- The Arctic Circle trial proved that LEO satellites can effectively support public transport networks in regions with comparatively low cellular network capacity, offering a viable alternative where traditional infrastructure falls short.
- Starlink, of which Icomera is an authorised reseller, delivered speeds nearly ten times faster than cellular networks, making it ideal for bandwidth-heavy applications like real-time video surveillance and passenger Wi-Fi.
- In the sparsely populated testing region, Starlink offered higher speeds, while cellular networks provided more consistent baseline coverage. A hybrid approach combining both networks, which were fully uncorrelated, significantly improved overall availability.
In preparation for its Starlink connectivity solution for trains, Icomera conducted a pioneering research experiment in collaboration with Sweden’s KTH Royal Institute of Technology, exploring the performance of cellular and Low Earth Orbit (LEO) satellite connectivity in the sparsely populated Arctic Circle region, where cellular network capacity is relatively low.
Navigating the Digital Divide in Sparse Environments
The vast, sparsely populated regions of Northern Scandinavia pose unique challenges for providing Internet connectivity, particularly where public transport is concerned. Despite impressive coverage, some rural areas receive little overall network capacity from traditional cellular infrastructure and the business case for mobile network operators investing in upgrading their networks in these regions may not be strong enough to warrant the significant capital outlay required to do it.
Sweden is not alone in this regard – There are many regions across northern latitudes that still receive patchy network capacity across public transport routes, regardless of population density, for example, Canada, Alaska, northern parts of the United Kingdom, and other Nordic countries.
With questions around the capabilities of cellular networks to provide sufficient capacity to northern regions, Low Earth Orbit (LEO) satellite networks such as Starlink present a compelling solution. At the time of testing, Starlink’s constellation of satellites was comparatively less dense over northern latitudes compared to the rest of the world, however the total number of satellites entering service is increasing at a rapid pace, further increasing Starlink’s potential to deliver high-speed Internet where terrestrial networks fall short.
Figure 1: The Starlink constellation is less dense across Northern Latitudes, however the overall number of satellites being entered into service is increasing at a rapid pace. Credit: https://satellitemap.space/
But how well can Starlink complement terrestrial cellular networks in real-world conditions in the Arctic Circle, particularly for mobile applications? Icomera’s study took a data-driven approach to answering this question.
The Arctic Test: Measuring Connectivity in Motion
To assess the feasibility of Starlink as a broadband solution for mobile environments, a research team conducted a 970 km test across the Arctic Circle, spanning Northern Sweden’s Norrland region, from Umeå to Vilhelmina. Using an Icomera X5 router paired with a Starlink Flat High-Performance terminal, alongside a commercial 5G cellular setup, connectivity performance was measured under varying conditions.
The test route encompassed both urban areas and remote wilderness, providing a robust evaluation of network coverage, throughput capacity, and availability. By aggregating data from over 50,000 Starlink observations and 23,000 cellular observations, a comprehensive understanding of how these technologies compare in challenging environments was achieved.
Starlink and Cellular: Key Findings
Figure 2: Scatterplot of the 11595 observations with simultaneous traffic load on both Starlink and cellular links, demonstrating the difference in throughput between both.
The results of the study highlight the distinct advantages of each connectivity solution, as well as their combined performance:
- Throughput Performance: Starlink demonstrated a significant advantage in median throughput, delivering speeds nearly ten times higher than the cellular network. This makes it a viable option for bandwidth-intensive applications such as real-time Digital Video Surveillance and high-performance Passenger Wi-Fi. It should be noted, however, that in this environment, Starlink’s lowest recorded measurements delivered less throughput than cellular.
Figure 3: Starlink excelled in overall performance but exhibited more frequent connectivity losses than cellular, due to the low number of satellites above the testing region. By aggregating both networks, the vehicle remained connected across over 99% of the route.
- Connectivity Gaps: It was clear that despite the Arctic Circle being situated outside its main coverage area, Starlink still excelled in overall performance, but exhibited more frequent connectivity losses. Conversely, cellular networks provided more consistent baseline throughput but struggled to match Starlink’s bandwidth capabilities.
- Hybrid Potential: By simultaneously aggregating Starlink and terrestrial cellular connectivity, one network could fill in for the other whenever its connection dropped, offering consistent availability across the route. During this test, the combination of both networks provided a stable Internet connection capable of offering video streaming for over 99% of the route.
- The Implications for Transport: Therefore, in real-word transport applications, simultaneously aggregating Starlink with terrestrial networks along the route offers improved overall network performance, which translates to more availability and capacity for onboard devices and applications, with fewer interruptions.
Bridging the Gap with Hybrid Connectivity Solutions
In the past, when LEO satellite connectivity was not a commercially viable option, northern countries, including Sweden, attempted initiatives aimed at improving capacity along rail tracks. Due to the technology available at the time, these initiatives predominantly focused on building out fibre and cellular networks and would potentially have cost billions in capital investment to fill in their connectivity gaps.
As an authorised reseller of Starlink satellite connectivity for trains, Icomera is uniquely positioned to integrate satellite-based solutions into public transport networks. This study suggests that combining satellite and cellular networks as part of a wider connectivity strategy could offer increased network availability for trains travelling through remote or sparsely populated areas, rather than waiting for the costly development of terrestrial infrastructure, if it were to expand at all.
By adopting a flexible, multi-layered approach to connectivity, transport operators can ensure that even the most isolated routes benefit from high-throughput Internet access.
Figure 4: Icomera’s SureWAN™ technology aggregates all available capacity along the entire route.
The Future of Connected Mobility
Icomera has been actively involved in multiple successful satellite connectivity tests since 2002, having identified its potential for public transport applications more than two decades ago. Some of these have included tests on trains operating in full commercial service, while others, such as the Arctic Circle study, have been technical trials aimed at finding ways to use the technology to achieve its full potential.
Recent results of LEO satellite connectivity have been impressive, delivering the equivalent of inner-city 5G capacity to trains in rural environments with throughput consistently in the range of 200+ Mbps when aggregating Starlink terminals for rolling stock, and some tests demonstrating a latency of less than 40 milliseconds.
As Icomera celebrates 25 years of innovation, its commitment to advancing connectivity remains stronger than ever. This study is just one example of ongoing efforts to push the limits of what’s possible, bringing cutting-edge technology to the world’s most challenging environments.
With hybrid connectivity solutions, the industry is paving the way for a future where passengers, businesses, and communities stay seamlessly connected – whether in bustling city centres or the remote Arctic wilderness.
Read the full research paper here: https://ieeexplore.ieee.org/document/10536679
