Better signal on the Østfold Line

The signal on most of the Østfold Line is so strong and stable that train passengers are now able to spend the journey reading their emails, downloading data and streaming something on Netflix, says Øystein Risan, CEO of Norske Tog.

Throughout 2020 and 2021, Norske Tog has worked on installing modern 4G signal boosters, otherwise known as repeaters, in 184 train carriages, including the FLIRT-trains, which will be delivered next year. Tests have also been carried out to measure the data rate on board our trains on the route between Ski and Moss, which have shown that this has also significantly improved since the installation of the repeaters.

However, there are still routes that do not have adequate coverage. There are a few factors causing the varying levels of signal available on some lines; this is partly due to the fact that there has not been enough development carried out regarding network coverage along the railway and in the tunnels, and partly because the carriages themselves reduce the strength of the mobile signal available outside the train. Signal boosters will also be installed into a further 51 carriages.

- Our goal is to help make the railway an even more attractive means of transport. Strong network coverage is therefore crucial. Our passengers expect strong enough signal on our trains that they will be able to work, stream or surf the net throughout journey, Risan says.

An important offer for passengers

Tests carried out to measure the data rate along the Østfold Line, with a particular focus on the route between Ski and Moss Station, were done by the consultancy firm Gamba. This is a stretch of railway with diverse terrain and numerous tunnels. The tests have shown that the download speed measured in at a minimum of five Mbps (Megabits per second) for 98 percent of the time, Risan says. (LINK TO THE GAMBA-report)

The Norwegian Railway Directorate has defined five Mbps as the minimum value that can be offered in order to provide a positive customer experience.

- This is a good result for the route between Ski and Moss. At the same time, it is important to underline that these tests have only been carried out on the Østfold Line. There are still routes that do not have the same level of network coverage as we are now pleased to have on the Østfold Line, Risan adds.

Sharp increase in mobile data usage

Norwegians’ use of mobile data has significantly increased in recent years. According to NKOM, data traffic for mobile subscriptions increased by 30 percent in the first half of 2020, compared to the same period the year before.

At the same time, the level of signal passengers are offered on board these services has not been strong or stable enough. This has partly been down to the fact that the infrastructure for mobile coverage along the railway and within the tunnels has not been adequately developed, and that the trains had not yet been equipped with signal boosters.

Thus, in cooperation with the Norwegian Railway Directorate, Norske Tog prioritised the installation of four-band signal boosters in our train carriages throughout 2021 and 2020.

- The signal boosters amplify the already available signal outside of the train, and distributes the signal throughout the carriage, Risan explains.

Both Telenor and Telia have conducted tests that have proved that the signal boosters are providing improved coverage and higher data rates on board the trains.

In a statement, Telia said that ‘the measurements have shown that the signal boosters are providing a higher data rate’. Regarding Telenor’s test, they observed that ‘with the repeater, the signal has been raised to the perfect level throughout the entire train’. Telia and Telenor’s quotes have been included in Gamba’s report.

Particularly challenging tunnels

However, efforts to provide train passengers with even stronger and more stable mobile coverage have not been fully realised. We still face challenges in ensuring strong mobile coverage on a number of the trainlines. This is especially so in the tunnels and the areas with minimal mobile network infrastructure.

This autumn, the Ministry of Transport have asked that the Norwegian Railway Directorate implement a pilot project to provide better network coverage along the railway. https://www.regjeringen.no/no/...

- Norske Tog’s installation of repeaters in Norway’s train carriages will work as an important contribution in ensuring that this is achieved. We are now continuing our work in installing signal boosters in the remaining 51 train carriages, Risan explains.

However, work must also be carried out outside the train, in the form of improvements along the railway lines themselves. The mobile network operators are responsible for developing the commercial network around the lines, and Bane NOR is responsible for coordinating and facilitating that the commercial telecommunications operators are able to carry out the work to provide coverage within the tunnels.

- All those involved in the railway will work together to ensure that the network coverage on offer in our trains is stronger and more stable throughout one’s entire journey, Risan promises.

Fact boxes

About Gamba’s test:

• The on-board testing was carried out on the Østfold Line, on the stretch between Oslo and Moss Station, with a particular focus on the area between Ski and Moss.
• The tests were carried out with a specific focus on the quality of the signal on board, the stability of signal available and the speed measurements.
• The tests were carried out over the space of a week, during rush hour in the morning, and again in the afternoon when there was more of a demand on the mobile network. It should be noted that the tests were completed in February 2021, a period affected by Covid-19 restrictions, which thus resulted in fewer passengers as usual on the trains. Fewer passengers on-board means that there was less pressure on the system and the available bandwidth, which could have resulted in test results that were better than they would have been, had the train been at full capacity.

Gamba’s main findings:

• During the testing period, the quality of signal and level of coverage was measured when the signal booster turned on and then again when it was turned off. The measurements indicated that there was a significant difference in both signal quality and coverage.
• The signal was faster, better and more stable in areas that suffered from weaker signal from the macro network, such as in valleys and tunnels. Something that will provide passengers with a more stable user experience.
• The results show that further optimisation is required in areas with particularly strong coverage but are still affected by other frequencies from the commercial networks. This applies to train stations, for example. In this case, Norske Tog will carry out adaptations in order to compensate for the strong signals interfering from the telecommunications network.