Mobile Signal Boosters

Background

Norwegians are world leaders when it comes to smartphone usage and mobile data, and are accustomed to having the internet in their pockets. However, 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 because trains have not yet been equipped with signal boosters.

In order to ensure the best possible comfort, train chassis are built to dampen vibrations and noise, provide protection from the sun and reduce heat loss. This means that the chassis also prevents mobile signals from getting inside the train, which in turn means passengers suffer from poor coverage while on board.

Norske Tog is responsible for bringing the coverage available on the outside of the train inside. 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.

Project overview

In 2020 and 2021, Norske tog have installed mobile signal boosters in 176 train sets (133 carriages and 26 train sets), which constitutes approximately 68 percent of the fleet, to provide better connection on board the trains.

A mobile signal booster fitted to the train captures the mobile coverage provided by operators on the outside of the train, amplifies the signals and re-transmits them as traditional mobile coverage inside the train. This is a technological solution that is considered to be better and more stable than alternative Wi-Fi solutions. For passengers, this will mean that it is possible to stream video and use the internet for work and pleasure provided that there is adequate coverage outside the train.

Several of the trains that had new mobile signal boosters installed first have now reached their service life and have therefore been taken out of service. Norske tog has dismantled the mobile signal boosters in these trains and plans to reuse and install the equipment on class 93 during 2023. Class 93 operates mainly on the Røros Line.

The company Site Service was awarded the contract of installing and monitoring the mobile signal boosters in the older train sets. The train supplier Stadler have delivered the new FLIRT-trains with mobile signal boosters installed.

In 2024, Norske tog plans to issue a competition for installation of mobile signal boosters in class 72, which are are currently undergoing a mid-life upgrade.

Project status/Results

The consultancy firm Gamba has conducted testing on the Østfold Line to measure the data speeds available, with particular focus on the route between Ski and Moss, following the installation of the mobile signal boosters. This is a railway line 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. The Norwegian Railway Directorate has defined 5 Mbps as the minimum value that can be offered in order to provide a positive customer experience.

Both Telenor and Telia have also conducted tests that have proved that the signal boosters are providing improved coverage and higher data rates on board the trains. Reporting its findings, Telenor writes that ‘with the repeater, the signal has been raised to the perfect level throughout the entire train’.

The GAMBA report can be read in full here.

Planned progress

• 2020-2021: Mobile signal boosters have been installed in 176 train sets.
• 2022-2023: Effect testing of the mobile signal boosters together with the tele operating companies.
• 2023-2024: Installation of mobile signal boosters on class 93 (reuse of equipment from trains that have been taken out of service). Planned competition for installation of mobile signal boosters on class 72.