Satellite-based positioning, commonly referred to as a global navigation satellite system (GNSS), relies on a constellation of satellites to deliver precise location data to Internet of Things (IoT) devices.
In the Internet of Things, device location is everything, says Brandon Satrom, SVP of product and experience at industrial IoT provider Blues. Much of the value organizations seek to gain from connectivity is not only about unlocking the data collected by sensors and machines but also the ability to orient that data to the physical location of its capture, whether it’s in the field or on a factory floor.
“When dealing with the massive scale that connected devices represent, having to manually log device location is cumbersome and prone to error,” he says.
“What’s more, many connected things move, and stale or inaccurate location information can be worse than no location at all.”
Satellite-based device positioning, the most common global version being GPS, is currently the most broadly useful approach for obtaining accurate device location within a few meters, according to Satrom.
When paired with IoT connectivity over cellular, Wi-Fi, or LoRa, GNSS can provide quick and accurate device location of assets at rest or on the move.
“Accurate device location via GNSS has unlocked several use cases in mobile asset tracking, including logistics and cold chain monitoring, as well as a number of fixed-asset and anti-theft use cases in heavy machinery and agriculture,” Satrom adds.
Unlike cellular networks with limited coverage and reliability, satellite-based positioning is available anytime, anywhere in the world, including remote locations, says Arn Hayden, business development manager of IoT technologies at technology company Trimble Inc.
“This provides numerous advantages in industries ranging from transportation to mining and more,” he says.
GNSS is inextricably linked to IoT, and it acts on the two different aspects of IoT ecosystems and provides two critical functions, says Will Thornton, product marketing manager at Spirent Communications, a telecommunications testing services provider.
“These [two] are the better-understood positioning aspects for devices and the lesser-known impact of distributed timing utilizing GNSS in the function of the actual data networks supporting the IoT devices,” he says.
The Importance of Positioning
Positioning is the better understood of the two GNSS dependencies, Thornton says. For companies to fully realize the value of many devices in an IoT network, they must ensure that accurate positioning is always available, Thornton says.
Ian Itz, director of the global IoT line of business at Iridium Communications, a satellite communication company, agrees.
“Most devices outside of terrestrial coverage are going to rely on space-based positioning for their applications,” he says. “And that’s primarily due to the ubiquity of those satellites.”
However, for some applications – those for which positioning continuity is critical and for which indoor or deep urban operation is required – this will mean that a secondary source of positioning information is needed, according to Thornton.
“That could be an alternative source of absolute positioning information or a supplementary relative positioning system,” he says.
The Importance of Timing
According to Thornton, communications networks, such as 4G and 5G, depend on tight time synchronization. The source of timing across the networks is typically GNSS – whether through GNSS receivers distributed across the range of the network or via Ethernet switching using GNSS as a primary reference time source.
“This timing dependency is also relevant to the performance of some products and services provided by the IoT devices on the network,” he adds.
Most IoT applications are using satellite-based positioning, not only for the global positioning side of it, but they’re also using it for timing to ensure that they have precise timing within their applications, Itz says.
“A lot of those applications are using the global satellite network to check elapsed time or the current time,” he notes. “Without a local terrestrial-based system, the only thing that you have at that point is the space-based triangulation systems.”
In 2022, Spirent supported a company called Astrocast with testing for its IoT satellite service, says Thornton.
Astrocast provides a satellite-based communications network for registered IoT devices that extends beyond the reach of traditional cellular and Wi-Fi networks, he says.
The provisioning of this network depends on Astrocast’s ability to track and maintain the orbits of its satellites, which use GNSS for positioning and synchronization.
“Therefore, GNSS is relevant from the building blocks of an IoT network to the distribution of that network across cells (or the world) and to the devices on that network,” Thornton says. “Hence, inextricably linked.”
GNSS and IoT Monitoring Applications
GNSS works extremely well in tandem with IoT monitoring applications, says Allan Cannon, co-founder and CEO of Krucial, a Scotland-based digital solutions provider.
By integrating positional data with condition monitoring, industries worldwide can gain a complete overview not just of how assets are performing but also of where and whether location impacts performance.
“Let’s take an energy example – supply chains are extremely complex, with a lot of specialist equipment being hired from companies overseas for individual sites and projects,” he says.
“Not only do users need to understand where an asset is at all times, the hire company might also need that information to confirm it is being used as agreed.”
According to Cannon, by using GNSS combined into one application with IoT data, companies can measure location and performance in the same solution.
“Understanding usage by monitoring vibrations on an engine, for example, provides significant insight for asset users and owners, allowing for predictive maintenance models to be built with confidence,” he says. “That can then be combined with location data to understand if the ‘where’ of an asset being used impacts the ‘how.’
GNSS – combined with IoT devices – also contributes to the optimization and efficiency of agricultural practices, Thornton says.
“This enables mapping and planning, automated steering, and navigation of farming machinery as well as providing accurate location data for individual plants or specific points within a field, minimizing waste and optimizing crop yields,” he says.
READ MORE: 7 Ways to Use IoT in Agriculture
Any machine/device that can benefit from knowing where it is on the earth can be enhanced or even improved with satellite-based GNSS, Hayden says.
“Making things more efficient, cost-effective, and other benefits are realized when something like an autonomous tractor can plant seeds more accurately and with less waste,” he says.
And combining IoT data on parameters, such as soil moisture or stock condition, with location means that such practices as spraying and irrigation can be targeted accurately at areas genuinely in need, with no guesswork required, according to Cannon.
Traffic Management and Logistics
The real-time positioning provided by GNSS integrated with IoT devices enables route optimization, optimizing traffic signal timings, managing congestion, and improving overall traffic flow, says Thornton.
“GNSS also supports the implementation of geofencing for enhancing security and overall operational control – precise location information that’s critical for quick and targeted interventions and rescue operations,” he adds.
Additionally, companies can use IoT-enabled asset tracking combined with GNSS to track assets, such as vehicles, shipments, and equipment, in real-time.
“This is valuable in logistics, transportation, and supply chain management where knowing the location of assets is critical for efficiency, security, and compliance,” Thornton says.
Drawbacks of Using Satellite-Based Positioning With IoT
While GNSS can be fast and accurate, it is a power-hungry technique and can be challenging to use reliably in low-power solutions that rely on solar. However, it is possible to get the best of both by reducing the frequency of polling for device location, according to Satrom.
“This does result in potentially stale data, but it may be an acceptable tradeoff when dealing with extremely remote device locations where a device is unlikely to move or doesn’t move far in a fixed period of time,” he adds.
Another drawback of GNSS is that it does not work indoors, meaning that it is not appropriate for a number of industrial IoT use cases that would also benefit from accurate device location.
“For these use cases, vendors often will complement GNSS-location services with a triangulated device location using cellular towers or Wi-Fi access points, known locations of these, and device signal strength,” Satrom says.
“Much like GNSS, these approaches have been found to provide single-digit meter accuracy for indoor devices.”
Working together, IoT and satellite-based positioning can transform the way organizations operate, particularly in remote areas without the benefit of traditional cellular networks.
And with advancements in technology, the collaboration of IoT and satellite-based positioning will likely result in additional improvements and innovations in a variety of sectors.