We may live in a global economy, but the internet of things (IoT) is not global – not even close. Only 2.7% of the world's land is urban, and even landmass only makes up 29.2% of the planet's total surface.

"Mainstream communication systems only cover a small fraction of the Earth," says Richard Traherne, Chief Commercial Officer, Cambridge Consultants, who says that mobile phone coverage extends over only 10% of the planet – and that's being generous.

"It will take many years before IoT technologies are rolled out to achieve the same level of coverage as mobile networks even," he adds. No wonder, then, that in a quest to create global services, IoT infrastructure is slowly being sent into orbit.

Autonomous ships would need to use IoT by satellite. Image credit: Rolls Royce

Why does the IoT need satellites?

"IoT by satellite is an important part of IoT – it's intrinsically wide-area, low-power, and globally available," says Traherne. Any IoT project that requires wide area mobility and coverage – such as logistics on land, sea and air, asset monitoring (including oil, gas, electricity and water pipelines) and environmental monitoring – are key areas for IoT by satellite.

Cue satellites from Iridium and Inmarsat, although both are completely different in terms of technology and use-cases.

"For a long time we've been about voice, data and email with only some machine-to-machine (M2M) use-cases, but it's been fairly unsophisticated," says Paul Gudonis, President, Inmarsat Enterprise, which has just paired-up with Actility to deliver the world’s first global IoT network. "But over the last 12 months we've seen an explosion in companies wanting to get as much access to data as they can to drive efficiency – and much of it sits outside terrestrial coverage." 

"Satellite links are used in cellular networks as backhaul technologies for remote areas or areas in which traditional backhaul technologies are unsuitable," says Traherne. Increasingly, satellite fleets are being integrated into the IoT as backhaul – the link between an LPWAN network and a backbone network – typically where cellular coverage is poor or non-existent.

Iridium is generally used where other systems can’t provide service

What is Iridium?

The Iridium system is a network of multiple Low Earth Orbit (LEO) satellites, 500 miles up in the sky, travelling at 17,000 miles per hour (you can watch one flash dramatically just after sunset if you keep an eye on this website). "LEO devices rely on the ever-moving network above them to provide coverage anywhere as long as they have a clear path to the sky," says Traherne. 

SpaceX recently launched the first 10 of 70 satellites for Iridium (and landed the Falcon 9 rocket back on a drone-ship), which will add to its existing fleet of 66 satellites to create a $3 billion (around £2.4 billion, AU$3.9 billion) constellation called Iridium NEXT that's being described by some as the biggest tech refresh in the world right now. Iridium is paying SpaceX upwards of $500 million (around £400 million, AU$650 million) for seven launches.

"Iridium NEXT will extend Iridium's existing capability to provide higher speeds that unlock new possibilities in asset tracking, fleet management and other intelligent data applications," Traherne says. It could also bring mobile broadband to phone users in very remote areas. "Each satellite covers an area on the globe that's about the size of North America, and each coverage area overlaps so that there are no gaps in the coverage." 

Put simply, Iridium covers the entire planet, so fills in the gaps left by mainstream cellular and LPWAN IoT networks.

Main image credit: Iridium

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Inmarsat’s system uses 11 satellites

What is Inmarsat?

Similar global coverage is achieved by Inmarsat, but the hardware and service is very different. Inmarsat has 11 higher-power satellites in geostationary orbits exactly 22,236 miles above specific points on Earth. They have much higher capacity than Iridium hardware, but there is a bigger latency – the time it takes for data to travel between the satellite and the receiver – due to the much greater physical distances the data has to cover.

Does this matter to IoT applications? Only if projects need time-critical data links (most do not), but there are other considerations. "Devices on the ground must have higher transmit powers for the greater transmit distance, meaning a greater power requirement," says Traherne, who also explains that those devices on the ground must typically orientate their antennas towards GEO satellites.

"The Inmarsat network is in a fixed position, so once you've got a connection it doesn't change – you can forget about it," says Gudonis. "Whereas Iridium specialises in small-burst data, Inmarsat is more focused on high data so we're more suitable for sensor aggregation where there's a higher data requirement."

Remote oil and gas infrastructure can be put on the IoT using satellites. Image credit: Apache

A global IoT network?

 Inmarsat recently revealed that it and LPWAN provider Actility have created the first global IoT network on the LoRaWAN specification to connect low-cost, battery-operated sensors over long distances – and in harsh environments like farms, on oil and gas platforms, and in mines.

"We resell each other's technology to provide connectivity in places like the Northern Territory in Australia for agriculture and mining projects," says Peter Hogewoning, Regional Sales Director APAC, Actility. The tech is now being used to track cattle around remote ranches, to monitor water levels in reservoirs, soil moisture on plantations in Malaysia, and to identify potential failure points on oil platforms to minimise downtime.

Global asset tracking is also a flourishing area. "With connectivity from Inmarsat we can even put a gateway on a container ship and follow it – and everything on board – around the world," Hogewoning notes. "Satellite is becoming really important for the IoT." 

Both Iridium and Inmarsat are often used as the backhaul element in IoT projects that track endangered wildlife as part of IoT projects, though details are scant – such projects are top secret to avoid revealing the locations of the animals to poachers.

Is satellite too expensive for the IoT?

It's more expensive than any other form of connectivity, so it’s mostly used for high-value assets and government projects. However, that's about to change dramatically. "What I think is going to be the biggest impact on the satellite industry is the general change in the economics," says Gudonis. "The days of a very high cost-per-megabyte and cost-per-minute are gone, and we need to look at new ways to drive our business."

The technological revolution in rocket launches is critical in all of this. “SpaceX is bringing down the cost of launching satellites because it can reuse some of the launches, so we'll soon see the cost of using satellite services reduce significantly,” he adds. “It's going to dramatically change."

Could cube-sats be used to aggregate IoT data in space? Image credit: Nasa

What about cube-sats?

Although its network relies on 11 huge satellites which are 22,000 miles from Earth, Inmarsat is also looking at creating an IoT network that would orbit much closer to the planet. Though it hasn’t used SpaceX for any launches so far, Inmarsat is working with SpaceX on exploring a future of cube-sats. It's something SpaceX – and OneWeb – are looking into as regards 'space internet' for people, not things. But Inmarsat is thinking specifically about the IoT.

"Small, low-cost satellites in orbit could be used for IoT sensor aggregation points, rather than having devices on the ground," says Gudonis, who explains that the most expensive thing in an IoT deployment for LPWAN isn't the sensors, but the base station.

"If you could put only sensors out on the ground, and then aggregate their data in space, that would change the types of applications we could look at," he observes. "You could then track anything as it moves without the need for multiple expensive base stations on land, at sea or on a plane – what amazes me is the insane expanse of different applications we can look at for satellite and the IoT."

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