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.

About the project

Working in partnership with the Norwegian Railway Directorate, Norske Tog has signed a contract with Site Service for the installation and monitoring of new 4G mobile signal boosters on older train sets in order to provide better cellular coverage on board. 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.

Throughout 2020 and 2021, Norske Tog has worked to install modern signal boosters on 184 train sets, including the FLIRT trains, which will be delivered next year. Class 70 and 73B which operate on the Østfold Line are top priority and installation of the equipment to these train types was completed during the summer of 2021.

Results

Consultancy firm Gamba has conducted testing on the Østfold Line to measure the data speeds available, with a particular focus on the route between Ski and Moss, following the installation of signal boosters. 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. The Norwegian Railway Directorate has defined five 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.

• The contract with Site Service for the installation of mobile signal boosters on 184 train sets (vehicle package 1) has now been completed (133 carriages and 34 train sets).
• Still outstanding is work to install mobile signal boosters on Class 72 and Class 93 trains, which were not included in the Site Service contract.
• Installation of mobile signal boosters on Class 72 and Class 93 trains is scheduled to take place during the second half of 2022 and early 2023.