Information published on 17 April 2018 in the UIC electronic newsletter "UIC eNews" Nr 594.

Norway: World record set for mobile network in a tunnel

The mobile operators Telia and Telenor with Bane NOR have set a world record. With 560 megabits per second future train passengers can enjoy a high speed mobile network on their journey, also on routes with many travellers.

The mobile network in old rail tunnels does not meet the needs of today’s passengers in terms of mobile data. On trains with many passengers, it is difficult these days to get good network coverage. Therefore, the Norwegian Ministry of Transport and Communications has allocated funds to improve capacity and increase the transmission rate of mobile telephony in tunnels.

“Telia, in cooperation with Bane NOR the Follo Line project, has developed a pilot to show how this can be solved by technology that provides high speed and can be used in all rail tunnels”, said Dag Wigum, Technical Director of Telia Norway.

The need for speed
Together, Telia, Telenor and Bane NOR have built 4G + which in this case equals 1800MHz and 2600 MHz.
“It provides capacity and speed in the network that will meet passenger needs in order to e.g. work, download films, listen to music or read up on news”, explained Wigum.

Building a high-speed mobile network was a central discussion in the development of the Follo Line. The Follo Line, which opens in 2021, contains a 20 km railway tunnel with two separate tubes, between Oslo Central Station and Ski Station. The double track will cover the need for increased capacity for train passengers travelling south-east from Oslo. Project Director in the Follo Line, Per David Borenstein, is very pleased with what Telia, Telenor and Bane NOR have achieved.

“This is impressive work and Bane NOR are looking forward to offering a high-speed mobile network to our future train passengers. Now we are building a mobile facility with a capacity that will provide good, stable and satisfactory mobile coverage for the many train passengers inside the long tunnel on the Follo Line”, said the Project Director.

A world record in a tunnel
The world record was set in an old road tunnel in Holmestrand, Norway, where a test facility was installed. The test installation was built in collaboration by Bane NOR the Follo Line Project, Telia, Telenor and RFS. The measurements during the technical test came in at a total of 580 megabits per second, which is a world record in high-speed network in a tunnel. Inside the tunnel, four radiating cables was installed and connected to a radio transmitter with 4G 4x4 MIMO setup, instead of traditional one radiating cable. As far as we know, this has never been done before in a full-scale tunnel. In addition, modern trains in Norway today will be equipped with 4G repeaters, which makes the signal reception on the train much better and thus improve the user experience.

(Source: Bane NOR)