awdry’s railway series about Thomas the Tank Engine’s adventures on the eponymous island. It will use LEO satellites to improve integration and handovers and aims to address line-of-sight issues that occur with existing coverage. Reliable, low-bit-rate links will support signalling, for example, and keep track of passengers and physical assets. In addition, since only a third of rail users are reported to be happy with their onboard wi-fi, a consortium that includes CGI, Icomera, 5G3i and Strathclyde University will address how the LEO constellations can provide dedicated track-side broadband.
What’s exciting and profound about the new constellations is how various industrial trends are affecting space businesses.
“The industry has gone from handbuilt equipment to commoditisation, and the supply chain has had to keep up,” explains the Space Agency’s Rudd. “Companies that produced 15 items a year now have to produce thousands.”
The new satellites aren’t exactly disposable – they’re packed with valuable rare-earth metals and they need more maintenance than geostationary satellites, as their low orbit means more friction and the need for more adjustments to maintain their position. That means a typical life span of seven years before their fuel depletes. But the low cost of space shots means the network can be upgraded constantly. And entrepreneurs are already looking at in-space refuelling, and are even considering manufacturing the satellites in space in the future.
Many of these UK companies are growing dramatically because of the new communications constellations. The UK space sector contributes some £15 billion to gross domestic product, and its members are specialists at inventing and manufacturing ingenious small solutions that are particularly useful to LEO constellations.
“The start-ups are much more bullish, more savvy and more aggressive at trying to get things through. We’ve got the funding, and it’s a nice group of entrepreneurs,” says Arnold.
In the future, direct satellite connections from your phone are likely to be incorporated into the 3GPP standards that the world’s cellular infrastructure uses. That would enable continuous coverage for not-spots or sites that have temporarily failed.
Benn of Samsung has a seat at those discussions. He thinks that “probably in two to three years we’ll have a standard capable of dealing better with a satellite signal. So it’ll be 2025-2026 before the standards emerge, and 2028 before the equipment arrives. But ultimately the promise is seamless roaming from terrestrial to satellite”.